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Web Goblin
15-01-2011, 11:35 PM
Some of my parts have arrived so its time to get the build started. The bed frame is 1250mm long by 1065 mm wide. It will be running on linear rails and bearings with ball screws driven by NEMA 34 motors.
The whole assembly will sit on a purpose built angle iron frame with adjustable feet to level it.
Pics 25, 28, 29, 30 show the extrusion and the built base frame with part of the linear rail attached. 26,27 show the bearing riser plates and the y-axis risers. 14 shows the bearing mount plates and the risers and 16 shows how they fit together.
I havent got the ballscrews yet and some of the motor mounts are out of stock but should be here soon.
Hopefully tomorrow I will finish fitting rails for the x-axis and get the bearings and mount plates fitted. Then I have to work out the mounting plate for the frame to fit to the base which will also mount the motors and the ballscrews. If I can get that done tomorrow I can get them cut out on the Laser at work Monday.
I need to figure out attaching photos as well

Regards

Ian

h4ppy-chris
16-01-2011, 12:30 AM
look forward to seeing more pics all the best.

Lee Roberts
16-01-2011, 11:11 AM
Looking good, cant wait to see this machine come to life !

Web Goblin
18-01-2011, 09:29 PM
I managed to get my motor and bearing mounts drawn up and cut out and flanged. They have been fitted and are ok. On the first photo the top flat part of the mount is lying slightly at an angle. I know that the brackets are accurately flanged so I can only think that the angle iron of the frame is slightly twisted. I have gone round all sections of the base frame with a level and it matches the frame so it appears to be level.


36363637


I also got the chance to mount the y-axis risers as well so that I could get an accurate measure to get the y-axis bars cut. First photo shows the bearing blocks mounted on ther bearings.


36353638

Hopefully tomorrow I will get some time to paint the motor and bearing mounts.

Ian

andy_stephensni
19-01-2011, 05:46 PM
Ian / all,

i'd love to make a cnc but - a limited subject knowledge and reading between here / cnczone / mechmate forums - it all gets a little overwhelming sometimes. Anyway (I think I) need a simple approach (if not a total kit for which I have high hopes for AdCNC one of these fine days!) so thought i'd ask my first question here on Ian's Extrusion build.

Hope nobody minds or maybe can be moved to another thread ?

I've been looking at Ahren's R&P parts [http://www.cncrouterparts.com/index.php?cPath=21] and just re-reviewed a build at http://www.cnczone.com/forums/cnc_wood_router_project_log/99181-mini_mech_mate_-_off.html.

Has anyone looked into the detail of how the cncrouterpart parts (eg the rack clamps at http://www.cncrouterparts.com/product_info.php?cPath=21&products_id=64) might integrate into extrusion more widely available in the UK eg KJN / Valueframe?

http://www.aluminium-profile.co.uk/
http://www.valuframe.co.uk/

Andy.

Web Goblin
19-01-2011, 10:29 PM
Chip,
I will be using 20mm diameter 5mm lead screws from Gary at Zapp. Once the paint on the mounts has dried I will fit the motor mounts with one bolt and clamp the end bearing in place to get a measure on the screws then get them made to fit. I already have the motor mounts and the bearings to suit the screws. The linear rail is 25mm and I think it was around 150 per meter. Its not cheap but its very good. I will be using 15mm Linear rail for the Y-axis because I have three lengths of it spare from an old job. It will also be more than enough for the machine.

Andy,
most of ther uk profle that I have seen has either 6,8 or 10mm wide slots. I dont know if the american stuff will still be in imperial sizes so it might not fit very well at all. The valuframe stuff is great stuff. Thats what I have used for my build except for the wider 275mm profle for the y-axis riser plates because the valuframe range only goes to 200mm wide I think. Normally if you are using a rack and pinion drive I would space it out from the edge of the frame by maybe 2mm and centre the drive pinion to the rack so that it would have a little bit of float. The good thing about rack and pinion is that it can float about a bit and not cause any problems and also if your gearbox/motor assembly is spring loaded it helps to keep the pinion in mesh and also lets it follow an uneven rack.

Regards

Ian

Web Goblin
28-01-2011, 11:17 PM
Unfortunately I havent gotten much work done on my build over the last week.
I decided to change to motor and bearing mounts to straight plates. Got them made and fitted and levelled the frame up again.
366636673668


Also managed to cut and fit the rest of the X-axis linear rail.
The Y-axis extrusion arrived this week as well.


3669

I need to set up the Y-axis on the floor of the workshop to see where to drill the riser plates to take the Y-axis extrusion. I also need to see where I am going to fit the motor mount and then see where, if anywhere, I need to cut out a notch from one side to take the ballscrew. When I get that done I can get them fitted and it will start to look like a machine then. I also picked up my steel enclosure today to take all the electrics so I suppose I can get that started while I wait on the ballscrews to get machined.

Regards

Ian

Web Goblin
30-01-2011, 08:30 PM
I managed to drill and tap the Y-axis riser plates and the Y-axis beam.
Have them refitted to the machine and have also fitted two sections of the linear rail.
3675

Tomorrow I need to thread some of my 12mm setscrews to make the thread longer and I need to make a 3mm spacer for the Y-axis beam.
After that the next job is the Y-axis motor mount.

Regards

Ian

Briann
02-02-2011, 01:59 PM
Ian,

Interested to know what facilities you need to put something like this together. I see from the last pic that you seem to have access to a bandsaw, small vertical mill, and an ML7, but somewhere you also mentioned access to a "laser" at work! What do you reckon the minimum set of kit is to start a build like this? Something to cleanly cut the long sections to length squarely, then relatively small turning and milling jobs?

Thanks,

Brian

Web Goblin
02-02-2011, 10:35 PM
Brian,
I ordered the aluminium extrusin already cut to the lengths I needed. The best way to cut ali is a cold cut with a slow cutting saw similar to a wood chop saw. This leaves a nice finish. If you get everything cut to size them you just need tools for assembly. My bandsaw is only used for cutting timber before going on the wood lathe. Whats behind it in the picture is my old Meddings floor standing drilling machine. Its old and a bit noisy but does a very good job. My ML7 I class as a toy lathe. I'm sure I will probably upset a few people with that comment but thats my opinion. I have access to a colchester student at work which is much better but a bit worn and also a bridgeport milling machine. I look after a 3KW cO2 laser at work so I can usually manage to get some small jobs done like my motor and bearing mounts.
If you are looking for a lathe I would recommend trying to pick up and old one in good condition. Not too sure about the smaller milling machines but I believe the Warco ones are good. Add a decent socket and spanner set and a good quality set of allen keys and various drill and taps.

Regards

Ian

Briann
03-02-2011, 01:36 PM
Thanks for the info. I'll try not to take offence at comments about the Myford, given the Super7 sitting in my workshop! In my defence, I did buy it long before the flood of far-East machines hit the markets and when industry was still using their hardware instead of selling it off cheap. I also built a vertical milling machine (the Dore-Westbury part-machined kit, for those that know it) on the S7. I agree, though, that those two machines are second-best to the Smart and Brown lathe and the Bridgeports I have been able to use on odd occasions, certainly in terms of rates of stock removal (and a Bantam and a Student as well, come to think of it) but they are very versatile (I cut the rack on the quill tube for the vertical mill on the S7) and I could afford them and at least I can get them both in my garage at the same time!

Always wanted to have a go at CNC, partly because of my electronics and computing background as well, so shall follow your progress with interest and in the knowledge that I am probably sufficiently equipped to do something useful even if slower than someone with access to more "commercial" facilities!

Good luck with the project,

Web Goblin
05-02-2011, 07:04 PM
Managed to get my Y-axis motor and bearing mount finished today.

36853686

Also got it fitted to the back of the Y-axis beam although this position might change when the ballscrews arrive and are fitted. I have around 35mm adjustment to allow for tensioning of the timing belt.

3687

Now I need to get the coupling bored out to the correct sizes for the motor shaft and spindle and get that fitted as well.

Regards

Ian

Web Goblin
12-03-2011, 09:07 PM
Hi all,
I havent managed to get much done at all in the last few weeks. I have a few jobs to do around the house and I have also been waiting on my ballscrews and nuts for around four weeks now.
Anyway the ballscrews arrived on Thursday and I got them unwrapped tonight. Now I`m totally hacked off to find that one of them is short by a long way. Its completely useless for my job. So I will have to speak to the supplier on Monday and get it sorted out.
Think I`ll go and take my frustration out on some baddies in Dead Space 2.

Ian

Web Goblin
16-04-2011, 11:33 PM
Right several weeks on now and guess what? My ballscrews turned up, well nearly. One of them is wrong again and I am going to have another two week wait, at least, to get a replacement.
I have managed to get some time in the workshop and have been able to get some more of my build done.
The Z axis is more or less complete and fitted to the machine as per the photos.

395739533955395439563952

I have the ballscrew for the Y axis and have fitted the ballnut and mounting nut and the end bearings and it is just sitting on top of the frame at the moment for me to get some measurements. Next job on Monday is to mill a spacer block of aluminium 95mm x 75mm x 16mm thick to go between the ballnut mount and the Z axis frame.
The Z axis took quite a bit of work to get right. After it was made and assembled I ended up with about 1.5mm of movement in the screw from end to end so it had to be taken apart and a new spacer ring made to suit. Once this was done and re-assembled there is no movement at all that I can see so I`m happy with it now. :dance:

Regards

Ian

Web Goblin
11-05-2011, 10:31 PM
Right then I have managed to get some more time on my build so here is an update.
Timing belt fitted for my Y axis drive and motor mount set up and tensioned.
4006

I will eventually make a guard for it. I was thinking about clear perspex so that I can see any problems with the belt if they appear.

I have assembled the X axis ballscrews, nuts and mounts. Made up the spacer blocks and got them all fitted and set up.
40094007400840104011

Also got the couplings bored out and fitted and the motors mounted.
401340124014


I managed to get a start on the control panel as well. Job for tomorrow is to remember where I stashed a short length of 75mm x 75mm alu angle to make the mounts for the limit switches and get them done. The limit switch brackets will be fitted with tee nuts in the extrusion slots so that I can adjust then to get the best working area from the machine.
Hopefully the next update will be a bit sooner than the last ones have been.

Ian

Jonathan
11-05-2011, 11:50 PM
No flanges on the Y-axis pulley could cause problems, but I guess if the belt doesn't fall of then nothing to worry about. Why have you extended the motor shaft then put a pulley on the end? It seems an expensive way to do it. Surely the motor bearings are sufficient to take the belt tension, or was there another reason? The reason I mention it is you've now added the moment of inertia of that shaft to the system which will affect your acceleration a little.

Which motors are those? I'll be interested to see what feedrate you can get on the X-axis, and whether it's limited by screw whip or motor torque. I'd have been inclined to get 10mm pitch screws. With 20x5mm over that length you're limited to roughly 5000mm/min in theory. Twice that feedrate but less resolution (depending on pulleys) with 10mm pitch screws. Bit late now I guess.

What size is the box section you've used for the frame?

Looks like you're not far off running it now :smile:

Web Goblin
12-05-2011, 07:22 AM
Jonathan,
the y axis motor shaft was not long enough to got through the motor mount to take the pulley. I had looked at making a different mount for the motor but it was working out to be rather thin material to get the pulley fully on the shaft so I decided to go this way. I could have made it a bit shorter but I dont think it will make too much difference.
The pulleys I had at the time so went with them rather than buying new ones. If the belt does give problems and runs off I can always change them for castle ones later.
The motors are these ones from Zapp Automation : SY85STH156-4208. I ordered the 2-4 Axis Nema 34 kit 2 and went for the bigger motors. With these motors I should have plenty of torque to drive the machine around as it will be quite heavy when finished and I prefer to have the drive system over-rated a bit :whistling:
The frame extrusion is heavy walled 80mm x 80mm with 80mm x 40mm cross bars. I cant remember the exact size for the Y axis, around 340mm x 40mm I think and again the heavy walled section.

Jonathan
12-05-2011, 11:15 AM
Jonathan,
the y axis motor shaft was not long enough to got through the motor mount to take the pulley. I had looked at making a different mount for the motor but it was working out to be rather thin material to get the pulley fully on the shaft ...

I see, I got round that problem by making the mounts approximately this cross section:

4015

It's thin in the middle, but the motor is supported mainly on the thicker bits. I started with a piece of aluminium angle - the little cutout in the corner was to accomodate the pulley flange.


The pulleys I had at the time so went with them rather than buying new ones. If the belt does give problems and runs off I can always change them for castle ones later.

On my X axis I have a pulley with no flanges (the ones I made), and one with one flange. It's been fine so far so fingers crossed... You can always add your own flanges to the pulleys.

It looks like you've gone for the biggest motors you could find :lol:. What ratio are you using for the pulleys on the X-axis? Might be better off having a bigger pulley on the motor since there's plenty of torque. Then again if the critical speed of the screw limits the rapids anyway it wont make a difference.

I meant what size is the *steel* box section, as I'm going to make a frame soon for my router and wanted to get some ideas...

Web Goblin
12-05-2011, 01:11 PM
The pulley ratio is 1:1. They are 80 tooth pulleys if I remember correctly.
Sorry I misunderstood you on the frame:redface:. I have used 40 x 40 x 5mm angle for the base frame. As long as it is supported for longer lengths it will be fine. Simple adjustable feet made from large stainless steel nuts and bolts work well for levelling the whole machine.

Web Goblin
06-06-2011, 10:44 PM
Update time. I havent had much time again in the last few weeks but I am getting there slowly. I have managed to get some work done on the electrics now.
41244123

I have fitted the limit switches and have most of the wiring in place with just some tidying to do. All motor have been connected up.

412641274125

Drag chains and supports are fitted with wiring in place and the cables are glanded into the panel.
4128
I need to finish off the internal panel wiring now and get it fitted then hopefully I can start getting things connected up.

http://www.mycncuk.com/forums/images/misc/pencil.png

Web Goblin
12-06-2011, 09:55 PM
ITS ALIVE and moving!

I have finished the wiring and connected up the drives and limits.
41534154

The panel is a bit crowded but its what I had around and I didnt really want to spend 100 on a new one.
Those drivers generate quite a bit of heat so looks like I will have to install a couple of cooling fans.
I had a bit of a problem getting the pc to talk to the CPU4 control card but this was down to the pc and is sorted now. I have roughly set up the limits and Homed the machine in manual and can jog it around now. One problem I did find was when I tried to home all axes at once the machine homed X,Y and Z ok then tried to go find the A axis which is currently set to Slave X axis. I think I need to edit the Home all macro to fix this though. ( might have to pick Adcnc's brains a bit more)
The Y axis drive belt is sliding off the pulley as well so it needs a bit of fine tuning.

Regards

Ian

Jonathan
12-06-2011, 10:46 PM
ITS ALIVE and moving!

I have finished the wiring and connected up the drives and limits.
41534154

The panel is a bit crowded

Looks nice and tidy to me. I don't think you should connect the mains wires to the drivers one after the other. This will cause each subsequent driver to get a lower, and varying, voltage to the previous ones in the chain. It's better to have wires from the live and neutral all connected to the same point, then connect that point to the mains. It may well not make a difference, I'm not sure!


... One problem I did find was when I tried to home all axes at once the machine homed X,Y and Z ok then tried to go find the A axis which is currently set to Slave X axis. I think I need to edit the Home all macro to fix this though. ( might have to pick Adcnc's brains a bit more)...

I had a similar problem when setting up Chip's router. I didn't need to edit the macro. If I recall correctly the problem was with the breakout board - it failed to read the inputs if more than a couple of switches were active. That really messes things up when Mach3 tries to home both the X and slaved axis quickly.

Web Goblin
12-06-2011, 11:05 PM
Jonathan,
Linking the drivers should be ok as long as the supply cables can carry the load current without heating up. As long as they stay cool the volt drop should be minimal. I will check the full load drawn from the supply when I remember to get my current clamp meter out.
Did you have a look at the link I pm,ed to you?

Ian

m_c
12-06-2011, 11:06 PM
Looks nice and tidy to me. I don't think you should connect the mains wires to the drivers one after the other. This will cause each subsequent driver to get a lower, and varying, voltage to the previous ones in the chain. It's better to have wires from the live and neutral all connected to the same point, then connect that point to the mains. It may well not make a difference, I'm not sure!


Jonathan's right, in that ideally you shouldn't daisy chain the power wires, but I'd say interference/poor connections are a bigger hazard than lower voltages.

Jonathan
12-06-2011, 11:16 PM
Linking the drivers should be ok as long as the supply cables can carry the load current without heating up. ...Did you have a look at the link I pm,ed to you?

I'm working it out properly now to see if it actually matters. I'll post what I find out.
I did look at the link - it's a good link thanks!

What diameter cable did you use to the drivers?

It says in the driver manual:
'For better heat dissipation, two drivers shall be installed at a clearance of at least 50mm'
With sufficient fans I'm sure you'll be fine though.

Jonathan
13-06-2011, 12:14 AM
Let the resistance of a single piece of wire connecting the drivers be R. Let the current to each driver be the same, call it I. Assume it's steady state, which it's nowhere near so pretty poor assumption...Also assume no impedances other than the wire resistance ... again we should really include it but there's not really enough information to make it worthwhile so I didn't bother.

1st driver gets the supply voltage, V.
2nd driver: V-2*3IR = V-6I
3rd driver: V-2*3IR-2*2IR = V-10IR
4th driver: V-2*3IR-2*2IR-2*IR = V-12IR

So as you can see the last driver is in trouble if I and R are significant. The good thing with your drivers is they're at mains voltage, so I is not very high (maybe an amp, could peak at more) and R is (assuming 1.25mm^2 wire) about 14mOhm. That means you're loosing about 0.2V to the last driver. Compared to the 240V that's not much, but maybe when the currents are changing quickly it could be a problem as then the impedances I ignored would have an effect ... and all the drivers will be drawing different currents.

If you have 50V drivers then a reasonable average current might be 4 amps. Lets say you used the same wire, that's 50-12*4*0.014=49.3V
The thing is that DC voltage will now fluctuate, there's now about 1% ripple on the power supply. This could cause a problem if the smoothing capacitors are not big enough in the driver.

As m_c said, there's more to it than just the voltages.

(On reflection I guess working out the above didn't achieve much, but I thought it was interesting!)

CharlieRam
13-06-2011, 12:25 AM
Jonathan,
Linking the drivers should be ok as long as the supply cables can carry the load current without heating up.
Ian

Hi, Newly registered here but been lurking around :wink:

Why not ring wire it? It works for household wiring, you then have two paths for the current to flow so if one fails the other is active and also it can still look neater than lots of wires from one branch.

Web Goblin
13-06-2011, 07:07 AM
Supply cables are 1.5mm^2. I dont have my regs book handy but they should be good for around 16Amps. All cables are shielded are are grounded at one end only should interference should be minimal. I will check the load drawn and the voltage supply to the last driver and see what they are. If there is a problem it will be simple to change it. I remember the manual saying about the clearance distances between drivers but the panel was already there and begging to be used. A couple of 80mm diameter cooling fans should take care of the heat.

Web Goblin
13-07-2011, 10:51 PM
I had managed to sort out the homing problem with the A axis by modifiying the macro.cnc file in USBCNC but I am still having loads of problems with the homing procedure. I home the machine when it is turned on and get messages saying that the homing is complete and that the home switches now act as estops which is what it should do. When I try to run a job I keep getting a message telling me to home the machine first. The only way I can get round this is to turn off the "homing is mandatory" option in settings. I had the machine setup with a slave x axis using axis a for the slave and tried Adcnc's suggestion of splitting the the x axis signal to both amps but this still had the same result. I can only think that there might be a problem in the software but not really sure about this. I am going to try another couple of modifications to the drives to see if I can get this homing procedure to work properly but if not it will stay off for good. I have also managed to get my hands on an old Lincoln welding torch cooler unit which I am modifying to use as my router cooler. Its a nice compact unit so hopefully it will work well. I need to get some more photos posted as well.

Ian

Web Goblin
23-08-2011, 05:41 PM
Again I have not had much time on my build lately but I have managed to get afew things done. My workshop pc died a couple of weeks ago but I have now managed to get another one up and running. I have had the machine moving about with it again. I have started to get some work done on the spindle wiring.

43764377

I need to get this finished and get the interlock from my cooler done as well before I try to run it.

I had also been looking at a way to protect the linear rails from cuttings so this is what I came up with.

437943804378

Nice and simple idea. The perspex should keep the worst of the cuttings away from the rail and it will also let me see if anything gets in there.

Ian

Web Goblin
27-08-2011, 11:11 PM
I had finished connecting up my cooler last night and did the first version of my interlock circuit between the pump flow switch and the vfd. The circuit worked fine so I decided to run the pump and check it all out properly. So connected up the 110V supply to the relay and turned the pump on. The pump ran great for about 5 seconds then burnt out! I cant see any reason for it so it looks like I just have a bad one. I need to get this repaired before I can get anything else done.

Ian

Jonathan
28-08-2011, 12:35 AM
That's a shame, what pump was it? Something like this one would be more than adequate to replace it:

http://www.ebay.co.uk/itm/Submersible-Water-Pond-Garden-Pump-Filter-1400L-H-New-/310241101457?pt=UK_HomeGarden_Garden_PondsWaterFea tures_UK&hash=item483bcf8691#ht_2753wt_1139

Web Goblin
28-08-2011, 06:00 PM
Its a Shurflo pump. The good thing about it is that its Americam made and still available. I have disconnected the cooler from the machine and am going to take it to work tomorrow for a bit of surgery.

Ian

luke11cnc
31-08-2011, 11:55 AM
Ian How stable is your gantry ??

I've only just seen you CNC Machine looks good

If you had to start again would you do anything different ??

James

Web Goblin
31-08-2011, 09:55 PM
James.
the gantry seems stable enough but I have not actually cut anything with the machine yet.. I have had some problems with the USBCNC software and hardware and cant get any feedback from the supplier. He doesnt want to answer emails so I had had to try to sort them out myself. I think I have most of the problems sorted but time will tell I suppose. My workshop pc died as well and it took a couple of weeks to get another. I had gotten hold of a Lincoln Electric welding torch cooler to use as a cooler for the spindle but this had quite a few problems as well so it has now been scrapped.
I dont know if I would change anything yet except the Z axis screw. I am currently using an acme screw but I think it would be much better with a ballscrew. I may change this in the future. I also have an extra section of alu extrusion to fit across the front of my gantry but this has not been installed yet until I see how the machine runs without it. If there is any play in the gantry I will fit it.

A picture of the lincoln cooler is below.
4416

After powering this unit up I found the motor only ran for a few seconds then died.
I stripped the motor down to find the brush gear had collapsed and part of the brush holder had vanished.

441944184417
The comm is badly carboned up and needed a good clean.

44214420

It turned out fine after a good clean up as did the motor casing and permanent magnet.
The motor was re-assembled with new brushes and springs and seems to be running ok.
I have decided to make a new cooler unit from scratch using some of the parts from the old cooler.
I have fabricated a new tank from 3mm stainless steel. Then fitted the pump.
442344224424

As usual just need some more time to get it finished and tested now.

Ian

luke11cnc
31-08-2011, 10:10 PM
ok

but can I ask a question

what is wrong with a plastic box and a pond pump delivering 1000l/m ??

James

Jonathan
31-08-2011, 10:32 PM
what is wrong with a plastic box and a pond pump delivering 1000l/m ??


There is nothing wrong with that setup as far as I know. I'm using an extremely small pond pump that is probably less than 1l/m. Before I had an 8l/m pump and that was plenty...I would say that overkill is good to be safe, but if you're transferring the heat away fast enough anyway then all a bigger pump achieves is to heat the water up more itself. Pond pumps, such as this one (which is plenty), are also brushless:

http://www.ebay.co.uk/itm/Aquarium-Pond-Water-Pump-Garden-Fountain-Filter-Pet-Koi-/220825524373?pt=UK_Pet_Supplies_Fish&hash=item336a3a1895#ht_2736wt_905
These spindles don't need much cooling as most of the time we're operating them at nowhere near full power/speed and they are inherently quite efficient so the heat generated is not that great. This means that especially if you use a metal container the natural conduction of heat into the atmosphere is enough to keep it stable as long as you have a reasonable amount of water.

JAZZCNC
01-09-2011, 01:53 AM
There is nothing wrong with that setup as far as I know. I'm using an extremely small pond pump that is probably less than 1l/m. Before I had an 8l/m pump and that was plenty...I would say that overkill is good to be safe, but if you're transferring the heat away fast enough anyway then all a bigger pump achieves is to heat the water up more itself. Pond pumps, such as this one (which is plenty), are also brushless:

http://www.ebay.co.uk/itm/Aquarium-Pond-Water-Pump-Garden-Fountain-Filter-Pet-Koi-/220825524373?pt=UK_Pet_Supplies_Fish&hash=item336a3a1895#ht_2736wt_905
These spindles don't need much cooling as most of the time we're operating them at nowhere near full power/speed and they are inherently quite efficient so the heat generated is not that great. This means that especially if you use a metal container the natural conduction of heat into the atmosphere is enough to keep it stable as long as you have a reasonable amount of water.

You dont need high flow or pressure just good head height. . . . The thing to watch with these pumps is the Head height, this pump can only pump 1.85mtr max which if like me your using the simple pump in a tank under the machine then it's not quite enough. Even thou they say it will pump 1.85 meters this a max and puts the pump under too much stress if run for long periods. Try to aim for one in the 3mtr range and you wont have any trouble, mine's been going now for 3 yrs with out trouble and it's 2.5mtr head height. I've just bought a spare 24v 3mtr head height off ebay thou because it's starting to struggle so time to retire it to just pumping coolant on my lathe.!!

Web Goblin
01-09-2011, 07:14 AM
Personally I wouldnt use a pond pump. I dont think they like being turned on and off lots. They also like to be run with full bore pipe work to match their outlet size. I used to run the pond pump during the day and turn it off at night and I had also reduced the pipe size. The pump lasted about 2 years. I installed a Titan pump using 50mm bore pipe and it runs constantly. Only gets turned off about 4 times a year for cleaning. Its been going for about 5 years now.
As for a 1000l/m pump I seriously dont think you will get anything like that flow rate through the spindle.
As Jonathan has said the stainless steel box I have made will act as a good heat sink and will hold around 10 litres of water so should do the job fine.

Swarfing
01-09-2011, 07:56 AM
Are there any plans to put anything in with the water (antifreeze? coolant additive? etc)

Web Goblin
01-09-2011, 08:27 AM
I will probably add some anti-freeze when winter arrives. It was baltic up here last year ( had about 150mm thick ice on top of my pond ) and my workshop is only heated when I'm in it. I have some good anti-freeze somewhere that doesnt attack copper or aluminium or nylon/plastic tubing.

Ian

wiatroda
01-09-2011, 09:01 AM
Is CH water pump any good for coolant?
I assume coolant is filtrated and free from magnetic metal bits. There is no brushes in a motor so it should last ages I suppose.

JAZZCNC
01-09-2011, 09:57 AM
I will probably add some anti-freeze when winter arrives. It was baltic up here last year ( had about 150mm thick ice on top of my pond ) and my workshop is only heated when I'm in it. I have some good anti-freeze somewhere that doesnt attack copper or aluminium or nylon/plastic tubing.

Ian

Use Distilled water with a Good quality anti freeze and you wont have any trouble. It was -12 in my workshop last year and my 25ltr barrel of water didn't feeze and it's sat directly on the concrete floor.
Thou must say I pritty much used it every day (YES worked thru it. .Tough breed up here.!!! ) so the water was never left undisturbed for long periods, So if your not going to use it for weeks on end then I'd recommend you drain the system just in case we have another artic winter. . . . . . Oh and the water is the same original water I started with 3+ years ago with no nasty's or funny smells, the fact It's distilled water and it's a sealed dark container that no direct sun light can get to helps (No windows in my shop).

Web Goblin
01-09-2011, 10:32 AM
Not sure how good a central heating pump would be. You would be reducing its normal flow rate down alot but most of them have adjustable speeds so you could slow it down a bit.
Jazzcnc. I am using distilled water. Normal water just causes too many problems.
"No windows in your shop" Does it have bars where the door should be?:lol:

Ian

JAZZCNC
01-09-2011, 03:01 PM
Not sure how good a central heating pump would be. You would be reducing its normal flow rate down alot but most of them have adjustable speeds so you could slow it down a bit.
Jazzcnc. I am using distilled water. Normal water just causes too many problems.
"No windows in your shop" Does it have bars where the door should be?:lol:

Ian

Yes and my overalls have nice stripes on them. .:whistling:

Seriously thou I do have a great big steel door with no windows. . . And even that doesn't stop the scum bags.
A few months ago my workshop was broken into but thank fully we caught one of them.! . . wont go into details but lets just say we got the stuff back and real justice was served. .:mad:

Jonathan
01-09-2011, 07:25 PM
You dont need high flow or pressure just good head height. . . .

I compensated for that by putting the tank of water on a shelf at about the same height as the spindle.


As for a 1000l/m pump I seriously dont think you will get anything like that flow rate through the spindle.

I think Luke meant 1000 litres per hour...


Use Distilled water. . . Oh and the water is the same original water I started with 3+ years ago with no nasty's or funny smells, the fact It's distilled water and it's a sealed dark container that no direct sun light can get to helps (No windows in my shop).

I don't think distilled (or more likely de-ionised) water is required if, as you have done, you don't change the water. Once the water has deposited the calcium carbonate there is nothing more to deposit - it's essentially de-ionised. That does to an extent depend on the volume of water you are using (and where you live) as clearly if you have a 1000 litre tank there are a lot of ions it there to start with, and vice versa.



A few months ago my workshop was broken into but thank fully we caught one of them.! . . wont go into details but lets just say we got the stuff back and real justice was served. .:mad:

I take it you signed the relevant petition then recently.

JAZZCNC
01-09-2011, 11:00 PM
I take it you signed the relevant petition then recently.

Nope.!!. . . but I dont know what petition you mean anyway. Thou would a petition really stop the scum bags .?? Me thinks not.!

Web Goblin
01-09-2011, 11:06 PM
Jazzcnc,
I hope they learned their lesson.
Jonathan,
the problem with using water is that bacteria can grow in it quite well. Distilled water is a better option for long term. I have been to several factories in the past where they were too tight to buy distilled water or the correct coolant for their machines and eventually the bacteria hard grown into a type of algae or fungus and it blocks up the pipework. This usually meant an expensive repair for the customer.
We use distilled water for coolant on our Co2 Laser at work but we also add 1ltr of an anti bacteria agent to kill anything that might decide to grow in the coolant. This amounts to a 1% mix and the whoile system is drained and refilled with new coolant once a year.
A few years ago I miscalculated the amount of antifreeze required for the system and put in too much. Not quite sure what chemical reaction took place but the coolant mix started to turn to a gel. Right PITA is was to clean out. Now we go for about a 15% mix in winter time.

Jonathan
01-09-2011, 11:14 PM
Jonathan,
the problem with using water is that bacteria can grow in it quite well. Distilled water is a better option for long term.

I didn't mean just use tap water - that would be rather silly. I meant tap water plus some anti bacteria stuff/antifreeze.

Web Goblin
02-09-2011, 10:04 AM
Sorry Jonathan. I thought your were talking about normal water.

Ian

Web Goblin
02-09-2011, 09:48 PM
After a few weeks of going backwards I now have a working coolant pump.:toot:
The flow switch works well and the interlock for preventing the spindle from running without coolant is working as well.
Now for some well deserved lubricant:smile:

Ian

JAZZCNC
02-09-2011, 11:10 PM
Congrats.!!. . .sounds like you have earned a few squirts of lubricant. :beer:

Web Goblin
03-09-2011, 09:24 PM
Here are a couple of pictures of the cooler unit.
44434442

Just to add this will probably hold around 25 litres and not 10 like I said in an earlier post. Got my sums a bit wrong.
I have made a little control unit with a couple of switches, an estop and a pot for controlling the speed of the spindle. I need to have a read through the VFD manual now to see what to set up for it to take an external input for start/stop and speed control.

Ian

Jonathan
03-09-2011, 09:34 PM
Looks good. I could do with a box like that to put a coolant pump I acquired in.


I need to have a read through the VFD manual now to see what to set up for it to take an external input for start/stop and speed control.

Should be able to do it with the input the pot uses. Substitute the pot for the parallel port pin and use PWM output in mach. I'd put a capacitor (and possibly resistor in parallel) at the VFD from that pin to ground to smooth the PWM. It's all in the manual... you can do it with digital inputs but you probably wont have enough I/O on the parallel port to do that.

Web Goblin
03-09-2011, 10:27 PM
Jonathan,
I am using USBCNC which does have a pwm output as well but at the moment I prefer to have a manual adjustment via a pot. Maybe later on when I get more used to USBCNC I will connect it to the pwm output. Looking at the manual I have 4 or 5 settings to change to get the vfd to work on an external input. I might get a chance to give this a try tomorrow night.

Ian

luke11cnc
04-09-2011, 12:43 PM
I did buy once a new tank and pump for my lath and I'm sure that would work very well

only because the one that came with the machine didn't work and at the time it was cheaper to buy a separate unit

James

Web Goblin
04-09-2011, 08:46 PM
James,
a lathe coolant system will work perfectly well for your spindle.
Jonathan,
have you wired up a seperate start switch for your vfd such as via a relay or switch rather than using the controls on the front of the vfd?
I was trying to get the multi function inputs to work fpr direction selection and start function. I have linked DCM to REV and wired DCM to FOR via a relay. Set PD001 to 1 for external control, PD044 to 2 or 3 for direction. The VFD wont accept the start command and also wont change direction regardless of setting 2 or 3 in PD044. I get the feeling I have missed something.

Ian

Jonathan
04-09-2011, 08:55 PM
James,
a lathe coolant system will work perfectly well for your spindle.

Yep, but if it was me I'd use it to provide coolant for what I'm cutting on the router as I mainly use the router for aluminium. The annoying bit is how to make a coolant tray which includes a sacrificial bed? I guess I need to find a metal tray with decent height sides and maybe a suitably impervious bed.


Jonathan,
have you wired up a seperate start switch for your vfd such as via a relay or switch rather than using the controls on the front of the vfd?.

I just use the controls on the front.

Have you checked the voltage on the relevant signal terminals?

This is the manual I used, might be different to yours:

http://www.jinlantrade.com/ebay/invertermanual.pdf

Web Goblin
04-09-2011, 10:35 PM
Jonathan,
I have been off reading a rather long thread on Huanyang vfds on a woodworking forum. I think what I have setup should be working. I do need to change a few more parameters to get full speed from my 10K pot though.

Ian

Web Goblin
05-09-2011, 07:26 PM
Managed to get full speed control via my speed pot on my control box up to 400Hz.
4457
I needed to alter another setting on the vfd. I also have start/stop control working via USBCNC now as well. All I need to do is manually select the Coolant flow icon on USBCNC first then the program will start and stop the VFD.:dance:

What I need to do now is calibrate the travel distance of my Z axis and then I should be ready for a test cut.

Ian

luke11cnc
05-09-2011, 08:08 PM
I bet you can't wait

James

Rogue
05-09-2011, 08:35 PM
I bet you can't wait

James

HE can't wait? What about the rest of us! :rofl:

luke11cnc
05-09-2011, 09:00 PM
I know 9 month build. But looking at the build log it does look a excellent build

James

Web Goblin
05-09-2011, 09:29 PM
I know it has taken a long time but I have had a few other jobs to do along the way and I am still doing yet another job in the garden. Sometimes there just arent enough hours in the day!!

Ian

Web Goblin
12-09-2011, 09:11 PM
Right I have managed to sort out a problem with creating cutting files with the help of Adcnc, many thanks Adam, and have actually done two cuts tonight!!.
The material was standard 18mm thick plywood and a standard 12mm vee cut router bit, I didnt want to trash any good stuff to start with.
45254524

Cut quality wasnt the best by any means but the machine functioned properly. First cut was at 2mm depth and 20mm/sec feed rate and the second one at 4mm depth and 40mm/s feed. I did attempt to video the second cut on my HTC Desire HD but the wife phoned and the end of cutting the first letter and knackered the video so I will try it again later in the week.
I think I deserve some tea and biscuits now:smile:

Ian

luke11cnc
12-09-2011, 09:56 PM
looking good Ian I'm so jealous

I've been in the garage just looking at mine.

Progress has stalled or that's what it feels like waiting for ballscrews supported rails and bits and bobs

but I will take a photo of my bits tomorrow

James and Luke

Web Goblin
12-09-2011, 10:03 PM
Thanks. I really want to try some aluminium. I am going to see if I can get some tomorrow and have a go at it at the weekend.
I know how you feel about waiting on stuff. I had a few problems with getting my ballscrews. Lost a good few weeks waiting on them. Hopefully you will get them soon.

Ian

Jonathan
12-09-2011, 10:30 PM
Thanks. I really want to try some aluminium.

Walk before you run.

Admittedly the second thing I tried on my machine after the major rebuild was aluminium.

AdCNC
12-09-2011, 10:51 PM
Managed to get full speed control via my speed pot on my control box up to 400Hz.
4457
I needed to alter another setting on the vfd. I also have start/stop control working via USBCNC now as well. All I need to do is manually select the Coolant flow icon on USBCNC first then the program will start and stop the VFD.:dance

If you wanted you could edit the code and put something like this in at the beginning..

M8
G4 P5000


(P5000 donates the dwell in milliseconds so here would be 5 second pause while your spindle spools up)

Then at the end just before M30 command insert M9 to turn off the coolant (in your case spindle that is if you have set your spindle up under the flood coolant and not the mist, if you have set the on/off under mist then just replace the M8 with a M7 )

Web Goblin
16-09-2011, 07:10 PM
I have made up a tool height setter. Its a bit rough but I will make a better one when I get more time.
4543
The basic parts. The centre of the top section was a bit off so doesnt look quite right.


4544
Hole drilled and tapped to PG7 to accept the cable gland.


4545

The block was cleaned up a bit on the lathe and the inner edge recessed to accept the switch locking nut.

4542
The finished parts before assembly.
I have also set up the block in USBCNC and calibrated and tested it. Working fine it is.

Regards

Ian

Web Goblin
16-09-2011, 08:24 PM
I have posted a video of it in action on youtube. Link attached.

http://www.youtube.com/watch?v=AbBjttEyDQw

JAZZCNC
16-09-2011, 09:05 PM
Nice that Ian, are you going to change the script to touch down faster.?
I've set mine up so does a double touch 300mm/min first then retracts few mill's, can't remember what I set it at without checking, then does slow 75mm/min for accurate touch off in case over shoot. . . . . Works very good and one of the best things I've added to machine.

Jonathan
16-09-2011, 09:11 PM
Nice indeed. Can you link me to the switch you used? I had not considered using a switch, only measuring resistance. I thought at one point of using a piece of PCB as the contact as then if something goes wrong the PCB is weak (as long as it's not FR4) and will break instead of the cutter.

Have you checked the repeatability?

Your spindle mount looks a tad flimsy to me ... only one support.

JAZZCNC
16-09-2011, 09:21 PM
Nice indeed. I thought at one point of using a piece of PCB as the contact as then if something goes wrong the PCB is weak (as long as it's not FR4) and will break instead of the cutter.


Jonathan PCB works great thats what I use for quick top surface setting, very easy very quick and super accurate. . . . Doesn't even leave a mark on the cooper. You won't belive how sensitive it is.

Brilliant when combined with edge,corner and centre probing routines save hours of setting up time. Just the top of surface alone is worth the effort. . . All 5 mins it takes to make. . .:tup:

Jonathan
16-09-2011, 09:49 PM
Doesn't even leave a mark on the cooper. You won't belive how sensitive it is.

That's mildly surprising. Maybe the electrons tunnel across the gap :heehee:
If I put an op-amp in between it could be incredibly sensitive, though that may not be a good thing. Combine it with averaging of the readings ... assuming the difference is actually greater than the resolution.

Web Goblin
16-09-2011, 09:51 PM
Jonathan,
the link to the switch is : http://uk.rs-online.com/web/p/push-button-switches/7082967/ Its a bit expensive but I chose it to take a bit of punisment.

I checked the switch a few times with my digital vernier and repeatability is within 0.3mm so its not too bad. I had also looked at making a voltage touch probe like Jazzcnc is talking about, that might be version 2 if I can get my hands on some solid clear perspex square bar or similar. The spindle mount is 25mm thick alu so its stronger than it looks but I have started on making another two to replace that one to strengthen it up.
The head comes down quickly until 20mm above the estimated tool block, depending on the guess value you input into the tool database, then slows down to touch speed.

Ian

JAZZCNC
16-09-2011, 10:07 PM
I checked the switch a few times with my digital vernier and repeatability is within 0.3mm so its not too bad.



That wouldn't do for me.!! . . . 0.3mm is far too much for my liking.! . . . I would want 0.1 at the very very least.
My first thought when seen you where using a switch was it wouldn't be quick enough and your measurements backs that up.

Try pcb and you'll see what I mean by super sensitive, accurate and repeatable.

Web Goblin
16-09-2011, 10:40 PM
I am going to try the tool measurement routine a few times and see what it says. It might come out better than that. If not I can always make a voltage touch one.

Web Goblin
18-09-2011, 03:44 PM
Right I decided that I had to have a go at aluminium, just couldnt resist the urge!.
I made up a dxf through autocad for a box drilling jig for some welding test boxes that I make.
The material is 10mm thick alu and I used a 3/16 end mill, didnt have a 5mm one, I need to build up my cutting tool supplies.
455745564555

Admittedly I did forget about the top face of the jig, at the moment I am still too used to programming for profile cutting. This would have looked better with a bit of a clean up.


45584559
The box lid to be drilled and it fits snugly inside the jig.
All in all I am quite pleased with my first alu job. For using an old cutter and for a first attempt I'm a happy chappy.
I have also done a bit of video for parts of the cut and hopefully after my little gilrs 5th birthday party this afternoon I might get it loaded up to youtube.


Regards

Ian

Web Goblin
18-09-2011, 11:58 PM
Links to some video of the first alu job.

http://www.youtube.com/watch?v=ABNmolGdUJ0

and

http://www.youtube.com/watch?v=3agFg5x53JY

Regards

Ian

Jonathan
19-09-2011, 12:26 AM
What depth of cut, speed, feed, stepover was that? Looks like you took it very gently. Seems a bit of a random place to choose to cut it within the aluminium sheet, but I guess you had your reasons.

I see you're very generous with the cutting fluid!

Finished part looks nice, are there any marks in the corners due to backlash. Were you using G64? I think so, but it's difficult to tell in the videos.

Web Goblin
19-09-2011, 09:46 AM
Jonathan,
I did take it very easy with that cut. Depth of cut was only 0.5mm, step over was 20% which would be just under 1mm and feed speed was 10mm/sec for that cutter was 10mm/sec. The only cutter I was was not new so I did go slowly with it. The alu also has some hard sections in it so that was why the cutting fluid was generously applied. The starting point was a mistake, I for got to set my dxf to 0,0 in cad and I think cut2d picked that up.
I have had a look at the program file and cant see any G64 codes in it. Youll need to excuse my ignorance in G codes at the moment, I havent got round to learning them yet!!
Some photos are attched of the cut edge. Quality looks good for an old cutter.

456745654566

luke11cnc
19-09-2011, 11:40 AM
what would you look for or what would it look like . for backlash??

James

Web Goblin
19-09-2011, 12:40 PM
James,
backlash would look like an uneven cut. The finish edge at the corners would be like a wavey line. This happens when there is play in the mechanics of the machine like a set of cogs not meshing together correctly so that when your turn one cog it moves slighlty before the other one moves. In a profiling machine that drives atart to wobble a bit at a change of direction until the machine sort of balances itself out.
t I have found that the best way the check for backlash is to run your machine at a 45 degree cut so that both x and y axis are travelling at the same time ie cut a square but rotate it to 45 degrees on the bed. The corners should be nice a smooth without any wobble in the cut surface. Cutting at 45 also tells if your speeds are the same in both axis at the same time. If they are not you would have an uneven cut surface all the way along the cut.

Ian

Jonathan
19-09-2011, 01:01 PM
Whether or not you get a wavy line/arc depends on the direction of cut (climb/conventional), the cutting force and the friction of the slides. Either way you will get a 'blip' on the corners, or wherever any axis changes direction. Here's an example:

4569
4570

The corners should be smooth, but as you can see each corner has a line/offset portion where the axis changed direction. For that part it doesn't really matter - it's still shiny :smile:

That was on my milling machine which currently has more than it's fair share of backlash.

This part was made on my router which has very little backlash, so the corners are smooth with no 'blips':

4579

JAZZCNC
19-09-2011, 03:39 PM
Some photos are attched of the cut edge. Quality looks good for an old cutter.

45674565

Hi Ian,

Congrats on your first Hot Chip's. .:toot: . . . . . (Now the BUT.:lol:)
I think your single spindle mount is causing chatter/resonance looking at the edges I can see chatter lines.!
I know you say the cutter was old but that does look more like flex chatter..? Also when cutting it sounded ringy more like a resonate ring not a blunt cutter.

Too little DOC, too slow spend n feed or more importantly wrong chip load can be just as bad for cutter than too much, esp in sticky Ali. Don't be shy give the cutter some work to do as your going far too conservative. . . .Heat is the enemy so send it away with the chip.!!

Jonathan
19-09-2011, 04:21 PM
I think your single spindle mount is causing chatter/resonance looking at the edges I can see chatter lines.!

Just what I was thinking - the vertical lines are a bit of a give-away.

Definately too low feed and stepover - with only 20% stepover you need to feed much faster to attain the same chipload, look up chip thinning. This explains some of it, though it is aimed at making you buy the program...

http://www.cnccookbook.com/GWCalcFeedsSpeeds.htm


The alu also has some hard sections in it so that was why the cutting fluid was generously applied.

I was joking when I said that was generous!


I have had a look at the program file and cant see any G64 codes in it.

Mach3 may have defaulted to it anyway, it depends.
G64 puts mach3 in constant velocity mode, so that within reason the feedrate remains constant. This means that external corners will become slightly rounded - more if the acceleration is very low.
G61 puts mach3 in exact stop mode, so it stops once it has got to the point specified by each line of code, then continues. This makes the motion very 'jerky', though depending on the situation it will make the final part more accurate.

Using constant velocity makes the motion a lot smoother, and a constant feedrate is clearly faster overall and kinder on the cutter. To try it just type G64 at the begining of the program. You'll notice the most difference when a program uses lots of small lines to approximate a curve.

andrewbond
19-09-2011, 04:41 PM
Hi There,

How are you finding the High power kinco drives? I can't decide between those and the normal DC powered variety, any reason you chose those?

Regards

Andrew

Jonathan
19-09-2011, 05:26 PM
How are you finding the High power kinco drives? I can't decide between those and the normal DC powered variety, any reason you chose those?


The 2M2280 drivers run on 240VAC they run the motors at a high voltage, not sure if it is actually 230*2^0.5 as that seems a bit much. This get much much higher speed from the motors than the 'normal' 70V (or so) drives, however it will make the motors run hotter. That's not necessarily a problem - as long as the case temperature is not above about 80-90C it's fine.

I'm thinking of getting a couple to use on either my lathe/mill or router. They're only suitable for Nema 34 (or 42) motors, not 23/24. A Nema 23 motor with high inductance might be ok... but with how much those drivers cost that's probably not the best option.

JAZZCNC
19-09-2011, 06:31 PM
G61 puts mach3 in exact stop mode, so it stops once it has got to the point specified by each line of code, then continues. This makes the motion very 'jerky', though depending on the situation it will make the final part more accurate.


Ye Try G61 with an high feed rate/accelleration and watch it turn into a "Darlick on Whiz" as it try's to break dance thru the workshop wall after it's destroyed all in it's path. . .:rofl:

Web Goblin
19-09-2011, 09:21 PM
Andrew, the kinco drives are good. I have Nema 34 motors on them and they are fine. The only problem is that the drives generate alot of heat but a couple of cooling fans will take care of that.

Guys, thanks for info on cutter loading/feed speed. I willl have to play with it to get a feel for the right speed and loading. The step over and feed speed was what cut2d generated when I picked that cutter. They can be modified but I decided to go with the stock option as a first timer.
I do have plans for two spindle mounts but havent gotten round to them yet. I have ordered some of the single flute cutters off ebay so that could be a good test when they arrive.
Jonathan I am using USBCNC not Mach3. It has something called look ahead feed built in to it. I think this looks ahead of the block you are running and looks at the program to see what is coming up. It then tries to calculate the optimum speed for those upcomming blocks to keep the machine moving smoothly, well thats what I got out of reading the manual anyway!

JAZZCNC
20-09-2011, 12:26 AM
Jonathan I am using USBCNC not Mach3. It has something called look ahead feed built in to it. I think this looks ahead of the block you are running and looks at the program to see what is coming up. It then tries to calculate the optimum speed for those upcomming blocks to keep the machine moving smoothly, well thats what I got out of reading the manual anyway!

Mach also use's look ahead.
CV (constant velocity) and Exact stop are Gcode commands which basicly tell the control software how to react.
If your code outputs G61 then the look ahead won't apply because it's been forced into exact stop mode and look ahead only works in CV mode.

If your code breaks arc's down into tiny lines(like lots of software does) then this will have the affect of jerky movements, it will also have the affect of stopping and starting between arcs and straight lines as exact stop accelerates and deaccelerates point to point, this affects cut quality badly. (Plus it's bloody annoying)

Exact stop will not round tight corners like CV does at high feeds but it can cause the machine to run very slow and quite rough as it accellerates then deaccelrates between each point.
As you can imagine at high feeds this will hammer the machine and motors as it flys upto the corner at high speed then jumps on the brakes for the tight bend.!!

I think if you check there will be settings within USBCNC to help control CV's angular distance where it changes for tight radius and controls rounding at high feeds.

But I think even USBCNC can be put into exact stop mode so G61 will apply basicly cancelling look ahead and CV mode. . . . . Worth checking out.!!

andrewbond
23-09-2011, 02:32 PM
Thanks for the info,

I'll probably go for these as I won't have to buy seperate power supplies (I'm going to be using the 8nm nema 34 motors)

Did you mean the drives themselves generate alot of heat, or that they cause the motors to get hot?

Andrew

Jonathan
23-09-2011, 04:07 PM
Did you mean the drives themselves generate alot of heat, or that they cause the motors to get hot?

It's probably both - running the motors at a high voltage tends to make them hot, but as long as it's below about 80C it's not a problem.

Web Goblin
23-09-2011, 06:48 PM
Andrew,
the motors get warm to touch but nothing bad. The amplifiers do get quite warm so if you are going to mount them in a cabinet forced cooling would be required.

Ian

Web Goblin
02-10-2011, 03:19 PM
Had a shot at cutting some new spindle motor mounts today. The first one is cut and it came out well. I used one of the single flute cutters from ebay.
4662466046614663

There is a litte bit of marking on the third photo at one of the corners but its nothing to worry about. This is cut from 25mm thick alu. Inner size was programmed to 80.5mm and it came out 80.4mm so thats fine as well. Just need some more time to get the second one done and get them drilled and tapped out for fitting.

I also did some testing on my tool height setter. Fitted a new 6mm single flute cutter and ran 10 measurement cycles of the tool height routine. The results are below.
1, 30.5087
2, 30.5037
3, 30.5012
4, 30.5012
5, 30.4963
6, 30.5012
7, 30.4963
8, 30.4988
9, 30.4988
10, 30.4988
From min to max the difference is only 0.0124 so thats good enough for me.

Regards

Ian

JAZZCNC
02-10-2011, 05:13 PM
Hi Ian,

The corner marking is chatter probably due to radius being the same size as cutter, if you can make your radius just slightly larger than the cutter this won't happen.

Nice job as well by the way.! great aint it watching the machine build it's own bits. .:toot:

Web Goblin
02-10-2011, 06:48 PM
Jazzcnc,
thanks for the info on the cutter radius. It was a 3mm rad and a 6mm cutter. I will alter the drawing for the inner radius corners for the next one. I have alot to learn about milling, this is not something I would have to worry about in profiling.
Your right, its great watching the machine cut its own parts. I wonder if I can get it to build a replica of itself:lol:

Ian

Web Goblin
08-10-2011, 07:24 PM
I have been cutting two new spindle mounts this week to reduce the vibration of the spindle motor. After finishing the second one I had sent the machine to the home position which is where I usually leave it when switching it off. On travelling with the X axis I noticed a grinding sound. On further investigation I found this:

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Looks like the shaft I used to join the motor to the pulley had been working its way through the bearings and had the coupling rubbing against the motor mount.
I need to strip this out and make two locking collers for the shaft to stop it moving.
At least it hasnt done any real damage.

Ian

JAZZCNC
08-10-2011, 09:01 PM
Ian there's a big gap between the worn coupling and the bearing mount has it been floating.?
Sorry but I'm not familiar with your setup and can't tell from this close up pic but that looks like it's an FK bearing in the mount so it shouldn't float at all.?

Edit: Ok I stopped being lazy and went back and looked thru the thread I understand now, they are FK bearings but also fixed at the other end.!. . . . Still looks like float thou.?

AdCNC
08-10-2011, 09:06 PM
Ither a FK or FKA depending on what model mount hes go!

m_c
08-10-2011, 09:11 PM
I read it as the shaft has moved through the bearing block, which in turn has pulled the lovejoy into contact with the housing...

JAZZCNC
08-10-2011, 09:31 PM
I read it as the shaft has moved through the bearing block, which in turn has pulled the lovejoy into contact with the housing...

Ye but what shaft.? Motor shaft.? or Screw shaft.? Either way neither should be floating.? . . .something seems strange.!

m_c
08-10-2011, 09:42 PM
This pic from earlier in the thread reveals all.
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The motor coupling would have enough movement in it to allow the pulley shaft to hit the mount without losing drive.

Web Goblin
08-10-2011, 09:42 PM
The shaft that connects the motor to the x axis pulley is the one which has managed to move through the bearings so that the coupling was rubbing against the motor mount.
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A picture of the complete motor mount. I didnt think that the shaft would travel through the bearings so I didnt fit any locking collars. I will make them and fit them on the motor side of the last BK mount before the pulley. This will stop any further movement.
I suspect this has been caused by the pull on the shaft from the tension on the pulley belt but this is a guess. Seeing as I had to hammer the shaft through the bearings I really didnt think it would move.

Ian

Web Goblin
08-10-2011, 09:44 PM
m_c,
thanks, I really need to learn to type with more than two fingers.

Ian

Jonathan
08-10-2011, 09:53 PM
Seeing as I had to hammer the shaft through the bearings I really didnt think it would move.

I feel sorry for those bearings. Hopefully you just hammered on the inner ring. Often heating up the bearing first does the trick if it's that close.


thanks, I really need to learn to type with more than two fingers.

Then learn with this, you won't regret it. I have been using this layout for about 5 years now:

http://www.dvzine.org/

Web Goblin
08-10-2011, 10:01 PM
Jonathan,
I dont like heating up bearings. I just normally put the shaft in the freezer for a while and yes I used a tube the same diameter as the bearing inner to hammer the shaft in. With a nylon hammer I might add.

Ian

JAZZCNC
08-10-2011, 10:26 PM
The shaft that connects the motor to the x axis pulley is the one which has managed to move through the bearings so that the coupling was rubbing against the motor mount.
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A picture of the complete motor mount. I didnt think that the shaft would travel through the bearings so I didnt fit any locking collars. I will make them and fit them on the motor side of the last BK mount before the pulley. This will stop any further movement.
I suspect this has been caused by the pull on the shaft from the tension on the pulley belt but this is a guess. Seeing as I had to hammer the shaft through the bearings I really didnt think it would move.

Ian

Argh I see now but I would call this the Y axis and the earlier post said X axis thats what's thrown me.!!

m_c
08-10-2011, 10:39 PM
Jonathan,
I dont like heating up bearings. I just normally put the shaft in the freezer for a while and yes I used a tube the same diameter as the bearing inner to hammer the shaft in. With a nylon hammer I might add.

Ian


You don't have to heat bearings up that much. 100degC is more than enough for installation, and it won't do any damage to the bearing or whatever grease is inside it.
Often sitting them on top of a hot radiator for an hour or so is enough to give that bit vital clearance for easy installation.

Web Goblin
08-10-2011, 10:47 PM
jazzcnc,
I would normally call this the Y axis as well but USBCNC calls it the X axis. For some reason the designer has the axis the wrong way round from what have seen is normal. I have tried to change it in the software but there does not seem to be an option for it.

Ian

JAZZCNC
08-10-2011, 10:50 PM
You don't have to heat bearings up that much. 100degC is more than enough for installation, and it won't do any damage to the bearing or whatever grease is inside it.
Often sitting them on top of a hot radiator for an hour or so is enough to give that bit vital clearance for easy installation.

Better still do both that way they just slip on sweet.
I find oven on low works good for large items like crankcase's etc . . .We race motoX so with rebuilding engines and forks I get plenty of practice.!!

JAZZCNC
08-10-2011, 11:00 PM
jazzcnc,
I would normally call this the Y axis as well but USBCNC calls it the X axis. For some reason the designer has the axis the wrong way round from what have seen is normal. I have tried to change it in the software but there does not seem to be an option for it.

Ian

Dont know much about USBCNC but surely it's upto you which Axis moves by how you connect the drives to the board. Hisn't it simply a case of connecting the X axis motors to the USBCNC designated X axis output.?
Then when USBCNC see's G-code telling the X axis to move it outputs pulses to it's X axis output which are connected to your X axis drives. . Simplizz's.!!

Like Mach it shouldn't and probably doesn't care which Axis is which, it just outputs pulses to it's designated pins or in your case connector on the board.
You could call them Jim, spock and Mc Coy it doesn't care (Can you tell I'm watching Star trek.! Lol)

Web Goblin
08-10-2011, 11:05 PM
I did that to start with but it gave me some problems with homing the machine so I changed it. Also its really annoying to watch the machine go one way and the graphics on the pc go the other! I did ask the designer if it could be changed but I didnt get a reply to my email so I will take that as a no.

Ian

Web Goblin
08-10-2011, 11:10 PM
Here is a screen shot of the jog screen. You will see what I mean.
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The direction of the axis can be reversed but not the x and the y.

Ian

Swarfing
08-10-2011, 11:12 PM
Ian that looks right to me? orientation should be side on to the machine not head on as you may be thinking? It's not a mil

JAZZCNC
08-10-2011, 11:23 PM
Ian that looks right to me? orientation should be side on to the machine not head on as you may be thinking? It's not a mil

Yep I agree thats how I view it. . . . Mach works like this as well.

Ian I have downloaded the USBCNC software so I'll go have a look.

Web Goblin
08-10-2011, 11:25 PM
I see what you mean. It might just be me. I am used to profiling machinery and we always use the rail as the x axis and it is always head on on the screen as well. I am getting used to it slowly. I have plans to mount the pc under the frame of the machine and to mount the screen and keyboard on an arm at the front left corner of the bed so that the pc screen will be at 45 degrees to the machine so then I will be looking at the machine and the screen in the same direction so to speak so the machine movement will follow the screen movement.

Ian

Swarfing
08-10-2011, 11:29 PM
Think how a 2D cad screen is laid out, most routers are the same. A mill is head on and centered (point 0) so your machine will be xy axis positioned bottom left (point 0). Easy mistake :-)

JAZZCNC
08-10-2011, 11:34 PM
I've just loaded USBCNC with some of my G-code and it shows perfectly just like it would in Mach.

Like Poz says just view it as the side is your front view and it will make sense.

I'm now going to have a good rumage around in USBCNC software, I may just invest in one for a lathe project I have in mind.?

Web Goblin
08-10-2011, 11:45 PM
It makes more sense looking at the cad screen.
Like I say it might just be me. All the machine I have worked on always have the x axis as the rail and they all home , the ones that do home anyway, at the bottom left and some of them home at both sides left and right in they have two carraiges. I am getting used to it, I just have to remember thats it not a profiling machine:confused:

Ian

Web Goblin
08-10-2011, 11:47 PM
Jazzcnc,
I dont know about Mach but USBCNC can be configured for turning.

Ian

Web Goblin
06-11-2011, 08:31 PM
I decided that I wanted to see the display on my inverter so that I could get a basic idea of the spindle speed.
I removed the front cover from the inverter and found that the display box could be removed. As the photo below shows tha display box is connected by a 10 way ribbon cable.

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I made and fitted a new cable, 10 way flat ribbon ran inside some shielding then covered in heatshrink.


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Cut out the box lid and fitted the display unit.


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Fitted the speed control pot and an emergency stop button and connected everything up.
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Power on and test.
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All seems ok.

Regards

Ian

JAZZCNC
07-11-2011, 12:27 AM
I like to see my VFD screen but not for speed.?

I have it set to show current being drawn this shows me the load on spindle this way I can see when the tool is getting worn. Also good for gage to show material hardness, esp usefull with shity ALi that has soft or hard spots.! . . Also tells me If I'm being greedy on the DOC.!

Jonathan
07-11-2011, 12:42 AM
Everything Jazz just said... I almost invariably leave mine reading current. Especially on the lathe as there it's actually possible to hit the current limit, though I don't cut that fast often :naughty:
I mounted my VFD on the ceiling above the lathe so it's easy to read and accessible which is handy when thread-cutting.

How long is the ribbon cable? Good to see that the signals made it that far.

Web Goblin
07-11-2011, 07:14 AM
I might well change the display to current later on. At the moment I am still taking it easy with depth of cut and feed speeds till I get used to what I can get away with.
Jazz, I know what you mean about Ali. You can hear the change in the tone of the cutter when you get a change in the material. We also get it alot when cutting mild steel on the laser at work. The cut quality will be really good then it will go crap for a while when we hit a bit of crap steel. Sometimes it can be right down one edge of a plate. Makes the operators think the beam alignment has gone out.
Jonathan, the ribbon cable is around 2.5mts in length at the moment. This might get shortened a bit when I decide where I am going to mount the box.

andrewbond
30-11-2011, 05:56 PM
Hi,

I know I'm a bit late coming back with this but..

Just curious, did you use a brake resistor on your high power drives?

Andrew

Jonathan
30-11-2011, 06:05 PM
Just curious, did you use a brake resistor on your high power drives?

Brake resistor allows the VFD to stop the motor faster ... increases the deceleration.
Sounds good at first, but really since the spindle stops in about a second without one, and my lathe will stop on the VFD in 2.5s without a brake resistor I really don't see the point. You're just stressing the motor more by putting a much bigger force on it during deceleration. Or if it's on a lathe the gears/keyways in between will wear faster.
The only exception to this is for an emergency stop where you want the spindle/motor to stop as fast as possible.

Web Goblin
01-12-2011, 07:05 AM
Andrew,
no brake resistor. I just let the spindle slow down as normal.

Ian

andrewbond
01-12-2011, 09:52 AM
I meant the resistor terminal on the stepper driver?

Andrew

Web Goblin
01-12-2011, 11:00 AM
Andrew,
sorry I misunderstood you as well. No I didnt fit one to the driver either. I remember speaking to one of the manufacturers techies and he said that it wasnt needed.

Ian

Web Goblin
14-01-2012, 10:32 PM
I had decided that I was fedup with using the keyboard to jog the machine around and started to look at the idea of using joystick controls for the X, Y and Z axis. The USBCNC control board I am using does not have any inputs for joysticks so I looked at a USB keyboard interface and I found this one. Which fitted nicely inside a spare enclosure I had. I emailed the supplier and outlined the requirements I needed and he customised the interface for me. Including postage it was around 32.


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The box lid drilled out and one of the joysticks wired.


52325231

Both joysticks fitted to the lid.

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The nearly completed controller apart from the labels. Need to change the size of them to fit the left side of the joystick without overhanging the side of the box.


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There is no software to load, the USB port recognised the controller easily and it works perfectly alongside USBCNC V4.
Now I have joystick control for all axis of my machine. Much easier than the keyboard. Also this gives me the option of portability as I can have the control box in hand when positioning the machine.

Regards

Ian

luke11cnc
14-01-2012, 10:41 PM
that's a bit clever Ian

nice job

James

Jonathan
14-01-2012, 10:42 PM
Now you just want it wireless!

Web Goblin
14-01-2012, 10:55 PM
Wireless? Now thats an idea. You do realise that I will probably spend most of tonight trying to figure out if I can make it happen!

Jonathan
14-01-2012, 11:07 PM
Looks like it's either difficult or expensive:

http://www.ebay.co.uk/itm/Belkin-4-Port-USB-2-0-Wireless-Hub-F5U302ea-New-/250938085379?pt=LH_DefaultDomain_3&hash=item3a6d135003

This should work with a bit of effort:

http://www.ebay.co.uk/itm/Arduino-Wireless-RF-Transmit-APC220-Kits-USB-Converter-/160590892568?pt=LH_DefaultDomain_0&hash=item2563f68e18

Edit: It's rather slow though...
Edit 2: Slightly cheaper but still silly money:

http://www.ebay.co.uk/itm/Belkin-High-Speed-Wireless-USB-Hub-F5U303-VISTA-New-/110809027797?pt=LH_DefaultDomain_0&hash=item19ccbb94d5

Now we know why people just use wireless Xbox 360 controllers.

Web Goblin
14-01-2012, 11:12 PM
I would also need to get a power supply for the box as well preferably a rechargeable one. For the moment I will stick with the cabled version but in the future whos knows?

Ian

Web Goblin
25-01-2012, 05:07 PM
As the old saying goes "If it works, then modify it to make it better".
I had a play with the usb keyboard interface I am using to get joystick control for my machine. The thing I was missing was feedrate control for jogging so decided to add some.
The initial jog speed is 10% of full speed after the machine is homed which is a bit slow. I have added buttons to map the keys for 50% and 100% speed override to give me much faster jogging speed. I also changed the orientation of the controls to make it easier to hold and use. ( No wireless though :tongue: )


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You can view a short video of it in action here : http://www.youtube.com/watch?v=OSb7vJyVlIY

Regards

Ian

AdCNC
25-01-2012, 06:13 PM
Looking good Ian, BTW i forgot about your pm ill reply to it later ;-)

Jonathan
26-01-2012, 12:31 AM
The acceleration settings you have used look much too low to me. What have you set it to? Should be aiming for at least (roughly) 1m/s^2.

Web Goblin
05-02-2012, 12:38 PM
Jonathan,
the setup page on USBCNC for acceleration shows Acc.[AU/S^2]. In this box I have left it set to 50 which is the default setting. I cant remember what this setting means. I think I did ask Gary at Zapp about this a while ago and I have been looking through some old emails trying to find the answer but cant find it so I dont really know what Ive got it set to. I think I will have to email Gary again about it.

Ian

Jonathan
05-02-2012, 01:51 PM
Jonathan,
the setup page on USBCNC for acceleration shows Acc.[AU/S^2]. In this box I have left it set to 50 which is the default setting. I cant remember what this setting means.

It sets how fast the speed of the motor can change, which is important since when the machine changes direction one or more axis must accelerate and decelerate, so if the acceleration value is too low the feedrate will reduce significantly every time it changes direction which includes just moving in arcs and circles. In addition to increasing the time taken to cut it causes the chipload to vary on the cutter which, depending on the size of the cutter, could damage or at least increase the rate of wear.

See 3.4.3.2:
http://www.planet-cnc.com/files/CNCUSBController.pdf

Assuming you're using millimetres, the value is probably in mm/s^2 in which case 50mm/s^2 is far too low. You want more like 500-1000mm/s^2, but not too high as it can cause the machine to shake excessively. Keep increasing it until the motor stalls, then back off a bit to be safe.
As 50mm/s^2 is such a small number you will notice a big difference in the time it takes to cut most things, but particularly parts with small moves, such as engraving.

HankMcSpank
05-02-2012, 02:01 PM
Jonathan,
the setup page on USBCNC for acceleration shows Acc.[AU/S^2]. In this box I have left it set to 50 which is the default setting. I cant remember what this setting means. I think I did ask Gary at Zapp about this a while ago and I have been looking through some old emails trying to find the answer but cant find it so I dont really know what Ive got it set to.

Hii Ian,

I've just taken delivery of a USB-CNC 9 axis board....not sure if you know, but there's now a proper support forum (it's only opened recently)....

http://forum.planet-cnc.com/index.php

the software author (Andrej) is very responsive to posts on there.

Web Goblin
05-02-2012, 02:23 PM
Its USBCNC and not CNCUSB. They are different bits of software.

Jonathan
05-02-2012, 02:28 PM
Its USBCNC and not CNCUSB. They are different bits of software.

Fair enough, but this is very basic / universal concept so it shouldn't make a difference.

Web Goblin
05-02-2012, 03:09 PM
Jonathan,
You could be right but the manual doesnt specify this. I have emailed Gary at Zapp so he can remind me.

Ian

Web Goblin
08-02-2012, 02:16 PM
Jonathan,
I have recieved an email from Gary and he descirbes the App/unit as being made up of mm per step of the motor/ seconds squared.
So it looks like you are correct in what you were saying. I will increase the setting to 500 first of all and see how the machine performs and maybe get higher than this depending on how it is. I have noticed in the newer version of the manual that the setting page does have a value of 950 in the Acc. box so I will see what I can get my machine to run comfortably at.

regards

Ian

Web Goblin
12-02-2012, 08:49 PM
Jonathan,
I have altered the acceleration setting to 300 and this seems to be ok. I did try 500 but this wa a bit too abrupt for the machine, it was shuddering a bit at start and stop. I need to email Gary at Zapp to see if it is possible to alter the acceleration and deceleration distances in the software. If this can be changed then I could have a bigger acceleration value.
The new bed for my machine arrived yesterday but this needs a fair bit of work to get it finished to what I have planned. Its 15mm thick aluminium at 1260mm x 910mm. It needs to be cut to 1250mmx900mm then fitted, levelled and drilled and tapped for clamping.
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Regards

Ian