Web Goblin cnc has begun

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

look forward to seeing more pics all the best.

Looking good, cant wait to see this machine come to life !

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.


Attachment 3636Attachment 3637


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.


Attachment 3635Attachment 3638

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

Ian

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_wo...ate_-_off.html.

Has anyone looked into the detail of how the cncrouterpart parts (eg the rack clamps at http://www.cncrouterparts.com/produc...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.

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

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.
Attachment 3666Attachment 3667Attachment 3668


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


Attachment 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

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.
Attachment 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

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

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

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,

Managed to get my Y-axis motor and bearing mount finished today.

Attachment 3685Attachment 3686

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.

Attachment 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

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

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.

Attachment 3957Attachment 3953Attachment 3955Attachment 3954Attachment 3956Attachment 3952

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

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.
Attachment 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.
Attachment 4009Attachment 4007Attachment 4008Attachment 4010Attachment 4011

Also got the couplings bored out and fitted and the motors mounted.
Attachment 4013Attachment 4012Attachment 4014


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

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:

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.

Quote:

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Originally Posted by Web Goblin

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 ...

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

Attachment 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.

Quote:

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Originally Posted by Web Goblin

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.

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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...

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.

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.
Attachment 4124Attachment 4123

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.

Attachment 4126Attachment 4127Attachment 4125

Drag chains and supports are fitted with wiring in place and the cables are glanded into the panel.
Attachment 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

ITS ALIVE and moving!

I have finished the wiring and connected up the drives and limits.
Attachment 4153Attachment 4154

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

Quote:

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Originally Posted by Web Goblin

ITS ALIVE and moving!

I have finished the wiring and connected up the drives and limits.
Attachment 4153Attachment 4154

The panel is a bit crowded

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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!

Quote:

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Originally Posted by Web Goblin

... 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)...

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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.

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

Quote:

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Originally Posted by Jonathan

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!

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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.

Quote:

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Originally Posted by Web Goblin

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?

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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.

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!)

Quote:

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Originally Posted by Web Goblin

Jonathan,
Linking the drivers should be ok as long as the supply cables can carry the load current without heating up.
Ian

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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.

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.

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

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.

Attachment 4376Attachment 4377

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.

Attachment 4379Attachment 4380Attachment 4378

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

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

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/Submersibl...ht_2753wt_1139

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

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

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.
Attachment 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.

Attachment 4419Attachment 4418Attachment 4417
The comm is badly carboned up and needed a good clean.

Attachment 4421Attachment 4420

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.
Attachment 4423Attachment 4422Attachment 4424

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

Ian

ok

but can I ask a question

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

James

Quote:

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Originally Posted by luke11cnc

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

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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-P...#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.

Quote:

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Originally Posted by Jonathan

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-P...#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.

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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.!!

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.

Are there any plans to put anything in with the water (antifreeze? coolant additive? etc)