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swisscheese
28-09-2013, 03:09 AM
Hi all,

Been a bit of a dweller and thought I better introduce myself and show my build, asking lots of questions in the process. :highly_amused:

I'm from the land down under, Australia, it seems pretty much all of you are in the UK!

The Build

The frame is made out of 65x65x4 mm box section steel. I think I may have gone a bit over board in this department, I'm sure you'll be able to tell me if its too much or too little. Originally the rails being used (all 20mm fully supported round rail) were going to be 1600mm for x 1000mm for y and 300mm for z. When I went to buy them there were no 1600mm in stock so I got the 1800mm for the price of 1600mm. This also forced me to get 1600mm ball screw instead of the planned 1400mm ball screw. The thing is I had already built the frame so now the x rails overhangs one end by 200mm. Instead of just cutting the rail I thought it would be good to leave it and modify the frame to accommodate it by adding a triangular section under each rail. This will allow me to do cuts that otherwise wouldn't be able to be done.

To level the table I will be using the self leveling resin method. I've already drilled and tapped all the holes for the x rail so these holes will obviously have to the bolts in them when I do the resin. What do I do to stop the resin from sticking to the bolts?
Cover them in a little oil?
I was thinking of using fiberglass resin. Anyone had any success with this? Other options?

Now the gantry.
I really cannot find anyone that can supply any suitable aluminium section for the gantry. This means that I have to use steel. For a length of 1.2m do you think 200x100x3 mm will be sufficient? I'm a bit worried about the weight of it. That section just mentioned will weigh around 12kg. The two sections that will hold it above the x rail come in around 13kg. Thats around 25 kg with nothing else added or accounted for. The x axis is moved by a 425 oz-in nema 23 motor. Will this handle it? It will be run with 1610 ballscrew, one on each side with belts. 5mm pitch 15mm wide htd belts and pulley will be used. Thinking a ratio of 1, can be swayed either way though to change this ratio.
Both the other axis will be powered by, I think 312 oz-in nema 23 motors.

Are all these motors alright to be run at about 60-70 volt? Heres the drivers I brought

3 Axis CNC Kit Stepper Motor Driver Controller 2M982 Interface Breakout Board | eBay (http://www.ebay.com/itm/300865568475?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

I hope these will be okay??
I think I'll be asking lots of questions about the electronics part when it comes to that so be prepared! :highly_amused:

And the spindle brought
1 5KW Water Cooled Milling and Grinding Spindle Motor with Inverter Drive VFD R3 | eBay (http://www.ebay.com/itm/170923177097?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

Again any specific things I should know about this spindle?

Also through reading the threads I've read its better to have the supported axis rail for the z axis on the bit that moves up and down. Why is this?

I think thats enough for now.

Thanks and will eagerly await the replies.

Jonathan
28-09-2013, 12:34 PM
To protect the bolts from resin I just covered them in grease and they came out easily. For the resin you want something with the lowest viscosity you can find and a long setting time, to maximize the chance it has to self level. I'm not sure if the viscosity of polyester resin will be low enough, probably not? The resin I used is west system 105 with 209 hardener.

Don't concern yourself too much with the weight of the gantry. What's more important, to have a strong machine or a fast machine? Your answer is almost certainly the former, so make it as strong as you can and then worry about possibly needing a bigger motor. Since you've already got the motor you might as well try it, but 3Nm is a bit on the small side. If you got another of the 425 oz-in motors and drivers, then connected one to each X-axis screw you would have enough power to move (at least) a 50kg gantry at a decent feedrate and acceleration.

Shame you got the 1.5kW spindle not the 2.2kW one. The 2.2kW spindles come with ER20 collets, so instead of holding up to 10mm tools they can hold 1/2" tools. That's useful if you want to use cheap router cutters.

Generally putting the rails on the part of Z that moves up and down reduces the overhang, i.e. the distance between the tool tip and the linear bearings.

Have you done a drawing of the gantry? It's a bit late now but it would have been easier to make a strong machine if you'd gone for an adjustable height bed and had the Z-axis working below the level of the X-axis rails, like in my build logs. Still, if you're not planning on cutting metals then you'll get away with it.

swisscheese
28-09-2013, 01:34 PM
Thanks for the fast reply jonothon, good man. On the train at the moment so wont do full reply. Are the photos showing up out of interest. Almost certainly wont be using machine for metals 99.5 percent o the time.

swisscheese
21-10-2013, 01:42 AM
Update

So the build has been coming along slow as uni is getting in the way.

I used the west system resin recommended and it worked really well. However it could have been a lot better if i had of sealed the edges better as quite a bit dripped out so there were some low spots.

The x axis is nearly complete, I'm just waiting on the belt and pulleys to arrive. I ordered 20 tooth pulleys and a 2525mm long 5mm pitch 15mm wide htd timing belt. Belts will also be used for the other two axis.

I had to use steel for the gantry as no one would supply the aluminium I needed. I could only get aluminium if I brought a 6m length.

I'm having a bit of trouble with working out how to arrange the bearings for the z and y axis. I know I asked in my first post about mounting the supported rail so it moves with the spindle but I want to know how important this is?
I ask because it will save a lot of mucking around if I can mount it the other way with the bearing blocks on the spindle.

Thanks again

EddyCurrent
21-10-2013, 10:50 AM
I could only get aluminium if I brought a 6m length.

Maybe you could have sold the remainder on ebay for profit ?
I think another reason for putting the Z rails on the moving plate is to add stiffness to the plate, you could argue that the rails should not be used to add strength but undoubtedly they will. There are plenty of machines with the rails mounted both ways and likely it will work both ways, it's just that one way is slightly better than the other.
Machine is looking good by the way, I can see the frame is well put together but I don't see any triangulation such as diagonals. Will you be fitting adjustable feet ? or maybe your floor is flatter than mine. As Jonathan says the 2.2kw ER20 spindle would have been so much better and I suggest you should go this route to have the 1/2" capability.
I found the round rails to be a bit bulky for the Z axis but they do allow more space for the ball screw.

swisscheese
21-10-2013, 11:39 AM
Hi,
I could have done that but a bit meh with the fuss involved.

I think I will mount it with bearings moving with spindle. It just makes everything a lot easier. I'll take into account the lost rigidity of spindle mount without the rails. 20mm thick aluminium seems to be the standard isn't it? I think it should suffice. And yes having some hywin type rails would be nice but the ballscrew is the limiting factor at the moment as I can't machine into the aluminium so their profile could be lowered. Hmm maybe a project after this is complete is to make a new z axis with hywin rail. :biggrin:

The table is bolted to the ground in 8 spot(one each leg) so I'm guessing this might mean I don't need triangulation?? Will wait and see. The epoxy leveling was done after. This means that I can never move the machine(as it would have twisted when I bolted it down), at least without redoing the epoxy each time.

EddyCurrent
21-10-2013, 04:20 PM
I'm going with 20mm aluminium plate. It sound like a good idea to fasten the machine down but I think you could still have adjustable feet too just in case :suspicion:
I'm not an expert on cnc (yet :wink:) but from your pictures, my past engineering life and what I've learned from this forum, I'm thinking the square tube bracket down to the x axis ball screw is not strong enough. It would be better if there was a triangular fillet each side to prevent flexing, I can imagine it vibrating causing tiny oscillations.

JAZZCNC
21-10-2013, 05:56 PM
The table is bolted to the ground in 8 spot(one each leg) so I'm guessing this might mean I don't need triangulation?? Will wait and see. The epoxy leveling was done after. This means that I can never move the machine(as it would have twisted when I bolted it down), at least without redoing the epoxy each time.

If you had triangulated and made a stiff frame then yes you could have moved the machine. Even now you can move the machine but you will need to ensure the frame is not in twist when set in new location. The rails will still be on the same plane if no twist exists has they levelled on same plane and the only thing you can introduce is twist.

Regards the rails on front then mostly depends on how much extension you have on the front plate when cutting and also what your cutting. If mostly extended and cutting harder materials, hard woods,aluminium etc then it will make enough of difference to matter. Low extension and softer materials it will hardly make difference.

swisscheese
23-10-2013, 09:15 AM
Thanks for the replies :beer:

Few Questions

How tight should the belt be? As in should I be able to turn the pulley on one side a little bit(maybe 8th of a turn) while holding the pulley on the other side still? It runs between the two sides and has a center distance of about 1100mm.

Also with the pulleys the length of the bore is about 29mm and it has two set screws. The shaft for the pulley on the end of the ball screw is only 15mm long. Should I be concerned that the shaft isn't long enough? Is tightening down the set screws onto the round shaft fine or should I grind down two flat areas on the shaft for the set screw to tighten onto?

thanksssss

irving2008
23-10-2013, 10:03 AM
Re the belt tension - you need to minimise backlash, 1/8 of a turn is way too much. Use one of the online belt calculators to see what the centre distance should be - it will depend on pulley size. If you can't get the exact centre distance you will need an idler pulley or other tensioner - e.g. a bearing on a stud pressing against the back of the belt.

swisscheese
23-10-2013, 10:13 AM
Hi,

Sorry maybe I should have been clearer. The belt is too big, i.e. tensioner is needed and have made one. Just not sure how tight to pull it. Is it weird that if I pull the belt tight the ball screw bows inward a little bit? Is this normal. It's 1.6m long. Bows in a few mm.

swisscheese
27-10-2013, 10:01 AM
Anyone have any opinions on this?


Also with the pulleys the length of the bore is about 29mm and it has two set screws. The shaft for the pulley on the end of the ball screw is only 15mm long. Should I be concerned that the shaft isn't long enough? Is tightening down the set screws onto the round shaft fine or should I grind down two flat areas on the shaft for the set screw to tighten onto?

thanks in advance

JAZZCNC
27-10-2013, 11:04 AM
Anyone have any opinions on this?



thanks in advance

Yes Grind one small flat the other is fine on round shaft.

There is another option but requires a lathe to do easily. Bore and Thread the Boss end of the pulley the same diameter has the threads on Ballscrew and use this to replace the Locknut on the Fixed end. This then gives full engagement on shaft and combination of grubs screws and threads lock it solid.!

swisscheese
01-11-2013, 12:51 AM
Jazz thats a great idea, will look into it, thanks.
Just a query about the wiring. I have heard you need to wire the emergency stops to stop the ac circuit and you cant wire them in with limit switches because motors will produce power and possibly fry motor drives? Is this true?
Also ive heard a lot about a 'ground star point' or similar. Can someone take me through this, never really understood it. What grounds go back to it?

Thanks all again

AndyGuid
01-11-2013, 03:11 AM
Also ive heard a lot about a 'ground star point' or similar. Can someone take me through this, never really understood it. What grounds go back to it?


Rightly or wrongly I've filed away Jazz's summary at posting.... http://www.mycncuk.com/forums/general-electronics/5036-earthing.html#post35083 .... as gospel.

Btw @swisscheese, whereabouts in this great city are you based?

swisscheese
06-11-2013, 12:29 PM
Rightly or wrongly I've filed away Jazz's summary at posting.... http://www.mycncuk.com/forums/general-electronics/5036-earthing.html#post35083 .... as gospel.

Btw @swisscheese, whereabouts in this great city are you based?

Thanks for the info, makes sense. I'm located in the south eastern suburbs, Caulfield area.

Here's where the machines at. I finish exams tomorrow so will be working on it full time now :yahoo:

Nice and pretty now all painted.

swisscheese
08-11-2013, 01:41 PM
Hi all, some help with respect to a motor drive would be really good.

It's a 2m982 driver.

Anyway me being stupid some motor wires got crossed and there was a spark and now it doesn't work is the short of it. I looked a bit on the net and it says it has voltage and amp protection. I opened it up and no current flowed over the 10a 250v fuse. I then got some new fuses, however the ones I brought are an enlarged version, they also don't have the wire coming out the ends. I put this in. I then powered it up and what happens is the PSU powers it for a fraction of a second then the psu shuts off then the red led on PSU dims. I also soldiered a piece of wire where the fuse would be, exactly the same things happens as above. The PSU works fine on the other two drivers.

Any help would be greatly appreciated. Don't want to have to wait two weeks for new driver :(

Here's some pics

swisscheese
10-11-2013, 12:08 PM
Anyone have any ideas about the above? I've already brought another but looking at a two week wait :apologetic:

cheers

danilom
10-11-2013, 10:06 PM
I once fixed Leadshine DM856 after a short of one wire with ground, changed one mosfet IRF540 and a 2W resistor.
I have couple of 2M982 on my machine will look in the morning what parts could be the problem on it.

swisscheese
11-11-2013, 01:13 PM
I once fixed Leadshine DM856 after a short of one wire with ground, changed one mosfet IRF540 and a 2W resistor.
I have couple of 2M982 on my machine will look in the morning what parts could be the problem on it.

That would be great thanks. Is the easiest way to find what's wrong to get two drivers side by side, one working, one not and pretty much test resistance across the separate components?
I hooked they driver to PSU with a 5 A fuse between the two. It blew it straight away so somethings shorting.

danilom
11-11-2013, 09:19 PM
Solder off the mosfets one by one and check them with multimeter like this
Testing a MosFet (http://www.utm.edu/staff/leeb/mostest.htm)

but first solder off the large resistors and check their resistance, you can check them with basic diode (continuity) test and as they are low ohms will seem like a short, they are broken if there is no reading at all.

I fried 2 drives and nothing but a mosfet and the resistor got fried inside :)

and you have to solder them off the board because the readings won't be correct while its connected to other components.

swisscheese
14-11-2013, 04:34 AM
Thanks for your help. Its appreciated.

The day before last a spent the day going through the driver, taking mosfets out and checking them. Well using the test you posted one of them gave different results compared to the other 4 I tested. I left 3 in there as I assumed they would be still working , ,maybe I should have tested those too as its still not working?? Anyway I replaced the bad mosfet with a new one and went to try it straight away and the fuse blew. Am I meant to test the other two smaller mosfets on the upper side of the board with the rest of the circuitry?

I had a bit of trouble measuring the resistors. The first one is 0.05 ohms(from colours), which seems very low to me. Not even sure if you can get them that low? I then tested the other two resistors which have much higher resistance (going by colours) and they came up at about 1 ohm resistance if I remember correctly. The thing is though I measured the same resistors out of a board that was working and they gave the same readings. Starting to think maybe my electrical meter isn't working properly.

I'm also wondering why the over voltage protection didn't do its job also?

Cheers

EddyCurrent
14-11-2013, 10:08 AM
When components are still soldered into the board the results can be miles away due to parallel components. You should test everything you can and you are in an ideal situation because comparative tests can be made against the working board. Can't you test your meter on a known resistor ?

swisscheese
14-11-2013, 10:23 AM
The thing that gets me is that I measure the resistors from the working board and I get the same result as measuring the resistors from the stuffed board, however the reading is nowhere near where it should be, i get about 1 ohm for a 18000 ohm resistor.

Just before I swapped a resistor over and put a new mosfet in one that I though may have been broken. Went and plugged the driver in and it worked!!! Was happy so then sat down wiring everything up to go, go and turn it on and now there's nothing, doesn't even blow fuses anymore, just nothing. Anyway I've swapped in so many different mosfets from things i have lying around, think I've given up and will just wait till the new one arrives. Thanks again for everyones help.

Eddy I've been taking the components out when measuring. And the meter seems to work fine on every other resistor but the ones from the drivers!!!

swisscheese
15-11-2013, 12:42 PM
I'm having some problems with the limit switches. I'm using LinuxCNC. For each axis they are wired in series and are done so when a limit is hit the circuit is broken(normally closed?). Anyway I've tried every combination and when I start up Linux CNC and press the 'power' button on the screen it straight away comes up with limit reached. I have inversed it in the stepcon. Same thing happens. I then put a little bit of wire in one of the x limit terminals and then just looped it straight back to the second x limit terminal and this fixed the problem, however obviously having it set up like this is no use. It's almost like the long wire and 2 switched delay the return signal so it thinks a limit has been reached. Another thing, it works fine if I set it to E-stop. Anyone had anything similar to this?

I'm also having a fair bit of trouble with my pulleys on the x axis(largest axis on my build). The set screws seem to keep coming loose. I thread locked them but this didn't help. Kind of made it worse. They loosened and then when I went to undo them they were jammed, ended up having to drill them out!! :(
I think I'll have to give the alloy pulleys the boot and get some steel pulleys. I just don't think they're up to the task, especially with only 8mm D shaft and only 15mm long when the pulley is 28mm wide.

I also want to put less stress on the machine overall, I had it set at about 800mm/s^2 for accel. I think I might drop this back a bit? Also will probably drop the max velocity back a bit also. It can do 11m/min just on the x axis but have it set at about 7m/min now(pulleys came loose at this speed) but think I'll drop it down again to about 5m/min. Acceleration would be the killer though with respect to forces experienced by all the componants.

m_c
15-11-2013, 01:48 PM
Regarding the limit switches, have you checked with a multimeter what reading you're getting at the BOB?

I've just had a quick look at a photo of the bob, and with the switched not actuated, the voltage between the two connectors should be near 0V.

swisscheese
19-11-2013, 02:22 AM
Regarding the limit switches, have you checked with a multimeter what reading you're getting at the BOB?

I've just had a quick look at a photo of the bob, and with the switched not actuated, the voltage between the two connectors should be near 0V.

I get 5 volts at the break out board. Have virtually tried every combination now. Even just doing the one z axis switch it still works intermittently or not at all. Just so I'm doing it right. I put one wire in first z limit terminal, run it to switch, run second wire back to second terminal from switch. Now there is a closed circuit. When switch is hit circuit opens. Have tested all with multimeter and all works as it should. Not sure where to go from here. Have tried 'invert' in linux setup also.

Heres a vid, notice only two axis running, third done by hand

DIY CNC router - YouTube (http://www.youtube.com/watch?v=ZFTLn7bpI1k)

m_c
19-11-2013, 07:43 PM
Just measuring voltage at the terminals, does the voltage change when you actuate the switch?

EddyCurrent
19-11-2013, 11:15 PM
Does the limit switch problem occur when nothing else is powered up on the machine i.e. spindle not running, stepper motors not running ?
If the answer is yes then it sounds like a bad connection or a faulty switch, if the answer is no then you may be getting induced voltage into the limits wiring.
Sorry if this seems too basic but I have seen these giving bad connections in real life situations; wires pushed too far into terminals so screw grips insulation, wire that looks like it's 'bare' but has a coating of clear lacquer, badly soldered joints that connect intermittently, wire where the insulation is intact but the metal core is broken, terminals that are tight but the wire has been inserted incorrectly (it missed the hole) and is not being clamped.

swisscheese
19-11-2013, 11:38 PM
Does the limit switch problem occur when nothing else is powered up on the machine i.e. spindle not running, stepper motors not running ?
If the answer is yes then it sounds like a bad connection or a faulty switch, if the answer is no then you may be getting induced voltage into the limits wiring.
Sorry if this seems too basic but I have seen these giving bad connections in real life situations; wires pushed too far into terminals so screw grips insulation, wire that looks like it's 'bare' but has a coating of clear lacquer, badly soldered joints that connect intermittently, wire where the insulation is intact but the metal core is broken, terminals that are tight but the wire has been inserted incorrectly (it missed the hole) and is not being clamped.

m_c and Eddy I will go and check these when I get out and report back.

cheers

swisscheese
20-11-2013, 02:26 AM
EDDY I can confirm that the switches work as they should when there is no power going to the stepper motors. I'm guessing I have to now re wire switching wire with shield wire of some kind??

thanks

swisscheese
01-02-2014, 12:29 PM
Man its been a while since I've been on here. Time for some pics!
Overall I'm pretty happy with how the machine runs, especially seeing as I made it with zero plans/planning, a big no no on here haha. Haven't had any major problems and once I received the new driver everythings been sweet. Still haven't wired up any limit switches, I'm lazy.:devilish:


Some videos

DIY CNC Router Flush Handle - YouTube (http://www.youtube.com/watch?v=UTVdoI-B1R8)

DIY CNC router pocket - YouTube (http://www.youtube.com/watch?v=EiJSLtEpkho)


Here's a few things I've been making....

EddyCurrent
01-02-2014, 09:40 PM
Those doors are great, what cutter did you use for that ?

swisscheese
02-02-2014, 03:23 AM
Those doors are great, what cutter did you use for that ?

Hi,
I used a 85 degree 2 flute v cutter. The holes are all the same distance apart centre to centre however there size changes according to depth(deeper equals larger). I'll put up a link to the free program when I'm on a computer.

GEOFFREY
06-02-2014, 09:51 PM
Great stuff. G.

EddyCurrent
06-02-2014, 10:16 PM
Hi,
I used a 85 degree 2 flute v cutter. The holes are all the same distance apart centre to centre however there size changes according to depth(deeper equals larger). I'll put up a link to the free program when I'm on a computer.

Any chance you can post that link ? thanks in advance.

cncJim
06-02-2014, 10:37 PM
My guess would be the software by this guy...?

http://jasondorie.com/page_cnc.html

In fact, seeing a link to his software was one of the first things that got me into cnc machines!

Nice job swisscheese, looks really good!

swisscheese
06-02-2014, 11:01 PM
My guess would be the software by this guy...?

CNC Software (http://jasondorie.com/page_cnc.html)

In fact, seeing a link to his software was one of the first things that got me into cnc machines!

Nice job swisscheese, looks really good!

Yes that's the link.
Might take you a few shots to get it working well.
A few tips
Make centre distance between holes about 0.4mm bigger or more than hole size.
Set z retract limit quite low, I do mine at 2mm
High contrast images work best


Also look up iannonne design. He has some great furniture with nice disigns on it using this and other techniques.

Cheers

cncJim
06-02-2014, 11:14 PM
Good tips, thanks. I haven't tried using the software yet as I think my machine might die from all the z action! First thing I will try when I upgrade though.
What sort of times did your half-toning take to machine?
Jim

swisscheese
06-02-2014, 11:31 PM
Good tips, thanks. I haven't tried using the software yet as I think my machine might die from all the z action! First thing I will try when I upgrade though.
What sort of times did your half-toning take to machine?
Jim

Also another
Start with min hole size at 1 mm and max around 4.
Melamine faced chip board and laminated mdf work good.

I have never timed but I would estimate that one of those doors ( from the tree cabinet) took around 1 to 1 and a half hours. Those doors were 15 thousand holes each. Probably could go faster but as you say you don't want the z axis losing steps as it works very hard and would be a bugger to reset.

Washout
06-02-2014, 11:43 PM
That is some really nice work - I have been toying with replacing my kitchen with some CNC work (will need a bigger machine), but those furniture pieces are very inspiring.

cncJim
06-02-2014, 11:58 PM
Also another
Start with min hole size at 1 mm and max around 4.
Melamine faced chip board and laminated mdf work good.

I have never timed but I would estimate that one of those doors ( from the tree cabinet) took around 1 to 1 and a half hours. Those doors were 15 thousand holes each. Probably could go faster but as you say you don't want the z axis losing steps as it works very hard and would be a bugger to reset.

Melamine faced chip board is a good idea. I can't remember where I saw it now but after cutting this guy covered the board with black dye. The dye stained all of the cut sections but wiped clean from the melamine leaving a very high contrast design.

15,000 holes for each door! Wow! So that's a minimum of 30,000 z movements? 60,000 for both doors.... Amazing.

I wonder what kind of strain that puts on the z screw?

Jim

EddyCurrent
07-02-2014, 12:08 AM
I was thinking about using contrasting hardwood veneers, thicker than normal veneer.

swisscheese
07-02-2014, 12:10 AM
Melamine faced chip board is a good idea. I can't remember where I saw it now but after cutting this guy covered the board with black dye. The dye stained all of the cut sections but wiped clean from the melamine leaving a very high contrast design.

15,000 holes for each door! Wow! So that's a minimum of 30,000 z movements? 60,000 for both doors.... Amazing.

I wonder what kind of strain that puts on the z screw?

Jim

I think this may be the video you're thinking of...

Aventador Halftone cut by DIY cnc router - YouTube (http://www.youtube.com/watch?v=jqksgmyWI3k)

I have tried this but couldn't get all the black stain off the melamine. I tried ink, watered down ink, acrylic paint and water based paint, all left a grey/light black on the white. The program mentioned above also has an option to do images in the wave pattern.

With respect to the images yes there's a lot of stopping and starting, from memory it was around 45,000 lines of code. I wouldn't be too concerned about the ball screw, that should be alright. My main worry would be with the connection between pulleys and ballscrew with respect to how well they are mounted onto shaft. If you have read my thread you would know I had a few problems with the pulleys coming loose on shaft and chewing the shaft up. I was always checking that the set screws are tight. Now its been a while with no loosening I can be pretty certain it should stay that way.

EddyCurrent
07-02-2014, 12:21 AM
That's a great video. With regard to getting stain off melamine, maybe before you start you could paint it with a thin coat of PVA, cut it, stain it, then the PVA + stain should wash off with water leaving the melamine clean.

cncJim
07-02-2014, 12:30 AM
I think this may be the video you're thinking of...
Yes, thats the one.



I have tried this but couldn't get all the black stain off the melamine. I tried ink, watered down ink, acrylic paint and water based paint, all left a grey/light black on the white.

That's a shame, seemed like it could be a good method. I wonder if maybe there are different types/grades of melamine?



With respect to the images yes there's a lot of stopping and starting, from memory it was around 45,000 lines of code. I wouldn't be too concerned about the ball screw, that should be alright. My main worry would be with the connection between pulleys and ballscrew with respect to how well they are mounted onto shaft. If you have read my thread you would know I had a few problems with the pulleys coming loose on shaft and chewing the shaft up. I was always checking that the set screws are tight. Now its been a while with no loosening I can be pretty certain it should stay that way.

I haven't read your full thread, I will have a look. I too have had issues with with couplings coming loose.....when mine came loose the spindle dropped and almost set fire to my garage! (To be fair it was my fault for not keeping an eye on the machine while running)


That's a great video. With regard to getting stain off melamine, maybe before you start you could paint it with a thin coat of PVA, cut it, stain it, then the PVA + stain should wash off with water leaving the melamine clean.

Interesting idea eddy. The other example shown on Jason dories site is to cover the board in self adhesive vinyl, cut, spray paint, remove the vinyl. Seemed to work quite well.

EddyCurrent
07-02-2014, 12:36 AM
The other example shown on Jason dories site is to cover the board in self adhesive vinyl, cut, spray paint, remove the vinyl. Seemed to work quite well.

That must be the Blue Peter method, sounds good though.
Instead of PVA maybe wallpaper paste would work ? obviously let it dry first.

cncJim
07-02-2014, 12:38 AM
Lol! At first I was going to write "sticky backed plastic" but thought it sounded a bit naff!

swisscheese
07-02-2014, 12:46 AM
Now that I looked at that video again it looks as though he didn't get all the ink off the melamine either. Hard to tell though. Some of those ideas sound good, I will give a shot when I do it next.

Just uploaded this vid, Quality isn't very good but you get the idea. Set it at highest quality (240p)

Halftone image CNC DIY router - YouTube (http://www.youtube.com/watch?v=J7Ko0sitAZo&feature=youtu.be)

cncJim
07-02-2014, 10:37 AM
Now that I looked at that video again it looks as though he didn't get all the ink off the melamine either. Hard to tell though. Some of those ideas sound good, I will give a shot when I do it next.

Just uploaded this vid, Quality isn't very good but you get the idea. Set it at highest quality (240p)

Halftone image CNC DIY router - YouTube (http://www.youtube.com/watch?v=J7Ko0sitAZo&feature=youtu.be)

thanks for sharing the vid - your machine look like its running really well, good job :applause:

AndyGuid
27-04-2014, 12:31 PM
Man its been a while since I've been on here. Time for some pics!

Overall I'm pretty happy with how the machine runs, especially seeing as I made it with zero plans/planning, a big no no on here haha. Haven't had any major problems and once I received the new driver everythings been sweet. Still haven't wired up any limit switches, I'm lazy.:devilish:

Here's a few things I've been making....

I had the pleasure of meeting swisscheese and his machine on Thursday.
Many Thanks swisscheese, the viewing and rundown of your build was much appreciated. I hope I don't bug you too much into the future.... Although having said that..... have you machined aluminium plate with your machine yet? ;-)
The half-tone furniture you've produced is not done justice by these pictures.... I found them far better in real life.... quite stunning really!
Cheers,
Andy

swisscheese
30-04-2014, 11:02 AM
Hi,

I have done some aluminium work with the machine. I will put a photo up of a gear I cut out when I get the chance.

Here is a video of it cutting alloy. This is when the z axis wasn't fully working so it was being moved by hand.

DIY CNC router - YouTube (http://www.youtube.com/watch?v=ZFTLn7bpI1k)