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CNC milling/router DIY build WIP

Posted by Desertboy 
Re: CNC milling/router DIY build WIP
August 08, 2017 12:54AM
I mostly want to work MDF/wood but when I do want to cut aluminium I'll dry cut it with compressed air clearing the chips.

[www.mycncuk.com]

But when I feel better off will upgrade the waste board to a phenolic sheet which is oil resistant but think I'm better off upgrading the stepper drivers next and build a 68v power supply. Then I need to get a newer PC as I can't run Fusion and my cad program is getting long in the tooth and also no Cam functions. So phenolic sheet will probably have to wait till after xmas lol.

I'm lucky I have compressed air on tap at work 24/7.


What size hose did you use for your spindle?
Re: CNC milling/router DIY build WIP
August 09, 2017 12:43AM
I got 8mmOD / 5mmID silicon tube. It's pretty thin walled. I have to route it carefully to keep water flow. Even thought of using a flowcontrol-meter to send alarm and trigger one of the spindle off inputs in the inverter.
Re: CNC milling/router DIY build WIP
August 09, 2017 01:12AM
It's cheaper to monitor the temperature of the spindle than water flow so I would add protection to the spindle by buying one of these

[www.ebay.co.uk]

Stick the thermostat probe on the spindle. It's just a thermistor, so strip the case off and tape the thermistor to the body of the spindle then wire to a latched relay, set the temp to 40C. If the spindle heats above 40c the thermostat will trip the relay which will be off until reset. You then wire the machine to the side of the relay you can also wire all your stop switches to this as well.

I read somewhere that over 50c and the grease in the bearings becomes liquid and seeps out.

Edited 1 time(s). Last edit at 08/09/2017 04:58AM by Desertboy.
Re: CNC milling/router DIY build WIP
August 15, 2017 02:12AM
O_lampe I was going to get one of these for clearing the chips when milling aluminium
[www.ebay.co.uk]

but you can't use the misting function with mdf wasteboard they're are more expensive waste boards you can use oil lubrication with.
Re: CNC milling/router DIY build WIP
August 18, 2017 05:10AM
Bought a 2nd hand Core I7 3.4GHZ Desktop, going to put 32GB of ram in it, 240GB SSD & a GTX760. (2nd hand of course lol) will cost me £400 in total. This machine is for Fusion 360 only going to reformat my current machine to Ubuntu for day to day work and anything internet related. The new PC I will only sync to Fusion once a week other than that I will keep it unplugged from the Internet.

Hoping this PC will run Fusion decently

Edited 1 time(s). Last edit at 08/18/2017 05:11AM by Desertboy.
Re: CNC milling/router DIY build WIP
August 19, 2017 10:49PM


Nearly all the plates are done now, next couple of days hopefully and we'll have the gantry mounted and all 3 axis moving winking smiley Then the real fun starts lol.

20mm thick tooling plate, the extrusion is recessed 5mm into the plates for extra strength I got the idea from commercial printers we scrapped every single one of them recessed the extrusion so I figured there must be something to it.

Got a 2nd hand GTX760 now, just waiting for the desktop to come so I can ID the ram chips but as long as it's the same as listed I can get the ram 2nd hand for £72 for 32gig which seems a bargain to me! Need to order an SSD as well want to give the pc the best chance to get reasonable performance out of it winking smiley It's an I7 2600k so I should be able to overclock to 4.5-4.7ghz with no issues but might be worth getting a better cooler.

It's finally coming together might even see some movement next week

Edited 4 time(s). Last edit at 08/19/2017 11:57PM by Desertboy.
Re: CNC milling/router DIY build WIP
August 20, 2017 08:57AM
Almost there now, starting assembly it's always nice when you're cad models work out especially for this as it was far outside my comfort zone lol.

Ballnut aligns with spacer and bolts in perfectly


Y axis Nema's align



And I tried the recess's which are spot on for the extrusion, within a week hopefully we will have movement on all axis!



I spent about £1k now, including the spindle, some end mills. I also have bought a PC and will buy proper steppers, breakout board and build a 60v+ power supply total cost will be about £1500 for the whole build including PC so I can't grumble too much but the original budget is out the window.

Edited 3 time(s). Last edit at 08/21/2017 12:18AM by Desertboy.
Re: CNC milling/router DIY build WIP
August 28, 2017 01:20AM
Final plate is finished, should be able to finish the assembly this week.


Re: CNC milling/router DIY build WIP
August 31, 2017 03:54AM




Almost there now, Z axis is coming together.
Re: CNC milling/router DIY build WIP
September 01, 2017 06:37AM




Coming together bit by bit

Gantry is sat in recess at moment not bolted in.

Edited 1 time(s). Last edit at 09/01/2017 06:45AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 02, 2017 06:44AM




Including 4 AM882 Steppers (£200) and a self build 68v PSU (£60) my final costs to end will be just under £1500 over budget but under what it would have cost me for equiv size shapeoko or X carve in the UK when kitted out.

I also will have vac bed, legs, bottom shelf to take 2 vacuum cleaners (One for vac bed 1 for dust shoe) & the various other things.

Going to be a beast on the power socket lol but I'm wiring a 32 amp socket for this direct to the mainboard.

This will not be arduino powered in the end (Linuxcnc obviously) I need stall protection for the twin ballscrew axis. I think grbl can do this but might as well get a £3 breakout board use linuxcnc and take advantage of the extra hz's.

AM882's are ordered and PSU parts will get ordered in the next week so hopefully 2 weeks we'll have all the wiring on, water colling, dust shoe, cylcone, etc and the machine can finally start cutting. I Will use the cnc shield and Poulou drivers to make sure it moves ok until I get the proper drivers.

A 4 months trip with highs and lows but the end is in site now and I'm very glad I went the build my own route.

Edited 5 time(s). Last edit at 09/04/2017 04:50AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 06, 2017 06:38AM
Self build PSU cost £90 in the end but it should be plenty beastie when built and give me ~68v and 12amps in an unregulated power supply.

This is from the AM882 (Stepper driver) manual

"6. Power Supply Selection
The AM882 can match medium and small size stepping motors (from NEMA frame size 14 to 34) made by Leadshine or other motor manufactures around the world. To achieve good driving performances, it is important to select supply voltage and output current properly. Generally speaking, supply voltage determines the high speed performance of the motor, while output current determines the output torque of the driven motor (particularly at lower speed). Higher supply voltage will allow higher motor speed to be achieved, at the price of more noise and heating. If the motion speed requirement is low, it’s better to use lower supply voltage to decrease noise, heating and improve reliability.


Regulated or Unregulated Power Supply
Both regulated and unregulated power supplies can be used to supply the drive. However, unregulated power supplies are preferred due to their ability to withstand current surge. If regulated power supplies (such as most switching supplies.) are indeed used, it is important to have large current output rating to avoid problems like current clamp, for example using 4A supply for 3A motor-drive operation. On the other hand, if unregulated supply is used, one may use a power supply of lower current rating than that of motor (typically 50%~70% of motor current). The reason is that the drive draws current from the power supply capacitor of the unregulated supply only during the ON duration of the PWM cycle, but not during the OFF duration. Therefore, the average current withdrawn from power supply is considerably less than motor current. For example, two 3A motors can be well supplied by one power supply of 4A rating.

Multiple Drives
It is recommended to have multiple drives to share one power supply to reduce cost, if the supply has enough capacity. To avoid cross interference,
DO NOT daisy-chain the power supply input pins of the drives. Instead, please connect them to power supply separately.

Selecting Supply Voltage
The power MOSFETS inside the AM882 can actually operate within +20 ~ +80VDC, including power input fluctuation and back EMF voltage generated by motor coils during motor shaft deceleration. Higher supply voltage can increase motor torque at higher speeds, thus helpful for avoiding losing steps. However, higher voltage may cause bigger motor vibration at lower speed, and it may also cause over-voltage protection or even drive damage. Therefore, it is suggested to choose
only sufficiently high supply voltage for intended applications, and it is suggested to use power supplies with theoretical output voltage of +20 ~ +72VDC, leaving room for power fluctuation and back-EMF. "

I really didn't want to spend another £300 on electronics but it just made sense having stall protection and get the most out my motors although if they are underpowered I can drop in 3 * 4nm Nema 23's on 2 axis (X&Y) in 20 minutes including the time to wire them up. The PSU I'm building has enough wiggle room for upgraded motors.

Edited 1 time(s). Last edit at 09/06/2017 06:39AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 07, 2017 03:19AM
Z axis is getting there but need more bolts waiting for delivery.

Energy chain wasn't as hard to mount as I thought need to connect it to the z axis. No way are the water lines going inside the energy chain.

This is from Joe's excellent build thread
[www.mycncuk.com]

I've had the parts delivered this morning will build up mine at the weekend 68v's of goodness.

If I find it underpowered and slow I'll sell the 1605 ballscrews from the X&Y with the nema's and replace with 2510's and 4nm nema 23's (The most powerful available in nema 23 profile.)

At the moment we're just under £1500 but by the time I've built the table for this with shelf and added a waste board it's going to about £50 over £1500. The bed has another 4 pieces of 4545 extrusion to go into yet.

Edited 2 time(s). Last edit at 09/07/2017 03:44AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 07, 2017 08:58AM
Wow, this PSU looks huge. The capacitors will be a challenge to switch on.
Is there a precharge circuit planned?
Re: CNC milling/router DIY build WIP
September 07, 2017 09:20PM
Quote
o_lampe
Wow, this PSU looks huge. The capacitors will be a challenge to switch on.
Is there a precharge circuit planned?

I wasn't going to because I didn't know I needed one, will ask on the other forums where I found people building their own. I know a couple of people have built identical power supplies to one I pictured and they're working fine years down the line.

This does have a 10k resistor wired to the output so it will drain the capacitors when off.

I bought this transformer
[www.rapidonline.com]

and 4 of these but I intend to use only 3 of them (with the holders)
[www.rapidonline.com]

also of course a rectifier
[www.rapidonline.com]

The PSU is powerful enough to run 4nm nema 23's (most powerful available) on all the axis at 68v with the AM882's so if I do upgrade anything I'll sell the X&Y ballscrew's with my nema's and buy 2510 ballscrews with 4nm nema's which will double the speed and torque of the machine.

Good thing when you import everything from China you can normally sell them for at least what you paid 2nd hand winking smiley

Edited 5 time(s). Last edit at 09/07/2017 10:58PM by Desertboy.
Re: CNC milling/router DIY build WIP
September 07, 2017 11:56PM
You can get away without precharge circuit, but don't be cheap on the on/off switch then.
Re: CNC milling/router DIY build WIP
September 08, 2017 04:57AM
Quote
o_lampe
You can get away without precharge circuit, but don't be cheap on the on/off switch then.

This is what I was eyeing up for an on/off switch
[www.toolstation.com]

Or

[www.ebay.co.uk]

Both cheap lol.

Z axis is almost finished now need to drill the spindle mount, the spindle mount will be bolted with 3 m4's per side directly through the top Z axis plate and into the Hiwin's



An early project will be remaking the Z axis to get more travel it'll cost over £20 to increase the travel from 8cm now to just over 20cm which is more in the zone. 8 cm is enough for me though but it's also an interesting project.

I'm also going to remake the Hiwin spacers because they look crap (They actually were Hiwin mounts I cut out of an aluminium plate). I have plenty of scrap aluminium for the spacers but the Z axis needs new tooling plate.

Edited 3 time(s). Last edit at 09/08/2017 05:33AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 09, 2017 04:21AM
Tried to spin the motor's up today using a cnc shield connected to 12v pc power supply, the nema's made a ticking sound but no more, what could be wrong?

I spun them up using my 3d printer before I fitted them into the machine connected to a ramps board and all 4 worked fine?

Tempted to drag the printer to the machine and try with the 3d printer electronics instead.

I couldn't try adjusting the stepper drivers as my cheap ass poulou clones has a micro screw (sunglasses size) for adjustment and I have nothing that small.

But I will try swapping the Poulou's off my ramps board that I can adjust and are originals. I also know the ramps board has powered these motors up.

Bought a cheap ass ratchet and spanner set off banggood £21 if you click the EU warehouse, cheaper than shipping from China! That never happens.

[www.banggood.com]

Edited 3 time(s). Last edit at 09/09/2017 11:36PM by Desertboy.
Re: CNC milling/router DIY build WIP
September 10, 2017 04:37AM


She moves at least the gantry winking smiley Powered up the axis using the ramps board.

All motor's are on and aligned to ballscrews, the dsg16 (Ballnut mounts) are all bolted in as well and if you turn the couplings everything moves.

Edited 1 time(s). Last edit at 09/10/2017 11:54AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 13, 2017 07:01AM
[www.youtube.com]

She moves very slowly lol using ramps board doing an X axis home (Repeatedly).

I guess this is the Gcode I want to move it manually and up the speed?

"G0 X12 ; move to 12mm on the X axis
G0 F1500 ; set the feedrate to 1500mm/minute"

Is there a way to make it move a set number of steps as I know 1 rotation is 5mm movement so 40000 steps should be 1000mm.

Edited 2 time(s). Last edit at 09/13/2017 07:03AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 13, 2017 10:31PM
I guess you can use :

M83  ;relative moves
G92 X0   ; set X axis to zero
G1 X1000 F1500  ; move 1000mm relative from there (-1000 to reverse direction )

Edited 1 time(s). Last edit at 09/13/2017 10:31PM by o_lampe.
Re: CNC milling/router DIY build WIP
September 14, 2017 03:55AM
Quote
o_lampe
I guess you can use :

M83  ;relative moves
G92 X0   ; set X axis to zero
G1 X1000 F1500  ; move 1000mm relative from there (-1000 to reverse direction )

Not had a chance to play with her again but nice one winking smiley

2 of my AM882's came and the other 2 will be next week so I doubt she'll ever cut with the arduino (Kind of sad about that, one day might wire the AM882's to the arduino just to compare grbl performance vs linuxcnc) but it's real nice to be able to make her go left/right, up/down winking smiley

Hows your machine coming on? Have you managed to fit your slides yet?

Edited 1 time(s). Last edit at 09/14/2017 03:56AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 14, 2017 08:34AM
Quote

Hows your machine coming on? Have you managed to fit your slides yet?

I figured, I have only one chance to press the spindle in the bracket. I haven't yet found the nerve to do it.
Re: CNC milling/router DIY build WIP
September 14, 2017 12:36PM
You're spindle mount is like this one isn't it?

[www.ebay.co.uk]

Because my spindle slides super easy inside the mount and only when I tighten the bolts does it become rock solid.

If it is I would complain I know it's been a while since you bought but if you got it from ebay from Chinese like I did you'll be surprised sometimes how helpful they can be I've had a few items replaced no hassles no fee when I've had problems last thing was my flexible coupling's (They wer £10 each) which took me 4 months to realise they sent the wrong ones lol. They sent me the right ones and told me to keep the originals.
Re: CNC milling/router DIY build WIP
September 15, 2017 07:51AM




Just got to work out where the grey and purple one goes and we can wire it up hopefully tomorrow we can start think about testing the output voltage.

I'm assuming they are the other primary coil so should be wired in series I believe but will double check this lol.

There are 2 primary coils at 115v.



Right think I worked it out with help from another forum

On the primary side
Blue/Brown go to mains
short grey/violet together

on the secondary side
Orange/red got the rectifier
yellow/black short together

Edited 3 time(s). Last edit at 09/15/2017 09:39AM by Desertboy.
Re: CNC milling/router DIY build WIP
September 16, 2017 09:02AM
Correct, in case you have 230V mains where you live.
What's the spec. of the output side? Each output delivers ~30V?

Edited 1 time(s). Last edit at 09/16/2017 09:02AM by o_lampe.
Re: CNC milling/router DIY build WIP
September 16, 2017 04:25PM
25v per output core, I was told once it goes through the rectifier it will end up around 68v's. (2 cores in series).
Re: CNC milling/router DIY build WIP
September 21, 2017 08:10AM
Stepper Drivers arrived winking smiley That's a 24v power supply in the picture was going to power the machine originally but not going to cut it anymore lol so I'll upgrade the ramps board to take 24v so I can run my printer nema's and heated bed at their full potential.


Spindle is on! I like this angle makes her look massive (She's already pretty big lol took 3 of us to lift her, 1.5m*1.1m)


Edited 2 time(s). Last edit at 09/21/2017 04:13PM by Desertboy.
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