First Proper CNC Router

[Desertboy]

Yes it is worth £20 an axis, don't be scared of the PSU build I was then it turned out to be nothing but if you're near Leicester I'm happy to help build it with you to take the scary edge off with and you can check out my router so you don't make the same mistakes I did, you can make other ones lol.

I do love your design because it's just so raw but over engineered that raw becomes pure.

[diycnc]

Is there much of a saving when building rather than buying?
I see zapp automation sell a 68v one for £115.

Im in north Manchester, so Leicester is a little far. I do travel with work from time to time, so i might take you up on that offer if im in the area soon.

I tried to keep with the KISS (Keep It Simple Stupid) methodology when designing this. I find is often the easiest, cheapest, and quickest way to design and make stuff.

[JAZZCNC]

Is there much of a saving when building rather than buying?
I see zapp automation sell a 68v one for £115.

Depends on how many motors your running and motor size. Zapp 68V PSU only provides 6A which isn't really enough for 4 motors or leaves any room for upgrades with 3 motors.
Can make one for about £70-80 with exactly what you require and bit to spare for upgrades.

Regards the Drives then if your using slaved axis then go with AM882 for stall detection it's a Must Have feature really.
If not then save the money and put to motion control card it will be worth the investment.

[Clive S]

Is there much of a saving when building rather than buying? I see zapp automation sell a 68v one for £115.

Check out Joe's excellent vid.
https://www.youtube.com/watch?v=4OoQ...zD30sZjtp_VyqY

here is a shopping list from Rapidonline https://www.rapidonline.com/

I would go with a 45-0-45 V toroidal instead of the 50V

[Desertboy]

Listen to Clive I speak from experience lol
http://www.mycncuk.com/threads/10880...6816#post96816

get a 45v not a 50v, if you do insist on a 50v buy mine of me it's only had 10 minutes on time before I bought a 45v one lol. Luckily I got both 1/2 price so it evened out in the end and one day I shall find a use for it.

If you were in mainland europe 50v is fine as the mains is 10v-20v less.
Best thing about having screws under the bed is they're out the way so not crap can get into them, I also toyed with slinging the hiwin under the bed but too much hassle, for reference hiwin's are 95%+ efficient in sideways or upside down mounting vs horizontal it's for me their main selling point.

[diycnc]

Thanks for the info guys.
The power supply build looks a lot less scary than I expected, and I will defiantly consider this when I get around to buying electronics.

Regarding drivers I plan on just using 1 motor to drive both Y axis screws, so will go with the cheaper drivers.
Does anyone have any thoughts on how well a single 3Nm motor will move a 40Kg gantry, assuming im using 1610 screws and ~70V PSU?

Other than noise, are there any other major benefits of digital drivers over analogue drivers?

At the moment I am finalising the mechanical side of the design, particularly the stepper motor brackets and connection to the ball screw.
The plan is to use 16mm HTD belts on all axis.
To connect the two Y axis ball screws I will go with the setup jazzcnc sugests here
http://www.mycncuk.com/threads/4513-3-Axis-CNC-router

I just need to get a custom end machining on the ball screws so I can fit 2 pulleys on the drive end. All 3 X and Y axis screws are the same length, so will just get the same extra long end machining on all for simplicity.

[Desertboy]

My thought is ditch the 1610 for a 2010 with BK15/BF15 you can spin it 30% faster before it whips (Ballscrews become skipping ropes at a certain speed the thicker it is the quicker you can spin it)

Also if going the single motor, dual ballscrew route cnc4you do a 4nm nema 23 not sure how good it is but worth investigating.

Also the prices of Hiwin's from cnc4you is very good, the rail is clone but the carriages originals I intend to buy mine from there for my upgrade.

[JAZZCNC]

My thought is ditch the 1610 for a 2010 with BK15/BF15 you can spin it 30% faster before it whips (Ballscrews become skipping ropes at a certain speed the thicker it is the quicker you can spin it)

Nope bad idea with nema 23 motor.!! The inertia of the larger diameter screw and ballnut means more load on motors and less speed before torque falls away.
However there is one way to use 20mm screws while keeping same speed and lower whip. Use 2020 and gear 2:1 this increases torque and halfs the screw speed while keeping same speed as 10mm pitch.

DIYCNC:

There's massive difference between Analog and digital drives. Night & Day difference don't buy Analog drives you will regret it.

Watch or should say listen to these to see difference. Same machine same Motors only change was drives.

Analog https://www.youtube.com/watch?v=WnuLnKtqDX0
Digital. https://www.youtube.com/watch?v=K2-Aub2fetw&t=4s

[Davek0974]

Also if going the single motor, dual ballscrew route cnc4you do a 4nm nema 23 not sure how good it is but worth investigating.

I have only ever used these motors along with their "digital" DSP drives - the pair make a great combination.

[Clive S]

1610 screws are a good choice for X & Y with 1605 on Z. With a cutting area of 600x600 you could use just one screw for the Y put up the centre. Get the end machining to suit the machine it makes no difference to the supplier.

I would not buy any electronics until you have the frame built. Re the Spindle in post #1 The water cooled ones are very quiet and generally cost about £210 inc. the VFD that drives it.

Good luck with the build.