Specs for cnc small parts - Shoptask Eldorado

[pfarber]

I am looking into CNC'ing my Shoptask.

I don't want to buy their cnc kit (what fun is that?) but I also don't want to buy the wrong small parts (belts, cogs, etc).

Does NEMA 32 or 34 'size' motors matter?

What shaft diameter do the drive cogs need to be to fin into the stock mounts?

Would be good t learn hwo to find that stuff out, or maybe compile a list for others to referance.

Any help appreciated.

[PoppaBear10]

Well, the Ball screw cogs will depend on what size ball screws/ends you choose. The screws from ST are cold rolled and are only about 0.004-5/inch. You can get them cheaper elsewhere, but you will need to turn the ends yourself for your bearing types.

Dan Mauch sells the Clifton 140 oz/in servos (with you choice of encouder types from US Digital), for a good price that will run your ST very well.
Drives you can get from Gecko 320's if you want servos which are superior in my opion to the steppers in that same size range.

You can buy a Transformer, Caps, Bridges, bleeders, etc. from places like Mouser, allied, Jameco and others. (Including shielded signal cable, and other wiring from the above places as well). Dan Mauch and others also sell "Kits" that contain the above that you can assemble yourself.

Since you have a ST you can make your own mount plates.
Your probably looking at $1,500-2k for all the stuff you you need to do the macine. Don't forget the computer/OS, and other miscelanous stuff.

[Dan Mauch]

I am looking into CNC'ing my Shoptask.

I don't want to buy their cnc kit (what fun is that?) but I also don't want to buy the wrong small parts (belts, cogs, etc).


Does NEMA 32 or 34 'size' motors matter?

What shaft diameter do the drive cogs need to be to fin into the stock mounts?

Would be good t learn hwo to find that stuff out, or maybe compile a list for others to referance.

Any help appreciated.

If you go with steppers, then I would get a 452 oz in step motor in a nema 34 frame with a .375 shaft then you will need a 14XL037 timing belt pulley even though the shoptask uses a 21XL037. On the leadscrew/ballscrew I would use a 42XL037 pulley. If you go with ballscrews I would get NooK ballscrews 5/8:diamter and with a .2 pitch

The stepers are .375 but most pulleys come with a .250 bore so you can use your lathe to drill the hole out to fit the stepper or better yet ream it to fit.


I would stay away from the cheap drivers that are sold for around <$150 for 3 axis. They tend to have a lot of problems with resonance with motors