Re: [CAD_CAM_EDM_DRO] size stepper motor for cnc conversion of a mini-mill

At 08:39 PM 3/19/02 -0000, you wrote:

>I like to directly drive the x, y and z axis with stepper motors (no
>gear reduction). What torque rating stepper motor do I need?

It's going to be a tricky call but I ran ball screws directly with 420
oz/in on my conversion. Here's the formula you need:

M= Fp/1800pi, where M is torque and p is pitch. Result is in Newtons.

>The reason I didn't want to use gear reduction is the backlash
>introduced by the gear train. Is this a concern I really need to
>worry about?

Not necessarily but steppers will rattle gears to amazing levels of noise.

> Also, would using belt and pulley solve the backlash
>problem?

I went to 2.5:1 cable belt drives, from Berg. I hadda get them to make me
some with double splicers, as otherwise I broke them in every little crash.
There seeme to be no loash if you keep them snugged up. Typically an
adjustment lasts a long time.

>Lastly, if you have done this and have a web page describing your
>effort, I would love to read about it.

See the tagline.

Regards, Hoyt

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