Re: [CAD_CAM_EDM_DRO] motor/leadscrew/ps recomendations and calculations

Richard,

You didn't mention current/voltage ratings of motors, but I'd bet that a
24v (or more) supply would give you a lot more out of your motors!

Alan KM6VV

Richard Spelling wrote:

>
> I've built a prototype cnc router using 3/8-12 leadscrews, Dan's 2 amp
> driver, and the following motors:
> X - 210ozin from Dan Mauch
> Y - 180ozin, high torque (read SLOW), from www.amsicorp.com
> Z - ???ozin, salvaged from a printer
>
> The power supply is an old AT supply.
>
> For X I can get about 12 ipm before the motor stalls
> For Y I can get about 8 ipm
> for Z I can get about 10 ipm
>
> I'm using half step mode, with 4800 steps per inch and CNCPro.
>
> I'd like to increase the speed, but still have at least 50 lb of linear
> force available.
>
> I figure if I went to 3/8-4 screws, I would still have 1600 half steps per
> inch, more than enough for me, and this would bring the machine motion
> further down into the motors torque curve, but I'm not sure if this would
> kill my linear force or not. What is the formula for calculating the linear
> force available at different leadscrew pitches and motor ozin?
>
> Another option I'm considering, at about the same cost, is to get another of
> Dan's motors for Y, and increase the voltage of the power supply. Under load
> right now, it puts out about 9v. Dan suggests I would get a 50% increase in
> speed from the motors by going with an 18v supply. This would give me about
> 18ipm for X and Y. This route would keep the high linear force, at the cost
> of higher screw rpm and a lower top speed than the new leadscrews.
>
> What I like about the AT supply is the readily availble 5v for limit
> switches, but I suppose I could pull 5v off Dan's board somewhere for the
> same purpose...
>
> Suggestions? Comments? Questions?
>
> Richard Spelling, http://www.spellingbusiness.com/boats
> >From the muddy waters of Oklahoma