Re: [CAD_CAM_EDM_DRO] small 3-axis micro stepper

Tim Goldstein wrote:

> No offense to Mariss and Gecko as I use his products and think they are
> great.
> <rant>
> But, for what ever reason the general thought has become that everything
> need to run at 20 - 25x rated voltage and have a zillion amps.

Where this all come from is the Sherline, with that insane 20 TPI leadscrew.
This requires the stepper motors to run very fast (for standard 2-phase steppers).
To get 25 IPM, that requires 25 x 20 = 500 RPM with a direct-drive motor.
500 RPM x 200 steps/rev = 100,000 steps/min or 1667 steps/sec. While not
outrageous, this is getting into the higher performance range of many motors.
To get any torque at these speeds, your power supply needs to be many
times the straight IR drop in the windings.

> I can
> assure you that there are lots of machines happily running on Camtronics
> controllers that max out at 36 volts and L297/298 setups. Believe it or
> not I had my Shoptask happily running on 3.? V motors with a 24 volt
> supply and was getting 90 ipm rapids.

Well, that's quite respectable! But, I've never seen a Sherline do that!

Jon