Re: [CAD_CAM_EDM_DRO] Apoligies !!!!!-Newbie building router

rmtuckeruk wrote:

> Sorry guys
> motor is running at 3 revs per second not 3 revs per min
> derrrr!
> any way does anybody think these will drive my m/c with or without
> gearing 1:2

So, you are only getting 180 RPM with no load? (Better than
3 RPM, for sure!) That, unfortunately, is not enough information.
It depends on acceleration and drag of the machine, as well as
the cutting forces. I'd say these motors, with this drive, probably are
not going to give much performance in the machine. I would not
be surprised if you hooked it up with a 2:1 speedup, that the machine
would not move at all! If it does break static friction, I'm sure it won't
hit 180 RPM from the motor, unless you have a severe resonance
problem, and you probably don't have that now. Well, we can
figure out the max power available. For ~1 A at 24V with a 5 Ohm
motor coil, you must be using two about 18 Ohm resistors. The
most power you can deliver would be 32 Watts per phase (24 V/18 Ohms).
Including both phases, that's 64 Watts. (Note that a unipolar driver
can never deliver the full power due to resistive losses in the motor.)
Including the motor resistance lowers this to 50 W total. I should note
that my milling machine has the motors geared DOWN 2.5:1, and I
am using 1/8 Hp CONTINUOUS rating servo motors. That is about
100 W continuous rating, and 400 - 500 W peak power. Since steppers
don't deliver peak power above the continuous rating (unless you have
a current boost when accelerating/decelerating) you would need a
stepper that delivered my peak power all the time to get the same
performance.

Jon