Re: [CAD_CAM_EDM_DRO] Re: Stalling motors?

monty60475 wrote:

> All axis are mounted with bronze bushings{x} and bearings{y} and
>both use ball bearing thrust washers & shaft collers to hold shafts
>in place. I have went through alot of trouble to make everything move
>easely and smoothly. Moving x znd y shafts by hand, I feel very
>little resistance and no binding. As far as the caculations I did not
>enter weight/mass for x axis (about 15#),recalculated with 20# and my
>requirments changed to 86 in/oz. Should my 125in/oz motors be able to
>move the gantry assy. at higher speeds than what I am seeing?
>

Remember that stepper motors deliver the rated torque ONLY near
standstill. As soon as you get
moving more than a few hundred steps/second, in most cases, the torque
drops severely.
The 4.3:1 stepdown may be too much. In many cases, due to the torque
dropoff, much lower
reduction ratios work better, although they also reduce resolution.

If you 86 In-Oz is an actual torque requirement, you need to consult
motor or driver maker's
charts to determine the torque delivered by your motors with your
drivers at that speed.
If the dynamic torque is less than 86 in-oz at THAT speed, then you have
your answer.

> As far
>as power supply I did check voltage with and without motors running=
>67V and reel steady. Any thing else I can check?
>
>

What about WITH motors running? Does the voltage drop more than a few
volts?

Jon