Re: [CAD_CAM_EDM_DRO] simple stepper power question.

Hi Dan,

That sounds like a good system. I haven't seen good spring scales
around, 'tho. Where did you find yours?

Also, I recall that Mariss posted a schematic of a Dynamometer circuit a
while back. It's under "circuits" in the files section.

http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/CIRCUITS/DYNOMOMETER%20CIRCUIT.pdf

I've been wanting to try this approach to motor testing.

Alan KM6VV

Dan Mauch wrote:

>
> When I first got started in cnc and step motor driver kits,I looked at
> ways to measure the torque of various motors and the performance of
> various drivers at various output voltage. I heard of using a weight
> with a pulley on the motor and figured that was too crude.
> So I designed my own and machined a flanged pulley for the stepper motor
> to a radius of .967 and that added to one half of the thickness of my
> nylon cord equaled 1.00" radius so my readings would be in oz inches. I
> made a motor mount and then using a deadhead on one side I attached a
> spring scale. With the motor running at the speed I wanted, it(the
> pulley)performs like a capstan. When the cord is slack, it slips and no
> torque is noted. As I pull (I have a spring scale on this side to
> measure this pull also)on the other end of the cord that is wrapped
> several times around the pulley which has a spring scale, I note the
> reading on the spring scale. I set up a matrix and recorded the torque
> and the current for each speed I wanted to measure. There's a bit more
> to it but is much more controllable than other methods and it got the
> measurements that I wanted.
> Dan
>
> -----Original Message-----
> From: dave_ace_me [mailto:davemucha@...]
> Sent: Thursday, April 18, 2002 5:07 AM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] simple stepper power question.
>
> is there a formula to determine power of a stepper ?
>
> I have a Slo-Syn NEMA 34, 1.7 volt, 4.5 amp
> single stack.
>
> Also, has anyone put together a simple test
> for stepper power ? Seems like a weight,
> and a long crank arm with holes drilled
> each inch would allow one to keep moving
> the wieght farther out until the motor
> started missing steps.
>
> Dave