Re: Need help with Dyno design

Doing a dyno with a moving mass gets tricky because
it takes some of the torque to accelerate the mass.
You will need enough range of motion to reach the
steady state speed without the stepper motor jumping
steps while accelerating or possibly use a linear
acceleration and calculate the additional torque
consumed in the acceleration.

Regards,
Steve Stallings


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@y...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@y...>
> wrote:
> > Wally, Wouldn't it be easier to turn a 2"long X 2.125 dia spool

in

> the lathe with a 16 tpi groove on its diameter. Mount spool on

motor

> shaft, wind a cable on the spool with different weights suspended
> from it? Steel is .282 pounds per cubic inch to calculate the
> standards. Run different Rpm's and distances to see where it skips.
> Could run that Eckstein's DRO system with an encoder mounted on

shaft

> to verify. Or a simple reference mark from shaft to motor body.
> >
> > Ron
>
> I was thinking of a simple home version. A motor mount, a pulley

as

> you described, possibly a 1" screw as the spool, and a pulley on

the

> ceiling with a rope to a bucket.
>
> add water, nuts and bolts, or whatever.
>
> you can mark the height that the ramping ends and run tests on that.
>
> Since most steppers fail entirly when missing steps, it would be
> interesting to see.
>
> I also though about adding washers on a string so as the bucket

kept

> moving it would have weights added automatically.
>
> Dave