Re: Torque when using Micro Step or Full Step

Hans,

You have missed the point and that is my fault. The moment a full-
step driven motor takes a step, it moves the motor at a high velocity
to the next step location (1.8 degrees away). This velocity is wasted
energy and must be accounted for.

A microstepping drive parcels out the "distance to move" in much
smaller increments. Energy is mass times velocity squared divide by
2. If the distance to move is 1/10 as far, velocity will also be
1/10, and the energy invested in momentum will be 1/100 compared to a
full-step drive.

The step rate doesn't matter if it is 5 steps per second or 1 step
per hour. The effect is the same.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Hans Wedemeyer <xyz@h...>
wrote:

> Mariss,
> The motor is brand new special made (spindle lengths) and

guaranteed to be new because of that.

> The spec. sheet only talks about Holding Torque and it's +- 10% so

the 445 oz-in motor may already only be a 400 oz-in !

> If Full step has an advantage at start up ( where my main problem

is) If I used a control that allowed me to switch Full Step for
startup and micro step for normal running, that may be a solution.

> I'll consider that and see what I can come up with.
> In Series mode this motor require 2.8Amp drive and I may be able to

throw together a L6203/L297 circuit and do the Full Step/Half Step
tomorrow.

>
> I'll post results.
> Best regards
> Hans W