Re: [CAD_CAM_EDM_DRO] Encoders on stepper motors.

In a properly constructed driver, with the properly set software
configuration and a proper machine you shouldn't lose any steps, however,
in addition to what other folks have mentioned there is stepper motor
resonance problems to content with. Just take some steppers and lay them on
the bench and do a G02x1.y1.i2 command and watch the motors as the
transition from one direction to the other. That is generally when you will
note stepper motor resonance. The use of encoders and the software that can
utilize encoders helps, if not eliminates this problem. Deskncrt and EMC
both use the Kulaga/Mauch DRO boards to take encoder feedback and compare it
to values set in the .ini files. If the error is greater than the
zero(error) it tries to speed up the motor and if successful continues the
toolpath. If the error is greater than the set value then the program stop
all three axis and an error message is displayed. If you want to add encoder
feedback to your program MC5 then I would be willing to donate an assembled
board for the task. I guess the source code can be found in EMC
Dan
-----Original Message-----
From: Art Fenerty <fenerty@...>
To: CAD_CAM_EDM_DRO@yahoogroups.com <CAD_CAM_EDM_DRO@yahoogroups.com>
Date: Sunday, March 25, 2001 8:31 AM
Subject: [CAD_CAM_EDM_DRO] Encoders on stepper motors.

>Hi All:
>
> I might be missing something here. I have heard alot about encoders on

stepper motor systems increasing accuracy. Am I wrong or is the only purpose
of an encoder in a stepper

>motor system only used in the case of a stepper missing pulses? If the

stepper never misses a pulse, the encoder does not do anything. The motor
can only be positioned to a multiple of its stepping resolution, right? If a
motor misses pulses, isn't this an indication of a poorly powered stepper

>system? I get the strange feeling I'm missing something obvious.
>
>Thanks,
>Art
>
>
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