Re: EMC Question. I have looked on the FAQ :(

[Ray Henry <rehenry-at-up.net>]

Hi Travis

Steppermod does not use PID.  Freqmod does.

Steps per unit for steppermod should be controlled by units and Input_scale 
for each axis.  For freqmod you will need to set output_scale the same as 
input_scale.  For smdromod you set input_scale to the number of steps your 
stepper moves for one unit and your output scale to the number of encoder 
pulses read per unit.

This is a wag and I don't mean to insult your intelligence.  Are you certain 
that the run file that you are using points to Travis-mini.ini.  You can see 
that on about line 27 of the run file.  I've done this -- edited one ini file 
and run another several times.  If this were the case and you are running a 
standard ini rather than the edited one, I'd guess that your stepper amps are 
running half step because 1000 pulses gets you an 1/8 turn rather than the 
1/4 I'd expect on the basis of your calculation.

I don't know what age of EMC you're running but the ini file you sent, 
version 1.4 is dated by at least a year.  There have been some additions 
since then -- nothing changed in the motion or axis sections.  Don't use the 
latest stuff from SourceForge either because there have been some variable 
names changed in the last month.

Hope this helps

Ray


On Thursday 11 July 2002 09:49, you wrote:
> Hello,
> Thank you for your time, I know that it is valuable and I do not want to
> take up much of your time.
>
> I was looking for a answer to a question on FAQ that was not answered
> directly.
> Does the Steppermod.o actually use PID?  If so, why is it that the changes
> in the PID do not effect the
> stepping? If not then what does actually change the steps.  I have tried
> the Input_scale and output_scale to no avail.
> I do not get the out come that I expect.  Here is my ini file attached to
> this email. Very little has changed from the original file.
> I can get my motors to turn, but not at the correct turns per inch.  I am
> using a 20 TPI rod now and will change to better material later.
>
> I have calculated the input as 360 degree rotation at 1.8 degrees per step,
> that is 200 step per rotation.
> now the lead screw is 20 TPI or 0.05" per thread 1 rotation, now using the
> equation. 200/0.05" = 4000 steps.
>
> My motor turns about 1/8 of a turn and stops. It should turn 360 degrees.
>
> I am running BDI install. 2.12.--- on three different machines and I get
> the same out come.
> All machines are from a pent. 100 to a pent.266MHz.  All have 128mb Ram and
> plenty of HDD.
>
> Travis Pierce
> Xerox Engineering Systems
> Research & Development
> 317 Main street
> Rochester, NY 14445
>  <<Travis-mini.ini>>