Re: following error problems

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

Hi Jason

Sorry to take so long to get back to you.  I've been wrestling with a 
Mazak spindle motor and drive.

This is a rather common complaint with freqmod.  It can be caused by one 
of several things.  

One is a metric definition for the units variable.  To fix this you need 
to multiply the following error values by 25.4.

Another is the default acceleration of 20.  Set this back to 5 or less 
and then set max_velocity in [TRAJ] a bit higher than you set it for the 
same variable name in any axis definition.  What happens is that during 
acceleration some steps get put into following error and don't get a 
chance to be fed back into the running axis.

A third problem can be the P parameter.  I'd start with this around 300 
and then shift up or down depending on how a real motor sounds.  If you 
don't have a motor connected you can set it as high as you like.

Hope this helps.

Ray



On Wednesday 15 January 2003 02:25 am, you wrote:
> hi all,
> 	finaly got all the hardware up for my axis's. all 3 are stepper motors
> and and operate correctly.
> The system is a 1.2GHz Duron with MDK9.0 (2.4.19-16mdk) with RTAI
> 24.1.10 ( I've got a patch if you need ?).
> The Problem is that it will run fine in a positve direction but running
> back to Y0 causes a following error. Is it just more tuneing ?
>
> also has anyone got a patch to direct the IO_BASE_ADDRESS to a device
> so that I could experiment with USB2.0 ?
>
> Thanks
> Jason Cox