Re: Ini file

["Dean L. Hedin" <dlh2001-at-comcast.net>]

> and restricting z axis acceleration orspeed does not help?

The only problem with that is sometimes I would like the Z to move 
quickly! 

The problem only seems to occur when I am moving at the fastest feedrate
(F7.0 units inchs) and more than one axis is involved.

Also keep in mind that this is in gcode produced by my emcprobe program
and consist only of a series G01 X Y Z movements.  on a 1/20in.  XY grid.
As it is moving along it suddenly hits a point where the Z drops quickly.
and this is the time that I loose Z steps.

So what I've done in the filter program is to watch the delta z between two
succesive points and insert a feedrate command to slow it down.  I've set
it up to apply a different feedrate for various ranges in delta Z so that
I don't end up jumping drastically from one feedrate to another.  For the time
being this has resolved the issue at hand.

I should also mention that I am running NEMA34 motors 1.4 AMP 5V rated
and I am not running them above rated voltage.  I have'nt improved my driver
board yet!  I don't think this is an issue because the problem occurs even on
dry runs with no workpiece in place.  As configured the motors have
sufficient speed and torque for the task at hand.

I will fiddle with acceleration values to see if that helps.

> > perhaps if you have a shared power supply, it has insufficient reserve
> > power to move all the axis at once ? You could use more/bigger supply
> > capacitors or
>
> unlikely with stepper motors.  the current they draw goes down a touch
> when they are moving.
> john

Concur,  When I initially encountered this I added a large electrolytic to the
motor supply.  Did'nt help.   Supply looks good on the scope.