[Krabbie]

Hi, we are having problems with our 2.5D Pedersen with acu-rite (MILLPWR, version ?? MS-DOS).

When we enable all axis, they all (3) move a little (X-axis, about 0.2mm). When we disable them and enable again, they move about the same distance again.

The X-spindle has a play of about 0.1mm. The Y-spindle has been replaced recently (play about 0.02mm)

The mechanic advised to have the PC checked by the supplier (in the UK ?), but i can hardly believe the PC is causing this problem.


Has anyone any idea what is going on?

[gus]

I do not know this control, but I am wondering if there is an offset in the servo amps that is causing them to jump. Older controls with slower update rates would always hunt, slowly rock back and forth through whatever backlash was in the system. If such a system had an offset[IOW the tach always outputting say .1 volt high or low] it would always sit in one direction. It is possible that in this situation, when the amps are enabled, it might jump to that direction

[photog1098]

Sounds like it at least needs a tuning (gain and balance). Is it a color MillPwr or a black and white MillPwr? Shouldnt take but a few minutes to do.

Jon

[Krabbie]

I guess you mean the colors of the computer screen. It is a color screen. They told me they had done the (auto) tuning. But i have read a part of the manual with some potentio-meters to adjust (manually of course) and i am sure they have skipped that part. Another problem is: the manual describes it as if all 3 axis have the same controller (hardware), but the Z axis has a different one, so i cannot do that procedure for the Z-axis.

Anyway i will try to do it myself next week. Until now i had no experience at all with CNC machines. That will change next week :-)

The 'operator' told me the problem started some time ago when he was drilling really large holes and the machine was heavily shaking during drilling that large holes. As mentioned before they had replaced the Y-spindle, but the problem still occurs.

[photog1098]

The auto tuning doesnt do much, you need to do the manual tuning. There are two pots you can adjust on each motor (well not on the motor, but it is near the motor) that should get rid of that excessive movement.

What is different about the Z axis? Pictures?

Jon

[Krabbie]

I will try it next week, since the machine is at work and not at my home.

[Krabbie]

Problem is solved by repairing the PC (by MillPwr).