Metric machine - balancing amp

[Trebol]

Hello.
I have a DC metric 3016, have replaced the X motor, and am looking to tune the amp.
I have used the program from the manual to do this:

X-4. Y-4. Z-4. G1 F150. M49,M91.
X4.Y4.Z4.
M99P1

I've searched the forum but cannot find any specific answers to the following questions:
1. Does the F150 (IPM) need to be changed to F3810 (i.e. 150x25.4 to get mm/min in my case) to read the correct following error of 302?
2. Does it matter if I change the XYZ travels to larger figures as a move of 4MM (as opposed to 4 inches) doesn't seem to allow the travel to settle down to see an accurate following error for adjustment
3. Is it better to adjust using following error or voltage at the sig2 plug (.735VDC) and if so where is the sig2 plug and its common, is it accessible from the square white cannon plug under the 1010 card rack, i.e. the tacho wires coming in? Or the plug at the bottom of the 1010 card in which case where is the common?
4. If I run the prog one axis at a time I get higher following errors on the individual axis. Is it therefore necessary to always run all three axis' together when adjusting/balancing an amp?

Thanks for all the good advice. As I said, I searched but couldn't find anything on the above with reference to a metric adjustment.

Cheers,

Trebol.

[denmar]

Save all your programs to a PC, erase all the programs at the mach.; type TA,2, this will bring the Service Programs inside memory; type PR 5811, that's the program for balancing Amps; Metric/inche.

[Trebol]

Thanks, appreciate it!

Still doesn't really answer any of the questions above.

Any guidance on those?

Thanks kindly

[Andy Fritz]

This is what I have figured out with help from the guys on this board who actually know what they are doing:-)

The fastest is to just load the service program for balancing XY and Z. I think it is 5811.

Move all axis to the CS marks and do a CS.

Type SETP and change default input units to inch and press MANUAL. Next you may have to CS the machine.

Manually jog XY and Z to -4. to check that no table fixtures are in the way.
Return all axis to the CS marks.

Run the balance program. If you have old motors / amps it will be hard to get a straight 302, so you have to try to look for the average following error.

You will find the SIG 2 LUG (NOT PLUG:-)) on the amplifier card. It is easier to set the balance and following error with a fluke / DMM, but I found that circle cuts was not really round that way so I re-tuned by looking at the following error and set the balance between -1 and 0.

As for running only one or all three axis I think it is better to run all three. The whole point is to balance the amps together so interpolated cuts come out to spec.

If you dont want to change over to inch then just multply both feed and travel by 25,4.

You may have to tweak the COMP pot a little, but DO NOT touch the TACH pot.

Andy

Hello.
I have a DC metric 3016, have replaced the X motor, and am looking to tune the amp.
I have used the program from the manual to do this:

X-4. Y-4. Z-4. G1 F150. M49,M91.
X4.Y4.Z4.
M99P1

I've searched the forum but cannot find any specific answers to the following questions:
1. Does the F150 (IPM) need to be changed to F3810 (i.e. 150x25.4 to get mm/min in my case) to read the correct following error of 302?
2. Does it matter if I change the XYZ travels to larger figures as a move of 4MM (as opposed to 4 inches) doesn't seem to allow the travel to settle down to see an accurate following error for adjustment
3. Is it better to adjust using following error or voltage at the sig2 plug (.735VDC) and if so where is the sig2 plug and its common, is it accessible from the square white cannon plug under the 1010 card rack, i.e. the tacho wires coming in? Or the plug at the bottom of the 1010 card in which case where is the common?
4. If I run the prog one axis at a time I get higher following errors on the individual axis. Is it therefore necessary to always run all three axis' together when adjusting/balancing an amp?

Thanks for all the good advice. As I said, I searched but couldn't find anything on the above with reference to a metric adjustment.

Cheers,

Trebol.

[Trebol]

Thanks Andy.
This is EXACTLY the sort of info I was after and is the precise reason why this forum is such a fantastic resource!!!
Thanks again for the length and detail of your reply.
Kind regards,
Tre.

PS One last question. You mentioned balancing the amps between -1 and 0. The Maintainence Manual (March 2003, page 191) states:

Press the SLIDE HOLD button on the keypad and adjust the balance of the
amplifier to read between 0 - 1

which seems to infer balancing in the range of 0 to 1 as opposed to - 1 to 0.
Wondering if you could clarify the above.
Again many thanks

[Andy Fritz]

I am not sure what is best to be honest.
I just saw -1 - 0 in a DC amp tuning guide that came with an AMP-0021 I bought new a while back. Maybe it was a typo:-)

For me it is a moot point as that balance value changes a little between auto and jog mode. If I tune for 0 - 1 in auto mode I will see 1 - 2 in jog mode.
I also varies a little with amp and ambient temperature.
I have heard that the following error is more stabile with new motors. Maybe you can confirm? If that is true then I would guess you should go for a steady 0 instead.

Another strategy could be to set the balance at idle using a DC clamp on the brown motor wire. Providing gibs are adjusted, ball screw aligned and you have sufficient oil on the ways you could simply turn the balance pot until the current drops to the lowest point. Then jog a little and check if the current is still low at idle. I am not sure that would also give you round circles, though. Maybe you have to choose if you prefer low current at idle or round circles:-)

Andy

[Trebol]

Thanks Andy.

I've balanced for 0 at slide hold in Jog mode. I'll see how that goes. Think now the thing to do is run parts and see how the old girl handles it.

Thanks again!
Cheers,
Tre.