Perfect Jeff ! you are the one of the best forum users interactive with me very efficiency.

You see the more detail information your provide, the more accuracy help I can send to you.

Enjoy your working with Siemens automation 

 I think you are talking about  spindle orientation. I had asked you who replaced Siemens drive for you --and now I guess It may be done by yourself? whatever, see here , I attach related pages copied from Siemens manual. if you want to modify any parameter, following the common rule--write down the value before any change. set P051=4 (password), after change every time save to Flash rom by set P052=1 (change back to 0 automatic)  some time the function will effective after cycle the power  

make sure your spindle position is good or you can handle to adjust it if need.

The "vibration" coming from spindle positioning loop gain, check P136,P137 and P138 maybe to larger , reducing one at the time to see effect 

the whole sequence is on the last page 

Good luck!

sputniktool

I did notice something this morning about the spindle.

when the spindle motor is holding spindle in position for a tool change it has a slight quiver to it.  I remember when i replaced the spindle servo drive i needed to adjust a pot on the servo drive to dial out the quiver in the spindle.  have you an experience in this?

 Busy again!

Now, you need have basic ideas for Siemens drive.(when Not busy, read the book, i attached--spindle drive is under HS/)  which designed for 8 gear step normally. But most machine builder use only gear -1 , related to P136.1 and so on. I think less than 10% old machine, using gear-2 and gear-3 (P136.2 and P136.3) 

I think your machine use gear-1 only so try P136.1 

The value input is Hex. you can adjust a little -->save-->and try effect--> re-adjust 

Gain too larger making vibration but too small will cause spindle no enough toques to hold the position, I think you just reduce a little--see no  vibration, it OK. 

attention--I did not check Parameters effective--some effective right the way after change some should re-cycle the drive power. if you not sure, every changing , save it (P052) then power off/on 

waiting for your good news

sputniktool

thanks

when i go to adjust parameters there are a number of sub parameters within 136,137 and 138

136.1 is 220H

136.2  220H

up to 136.9 is 220H

137.1-137.9 is also 220H

138.1-138.9 is 44H

when changing parameters lower it goes from 

220H to 21FH,21EH,21DH,21CH21BH,21AH, 219H,218H,217H  etc…

how much should i adjust each parameter and do i need to do all 136.1-136.9, 137.1-137.9, 138.1-138.9

or just the first variable?  vibration is effecting spindle orientation for tool change

 Thanks for update. I think "voltage coming out of transformer in machine was 408,408,407" is not perfect but should be very balance, suggest if possible (using jumper ) to raise to 415,415,414, and switch setting on top of Power supply for 410VAC. 

you mentioned spindle using 2nd encoder for speed feedback and positioning --which should be done by your CNC system parameter. you tighten the loosen belt , also good .

You agree?  we close this case, if you have question in the future, welcome to come back any time.

sputniktool

Adjusted the parameters a couple of times with no noticeable change. decided to chase another path.  

the spindle drive has a separate encoder connected to spindle thru toothed belt.  belt was loose which i think made the encoder search for zero.

tightened belt and machine has been running perfectly.

I am not sure the transformer in the machine was ever the issue.  I think the 3 phase convertor was the problem.  Worn out capacitors were playing havoc with the output power to the machine.

Thank you  for all your help on this issue

jeff