VM16 homes but tool changer position is too low

[Fig]

Hi guys, just registered, but I read occasionally on these boards. We have a VM16 with Cent VI controls. I just went through rebuilding the Z axis servo because it looked like the brake was open. When I got in there, the brake was fine, but may have come disconnected...anyway..fixed the brake and replace the bearings....got the motor working fine. There was also a loose connection on teh patch panel for those interested on the brake line...

So to my new problem. The machine homes and the homing is set to home on the mark not the switch. When it goes to tool change, the head is too low. I actually spaced out when it was doing a null tool change and had it come down on the the carousel.

-Is there a procedure for aligning the tool changer offset?
-Is there a proceure for aligning the coursel now that it is cocked. It looks like the mounts are flexible enough that I just need to destress the studs and then realign, no damage to the acutator etc.

Any help would be appreciated...I am getting quite familiar with this machine, just wondering if there is a quick answer that is not in the FM.

Thanks, Mike

[LYN BYRD]

I AM RUNNING A CENTURIAN 7 ON A VM17
PUT A TOOLHOLDER IN SPINDLE
GOTO MDI T0M6 (TOOLCHANGE TO TOOL 0)
G0G32 (MOVE TO TOOLCHANGE POSITION)
FROM MAIN MENU GOTO PARAMS,SETUP,AXIS,TOOLCHANGE
YOU CAN ADJUST TOOLCHANGE HEIGHT ON Z AXIS THERE
YOU CAN ALSO UNPLUG AIR AND SLIDE TOOLCHANGER IN AND OUT MANUALLY
AND YOU CAN JOG THE Z AXIS BY HANDWHEEL TO GET THE RIGHT ENGAGEMENT HEIGHT AND THEN RECORD THAT NUMBER IN THE PARAMETERS.
HOPE THIS HELPS.

[Fig]

thanks great help. Once I put the thread insert into the carousel and get it back together, I will give it a shot. Turns out the threads in the tool change arm plate just bent and egged out. So we had to drill up to 1/2" and make a thread insert on the lathe with a nice backing piece. I guess the next time it will just bend something else. One nice thing about a shop...you can make what you break

Mike

[msomerville]

If you need any other adjustment the bolts for the "V" wheels on the bottom of that plate work on a cam.

[chipsinpan]

Not really related to the tool changer , but I spent most of today working on the z servo for my old Partner 1 .
If you have a servo that ossicilates or hunts for z position , there is a procedure to remove the moter and blow out the dust , that is bridging the poles that will cause this .
Found out the hard way , that there was a loose piece of the coupling that connects the encoder to the end of the moter . plenty of dust to blow out . as well as dusty main moter brushes . A good thing I have a machine shop , so I could make the missing coupling piece !
Any how , it fixed the prob .
I am interested in the brakes in this component . Do these need servicing ?
look like they'd be a ***** to get at . I did all my service with the wires still connected , and the moter dissassembled on top of the vert column .

[single phase]

chipsinpan,

Did you take any pictures of the disassembly or the servo?

A little how to writeup with pics would be nice if anybody has done this.


Cheers
SF

[chipsinpan]

Milltronics has a service bulliten titled "cleaning brushes on DV servo Motors".
Perhaps JPawlek could post it here .
Please remember this is only for my partner 1 . other versions may be different .
I am not yet sure how to post photos , but I did take them and they are still in the camera .
The bulletin needs to have a few things added : be sure to physically block up the head , because it will crash down when you remove the belt .
2. you cannot rotate the motor by hand to scotchbrite the armature , because this motor has a mechanical brake that needs power on to release .
3.scratch a witness line to reassemble the case parts .
4 be very careful when you pull the encoder apart from the end of the case .
there is a small plastic bushing thats part of the coupling that hooks the encoder to the end of the main motor shaft . This part snaps onto the coupling ends , and I lost it when I blew the dust out . ( had to make a replacement out of 1/2" brass bar ).
5. there is a wiretie that bundles the wires around the encoder . you need to cut this off to slide the bakelite cover to get at the brushes .
you might want to hold a shop vac hose there before you blow it out .
I got a big dose of carbon dust in the face .
6. You might consider putting a piece of wood or cardboard on top of the column , in case you drop something -- a long way to the bottom to retrieve it !
7 . while the moter is out , inspect the 4 main brushes on the motor side .
take them out and blow out dust one at a time . make sure you put them back in the same way .
I did this all by standing on the table , and never disconnected a single wire .
It would have only taken about 4 hours if I had not lost the coupling piece .
Remember to sync your belt so it does a 1/2 turn on the last home sequence .
( params/level/axis /home seq/ [chg to 1,0,0] ) HOME;HERE
by the way 1/2 turn is measured on the motor pulley NOT the ballscrew pulley as there is a 1;2 ratio .
hope this helps

[single phase]

Thanks chipsinpan

I am glad you took pictures. See this thread on how to post pictures.

Cleaning out the dust does not sound too difficult.



Cheers
SF

[jpawelk]

Attached is the procedure for cleaning a dc motor.

[fcycles]

I had major issues with my x axis servo jumping all over , cleaned out the tach brushes and it worked great , but i had to learn the hard way about putting the body back together correctly , i had rotated the main body with the magnets and reversed the poles . When i reinstalled it would jump then throw an error for the axis drives , i had to reverse the + & - motor leads to figure that out. so if you accidently do what i did and it tosses drive errors try switching the + and - and see if that fixes it. Having issues with my z now i bumped my home switch while pulling the z servo and had the same issue but instead of rewriting parameters i readjusted the home switch untill it came back to the correct height for tool change (mine kept throwing the limit switch at tool change and my tool offsets were all higher than normal because the home position was higher) i just posted a thread with my z issues that i still havent fixed before i saw this one, which is fairly similar to my issues. Im new to these forums, is it o.k. to re-ask the same questions i just posted on someone elses thread without being considered an a-hole? Dont want to step on any toes