Need Help!- sub spindle orientation fault

[birchie]

I have recently changed the position encoder on the subspindle on a Puma . I can be set up using para4077 and will will locate using M119 S0 ok. If the spindle is run for 5 secs at 1000rpm when I programme M119 S0 the position has changed. If I run it in the opposite direction for the same amount of time it returns to the original position. Any ideas if there is a set up procedure that can solve this fault.

Many thanks

Birchie

[philserveng]

why not try M5 and then M119 S0, why do you need to program from 1000rpm ?. Are you sure you have no slippage in motor, encoder coupling or timing belts ?

[birchie]

Thanks for the reply phil

I am using the M5 before using the M119. so the spindle has stopped before going to orientate. The reason why I used 1000rpm was because it showed a pattern in the error. Everytime I ran the spindle for 5 seconds at 1000rpm the position the machine thought was S0 moved on approx 2.5 cogs. Stopping the shot pin from engaging. The timing belt is new and the spindle belts have been tensioned correctly.

Any further ideas would be greatly appreciated.

Thanks

Birchie

[philserveng]

Spindle encoders are generally pulse encoders, with a reference pulse channel once per revolution of the spindle. If there is no slippage, the spindle should stop in the same place every time. It may not be the right place, but it should be the same place.... that is why you have parameters. So long as the number of encoder pulses is correct ie; 1000 or 1024 pulses per rev, you can then set the parameter to fix the stop position correctly for the shot bolt.

[g30u0w0]

Probably a dumb question but-
I have never used the m119. What's the difference between stopping spindle and calling out M119S0 and calling out just A0? What application would it be better to use the m119 rather than straight A calls?
TY,
g30

[GrantM]

Two things to try to get more info...

1. Does it do the same thing and the same distance out if you run a *much* lower spindle speed?

2. What happens if you go the opposite direction from the original correct orient position, still the same?

Also, if you've just changed the encoder, that would seem the logical place to look. Double check all your wiring is correct, especially the index pulse connection (or connections if line driver type).

[cnc-king]

Originally Posted by g30u0w0 Probably a dumb question but- I have never used the m119. What's the difference between stopping spindle and calling out M119S0 and calling out just A0? What application would it be better to use the m119 rather than straight A calls? TY, g30

with the mii9s# you can increment in 1 degree increments, the A address will only allow 5 deg increment indexing. if the machine is 2000sy and bigger you can invert the spindles with a m291 where the sub spindle becomes the C axis and the main becomes the A and then you can prog in infinite degree indexing

[g30u0w0]

Originally Posted by cnc-king with the mii9s# you can increment in 1 degree increments, the A address will only allow 5 deg increment indexing. if the machine is 2000sy and bigger you can invert the spindles with a m291 where the sub spindle becomes the C axis and the main becomes the A and then you can prog in infinite degree indexing

Really, only 5 degrees. I have done engraving on the face of a part on the sub that had c commands everywhere, posted from Mastercam. Was it ignoring all the small c moves or is this a different kind of thing. It's a 2000sy. so anytime I want c movement less than 5 degrees I need to use 119? Or am I still confused?
TY,
Chris

[cnc-king]

Originally Posted by g30u0w0 Really, only 5 degrees. I have done engraving on the face of a part on the sub that had c commands everywhere, posted from Mastercam. Was it ignoring all the small c moves or is this a different kind of thing. It's a 2000sy. so anytime I want c movement less than 5 degrees I need to use 119? Or am I still confused? TY, Chris

what you are seeing is the cam system posting out polar interpolation where the spft ware converts all Y moves into C moves with engraving the spindle is not indexing but feeding. you should see a g112 or g12.1 at the beginning of your toolpaths and g113 or g13.1 at the end of the toolpath

if you use M291 the sub spindle becomes the main spindle and the main spindle becomes the sub spindle. it is all explained in the live axis programming manual fo the 2000SY

[g30u0w0]

You know just when I start to think I am getting a feel for what I'm doing a post like this comes up and I'm like what am I doing. : )
Ok I do not get a g112 call before the engraving. However i switch to g17 before and g18 after the engraving. Is that the same thing? Not sure i've used the g112.
Now you have me thinking this might be the problem I have when I try to helical bore a part off center on the face with an endmill. Sometimes using C axis they can come out more eliptical than circular. I switched to doing these types of operations in Y axis and it works fine. But help me! I should get your work # and just call you for an explanation!! For the most part any interpolation or plane changes I use g17 or g19 depending. hope you can shed some light on this for me.
I do switch often between the sub being A and C so I am familiar with that.
Ty,
Chris