[JohnnyTurn]

I have a 1980 SL3B with a Yasnac 2000G control. Machine runs great.
I am the 2nd owner of the machine. One thing I have always wondered about:
When indexing, certain stations bang into their pre-clamping positions.
Every station clamps and repeats fine. It seems like the hydraulic actuation is just a bit harsh. Like it needs dampining or some adjustment is off.

Does anyone know what adjusts/controls the smoothness of the indexing of the turret?
And mind you, not every station does this. Maybe 4 out of 8 stations bang.
Thanks!

[underthetire]

If half the stations do it, im guessing the turret is out of balance ie too many BB holders on one side.

[JohnnyTurn]

Nope. That's not it. But thanks for the reply.

[Waynno]

Could be somebody fiddled with one of the timed relays, Im not sure
witch relay holds the turret open for a split second while it seeks
its respective spot, but sounds like it may be set too fast to clamp

[underthetire]

My guess then would be the splined coupling is loose after 33 years. Unclamp the turret and hit estop while it's unclamped. Also while it's unclamped, check the 2 3/4" nut in the center of the turret to make sure it's tight. Those get left loose all the time from turret alignments. Rock the turret and see if there is any play. The center shaft also supports all the weight of the turret while its rotating, so the bushing may be worn as well. There are some adjustments for rotation, not sure if yours is switches for position or resolver.

[Waynno]

UDT, Those have an array of proximity switches located in the big rear cover

Anybody who has had one of those go bad know it throws the turret spinning
endlessly until it finds the sequence it desires to orientate, its actually a pretty
stupid design IMHO, they could have done it with a simple encoder as you mention:idea:

[underthetire]

Some were. An antique resolver that has been NLA for over 10 years even. A real PIA to mount the replacement, and horribly expensive. Count your blessings it's just switches .