Live tooling, backlash, slop? Chatter issues.

This is on a puma 2500 sy, the live tooling seems to have slop in the rotation of of the tool. It's been like this the entire time I've work here, but I just thought what if it wasn't normal? Probably not since no other spindle on any other machine has that type of slop, I'm guessing there is a coupling that could be replaced to fix this?

Drills and taps are not as bad but end mills are horrible,l. I'm guessing around 2-5 deg of slop.

Sounds like the bearings in the live tool are torched.

Chuck up a gage pin in it (assuming it's an er32 or er 20 style) and using an indicator on the pin see how much play you can get by pushing on the pin itself. It should be basically nothing.

If it's not, find a rebuilder and get er fixed!

I really don't follow your statement...

2-5 degree of slop - this is rotational, and once the lash is out - it should run the mill fine.

Rotational lash w/o endplay lash will play havoc with your taps tho!

If you are having endmill troubles, and not drill/tap troubles, then it sounds like worn bearings (par for course) to me.
I prefer to have a cpl of heads that are worn - just for drills/taps/reamers, but you gotta have tight ones for the mills!

You need to go back and doo some more detective work on that heifer.

2-5* rotational lash is nothing, and sounds pretty tight to me.




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I am Ox and I approve this h'yah post!

What's the input drive end of those Puma live tools look like? I think a male tang, that doesn't look unlike the tang of a Morse taper tool. The drive shaft, inside the turret with the female slot, they have clearance, so the tools can pass through as the turret rotates. Normally about 0.1mm (4 thou) per side. That wouldn't translate to 2 - 5 degrees of lash, but there's some clearance there. You can always feel it, but once its turning it should take all that up.

That drive shaft inside the turret. Its alignment is often over looked, when you pull taper pins and do an alignment of the turret drum. You can move the turret, but you have to check that the drive shaft is looking at the tooling hole.

If your bearings are really shagged, and things are floating, you're also loosing mesh across the helical bevel gears.

I'm not aware of any coupling that's inside them, that can be replaced, and I've been inside hundreds of them.

You'd have set a dial test indicator on both the input and out side of the live tool to check for internal clearance. Because the input shaft / tang is so small, I'd use our version of a tenth clock. And a half thou or thou at a larger diameter, some where out at a larger diameter, like a notch in a tightened ER nut. When I have to re-mesh those right angle drives, I leave nearly a thou tooth mesh clearance. There has to be some clearance, other wise they tighten up when they get warm.

Regards Phil

The input drive is a tang, and I believe that is where the "rattle", comes from. Im just curious if that's the way these have always been or is there a way to decrease the amount of "rattle" in the tool.

I have some newer holders and older holders that both perform about the same. You can physically feel the lash with your hand if you rotate the tool yourself.

You're always going to have that backlash.
It shouldn't be an issue at all for anything that is constant direction.
The backlash there would only give you problems when rigid tapping when the hear reverses.

Have you chucked up a gage pin in a collet and given it a tug? Chatter is most likely from worn bearings, like Ox said.