PM-1640TL Spindle Collar - Purpose?

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Hi All,

Can someone tell me what the purpose of the collar on the back side of the spindle is, on my (now cleaned) 1640?

It's held on by a couple of set screws, and there appears to be a drill spot on it. Going with the manufacturers don't just randomly drill things if they don't have to, does that mean the collar is dynamically balanced on the spindle and would therefore throw everything out of whack if it were removed and then put back in other than the identical position?

I can't believe they add a chunk of machined metal and drill it for no reason, but I'm at a loss for what that reason might be and would appreciate any ideas.

-Doug

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For you to make a spyder? Just a guess on my part though.
 
For you to make a spyder? Just a guess on my part though.

Could be, although it'd be quite an apparatus to get out past the end of the spindle. There's an interior thread on the end (not shown in that angle), I thought maybe that would be useful for a spyder but you'd lose some I.D. and it'd need a set screw or something to ensure it doesn't unwind.

Is there a common collet closer or something similar that might attach to something like that ring? The fact that they drilled it makes me leery to mess with it, if it is indeed related to balancing the spindle.
 
I've no experience with lathe mounted collet closers, sorry.
 
I'd guess that it has to do with spindle bearing adjustment.
 
Call PM with your serial numbers and they can help you out
 
It is a spindle balancer. Do not remove it or change the position. I assume they dynamically balance the spindle and adjust the screws/holes for minimum vibration.
 
It is a spindle balancer. Do not remove it or change the position. I assume they dynamically balance the spindle and adjust the screws/holes for minimum vibration.

Thank you for the definitive answer Mark. It's one thing to suspect, and another entirely to know. I'm pleased they took the time to do that and I'll keep the whole balance thing in mind when I get around to attaching anything to the spindle (tach, spider) one of these days.
 
It's where the magnet goes for an rpm pickup also..
 
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