This isn't normal, right?

rficalora

H-M Supporter - Silver Member
H-M Supporter - Silver Member
Joined
Dec 23, 2020
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While waiting on parts to dry and for warmer weather to paint, I started to work on removing the headstock and noticed this play between the drive pulleys and the gears. You can see the movement beginning at about the 30 second mark in this video if you watch the detent mark's position relative to the gear's tooth nearest that detent.


Is it safe to assume that when I get it apart I'm going to find the hole in the pulley for the lock pin will be ovaled out? And, assuming so, would you fix that by simply rotating the two some and drilling a new hole for the lock pin (updating the detent mark accordingly)? Or is there a better way?
 
All the back geared lathes I've ever operated, maybe 10 or 12, ranging from 9"/4.5" swing to 32"/16" swing, all appeared rather sloppy at the locking pin.
Admittedly ALL were well used and most came from Noah's workshop.
If the visible end of the pin only has a little movement, leave it be.
 
Interesting and good to know! That's the only issue I see in the headstock so far. I'll still remove it & clean it (I'm refurbishing the whole thing after finding missing keys, missing taper pins, a missing alignment pin, and a few missing bolts (and I haven't gotten into the cross slide or apron yet). If, that play isn't an issue and I don't find any other issues after cleaning it, I don't see any other reason to disassemble it.
 
My th42 atlas does the same thing. Pin hole isn’t ovaled at all.

The way I figure it, there needs to be a little clearance in order to move the pin out and in. Too tight and you either won’t get it lined up or it may be too tight to slide.

Thats just my guess though…
 
When cutting that pin will always be loaded to the same side. It will not be floating around in use.
 
When cutting that pin will always be loaded to the same side. It will not be floating around in use.
True, and yet not at the same time.

things like interipted cuts and such operations will load/unload as it turns. Bit of a technical point, but still valid.
 
I thought of interrupted cuts as I was typing. I don't think there will be much if any movement since there is no reverse load to actually move the pin away from the drive side of the hole. The load will vary just not the position.
 
My 12X37 has play in the back gear as well, a little less, but mine came with play in the pin.
 
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