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Lathe Repair
AntonUK - 5/8/15 at 10:20 PM

My really old but very handy lathe has developed a fault.

Its taken me a bit of research to identify the correct name of the parts. But it appears that the bull-wheel engagement pin has either failed of worn to a point where it no longer engages securely. As soon as any load applied it pop's out.

Part is shown as item P on this diagram.

If I can work out how to disassemble the the main shaft, am I safe to assume I could just remove the pin an replace with a suitable nut and bolt arrangement?




Another photo of a very similar lathe to mine.



theprisioner - 5/8/15 at 10:41 PM

On my Myford that pin is used in conjunction with a leaver to select the low ratios. In other words it scales the pullys to give you another four speeds. I guess if you bolt it you will always get the faster speeds. On the other and I could be talking c...p

SCAR - 6/8/15 at 08:13 AM

You could replace the pin with a bolt but that renders the back gears unusable (without removing the bolt again) You have a lathe so why not make a new pin? It looks like you can dismantle the headstock by undoing the 2 bearing caps. In the past someone may have tried to run the lathe with the pin located and the back gear engaged resulting in damage to the pin. Is your lathe a relm or relmac or super relm?

r1_pete - 6/8/15 at 11:31 AM

is it the pin or the hole that has worn, drilling another hole at the opposite side of the pulley may cure it.

Or if the pin is wobbling in the gear hole, a similar fix could work by re drilling the gear....

mark chandler - 6/8/15 at 12:20 PM

The schematic is an altas lathe, on mine you just unbolt he bearing shells and lift the shaft out, look in horror at the state of the white metal bearings and put back together.

It's just a pin, if you never use the back gear for very slow speeds just bolt up.

The Black Flash - 10/8/15 at 09:13 PM

quote:
Originally posted by SCAR
You could replace the pin with a bolt but that renders the back gears unusable (without removing the bolt again) You have a lathe so why not make a new pin?


This, most definately. It was made on a lathe in the first place, it can be made again...

AntonUK - 27/8/15 at 02:19 PM

quote:
Originally posted by The Black Flash
quote:
Originally posted by SCAR
You could replace the pin with a bolt but that renders the back gears unusable (without removing the bolt again) You have a lathe so why not make a new pin?


This, most definately. It was made on a lathe in the first place, it can be made again...


But as the lathe is broken, how do I make a new one?



After stripping down etc, the issue turned out to be excess end float. After tightening everything back up its all gravy again.