12" Craftsman Commercial Back Gear Missing Tooth

[powerpod]

Hi,
I'm new to this forum. I just acquired a 12" Craftsman Commercial Lathe with the Stand. The lathe sat in woodshop for the last 25 years unused. So it was coated in saw dust and crud. I have started to go through the machine, cleaning and checking for broken or missing parts.

The biggest issue I have come across is that the small diameter gear on the back gear assembly has one missing tooth. I assume this is from someone along the line in it's 70 year life, used the back gear engagement to take the chuck off.

My question is, how big of deal is this in the effective use of the lathe? And if I need to replace it, how difficult is to remove and replace? Anyone with experience with this repair, would be much appreciated.

 

[Bi11Hudson]

This isn't my area of expertise, so every comment should be taken with a grain shaker of salt. The back gear "assembly" is a secondary gear set that when disconnected spins freely on the shaft. This just to verify we're talking the same language.

In my opinion, the lathe can be run in the "fast" modes with no interaction. i.e. "normal" speeds. The countershaft only comes into play in the "slow" modes, the back geared modes. In essence, you lose the slower half of your speed selections. I have an earlier version of your machine and I very seldom use the back gears. That's a decision for the individual.

The biggest issue, to me, is where is the broken tooth. Having bought the machine "as is", I would make damned sure the part wasn't floating around inside the headstock where it can cause damage. When repairing any mechanical device the danger isn't so much the left over screw, it's the screw you're shy of to finish.

As far as replacing the damaged gear, I have no input. I have had mine apart to replace the bushings. But so long ago, I have no memories of doing the job.

.

 

[tq60]

Which gear is damaged?

On spindle or on the back shaft.

If on back shaft then it likely was as others stated, damaged by using to lock spindle.

This can be repaired with a few different processes.

One method is drilling holes where tooth goes and taping for screws that can be inserted then filed to shape.

Area then filed with epoxy mixed with steel grinding waste and filed to final shape.

The shaft also can be easily replaced.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[markba633csi]

If you don't plan on doing any threading operations you may never need the backgears, but they are nice to have
You may be able to order a replacement from Clausing or find a complete assembly on Ebay
-Mark
I'm sure the broken tooth fell down into the lower area of the headstock where it won't do any damage

 

[kcoffield]

In the under drive style of Atlas lathe, to replace the back gear, you'll either have to remove the spindle with the headstock in place, or remove the headstock to replace from the bottom.

Best,
Kelly

 

[powerpod]

Thank you all for your fast responses.
I found a set of replacement back gears on ebay for $60, and just ordered a pin spanner in order remove the retaining collar on the end of the spindle. As was stated by kcoffield I will have to remove the spindle in order to access the back gears (really the "down in" gears as stated by mr. pete of youtube fandom).