I was given a very old (circa 1930’s) Hobart Chopper, Model 612.  This has been in my extended family for a very long time.  The only attachment I have for it is the meat chopper (grinder).  The motor seems fine.  However, upon disassembling the gear box for inspection, it appears to me the motor pinion gear is badly worn.  Not surprisingly, this part is obsolete and unavailable.  I was considering refurbishing this unit for personal use, but am now re-evaluating putting any money or more time into it.

Below are a few photos, including a close-up of the motor pinion gear.  Any suggestions?

IMHO, that isn't "badly worn", just worn. Odds of picking up a replacement cheap enough to justify it are slim to none. You might get lucky and find a COTS item that is available reasonably priced. If not, I would have no issues putting that gear back in and running it.

An alternative would be to turn the gear around if possible. I would only recommend turning it around if you can turn both gears around though.

Find a company like this one:  Gears Made that can make gears from samples.  A local machine shop (if any are still around) might have the tooling in stock to make this.  However, a small one-off piece for a company not set up to specifically make gears would be quite a bit more expensive.

Hmm. 

This kind of fix will take money. 

Is likely steel for a reason. I would venture that one could easily enough design the gear on CAD, even print in PLA for lost PLA casting, but I'm not sure how long the aluminum would hold up.

Thank you for your comments.

Unfortunately, the pinion cannot be turned around.  Also, I contacted Al Meekins @ Gears Made and he was kind enough to reply with a very prompt quote of $275 for 1 – replacement pinion.  Probably a very fair quote given the time required to replicate the piece, but probably not a good option for me.

Can you pull the larger gear as well? If you can find a set with the same C-C' distance, opening the bores (or sleeving large ones) will be *much* cheaper than a custom gear. Even if the tooth count isn't exact, all that will do is change your speeds.

The gear box is entirely disassembled, with the exception of motor shaft bushing removal.  I considered what you are proposing already, but am uncertain of the feasibility.

I intend to push this project aside for a few days while I mull it over.  I have 24/7 access to a super clean and well maintained 1-1/2 HP unit about 25 minutes away and have not been hunting much the last few years.  I could simply reassemble and dispose of this unit.

What about a chain and sprocket.

Everything would turn in the wrong direction.

I'd probably take Al up on his quote then. $275 and it will be done correctly with out screwing with it. Probably the cheaper route if your time means anything to you as well.

This project has not moved along much as I am still mulling my options.  Have done some further disassembly and cleaning.  I have located 2 - NOS, obsolete, OEM pinions for a later model that may work.  Could be the last two in existence.  However, I would not know if it will fit until I received it.  Price would be ~$140 + S&H.  I would be able to return it, minus 2-way S&H.  Fully realize the pinion I removed still has life.

I am incredibly indecisive regarding this project.  Real hesitant to invest much time or $ given lack of replacement parts; small motor (1/4HP); and what I suspect is a leaky gearbox design.  Not knocking the designers; they did well with the existing technology in 1920’s/30’s.

Regarding the motor rating, I'd guess that's pretty conservative.  And I'm betting you could get it rewound at a motor shop for not much.

But the lack of replacement parts...that's a tough one.