# 10" Bull Gear Question



## David M (Nov 11, 2017)

I just brought home a 10" Logan lathe, seems to be in a reasonably good condition except for the multiple teeth missing from the bull gear. Can't find anything used right now, and don't need the low speeds badly enough to pay for a new one. How rare are these?  I've seen many stories of people replacing individual teeth in a variety of ways, but I'm missing 8 of them and not sure it would be worth the time. I thought of turning all the teeth off the gear and replacing them with a ring gear if I could find the right size ring, or donor gear to make one from, but haven't been able to find either. Has anyone else ever tried this approach?


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## 4GSR (Nov 11, 2017)

Go to Logan Engineering's website and see if they have one available.  Or call them.  Their pricing from what has been said is not too bad.


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## David M (Nov 11, 2017)

4gsr said:


> Go to Logan Engineering's website and see if they have one available.  Or call them.  Their pricing from what has been said is not too bad.



Logan Actuator Co? They sell a new one, but $433 is more than it's worth to me. I have a bigger lathe for heavier work so could do without the slower speeds on this one. I bought it because the price was right and because a smaller machine can be handy at times.  It's in pieces at the moment for a good cleaning so if I were going to replace any parts now would be the best time.


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## cjtoombs (Nov 11, 2017)

I had to replace all but one gear on a bevel gear on my shaper.  I built it up with bronze brazing material then turned the OD and filed the teeth to fit.  Probably not the strongest or pretiest repair, but I expect if I don't get it into a bind it will work for another 90 years or so.  

http://www.hobby-machinist.com/threads/bevel-gear-repair.50352/#post-433389


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## CluelessNewB (Nov 11, 2017)

They show up on ePay fairly often, prices range from reasonable to insane.


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## wa5cab (Nov 11, 2017)

Although I think that your best bet would be a good used replacement, the concept of a replacable ring gear has been common for decades on some better quality automotive applications.  So it will probably work.  But before deciding to go that route, you should determine the gear specs and see whether or not Boston or some other manufacturer makes a spur gear that would yield a usable repair part.  If they don't, then there is no reason to spend time thinking about it.


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## David M (Nov 11, 2017)

CluelessNewB said:


> They show up on ePay fairly often, prices range from reasonable to insane.



As long as they come up occasionally i'll keep an eye out. Haven't ever had the occasion to look so didn't know whether they did or not. Sometimes all the used ones really are gone.


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## David M (Nov 11, 2017)

wa5cab said:


> Although I think that your best bet would be a good used replacement, the concept of a replacable ring gear has been common for decades on some better quality automotive applications.  So it will probably work.  But before deciding to go that route, you should determine the gear specs and see whether or not Boston or some other manufacturer makes a spur gear that would yield a usable repair part.  If they don't, then there is no reason to spend time thinking about it.



Checked Bostons catalog, and a few others, so far haven't seen anything close. Kinda figured it was a long shot


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## Nogoingback (Nov 11, 2017)

CluelessNewB said:


> They show up on ePay fairly often, prices range from reasonable to insane.



+1   Since you aren't in a hurry, eBay is your best bet. They turn up.


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## Chuck K (Nov 11, 2017)

You won't have any problem finding a used one.  Logan parts are pretty easy to find.


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