# Change gear repair



## phaxtris (Mar 6, 2022)

Couple hour project that has been a month in the making waiting on tools etc

lathe was missing several teeth on one of the change gears, after making a guess as to what gear type/pressure angle/etc i printed a couple options on the 3d printer to make sure i ordered the correct cutter, and after the long 3 week wait from china ive been able to start and complete this little repair

now im sure i could have paid a member to repair this gear for far less than the 500$ i spent on an arbor, dividing head, and cutter set just to cut a couple teeth.....but where is the fun in that

the process involved making an arbor to hold the gear, grinding the areas with the broken teeth away, filling with braze, turning the excess off, and finally setting the gear cutter and dividing head up and cranking that handle 75 times


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## deleted_user (Mar 6, 2022)

good job

I dont know that I'd not just have made a whole new gear but kudos to those who are not afraid to braze cast iron like this...

I guess I need to go out and find some brken cast iron gears to practice such a repair on


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## 140mower (Mar 6, 2022)

$500 is a pretty cheap education and you have the  tools to enhance your shops capabilities. I 100% would have done the same thing, the whole hobby is based on new experiences and challenging our skill sets, not what might make the most sense time/money wise.  Imho....


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## phaxtris (Mar 6, 2022)

140mower said:


> $500 is a pretty cheap education and you have the  tools to enhance your shops capabilities. I 100% would have done the same thing, the whole hobby is based on new experiences and challenging our skill sets, not what might make the most sense time/money wise.  Imho....



i fully agree, i would always rather spend money on tools/equipment to learn rather than someone elses labor


TorontoBuilder said:


> good job
> 
> I dont know that I'd not just have made a whole new gear but kudos to those who are not afraid to braze cast iron like this...
> 
> I guess I need to go out and find some brken cast iron gears to practice such a repair on



brazing cast is no different that anything else, if you can braze steel you can braze cast......and its actually the preferred method of repair for a lot of cast iron items


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## 140mower (Mar 6, 2022)

phaxtris said:


> i fully agree, i would always rather spend money on tools/equipment to learn rather than someone elses labor labor
> 
> 
> brazing cast is no different that anything else, if you can braze steel you can braze cast......and its actually the preferred method of repair for a lot of cast iron items


When I consider what I spent on cigarettes and alcohol in past years, my shop has been a cheap investment in myself, not to mention the years of "couples therapy" it has provided as an added bonus.....


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## deleted_user (Mar 6, 2022)

phaxtris said:


> i fully agree, i would always rather spend money on tools/equipment to learn rather than someone elses labor
> 
> 
> brazing cast is no different that anything else, if you can braze steel you can braze cast......and its actually the preferred method of repair for a lot of cast iron items


yes true, but I dont braze much... I mostly silver solder.


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## 140mower (Mar 6, 2022)

TorontoBuilder said:


> yes true, but I dont braze much... I mostly silver solder.


Yup, that's gunna up the cost a little....  But for the discerning home shop owner.......
Brazing is another one of those little tools it's nice to have in the skill kit, and it is really not that difficult.....


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## Darren (Mar 6, 2022)

Nice work Ryan.

Brazing is definitely a proper repair. I have also seen a section milled out square and a close(ish) fitting block of steel silver soldered in place, then turned and teeth cut.


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## DPittman (Mar 6, 2022)

Good job.


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## YYCHM (Mar 6, 2022)

Where did you order your dividing head and cutters from?  What mill do you have?


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## phaxtris (Mar 6, 2022)

YYCHM said:


> Where did you order your dividing head and cutters from?  What mill do you have?



i always do lots of comparing for the cheapest price between amazon, ali, and banggood, seeing as it is all the same product just a different re-seller....so this is what i ended up with

dividing head....amazon 404$......1 week
gear cutter arbor...amazon 32$........3 weeks
gear cutter set (1.5 mod, 20deg press angle, 8pcs)....ali 84$.......3 weeks

i have a king pdm30 round column mill/drill


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## PeterT (Mar 6, 2022)

TorontoBuilder said:


> yes true, but I dont braze much... I mostly silver solder.


What kind of torch equipment do you have & what are some typical applications?


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## Rauce (Mar 7, 2022)

PeterT said:


> What kind of torch equipment do you have & what are some typical applications?


I do a fair amount of silver soldering and brazing for bicycle stuff but I’ve dabbled in brazed carbide tooling and cast iron repair as well. Silver is great for tight fits, stainless and carbide. 

I use a Victor medium duty torch handle with propane tips, a BBQ tank and a rented oxygen tank. 

For small stuff the Smith mini torch knockoffs from Asia are actually quite good.


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## deleted_user (Mar 7, 2022)

PeterT said:


> What kind of torch equipment do you have & what are some typical applications?


Acetylene B tank w/ air and acetylene model self-igniting turbo torch, no oxygen cylinder.  

On small copper boilers and piping I sometimes use MAPP gas and turbo torch.

When I go to do my bike frame I'll have to buy a set with small oxygen cylinder because I doubt I can pre-heat a bike frame in an oven


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## Rauce (Mar 7, 2022)

TorontoBuilder said:


> Acetylene B tank w/ air and acetylene model self-igniting turbo torch, no oxygen cylinder.
> 
> On small copper boilers and piping I sometimes use MAPP gas and turbo torch.
> 
> When I go to do my bike frame I'll have to buy a set with small oxygen cylinder because I doubt I can pre-heat a bike frame in an oven


Any interest in an oxygen concentrator? I have one I haven’t used in a couple years. It doesn’t have the flow for heavier use or cutting but for bike frame stuff it works. Only real downside is it take a few minutes of running to get the flow consistent. Once I took up tig and got an account with a gas supplier for argon I just went ahead and got an oxygen tank.


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## deleted_user (Mar 7, 2022)

Rauce said:


> Any interest in an oxygen concentrator? I have one I haven’t used in a couple years. It doesn’t have the flow for heavier use or cutting but for bike frame stuff it works. Only real downside is it take a few minutes of running to get the flow consistent. Once I took up tig and got an account with a gas supplier for argon I just went ahead and got an oxygen tank.


I've only a passing knowledge of what an oxygen concentrator is. 

My bike project will be the most intensive welding project I've personally done in a few years. My last few projects were tire racks and a welding table using stick welding... since I needed the practice striking an arc.

My brother has a cheap multifunction Chinese welder that does stick and tig, and a mig welder that for some reason we almost never use to weld with. We have an account with a gas supplier for nitrogen, argon and acetylene so it would be nothing to add a small oxygen cylinder for me.


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## Rauce (Mar 7, 2022)

TorontoBuilder said:


> I've only a passing knowledge of what an oxygen concentrator is.
> 
> My bike project will be the most intensive welding project I've personally done in a few years. My last few projects were tire racks and a welding table using stick welding... since I needed the practice striking an arc.
> 
> My brother has a cheap multifunction Chinese welder that does stick and tig, and a mig welder that for some reason we almost never use to weld with. We have an account with a gas supplier for nitrogen, argon and acetylene so it would be nothing to add a small oxygen cylinder for me.


Ostensibly a medical device but they have become popular with jewellers and hobby frame builders. They’re obscenely expensive new but usually get paid for by insurance so eventually end up getting sold for pennies on the dollar. I think I paid $100 USD, picked it just outside Buffalo 5 or 6 years ago. Provides up to 15lpm of 95+% oxygen, has a built in regulator and regular B-size fittings.


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## deleted_user (Mar 7, 2022)

Rauce said:


> Ostensibly a medical device but they have become popular with jewellers and hobby frame builders. They’re obscenely expensive new but usually get paid for by insurance so eventually end up getting sold for pennies on the dollar. I think I paid $100 USD, picked it just outside Buffalo 5 or 6 years ago. Provides up to 15lpm of 95+% oxygen, has a built in regulator and regular B-size fittings.


Yeah that's what I thought.

so larger than a 20 cubic foot tank


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## Susquatch (Mar 7, 2022)

phaxtris said:


> Couple hour project that has been a month in the making waiting on tools etc
> 
> lathe was missing several teeth on one of the change gears, after making a guess as to what gear type/pressure angle/etc i printed a couple options on the 3d printer to make sure i ordered the correct cutter, and after the long 3 week wait from china ive been able to start and complete this little repair
> 
> ...



I would have probably started with a steel plate or piece of bar and had at. Even brazing is outside my comfort zone. 

Great job.


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## Susquatch (Mar 7, 2022)

Rauce said:


> I do a fair amount of silver soldering and brazing for bicycle stuff but I’ve dabbled in brazed carbide tooling and cast iron repair as well. Silver is great for tight fits, stainless and carbide.
> 
> I use a Victor medium duty torch handle with propane tips, a BBQ tank and a rented oxygen tank.
> 
> For small stuff the Smith mini torch knockoffs from Asia are actually quite good.


Not sure what a Smith mini torch is but crappy tire sells small oxygen tanks that can be paired with propane, butane, or map gas bottles and a small torch that works well for tiny jobs.


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## Rauce (Mar 7, 2022)

Susquatch said:


> Not sure what a Smith mini torch is but crappy tire sells small oxygen tanks that can be paired with propane, butane, or map gas bottles and a small torch that works well for tiny jobs.


I tried one of those years ago and didn’t like it. Really tricky to get the mix right with those tiny oxy bottles and they are pretty expensive. 

The mini torch is like this: 






						1 Year Warranty!! Futuredirect Jewelry Micro Mini Gas Small Torch Welding Soldering Gun Soldering Torches Soldering kit with 5 Weld Tips for Oxygen Cylinders, Hoses - Acetylene for Jewelers : Amazon.ca: Tools & Home Improvement
					

1 Year Warranty!! Futuredirect Jewelry Micro Mini Gas Small Torch Welding Soldering Gun Soldering Torches Soldering kit with 5 Weld Tips for Oxygen Cylinders, Hoses - Acetylene for Jewelers : Amazon.ca: Tools & Home Improvement



					www.amazon.ca
				




The real Smith one is about $300. It uses typical regulators/bottles. Just have to make sure the one you get from Amazon/banggood/aliexpress comes with the North American type fittings.


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## YYCHM (Mar 7, 2022)

Susquatch said:


> Not sure what a Smith mini torch is but crappy tire sells small oxygen tanks that can be paired with propane, butane, or map gas bottles and a small torch that works well for tiny jobs.



Ya, I got one of those kits from PA.  Gave up on it.  Couldn't keep it lit


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## Susquatch (Mar 7, 2022)

Rauce said:


> I tried one of those years ago and didn’t like it. Really tricky to get the mix right with those tiny oxy bottles and they are pretty expensive.





YYCHM said:


> Ya, I got one of those kits from PA. Gave up on it. Couldn't keep it lit



Jezz, sorry about that. Mine works GREAT! Maybe because it's really old and predates the crap craze. Ya the bottles are expensive but WAAAY cheaper than leased bottles. 

Can't beat it when you need really small or gotta go into the house or out in the field with it. 

I should make some adapters to work with my big bottles but then I've lost all the portability advantages and might as well just use a tiny torch nozzle on my big Oxi-Acetylene torch.


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## Brent H (Mar 7, 2022)

My PA torch works very well.  Also is about 20 years old.  I put quick connects on the bottles and torches - works great! 

Nice gear repair by the way!!!


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## Tom O (Mar 7, 2022)

Some people will drill and tap for a set screw then braise it up the tooth.


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## Susquatch (Mar 7, 2022)

Tom O said:


> Some people will drill and tap for a set screw then braise it up the tooth.



Sounds just like a dental implant......


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