Bevel Gear Repair

cjtoombs

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This bevel gear drove the table lift on a 1924 Gould and Eberhardt 16" shaper. The PO (a machinery dealer) said he had bought it as part of a lot of macnhinery and it had been in a school before. From the shape of the machine, that doesn't surprise me, as there were sevearal things on it that were obiously damaged due to neglect and stupidity. This gear was one of them. There was only one tooth intact on it when I got it dissasembled. Luckily the mating gear was fine. This was the driven gear/leadnut combination that drove the cross slide and table up and down. I cleaned it, sandblasted it and then built up the teeth with a flux coated brazing rod. Since it had one tooth to go by, I was able to set it up in the lathe, indicate the compound to the angle of the tooth and cut the tops off to the right height. The rest was done in a tedious process of filing the teeth, fitting them in the cross slide with the mating gear (coated with dykem blue) and attempting to turn them. This process took about 2 hours to get them smooth. I have since reasembled the machine and they work quite well. I am fearful of putting to much oomph on them, as I don't know how they will hold up to abuse (the original didn'd fare well). You can see the original tooth on the right in the last picture
 
Just contact a gear company, they can duplicate it for you. Its not the cheapest, probably a couple of hundred but it will be right when done. tim
 
I ended up cutting a gear for the power feed on a lathe rebuild this summer.
It was custom.
Yep, if the tooth count angle and DP are standard, then off the shelf is a good call.
Hobbed will fit right without fuss.
However, I got two quotes on hobbing my custom cutting bevel. $875 and $1200 respectively.

I cut her from 4140 with an involute on a DH and filed the final profile.
Hardened and tempered.
Worked well.
This can be done!
Very rewarding and a whole lot of fun.
Especially as many sources said it couldn't be done.
Regardless, if it is standard tooth and DP it'd be far cheaper and more accurate to purchase a hobbed gear.

I feel your pain and reward.
Great job on yours!!!


Daryl
MN

IMG_1010.JPG The one on the shaft is the old one before I turned her off.
 
Last edited:
Here are the pics, I had trouble figuring out how to get them into the original post.

I expect that the cost would have more than doubled what I already had in the machine, which was already more than double what it is worth. The gear had two bearing surfaces as well as the leadnut built into it. I expect the 900-1200 quoted in the above post would not have come close to this gear.
 
I had an old shaper at one time with the same problem. I used bevel gears for farm equipment from the local tractor supply store. You may find a lot of scrap equipment with gears at your local farmers.
 
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