Different Size Keyways... Any ideas?

How-Tos & Esk8 mechanics Esk8 Mechanics
1

I have a motor axle with a 3mm keyway slotted into it. I also happen to have a sprocket with a keyway at 4mm.

I do not have the milling technology to modify the motor axle, but I do have many small files, metal saws and assorted tools. What do you guys suggest is best to do to make an adapter?

Is there a place to buy keyways that go 3mm to 4mm? Should I just get a 4mm key and file 1mm off of half of it? Should I use a 3mm keyway, but then jb weld another piece of thin metal onto it and file it into its final form? As of now Im leaning more on the idea of filing down half of a 4mm key to make the adapter.

I really need these adapters, and I am open to anything you guys recommend. I’ll need 6 of them so maybe even if someone had a mill, and could take a square rod of steel and mill it so its 3mm wide at the top and 4mm wide on the bottom. I could then cut it out and file the edges round.

2

Simply use a 3mm keyway, it will work just fine

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3

What about the 1mm wiggle room? Although its small, with every throttle punch uphill, and every hard break, won’t it be wiggling back and forth and end up having the grub screws cut into the axle, or the axle cutting up the screws and reducing their effectiveness?

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4

I have not had this issue at all. But you can put some locktite in the keyway slot to keep it from wiggling

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5

if the fit is slip on snug then you can use Loctite 680 to keep it from moving around.

6

Loctite 660 is designed for keyways that may be worn. Its a “paste”

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7

It will maybe for the first time, then from the big forces it will bite in the metal and stay in that position, also adding some loctite will do you good.

8

Snip a piece of a speed washer and stick it in there. Most are 1mm thick.

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