Reducing axle diameter by a smidge, suggestions?

[alcatraz]

Hey ww

I have some worn titanium pedal axles that I want to upgrade.

They used bushings between the pedal body and axle and the bushing has with time worn out, and the axle has some light grooves in it. Time to replace it with a small steel bearing.

I found that the bore in the pedal body is a snug 13mm. I can use an 8x13 mm bearing (id x od) and the fit into the pedal body is perfect.

The axle diameter tapers from around 7.6mm to about 7.2mm over about 20mm of distance. Right now the bearing is on the larger diameter position. I want to try and get a 7x13mm bearing on the smaller diameter section and reduce a 3mm wide section of that ~7.2mm axle down to 7.0mm.

I don't have a lathe. I was wondering what would be feasible without a lathe to get a poor but acceptable result? So far all I have is to mount it in a drill and just sand it down until the fit is snug, but hmm. Is there a better way?

Having to hunt someone with a lathe down is an option but if there is a trick out there, I'd love to hear it.

[joejack951]

Axle in a drill plus a rotary tool with a grinding bit. Go slowly and try your best to keep the diameter consistent as you remove small amounts of material. Worst case, you remove too much and have to Loctite the bearing in place.

A drill press makes this much easier than trying to use a hand drill but it is manageable with the latter.

[alcatraz]

Axle in a drill plus a rotary tool with a grinding bit. Go slowly and try your best to keep the diameter consistent as you remove small amounts of material. Worst case, you remove too much and have to Loctite the bearing in place.

A drill press makes this much easier than trying to use a hand drill but it is manageable with the latter.

Thanks joejack! It worked. I tried some stuff but in the end your solution was the winner.

It wouldn't have been possible without holding the axle by a (poor fitting) bearing near the cut zone. This way whatever offcentricity the drill has is reduced at the cut area, and it allows me to put more pressure sideways.

I used a dremel with a grinding stone to slowly but surely bring the diameter to within spec. As soon as I could get the bearing started snugly, I made note of where it would bind and only continue to grind that bit. With this method I got it to fit snugly the whole way. It even passed the light test (no light between axle and bearing when getting it started). Pretty cool. Didn't even have to use loctite when assembling the pedals together again. Zero play! And the bushings are in the trash can. Great.

[joejack951]

Nice! I’ve used this method quite a bit in the past to modify/chamfer fasteners, pins, etc. For aluminum or even steel items, a good, sharp file can also be used to remove material while spinning the drill.