advice please on boring a bearing diameter in a hub

[porter_jamie]

bicycle rear hub.

so, lathe, or bore with the boring bar in the mill? i want to open the bearing diameters out a couple of mm to accept a readily available decent sized standard cartridge bearing, instead of the angular contact ones which it currently runs. i will have to make a centre crush tube as well to space the inner races.

i am wondering about the best way to hold it - i am currently favouring clamping it on the mill, clocking up the bore, and boring it out, then turn it over and repeat. if i did it in the lathe i think i would struggle to hold it properly.

what do we think?

Jamie

edit add, probably clamp it into a v block on its side, using one of the flat machined surfaces to get it perpendicular to the bed?

 

[Bill Gruby]

Jamie;

Because both ends of the hub are different I would rule out the lathe. An angle plate and v-block arrangement to hold it vertical on the milling table and bore in the milling machine would be my suggestion.

"Billy G" :thinking:

 

[porter_jamie]

oh, i had not though of that, good idea. i need to try to get the bores to line up as best i can, or i suppose they might suffer premature wear.

 

[Bill Gruby]

Jamie:
Use a 1/4X1/2 metal strip vertical and square to the table. Clamp it to the angle plate along one side of the v-block. Now you woll be able to machine one side and turn it over to machinr the other side without losing your location.

"Billy G" )

 

[llarson]

I've done several "similars" to this project by turning a spud to whatever necessary dia. that works, bolting it to the mill table, indicating the O.D., clamping the part over it. Then bore the upper bore. The other end can then be done in the same manner, gives good accuracy, given that the surfaces setting on the mill table or blocks are parallel.

 

[kd4gij]

bicycle rear hub.

so, lathe, or bore with the boring bar in the mill? i want to open the bearing diameters out a couple of mm to accept a readily available decent sized standard cartridge bearing, instead of the angular contact ones which it currently runs. i will have to make a centre crush tube as well to space the inner races.

i am wondering about the best way to hold it - i am currently favouring clamping it on the mill, clocking up the bore, and boring it out, then turn it over and repeat. if i did it in the lathe i think i would struggle to hold it properly.

what do we think?

Jamie

edit add, probably clamp it into a v block on its side, using one of the flat machined surfaces to get it perpendicular to the bed?

You are going to have end play with the bearings you wan't to put in there. That is why thay use AC bearings. Your wheel will woble.

 

[Tony Wells]

Aside from any issue related to function, as I don't know much about bicycles, I'd probably turn up a set of soft jaws that would chuck the ID and bore the other end on the lathe. Probably take less than half an hour. Chuck it, indicate it in on the bore to be cut, or possibly just run a bell center in it while snugging the chuck, then checking it with an indicator. I think there is more than one right way to do this.

 

[porter_jamie]

all the cartridge bearing wheel hubs i own (two sets of Hope hubs and a set of superstar hubs) all have 'normal' ball bearings with a centre crush tube. the angular contact ones in this surly hub needed constant adjustment to stop excessive play. i admit that the rear mtb freehub hubs have 4 or sometimes 5 bearings in them (two or 3 in the freehub, and 2 in the wheel hub), but the fronts only have two.

there is plenty of material to go at, i only need to take 1mm off the radius, that will leave a tiny bit of meat in that counter bore you can see.

 

[Metalmann]

A very interesting hub indeed! It has both freewheel threads and disc brake flange, whatever is it for??

I'm not gonna argue with the gurus, but I can't see why it can't go in the lathe... Even if the spoke flanges are different, the center is the same. The lathe would make for a much quicker job IMO. Maybe I am missing something here? :nuts:

Personally, I'd go the lathe route, too.

 

[porter_jamie]

lathe:

i don't have much room to make some kind of clamshell arrangement to hold the hub on the small diameter.

mill:

i just mackled some 123 blocks and a couple of v blocks in the big vice - this is probably going to make the pros have a fit hideous?