Drilling holes for bearings in aluminum

[derf9h]

So my bearing for the shifting side of my rear sets is 28.5mm OD or 1.123in. How the hell do I drill a small enough hole to press fit this thing into my 1/4" aluminum plate? I tried a 1-1/8" hole saw just to see how big it was and it slipped in and fell through. A 1" bit is too small. Should I just drill a 1" and somehow perfectly grind out the inside to get the dimension I need? How do I do this with common power tools. I mean I have a nice drill press but I don't think I could sand the inside of the hole exactly the same all the way around donut fits perfectly. Should I get it close and the loctite it in?

 

[Flugtechnik]

To get the proper hole size to press fit your bearing into will take a precision bit or ream. It will not be a standard size. If you do not want to buy the specific size bit or ream, probably your best bet is is drill it small, open it up with your dremel or whatever and then JB weld it in.

Opening a hole in my gauge plate for my ignition lock.

 

[Tim]

Any reason you're designing bearings into your rearsets? I can understand bushings etc. but most/all rearsets don't have ball bearings in them.

 

[derf9h]

No reason in particular. Just trying something someone else did awhile back.

 

[AlphaDogChoppers]

Just take it to a local machine shop and have them ream it to fit your bearing. They will do it for less money than you could buy a tool for.

 

[ronnie]

Re: Re: Drilling holes for bearings in aluminum

Just take it to a local machine shop and have them ream it to fit your bearing. They will do it for less money than you could buy a tool for.

Second that.

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[DZach001]

If you aren't planing on the bearing being visible, you can always use your 1-1/8" hole saw and wrap the OD of the bearing with electrical tape. Pull the tape tight while wrapping and use a layer or two to build up the OD that extra little bit for a snug fit. If you trim the edge with a razer blade you probably wont even notice the tape unless you look close.

 

[DZach001]

P.S. if electrical tape is too thick, try some teflon tape plumbers use to wrap threads on pipes.

 

[ronnie]

I wouldn't suggest tape, or teflon for that matter. That teflon is made to slip so thats definitely not what you want.

 

[AlphaDogChoppers]

wrap the OD of the bearing with electrical tape.

Worst. Idea. Ever.

 

[Rich Ard]

 

[derf9h]

What about packing tape? Would that work

 

[ronnie]

No tape. I wouldn't shortcut something you rely on... Check into a machine shop, they may do it for so cheap it will make you wonder why you even questioned using any form of tape. Haha!

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[VonYinzer]

To put it simply...

The only way a bearing will function correctly is for the outer race to be friction or press fit into the piece its suppose to allow to move.
This also means that the hole the bearing is going to fit into must be perfectly round (or as close as possible) to keep constant and even pressure on the outer race as the load on the inner bearing race shifts (i e, when you shift or brake).
The positive of having an aluminum carrier (the rearset) is that its softer and more elastic (for lack of a better term) than the steel outer bearing race. This will allow the carrier to conform to the bearing when pressed in and "grip" the race.
Basically what I'm saying is that you want the carrier machined as precisely as possible to match the bearing. Any decent machine shop can help with this.
Than you can freeze the bearing (dry ice is great for this) and warm the carrier. Than just tap the bearing in. Once the materials come back to room temp, the will friction fit together and allow the bearing to function properly.
Another thing you should keep in mind... You shouldn't use a standard bolt through the bearing. The threads will wear and allow the bearing to "shift" over time. In your application it probobly won't matter as it won't be under constant load, but try to find a shouldered bolt so that the inner bearing race is tight to the shoulder.

 

[bradj]

Seem like alot of work for a few deg. of movement

 

[ronnie]

Seem like alot of work for a few deg. of movement

Second that. And not a lot of pressure or stress..

 

[derf9h]

I was joking on the packing tape comment. I ended up having my machine shop ream the hole and press fit it for me with their huge press. I'll post pics in a bit. I also found a good 1/2" bolt that only has about an 1" of thread which will work perfectly.

 

[derf9h]

Oh yeah. The start of my shifter lever.

 

[nerdsports]

That's exactly what I'm planning on doing but I'm using oiled bushings.

 

[Titan performance]

I really admire your attention to detail, but in my opinion it really isn't needed. If you are using a thin back plate, then maybe a steel liner or bush would be advisable to prevent any twisting action, but on thicker plate, pivoting the arm on the footpeg works just fine with some good quality grease. Honda have run cams in aluminium heads for ever, without the need for a bearing or bush....I hope you get it sorted, but you have made life difficult for yourself.