Smokin' rear bearings.

[Tim Kish]

Never on bearings but have on other things work related and it worked well.

Looking at the website the 609 should be more than enough to hold it.

You've got a lot of great information and help on this post and I am not near smart enough to question them but wondering if maybe you just had a bad bearing to start out with ?

Tim K

 

[Mark Bullard]

If I remember right that most locktite is made out of CA with fillers. And nitro and CA don't flare well.

 

[tnrcboatracer]

Mark, IIRC loctite is made of methylmethacrylate which is slightly different than cyanoacrylate. But I don't know how Nitro resistant it is.

 

[steve wood]

my experiance trying to locktite bearings to the crank doesn't work.too much hammering,knocks the locktite loose.

 

[nws]

Terry- try locktite long time ago, the nitro eat it up and goes in engine.

Not good Just some old fart that try is, that my two cents.

Norris

 

[Tim Kish]

495 general adhesive ,probably not as good as what your using .

Works great on the fingers though lol

 

[Terry Keeley]

Terry- try locktite long time ago, the nitro eat it up and goes in engine.

Not good Just some old fart that try is, that my two cents.

Norris

Thanks Norris, just a bandaid for now, gotta figure some way to fix the inner race to the crank.

Any ideas?

 

[Tim Kish]

If the crank dia is out of spec why not send it back to CMB ?

Tim K

 

[Charles Perdue]

Terry, you have a tool post grinder.

Have someone to build it up with hard chrome in the area where the bearing fits on the crank, warm it up to specs to relieve the hydrogen embrittlement and grind the crank to the correct specs.

Simple and permanent.

Charles

 

[Tim Kish]

Terry, you have a tool post grinder.

Have someone to build it up with hard chrome in the area where the bearing fits on the crank, warm it up to specs to relieve the hydrogen embrittlement and grind the crank to the correct specs.

Simple and permanent.

Charles

If you go that way make sure you grind it undersize first , otherwise the chrome will be to thin and peel off .

Tim K

 

[nws]

I use to take a solid cabide tool bit and grind to chisel on one side.

I use a diamond wheel to sharpen it.

chuck the crank in lathe, make sure it is running true.

make sure the center of tool is hitting the crank.

turn the chuck by hand, don,t put to pressure on tool,you only want to mark crank.

I did 2 spots, so the bearing fit tight.

use to do my OS maxs 45 that way.

Norris

 

[RodneyPierce]

I use to take a solid cabide tool bit and grind to chisel on one side.

I use a diamond wheel to sharpen it.

chuck the crank in lathe, make sure it is running true.

make sure the center of tool is hitting the crank.

turn the chuck by hand, don,t put to pressure on tool,you only want to mark crank.

I did 2 spots, so the bearing fit tight.

use to do my OS maxs 45 that way.

Norris

So your basically just making a small burr on each side of the cut to take up the excess tolerance. Interesting.

 

[camaroboy383]

I use to take a solid cabide tool bit and grind to chisel on one side.

I use a diamond wheel to sharpen it.

chuck the crank in lathe, make sure it is running true.

make sure the center of tool is hitting the crank.

turn the chuck by hand, don,t put to pressure on tool,you only want to mark crank.

I did 2 spots, so the bearing fit tight.

use to do my OS maxs 45 that way.

Norris

So your basically just making a small burr on each side of the cut to take up the excess tolerance. Interesting.

That is interesting.....

it deforms the edges of the cut just enough to enlarge the dia. slightly...... its just like running a pipe cutter gently around a piston to give it that pinch. never thought of using that method on a crank....

This would work for sure to tighten the fit,,,, only issue i see with it is after so many bearing changes its likely to go away,,, but who says you cant do it again... im just wondering if this now acts as a fracture point.......hmmmmmmmmmmmmmm

 

[AWaddle322]

Terry,

Have it flame sprayed and ground down to what you want.

Allen

 

[dwilfong]

spray weld work real nice. We use to do that to resize the rotors in the roots blowers. then put it in the lathe and use the tool post grinder to size.

With that fancy tool post grinder you have it would turn out like the bees knees.

 

[nws]

That was I had back in the late 70s and 80s.

Didn,t have all the nc machine to work with.

That was the cheap way to get done.

That is the way old fart like me did thinks back then.

Norris

 

[Terry Keeley]

Thanks for all the replys guys, amazing what a "think tank" this place can be.

Don't think they'd even consider it Tim.

Chroming was the first thing to come to mind but it would be a bunch of work to do right.

Never heard of "spray welding" will look into that.

I like your idea Norris, simple, I like simple. I too was thinking along those lines and maybe doing some sort of knurling etc.

BTW, Nike Nowicki mentioned having a hard time getting the rear bearing off the crank on his Nelson 45...

 

[nws]

Terry- you can't knurl the crank, it to hard. you can't even file the crank.

The it only handen about .005 deep.

to chrome or spray weld, you would have grind the spot for bearing.

Then the crank is weak, and will brake.

If you didn't grind for chrome or spray weld, don't it would stay .

You only need .0001 to .0002 to hold bearing.

Good luck.

Norris

 

[RodneyPierce]

Norris, your idea worked amazing!!! I had a crank here from one of my .21 motors, that had pretty good marring where the rear bearing goes, it was clearly spinning in the bearing. I chucked it up in the lathe, and made a couple light touches to it with a carbide tool, put it back in and it would only go in to the area i "touched". Tapped it in with a block of wood and its SOLID! Would have never thought to try that. Thanks man!!!

 

[Mark Bullard]

Spray metal or metalizing is what we call it will not hold up. We quit yusing that thirty years ago. We have had motors that have been repaired by other shops spraying metal and the bearing fits will not stand the rolling in the balancing machine waves by the rotor's own weight. It will flake off. So we have to weld to repair, sleeve or replace the shaft. And this is desided by what type of driven unit that this motor turns. Direct drive can be welded most of the time, belt driven must be sleeved if it can or just replace the shaft. So as you can see that most of the ideas are just bandaids. The only real repair is to chrome and grind or replace.