Best Bell Crank Bearing?

[Kao]

I'm trying to learn about bell crank bearings and I was wondering what type is best for FSAE application? (i.e. what kind of material is most suitable, possible places to purchase, and other general information)

[Kao]

I'm trying to learn about bell crank bearings and I was wondering what type is best for FSAE application? (i.e. what kind of material is most suitable, possible places to purchase, and other general information)

[Pico]

From experience
Brass is crappy, Nylon is too soft, steel and aluminium are no good either. Just buy some small radial ball bearings McMaster or FAG bearings. They're standard and more reliable that those listed above.

[Scalesy]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PÃ*co:
From experience
Brass is crappy </div></BLOCKQUOTE>

We've always used brass and the only time I've ever found it to be a problem is when tolerances are a problem. Ream the inside, mic the outside within a thou.

[Kirk Feldkamp]

Brass or bronze? There's a big difference. Most bronze bushings are oil impregnated (SAE 841 or similar).

-Kirk

[kapps]

We use bronze bushings (oil/graphite impregnated) and haven't had any problems. As Scalesy said, ream the inside and you shouldn't have any problems.

[VFR750R]

The best? Needle bearings.

Look at dirtbike suspension linkages for ideas.
They're more expensive then bronze but have no stiction to speak of.

If you are determined to use bronze, investigate 'tough-met'. It's very durable, and has better friction properties then straight bronze.

http://www.brushwellman.com/alloy/products/copper_nicke...opper_nickel_tin.asp

[rjwoods77]

Everytime in the past I have used something besides a anti-friction bearing I have always cursed myself for it later down the road. Anti-friction bearings(ball,needle,whatever)always seem to end up with less stiction and more importantly handle wear much better and mistake that dumb little formula/mini baja kids do like chewing up the ends of the journal bearings by slamming bolts through them and also handle the elements much better. These cars tend to pick up a fair amount of crud in the form of rocks, dust,etc since they are sitting so low to the ground.

[Mike Cook]

I use bearings in pretty much every rotating joint on the car. For a bellcrank, I have used a needle bearing/roller bearing combination with good sucess. The only problem with this setup is it has some axial play since you only are using 1 roller bearing. I know that indy cars use two needle bearings and two thrust bearings. This package gets kinda heavy/large for a fsae car. Having sealed bearings are nice.

[D J Yates]

For reasons the following reasons, i'd only ever use a plain bearing:

- very high (almost static) radial load
- shock loads
- probable moment loads
- never seeing a full rotation
- no need for low friction rolling resistance
- contamination and opperating enviroment
- cost
- stiffness

IMO, using a rolling element bearing would be fundamentally wrong for this application. I appreciate that stiction is an issue, but all of the other things that Rob mentioned are design issues for which simple effective solutions can be found. Do not use needle rollers for this application - they hate moment loads; and unless your pushrods and bellcranks are in plane throughout the full suspension travel you will get moment loads.

There are wealth of low friction polymer bearings out there. I expect you'd find something suitable from the iglidur range - i've never used one them, but they look good to me.