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my suspension "box" is above the floor plane of the frame..

you should first design the suspension, then go about designing the frame..

Yea I thought I had my suspension planned out but definitely need to re-think some things on how exactly to go about it.

Ben

I was planning on going with these parts from McMaster which will be really cheap.

Per bell crank
1x 5905K28 = $7.20
2x 5909k49 = $1.10
2x 5909k36 = $2.97
2x 5909k63 = $4.66

I think they will move move nicely.

What is the 5905K28 going to ride on?

I am also wondering this, in theory if you could get an aircraft grade bold the right size it may work or you could get a liner/race for it and use an Aircraft or Mil-Spec bolt.

there will be a stepped post off of the chassis in which you would place the 5905k28 that will be sandwiched between 5909k63,5909k36 and 5909k49 at top and bottom. Let me see if i can wrap up the bell crank and post a pic.

I thought the fellow using VW piston pins had a great idea... Maybe that was Kartracer or Kiki?

This is what i had in mind. Maybe a little over complicated

Do any of you guys have thoughts on using angular contact bearings like the one used in Mountain bike headsets?

I don't think your three piece design has enough contact area between the outer webs of the bellcrank and the center bearing. I'd be afraid of the bore for the center bearing failing in bearing.

I'd either make them from sheet metal and weld a tube to two pieces of sheet to support the the bearing or CNC it from one piece of aluminum.

I would also extend the trunnion for the mount almost all of the way to the red retainer cap. Having it partially load the needle bearing can't be good for it. It will also help to keep the upper thrust bearing and races in place. I'd also go out of the way to get that surface as smooth (and as hard) as possible since it is now acting as a bearing race.

when we did our FSAE car we used a design similar to what you are showing however we welded some thick wall reamed recieviers into the chassis. Into these short sections of the Hardened precision ground shafts (drillable in the middle) where inserted and retained with Circlip groves (ground in using a cutoff wheel). This allowed the needle bearing to work on a precision ground surface and was easy to remove. If I had it to do again I would probably use a Blind pocket and thread the center of the shaft to retain it with a bolt on the chassis side so it would be easier to assemble.

Yeah i have been looking at making a one piece design without adding a lot of cost since i want this thing to be really stiff. I may just have some sheet metal cut and welded with inner bracing. I did catch the issue you saw too with the trunnion mount. I increased it last night to align the upper bearings and for the cap to sit on. Thanks moore.

Do you have a pic of this set up?? sounds interesting.

Here are the RP parts. These work really really smooth even when cranked down and also considering the bearings are riding on plastic. I think the only changes i am going to make from here is adding an o-ring top and bottom to keep gunk out and shooting to make it one piece or welded.