Bearing holders for upper A-Arm bearings

[Christopher Crowe]

Does anyone sell ready-made weld-in bearing holder-plates for upper A-Arm fabrication? I need several to fit .810" OD Aurora SPWB-6TG staked spherical bearings. I remember seeing the pre-fabbed plates sold in England several years ago... but no more.

Maybe my nomenclature was wrong while searching for the things; but they look like this:





Thanks much for any help!

-- Chris

[Northwind]

http://www.f-2000.com/

I believe a discussion in the past with Tim said that he is making these.

[RobLav]

Chris, Why are you using -6 instead of -5 for uppers?

[Christopher Crowe]

One of those practical things. I was able to find an inexpensive -6 staking tool and the weight differential was pretty small (between the -5 and -6's).

Chris

[Christopher Crowe]

-- but found nothing via the link. Again, my fruitless search might have something to do with mynomenclature... I'm calling these things, "bearing holder-plates," and derivatives of that, "weld-in bearing plates," "weld in bearing holder," etc. etc.

Does anyone know the proper name for these things? Man, this has been a frustration, but I sure don't want to wittle these things if someone produces them.

Thanks again ---

Chris

[nulrich]

We use 5/16 sphericals, so I can't help you. Not sure how available these are, but Ralt shows several styles of 3/8 spherical housings in their catalog:

http://www.ralt.co.uk/2008%20CATALOGUE.pdf

Nathan

[RobLav]

I'm sure Nick Fuhs has them Chris. Not sure if he'd sell them but worth asking.

[John]

Call Doug Learned at Fast Forward he has them.

(831) 899-3636

John

[stephen wilson]

I've seen just the bearing cup from various sources, though without any "plate" or stub for A-arm mounting.
https://www.pegasusautoracing.com/pr...oduct=1825-150

[John]

He has the holders but not attached to a plate

You would need to get Doug or Pat Prince perhaps to make you some

[TimW]

Isn't the plate the Van Dieman mass(er) produced cheaper production method of ending the a-arms? On the Piper, the ProTech swift replacement parts, Nick Fuhs replacement parts and every ChampCar a-arm the cup is strapped and welded to the aero tube. The VD method with plates always looked like a bend and crack source to me.

[aims20]

One of those practical things. I was able to find an inexpensive -6 staking tool and the weight differential was pretty small (between the -5 and -6's).

Chris

Keep in mind that the larger bore requires a larger bolt, larger spacers, larger nut, larger housing, and more weld area. It's still not too big of a weight difference "for practical purposes" but in FSAE we were weight nazis, particularly for the mass that was far from the center of mass and/or was unsprung.

[R. Pare]

Isn't the plate the Van Dieman mass(er) produced cheaper production method of ending the a-arms? On the Piper, the ProTech swift replacement parts, Nick Fuhs replacement parts and every ChampCar a-arm the cup is strapped and welded to the aero tube. The VD method with plates always looked like a bend and crack source to me.

The plates do cost a bit more to make than just a simple circular boss, but the difference is more than made up by the considerably easier mitering of the arms to the plate, never mind the fact that the boss does not get distorted by the welding and negates the need for post-weld reworking. No, it's not quite as light as the direct attachment method, but a lot cheaper and easier.

Mitered in correctly, there is probably less chance of bending and cracking than welding the arms directly to the boss.

[Christopher Crowe]

Will now find a way.

-- Chris

[nulrich]

The VD method with plates always looked like a bend and crack source to me.

Unless it's a lower wishbone with a pushrod attachment, there is no bending load on the plate ends. The increased weld area of a shaped end is a big benefit. You also don't need to thin the plate except where it fits inside the streamline tubing (see image). A few grams heavier, but much stronger and easier to fabricate.

Nathan

[TimW]

Mitered in correctly, there is probably less chance of bending and cracking than welding the arms directly to the boss.

hmm...less chance of bending? There is 100% chance of bending, regardless of which way they are manufactured. Perhaps you meant less bending, but the plate becomes the primary load path for that span, and with the plate thickness having a lower inertia than the streamline tube it has to bend more for the same load & bearing size. The bearing should reduce bending moment on the arm, but its not entirely removed, no? (the bearing thickness is only marginally thinner than the streamline tube itself, so there is a mechanism for a bending load getting transmitted).

Also, on the VD, isn't the plate welded to the cup, removing the distortion benefit you mention?

[TimW]

Unless it's a lower wishbone with a pushrod attachment, there is no bending load on the plate ends. The increased weld area of a shaped end is a big benefit. You also don't need to thin the plate except where it fits inside the streamline tubing (see image). A few grams heavier, but much stronger and easier to fabricate.

Nathan

Yeah, thats not a plate like on the OEM VD arms. Yours is ~0.25 thick and spans the thickness of the bearing itself versus prolly 0.090 or somesuch on the VD.

[R. Pare]

The plate thickness shown in Nathans photo is overkill strength-wise, but easy to manufacture and miter to. The Citations have for years used basically the same sort of shape, but with the plate thinned down to around .100-.125" right up to the boss. Yes, you have to squash the end of the tubes a bit to allow welding to the thin plate, but that is very easy compared to trying to fit them directly to the wall of the boss. So far, in a crash, the tubing bends, but not the plates - Steve has always been able to reuse the plates.

Before we went to the integral plates, we tried just the simple round boss with the tubing welded directly to it. Total pain in the ass to miter and weld and not ruin the boss bore. In crashes, the boss would oftentimes actually get distorted - not enough for the staked bearing to come out, but enough so that you could see daylight between the staked flange and the chamfer in the boss.

In either case, the likelihood of stretching or bending the circular boss will depend a lot on how far the plate or the tubing wraps around the boss.

On an upper a-arm, the plates see zero bending moment (assuming perfect alignment) under normal use, unlike lower arms on a pushrod car. Crashes, of course, are a different story.

[TimW]

On an upper a-arm, the plates see zero bending moment (assuming perfect alignment) under normal use, unlike lower arms on a pushrod car. Crashes, of course, are a different story.

Yeah, nothing is perfectly aligned. The bending forces are small but the 0.090" plate welded onto the cup seemed to compromise manufacturability too far over strength/stiffness. The machined tube ends like Nathan's are not what I'm referring to (I can't seem to find a picture and need to go back to work...so other people can search for stuff...)

[R. Pare]

Yeah, nothing is perfectly aligned. The bending forces are small but the 0.090" plate welded onto the cup seemed to compromise manufacturability too far over strength/stiffness. The machined tube ends like Nathan's are not what I'm referring to (I can't seem to find a picture and need to go back to work...so other people can search for stuff...)

If the welder is even remotely decent, misalignment can easily be held to 1/2 degree or less - all it takes if proper fixturing and proper tacking before doing the full welds - and at that low a misalignment, the bending loads are so small as to not compromise the structural integrity enough to even begin to worry about - unless the streamline tubing is too small to start with already.

We also have used very long plates - maybe 3/16' thick x 1" wide x 4" long - for the inboard ends of the front lower arms. No bending issues there under normal use either that I ever saw or heard of.

[Christopher Crowe]

I now so fondly remember the way it was done in my real and actual era (about 1970) -- you used 1/2" rod ends that threaded into a thick tube that connected to other thick tubes that found their ways to the inboard pickups... So brutal and easy.

Thanks to everyone for the help. Also wanted to mention that I found Nick Skidmore Racing in the UK -- and they sell pre-fabbed wishbone (and tube) ends in all sizes -- drilled, chamfered and ready to go for 5 English Pounds per!

Again, thanks to all for the good help.

Chris