Interest in complete spherical bearing solution for upright?

[Def]

EDIT

Got a request to provide updates in the first post here since this thread is becoming quite long.

Status as of 10/11

4 sets of control arm bearings will be ready soon, 2 are already spoken for, and I'll be contacting people in the order they expressed interest to see if they'd still like a set.

No shock mount bearings at this time, but I am looking into getting the various bits machined, so depending on the details those could be happening soon.

EDIT over




I’ve got an idea for a useful product for the NRR community, but it’s going to take the community to get it going.

I’ll begin with a long engineering diatribe about safety and spherical bearings in the aluminum Z32 rear uprights…

I'm not totally satisfied with the safety factor that results when just pressing in a 30mm OD spherical bearing from Midwest Control in stock Z32 aluminum uprights. I've thought long and hard about it, and I'm just not comfortable with running them since you over double the tensile stress from a radial load on the upright pivot points compared with stock bushings. Every "conservative" approach I look at puts things pretty close to yielding under very hard cornering like in a dip where you can achieve over 1G even on street tires.

Additionally, you have to grind quite a bit of the pivot points away for off the shelf bushings since the stock bushings are designed to be a press fit.


So I've been contemplating a total solution that presses a bearing into a very hard sleeve that's as wide as the upright pivots and includes misalignment inserts/spacers for the bearing so you just press it in and bolt up your arms to it. I can't find anything off the shelf that will accomplish this, so I would need to get some raw materials and get some machining and put in some labor to assemble everything. For that to be economically feasible, I'd have to sell at least a few of them.


So I thought I'd throw this out there and see if there was any interest in what initially seems to be a very safe solution to significantly reduce friction in our rear suspension.

***Rant over***

The big thing I want to know is - what do people feel is a "fair price" for ready to go spherical bearing assemblies to replace the camber, toe, and traction arm pivots on a stock or Z32 aluminum upright? You’d need 3 per upright, or 6 total per car. I’d also have to do a reasonable production run of probably 20-30 bearings just to get a machine shop to even look twice at it, and even then it’ll be a challenge.

If you guys think there is interest, and can maybe say with some certainty you’d purchase something like this, then I’ll probably start doing some design work and looking into machining quotes. The only reason to do something like this is to come in below the cost of the “other stuff” out there, which is pretty astronomic given what they are. Hopefully there is enough demand at a lower price point to develop this product.

[McCoy]

I just got a set of Z32 uprights a few weeks back and am planning on adding them within the next week or two. I am always willing to try new things and help the community where I can.

I'm not sure on what a fair price is, not even sure what your going to have to pay (raw material, your time, machinist time). So, I guess what I'm saying is that I'll help by being apart of the first run of these... I'm sure the price won't be to bad, I'm not poor, but try to be wise on my car parts shopping for the sake of my marriage

[Def]

The machining cost is going to be the big question mark, especially if I can't find a place that won't mind the hard steel I'd like to use chewing up some bits.

If I had to guess, I imagine costs would be somewhere in the $35+ per bearing assembly range once things got rolling. Just curious as to where most would start to get into the "now I'm not as interested" phase before even starting to really pursue it.

I've got all the designs done in my head, and even did a few napkin calcs today and things looked good.

[AceInHole]

At $35 per bearing I'd put down money right now. I'm guessing it'll cost a lot more than that, though.

What about making a monoball housing that fits into the upright? Something with a C-clip or screw in retainer, to make it easier to replace the bearing? That way, you only have to machine the housings on a lathe, and pop in standard sized bearings. That way, you could replace bearings easily (and cheaply).

[a_ahmed]

id be interested... as soon as i get a hold of a z32 upright as the other guy backed out on me when i found it

[2Fass240us]

What about making a monoball housing that fits into the upright? Something with a C-clip or screw in retainer, to make it easier to replace the bearing? That way, you only have to machine the housings on a lathe, and pop in standard sized bearings. That way, you could replace bearings easily (and cheaply).

I like this idea, but would be down for the original approach.

[Def]

At $35 per bearing I'd put down money right now. I'm guessing it'll cost a lot more than that, though.

What about making a monoball housing that fits into the upright? Something with a C-clip or screw in retainer, to make it easier to replace the bearing? That way, you only have to machine the housings on a lathe, and pop in standard sized bearings. That way, you could replace bearings easily (and cheaply).

It probably will cost more than $35 a bearing, as I see that as a lower floor on the possible price range. I really don't think it's worth it if they're going to have to sell more than the $50-60 a bearing range, as that's a lot of money(risk) to take on and I have my doubts as to the ability to generate sales.

I'd like to avoid anybody having to machine their arms - and the only way this is going to get affordable is to use off the shelf bearings, so they would be replaceable in a sense. I'm still not sure what retaining method I'm going to use, but it likely won't be mechanical for ease of assembly and reducing machining costs.

[turtl631]

What about bearings for the Z32 shock mount? I'd be interested in those since using the uprights on a S14 causes a bit of twisting of the stock bushing that would be fine with a spherical bearing.

I'd like to stay I'd get in on this for the full upright set, but I don't think I can afford 6 x $35++ unfortunately.

[veilside180sx]

What i was looking at doing was having them machine the carrier wider to fit the Z32 spindle all the way across, but still use the standard com bearing. (somewhat similar to the SPL, etc design strategy.

Those bearings don't see an extremely high load on an individual basis, so I wouldn't try to get an amazingly strong bearing in there.

If you used a steel slide in retainer with c clips you would have to use a smaller bearing in the process I would imagine.

[Def]

A custom machined COM bearing sounds like you'd need a huge run before they'd bother.

So far the approach I like the most is machined stainless round stock into a sleeve that a MCP COM bearing can slide into, then also machining stainless bearing inserts to bring the ID down to the stock M12 bolt size and provide full bearing load on that as well. I'm thinking a chemical bond is the best option for holding the bearing in, as snap ring grooves etc. are going to start driving the machining costs way up in a hurry. So you could replace the bearing after heating up the sleeve to break the chemical bond then press in another $6-8 bearing with some bearing mount.

If the idea takes off for the upright pivots, I might do the same thing for the shock mount, but the cost will be higher due to the much larger material needed(a little less than 2").


I already modeled up a sleeve and simple insert, and the design allows for 5.7 degrees of articulation, which should be more than enough. I might send it out to a few places and get a rough idea of machining cost.

[AceInHole]

The grooves for the snap rings shouldn't add too much to the operation. I'd imagine it'd be one extra op to the machining process. You'll also only need 1 sharp edge, as the inside can taper up (inner part will be held by the bearing), making it easier to do on a lathe.

[Def]

I'm trying to make these as "lean" a machining operation as possible to get them affordable, and the 2 extra machining operations to do the snap rings would pretty much double the complexity of the sleeve. There isn't enough bearing area for a snap ring anyway. To top it off, I'm not that big of a fan of snap rings, as they can and do fail in cyclical loading situations like the bearing being slightly loose in the sleeve for whatever reason.

[AceInHole]

I'd snap ring one side if I were to do it, and just flange the other (just a step in the barrel). Looking at it closer, I'm not sure if you could get a bearing that would allow enough wall thickness to do that. Otherwise, I wonder if it'd be better to do it as 2 seperate peices, one as the bearing holder, and the other as the retainer.



I guess making 2 peices is still more work, so perhaps combine the stepped barrel with the glue, for at least 1 direction of solid restraint?

[Def]

The problem with reducing the ID of the sleeve is that you run out of articulation angle in a hurry. Not that you need much back there, but solid binding would be a bad thing so I'd like to leave as much articulation as possible. I did consider about the same design you drafted, but it didn't look like there would be much "meat" holding it in there. I wonder if the small stressed area holding the bearing in would eventually deform slightly and cause some play.

It really wouldn't be hard to change the bearing out if needed when held in with bearing mount. Just heat it over 350-450 deg F with a torch and the bearing mount releases and you press the bearing out. Installing a new one would make it need to be centered, but that's pretty trivial for anybody that would go through the lengths of replacing the bearing.

[Def]

BTW - if you're worried about strength, using loctite bearing mount stick will provide right at 6000 lbs of shear strength. I can't see needing more than that...