Cup Racer Uniball holders

[James363]

Hi,
I work as a CAD Engineer at a reverse engineering company Crosthwaite and Gardiner (as proof of competence, we've all seen some suspicious suspension components). I am looking to produce some cup racer style uniball holders, matching the original geometry of a 1*2 ball joint. This will replace the commonly fragile ball joints with a motorsport spec spherical bearing, in the same style as the PMS bearing replacement kits.
I will be making the holder out of billet EN24T steel, and the pin from EN16T steel, so these will be much stronger than the original forgings.
If anyone is also looking for these, I'd like to know to get a rough idea of numbers so that I can make a few sets and bring the price down for everyone. I'm not looking to turn a profit on these, so they'll be priced at the cost of materials + CNC machining only, which I would think would be between 150 and 200 for a set, but don't know yet. It's worth noting that once the bearings have worn on these, only the bearing will require replacing, which will likely cost around the same as an OEM ball joint.
I'll also be able to supply 12.9 high tensile bolts to hold these to the wishbone, also at cost, if required.
So if you are interested, let me know below. I will keep this updated with shots of the computer model once I have finished it, and updated pricing details. Not asking for any form of commitment at this stage, although before I am to buy the billets and bearings, I'll ask for a small deposit to cover that.
Thanks!
James

 

[haimsey]

Be interested to see how this little project pans out. Might be interested if funds allow at the time.
What CAD software are you using?

 

[James363]

Solidworks 2017, same as we use at work.

 

[haimsey]

Same as I use at work. Do you have Cnc machines in house? If you don't know how to use them would be a good chance to grab some experience/knowledge on the process (I know I would)
Be good if my work set us challenges like this

 

[James363]

Yeah, we've got a pretty comprehensive machine shop, 5th axis gear and that sort of thing. Just to make it clear, this project has nothing to do with my work, just wanted to prove I'm not some chancer with a pirate copy of solidworks and a set of verniers.
I will definitely watch the entire process of machining, would love to know how to actually operate a cnc mill, as I've no experience with cnc mills, only manuals and lathes.

 

[haimsey]

How you getting on with this little project? @James363

 

[James363]

Got the CAD models done, will order the billets this week. I'm gonna make a few samples to test on my own car and make sure they stand up to the punishment, and then get a batch done so I can give everyone an exact number for pricing. Ktec are interested in buying them as well, hence I will have a larger batch made up.

 

[bozothenutter]

C&G impressive.....you did the auto union rebuilds right?

 

[James363]

Thanks! And yes, the original rebuilds and the recreations as well as the mercedes W125 recreations, among other things.

 

[bozothenutter]

@NorthloopCup did something similar for his rollcentre kits:
http://www.cliosport.net/threads/roll-centre-bump-steer-corrector-hubs.717989/page-34#post-11317110

 

[James363]

Ah yeah, I'd be interested to see exactly what he did. I'm planning to make mine with the same lower and bearing as the cup racer ones, just with a pin so that it can be used on the road car. They've stopped supplying the cup racer lowers now, so it would make sense if I could use the same part and design for both cars, just with a different pin for the different hubs.

 

[haimsey]

Got the CAD models done, will order the billets this week. I'm gonna make a few samples to test on my own car and make sure they stand up to the punishment, and then get a batch done so I can give everyone an exact number for pricing. Ktec are interested in buying them as well, hence I will have a larger batch made up.

Good stuff, got any screen shots to share?
Good news about k-tec too! Take it the first batch for cs.net would come in a little cheaper once tested?

 

[mikekean]

Be good if you can make them with a grease nipple, I fitted some to my cup racer and being able to pump grease through the bearing massively improves the bearings life span.

 

[James363]

Yeah, I was going to add a nipple in, seeings as the bearings originally specced for the cup racer are designed to be greased in operation. Yeah, I will just cover the costs with the first batch for CS. A machinist at work is willing to do the first batch for me, as it will only be a few sets. Depending on how many I need to make after that, I will probably have to get them machined somewhere else, so the first batch is likely to be considerably cheaper.
Mikekean, I don't suppose you'd be able to confirm whether the centres on your cup racer lowers are the same as original 172 ones? The 172 ball joints are 45mm between mounting holes, and 50mm between the outer mounting hole and the centre of the spherical bearing.
If so, thanks.
I will get some screenshots after work!
Cheers!

 

[NorthloopCup]

Ah yeah, I'd be interested to see exactly what he did. I'm planning to make mine with the same lower and bearing as the cup racer ones, just with a pin so that it can be used on the road car. They've stopped supplying the cup racer lowers now, so it would make sense if I could use the same part and design for both cars, just with a different pin for the different hubs.

The pin will be your issue mate. They can elongate the hole in the hub using the standard bottom ball joint!! Also, cup racer bearings aren't cheap to buy either.

 

[James363]

Right, yeah, I had heard of that. Is it that common? Mine are still pretty round after some quite unkind rally treatment.
I did consider using a more common SKF bearing, although it's tricky finding one with a large enough outer race to retain with a circlip in the same way the Cup racer does. I didn't want to use a split ring ideally, as they are much harder to remove.

 

[NorthloopCup]

Right, yeah, I had heard of that. Is it that common? Mine are still pretty round after some quite unkind rally treatment.
I did consider using a more common SKF bearing, although it's tricky finding one with a large enough outer race to retain with a circlip in the same way the Cup racer does. I didn't want to use a split ring ideally, as they are much harder to remove.

Well I'd say that out of all the hubs we've done, there's about 70% that are showing signs of elongation around the ball joint pivot. This was why we spent a lot of time and resources to get it right. We've never had one fail either, other than in exceptional circumstances, and I'm talking a substantial impact from hitting a kerb at 3 figure speeds.

I think you're overthinking the bearing mate personally. The ones we use have never failed as a result of the circlip failing.

 

[James363]

Well the bearing is loaded radially, so shouldn't put any force on the circlip. I have found a supplier we use at work that can supply a bearing with the same dimensions as the cup racers bearing, and a greater static load capacity for a reasonable price.
You've got me a bit worried about the elongation though, I'll take my hubs in tomorrow and get them up on the CMM to confirm they're ok.
I heard somewhere that the cup racers used Renault Safrane front hubs, so I'll try and pick a set of those up next time I'm on the continent, and have a look.
Cheers

 

[MarkT]

Following this with interest!

 

[James363]

I've just inspected my hubs and found them to be a little under half a thou elongated, so I don't think that will be an issue for me. I've also had a think about where to go with this project, and I will be using a cup racer sized bearing and the standard ball joint mounting method as I originally intended. The main reason I started the project was my standard ball joints are prone to breaking down on rallies, and I think replacing them with bearings will prevent this. As it stands, I have several sets of hubs to use if I start to suffer from elongation.

 

[Waite_87]

Does anyone have a fix for the elongated holes in the hubs? or is it new hub time? Also whats the best way to check them? Vernier gauge?

 

[James363]

Does anyone have a fix for the elongated holes in the hubs? or is it new hub time? Also whats the best way to check them? Vernier gauge?

Elongated holes is a bin the hub job, as far as I am aware. If the ball joint wobbles side to side, it's definitely elongated. Vernier should be ok, if you are careful. I used a CMM haha