Just an update on my front running gear, I wanted to do away with the cortina hub and make my own that accepts a fiesta mk7 hub bearing, changes the steering rack position, and incorporate the correct lugs to mount my calipers. 3D printed this to mock it up.











Still needs work, but it’s coming along.

Rob

That’s interesting, what’s the plan, to print a slightly larger one to allow for shrinkage and use it as a casting mould?

Hey, plan at the moment is to just get it all working as a complete mock up.

Later I will either cast them or have them machined.

I have to do the rack next, it’s never been fitted correctly so I’m working on that part next.

Rob

Version 2.5 and the first iteration on the steering arm.








Rob

They look great! I wish I had the skill to design such things.

What are you building? Approx weight? I can't help thinking those brakes are very large for a light weight car.

I’ve weighed the chassis recently and it is 95kg, expect another 15kg to complete then the engine and box is 220kg. So my target weight was 500kg, but suspect it will end up more like 650kg.

It’s going to have a carbon body but try and remain minimalist.

I'm sure you know what you are doing.

I only mention it as I have just removed some Brembo (Fiat Coupe) calipers and 280mm vented discs form my Sylva Riot. It also had 280mm vented rear discs and Cosworth calipers. The braking was horrible, very much all or nothing. It was impossibe to get them warm. They were also very heavy. Calipers alone have saved 3kg each on the front! With changing to 13" wheels I estimate 8-10kg per corner saving (i haven't finished weighing everything yet). All unsprung weight of course. My Riot will now be around the 470kg mark.

I have replaced them with Wilwood powerlite on 260mm solid front discs on the front and 240mm solid on the rear. I have basically copied someone else with the same set up :-) after many hours studying this calculator https://brakepower.com/

[Edited on 23/5/21 by rdodger]

If you're actually planning to stump up the cash to get these machined, I'd strongly suggest you do some proper stress analysis and design iteration on them. Home casting would be a complete non starter for a road car imho, even if you sent them out for some proper NDT. If you do go cast, make sure you discuss it with your insurer!

There seems to be a lot of redundant material in the upright to optimise the design primarily for 3d printing. They look very square in profile top and bottom because the bearing face has been projected out to the ball joint planes. The material distribution on the steering arms looks to be optimised for loading in a vertical plane but apart from accelerating the mass and friction of the steering arms, the primary loading is horizontal.

Do these uprights change the geometry compared to cortina uprights or is it just for the caliper mounts and steering arms? If it's not for geometry change, I'd be looking at sourcing some off the shelf alloy alternatives. It'll save risk, cash and probably a fair bit of weight too.