CNC control arms

[Kershaw]

Will didn't seem to enthused on the design and then I quit my job and then some other things need to be replaced on my ix, yadda yadda yadda...

Once this turning bs is finally solved (might be a u joint or new rack or whatever) I'll go back to the control arms.

[The Dark Side of Will]

Carbon Fiber shafts and maybe billet aluminum strut housings/knuckles, that would save a good deal of weight.

Absolutely! Actually, I think carbon strut tubes would be workable, with the right (aluminum) end fixtures. A friend and I were discussing doing that to build Bilstein style inverted struts for our Fieros.

The tube + insert design is horribly inefficient from the weight (especially unsprung weight) prespective. It may be possible and perhaps even easy to convert iX struts to be *inverted* struts, however.

All the dimensions are taken using Mastercam/Verisurf, then I export all the lines, points, and surfaces into an iges file then the rest is built in Solidworks. Once it's in Solidworks I can save it as whatever.

Cool. I've worked in Spatial Analyzer, AutoCAD and now OnShape.

After looking at the control arm design a little closer, the only reason the whole thing can't be flat is the ball joints don't have enough travel. It looks like the "ears" that the ball joints press into are offset so the ball joint is close to perpendicular to the mounting surface while in the middle of the suspensions travel, that way it doesn't max out in one direction and not in the other. Since I'm running sphericals with high misalignments it doesn't matter, my design can be on one flat plane.

One of the things I'd like to do for my 24V swap crossmember is raise the inner ball joint bosses to restore suspension geometry for lowered cars. This *may* require moving the ball joints forward as well, for axle clearance. That would require making new control arms. In the situation of making a new crossmember and new control arms, then changing the angle of the inner ball joint boss in order to put the ball joint in the middle of its angular travel at static ride height with a "flat" control arm becomes pretty easy.

Then just cut billet aluminum knuckles as Nando suggested and we can "flatten" the outer ball joint boss on the control arm... the whole shebang becomes easier to make.

Will didn't seem to enthused on the design and then I quit my job and then some other things need to be replaced on my ix, yadda yadda yadda...

Once this turning bs is finally solved (might be a u joint or new rack or whatever) I'll go back to the control arms.

Are you talking about me?
I think the control arms are a great idea... I think the design just needs to be understood in a larger context AND things like the potential ball joint damage I talked about need to be examined.

For example, the failure mode I described may be moot, because the droop limit on a car with shortened struts is such that the suspension never rebounds far enough to damage the ball joint. How does anyone know if it does or not?

That failure mode needs to be investigated in hardware and safety verified using parts on the car.

[Kershaw]

Yeah I was.

[Nisse Järnet]

If making a new knuckle then making the steering "arm" shorter than stock for faster steering might work?

[The Dark Side of Will]

If making a new knuckle then making the steering "arm" shorter than stock for faster steering might work?

That is correct, it would.

Making the steering arm shorter would also help with wheel clearance when lowering the outer tie rod end to correct for bump steer induced by raising the inner ball joint.