Billet front control arms.

[Mattndew76]

I had posted the idea years ago and then was shown a picture of a set copied from my initial design.

Well I have a wild hair and want to start making these for dirt cheap. I will offer just the main billet body soon. What I need is a volunteer to lend me a stock control arm set. My original sketch doesnt have dimensions on it is why I need a donor set. The reward for lending me a set of lower control arms is a free set of 6061 control arm bodies.

I want to see if I can put these bodies out at about $160.00 a set. Im feeling kinda vengful for seeing how much they are being sold as a complete set by the people who snaked my design ($479.99).

Any takers?

Bitter
Matthew D.

[two_68_510s]

I have a set of '68s, will that work?

PM sent

[Mattndew76]

68 control arms will work great.

[S15DET]

Careful, there is a construction change in the arms after '69, I don't know if there is a dimensional difference. You can use my later arms if you want, my car is under the knife at the moment for other things, so let me know.

[StrutlessWonder]

Careful, there is a construction change in the arms after '69, I don't know if there is a dimensional difference. You can use my later arms if you want, my car is under the knife at the moment for other things, so let me know.

I agree. I'd use the later arms as a model. The 2 piece early bushings are quite different, and IIRC, the later arms may be a bit beefier construction.

But what do I know? My 510 doesn't even use OEM control arms.

[two_68_510s]

Maybe you should take a look at both newer and older, to document the changes if any. Just a thought.

[okayfine]

The 2 piece early bushings are quite different, and IIRC, the later arms may be a bit beefier construction.

But Matthew isn't going to CNC the part where it bolts to the crossmember, is he? He's making the outer ends of the LCA, and you'd use a heim and rod from the crossmember to the CNC'ed part?

[icehouse]

I don't see the point the LCA with everything removed doesn't way much at all. I myself would rather have something that would bend rather than break.

[two_68_510s]

To dredge up an old term, "bling"?

Do the billet arms break easy?

[okayfine]

I don't see the point the LCA with everything removed doesn't way much at all.

Probably not about lightweightness, but about adjustability.

Do the billet arms break easy?

Doubt they break easily. Aluminum will fracture instead of bend, though, and aluminum can have a finite life. I shuddered when I saw the aluminum rear brake brackets on eBay. Maybe Jeff could provide the backstory on his bent LCA picture. I kinda doubt the car was going anywhere afterwards, but the wheel wouldn't have gone AWOL either.

Maybe Matthew could CNC a steel tube/adapter to fit in the LCA channel. Then you cut off the inner part of the LCA at some predetermined point, weld in the CNC part, then thread in the rod and heim? Even cheaper, since that's the main goal. But then that's what Dave/FutoFab does...

[Mattndew76]

Well 6061 has the same tensile strength as 1018 Mild steel (most common mild steel). 6061 has impact properties but is not dent resistant like steel is. Also with a Nickle plating the aluminum has added stength.

Even though the Steel version don't weight much at all, aluminum weight even less. Aluminum has the durability unless you really plan on doing some hard very hard off road driving. I am in process of machining a set of upper and lower control arms for my 50 Ford trucks mustang 2 style front suspension. The Ford has a heavier chassis by far, and I'm looking forward to auto cross with the restomodded truck. It has IRS too

Heck the new UTV's see more abuse on the suspension then our 510's. Even if it's seen as a bling option. I still want it to be a inexpensive option because of the rip off.

Matthew D.

[HudsonMC]

The thing with aluminum is the fatigue limit. It's not so much the ultimate tensile strength and the loads it can carry. The presence of threads and/or sharp corners will provide places for fatigue cracks to start and propagate from under the cyclic loads it would see in an automobile suspension. Steel parts may be designed with a theoretically infinite fatigue life. Unfortunately, you can't really do this with aluminum, and any aluminum part will eventually fail due to fatigue. The big question is when. Even very small cyclic loads will weaken an aluminum part.

There are all kinds of cars running around these days with aluminum suspension components, but they've been designed by engineers to theoretically outlive the car. These are also somewhat isolated from road vibrations by rubber bushings. You'll be using spherical bearings, right?

I dunno, I'd rather see DIY parts like this made in steel...

[icehouse]

That pic I took was of Hainz's car. He smacked a curb going 35mph ish. He drove it home even though the front end was moved about 3" from it's original location.

Even if it's lighter it only counts as 1/2 unsprung weight. So I don't see the point. We work with aluminum parts at work. No way I want something like that on my car. I've seen what happens to aluminum when the machine crashes. Steel does much better.

[Mattndew76]

The thing with aluminum is the fatigue limit. It's not so much the ultimate tensile strength and the loads it can carry. The presence of threads and/or sharp corners will provide places for fatigue cracks to start and propagate from under the cyclic loads it would see in an automobile suspension. Steel parts may be designed with a theoretically infinite fatigue life. Unfortunately, you can't really do this with aluminum, and any aluminum part will eventually fail due to fatigue. The big question is when. Even very small cyclic loads will weaken an aluminum part.

There are all kinds of cars running around these days with aluminum suspension components, but they've been designed by engineers to theoretically outlive the car. These are also somewhat isolated from road vibrations by rubber bushings. You'll be using spherical bearings, right?

I dunno, I'd rather see DIY parts like this made in steel...

Absolutely. Why would any person NOT use Spherical bushings or Heim joints? So please before you over analyze my design. Consider that even the TC rods that are made from threaded 6061 rod see the same stress you speak of on 5/8-18 or 5/8-24. These parts are not for every day use but very rare that they fail because of daily use, And take a look over at http://www.race-dezert.com. Many of the off road race trucks put a huge beating on aluminum control arms. I am by no means trying to diminish your concern. I understand, But I never said my design had a threaded input with aluminum threads either.

Many of the modern cars with aluminum control arms in production are made with forged-plated material, and or compression formed MIC-6 type process. In most cases the aluminum was for weight reduction and designed as a break away component.

That pic I took was of Hainz's car. He smacked a curb going 35mph ish. He drove it home even though the front end was moved about 3" from it's original location.

Even if it's lighter it only counts as 1/2 unsprung weight. So I don't see the point. We work with aluminum parts at work. No way I want something like that on my car. I've seen what happens to aluminum when the machine crashes. Steel does much better.

I have worked all over the spectrum with many materials. I have been machining material for the last 19 years and have seen some pretty ugly happenings, but I have also seen how extremely durable 6061-7075 can be. I am by no means saying this is the end all to the 510 control arm or a steel alternative. Items like these are generally labeled as track use only, and can be made to take regular every day abuse. Ultimately they are track parts made for adjust-ability and not made to smash curbs or hop pot holes. You guys are 100% right.

I also want to reassure you guys I am not going about this irresponsibly. I started the post in order to provide a much superior product for less.

I appreciate everyone's input, and I hope to give you a solid model picture soon, but would assume that will ultimately be stolen too lol That is when crowd sourcing the REALM will be handy. You guys help make it better

[HudsonMC]

Sorry, man. I wasn't over analyzing anything, or criticizing your design (I haven't even seen it yet). Just giving you some feedback from a different perspective. Control arms used in top tier motor sports are replaced pretty often and checked for cracks (magnafluxed) periodically. I doubt the folks buying your control arms will perform the same level of preventative maintenance.

I think that the right material here is steel. The steel part may have twice the fatigue limit of a comparable aluminum part? The weight savings will be pretty small, and the steel will probably be cheaper. If you really do end up selling them for under $200 a set, you know people are going to be putting them on their street cars. I know the aluminum would be awesome, but think about the children!