Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

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dannobee
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by dannobee »

How difficult would it be for you to make a spacer to space the bearing further from the spindle upright? If you have access to CNC, make a bearing spacer. By the looks of it, even a 4-6mm spacer would give you plenty of room to fit whatever heavy duty ball joint you need.

If you're planning on making the upright/spindle/knuckle, just incorporate the spacer into the design. Don't forget about changing the caliper mounting ears by the same amount. If you're limited to the factory spindle, you'll need to trim the caliper mounting flange the same thickness as the spacer. Also, if the distance remains close, you'll need a sheet metal heat shield to keep heat from the brake disc away from the ball joint. They're usually held on by the ball joint nut.
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by emre2blue »

It is almost impossible for me to do an offset flange. I have to buy new calipers new disc + I don't know what else. I've thought that before. When my 330mm Front Disc are bad for me. I'll go 356mm Disc + 6 POT Caliper + 18" Wheel all around.  It Means I have to work more to earn money :D

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Also With this knuckle ( spindle upright ) I cannot offset my Caliper easily. Also Thank you for let me know that sheet metal works like heat shield to joint. 8)

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When you look at the picture above. You may see that original ball joint have room to touch the disc.
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I know that I missed the articulation of the arm. But When you cancel the sheet metal. Or When I open a window to it. I could easily increase the thickness of the outside material by 2mm. from 3.16mm 5.16mm
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dannobee
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by dannobee »

Space the hub and bearing out with a spacer and machine off the current caliper mounts and make an adapter similar to this.

https://pitstopusa.com/i-23982956-mpd-f ... brand:4897

If you really feel ambitious, you could make some brake hats and use racing brake rotors and space everything however you like.
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by allencr267 »

Maybe the factory is using a small amount or poor quality lube and you can add some or replace it, or add a grease fitting.
That or looking at other FWD cars(or Alfa models, do they make a truck) that have similar design with stronger ball joints that can be adapted to the Alfa without too much modification.
Good luck.
emre2blue
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by emre2blue »

allencr267 wrote: Fri May 13, 2022 2:31 pm Maybe the factory is using a small amount or poor quality lube and you can add some or replace it, or add a grease fitting.
That or looking at other FWD cars(or Alfa models, do they make a truck) that have similar design with stronger ball joints that can be adapted to the Alfa without too much modification.
Good luck.
I have some joints but the problem is that in the first place you cannot change the ball joint in the arm. Only you can make is add a lubrication that's it.

I'm sorry I was absent for a time. I had to work my ass off in my daily job. And I'm swapping the gearbox on the car from M32 to F40. Lots of problem came within swap. Now I'm waiting parts from Europe to finalize the swap. Anyway another subject.

Here is some news. I've checked the some dimensions on the car. And I found that I have 2 more millimeters between disc and the arm. So It means now I have more material to cover the ball joint. It's a good new.

Also I've bought Aluminum Knuckles from a younger car. Before the Alfa Romeo 159 out of production, Engineers put the car on diet and lost 80kg total. And knuckles are on of the part that we can bolt-on swap to our Steel Knuckles.

Steel - Image

Alu - Image

Weight of Alu - Image

Weight of Steel - Image

Together - Image

Together - Image

As you can see. Alu seems to have more material than steel. Bulky design, but less weight.

I wish I could find what material they are using in "forged aluminum arms" I've talked lots of guys in the market. They say our 7075 or 6061 has no strength.

Forged Alu is the key. They say if you go billet, you have to add material to compensate the strength. I've asked some data. I know they tested those materials for life expectancy, but I could not find any good data.

Some said go to China market and bought untouched forget material. And put it on CNC. That would be better. And I think its not. I saw lots of Billet arms on the WEB. And they are using them even on Off-road. I don't know how many years can you use your Billet Arm. But I'm curious.

I have two new CNCs and German cutters. I don't I'll have any problems on that side. I wish only I could trust the materials. Even I have the Factory designs of the arms. But I could not find the Design Calculation Forces to check and redesign the billet arm.
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frnkeore
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by frnkeore »

I'm a retired machine shop owner and I was a sub-contractor, for Erickson Air Crane. I made thousands of parts for the Sikorsky S-64, heavy lift helicopter, including Ericksons, first retardant tank, in '91.

To begin with 7075 has almost exactly twice the yield strength of 6061, both in T6. In general, yes a forging will have increased strength, compared to a fully machined part but, it will not be anywhere near twice as strong as a machined part. The forging will also be heavier than a fully machined part, matching the contours of the forging.

Your parts take a lot of aluminum and that eats up money. I'm guessing that the time is free to you though?

Here is how to make the parts with 7075, to aircraft specs:

1. Source your alum. It's extremely important that the grain of the alum, be in the plane of the most stress!

2. It looks like all your parts have at least one section, greater than 3" so, the parts have to be roughed out and then re-heat treated, before finish machining.

3. All inside contours should have a radius, as large a radius as possible in high load areas. Break all edges and radius outside corners.

4. If you want to see the grain, anodize to Milspec, MIL-A-8625 TY III.

5. Dye penetrate test.

6. Be aware, when it comes to bearing fits, that anodizing builds up the surface, usually a minimum of .0002, per side but, they can increase the thickness, if needed.
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Rick!
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by Rick! »

A forged 6061 T6 snowmobile spindle, circa 2010 Polaris, is about 10% stronger than a cut spindle made out of 6061 T6 billet.
7075, even with its incredible strength, needs generous fillets and radii due to its notch sensitivity. Basically, don't create a feature that could have microcracks in it after machining.
You may have to do some clever programming in order to get two parts out of one billet, kinda like 3D nesting. Otherwise, it'll be like making toothpicks out of logs. The hard part may be finding properly thru hardened billets.
One avenue might be to find out where the forge tools are for the spindles. If you can get your hands on those, then you just get a Taiwanese foundry to beat some parts out. The places I visited several years ago were very skilled in forging aluminum and making thick parts flow nice.
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by allencr267 »

It's hard to stop, we're too often thinking of/comparing forged to cast aluminum, BIG difference, when the comparison between forged and a billet/rod/plate/extrusion or fabricated/welded piece is there, but isn't nearly so significant.
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Re: Can Billet CNC Cut Suspension arm, replace factory cold formed arm?

Post by XiomarBorjas »

Thank for sharing.
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