Custom CNC / Fab guys

[wellis77]

Curious if any of you custom CNC / Fab guys have ever machined a steering knuckle? The project I'm building is using an AME chassis with C-6 front suspension. Problem is I'm using Viper wheels with a 6x4.5 bolt pattern. I can get the C6 hub pattern welded and redrilled but I wondered today if it's possible to have a C6 based knuckle machined to fit the Viper bearing hub assembly. Attached are pics of the C6 knuckle, Hub assembly, and the Viper hub assembly so you can see the difference. I know this would probably be costly but I'm curious if it's possible. Thanks a bunch.

hub & knuckle
https://static1.pt-content.com/images/noimg.gif

C6 hub
https://static1.pt-content.com/images/noimg.gif

Viper hub
https://static1.pt-content.com/images/noimg.gif

[JMarsa]

Only way I see it being cost effective is is you had an unfinished aftermarket spindle like the one ATS designed.

--JMarsa

[wellis77]

That's an interesting thought. My original thought was the C6 knuckle be modeled in Solidworks, and tweaked to fit the Viper hub assembly, ensuring the same offset and such, then CNC'd out of billet steel or aluminum. I know it is more costly but I'd be curious (1) if it's possible and (2) at what cost. It may just offset the cost of the knuckle & hub from AME plus having the bolt pattern welded and redrilled, or maybe only slightly more expensive. I don't know though. I do know I'm looking at about $1000 for two C6 hub assemblies, bolt pattern being handled, and shipping all ways. I figured it was worth checking into.

[Brandon Miller]

Just get the hubs redrilled. To get the knuckles you'd have to do one of two things first. Find someone who had the CAD data for the C6 knuckle or have someone model the C6 knuckle. Then your dealing with the amount of material to machine a knuckle plus the time involved. Material alone would probably cost you close to $1K so we won't even discuss the cost of machining the knuckles. Plus you gotta figure in the cost of heat treating the material too. It's cheaper and more cost effective to just get the hubs welded and redrilled.

[parsonsj]

Adding to Brandon's post: the GM part is forged aluminum, so you'd have to factor that in too if your plan would be to make it from billett. That engineering is above my pay-grade, but I believe forging allows one to use less material than if you use billett.

jp

[Taylor1969]

may also be cheaper to sell the wheels and get a set that fits the hubs you have

[wellis77]

Thanks for the feedback guys. I agree it is probably best to stick with having the hubs redrilled to my bolt pattern. It's not that big a deal and doesn't cost much to weld the current pattern shut and redrill.

Losing the wheels isn't an option as they are part of the theme of my build.

Thanks again.

[Brandon Miller]

That engineering is above my pay-grade, but I believe forging allows one to use less material than if you use billett.

jp

Yes you would use a much smaller piece of material. For a billet piece you would need a chunk/block of material that knuckle would actually fit in. With a forging, I'd say you are look at 50-65% less material needed. Either way, it's expensive.

[dipren443]

Just remember guys that "Billet" basically refers to a chunk of material. The forging process is secondary. A billet or ingot would be placed into the forging dies to generate a forging. The problem with forging of course is manufacturing the forging dies themselves. This is the reason for the high initial setup cost.

And the huge advantage of forging is the inherent strength. The forging process changes the grain structure. GIVEN the exact same part dimensions, the forging will have much better strength characteristics.

[Junkyard Johnney]

I have looked over your parts. First of all welding on the knuckle is risky buisness, that type of part has an incredible amount of force on it and the heat can weaken it. We used to weld and redrill 9" Ford rearend axle flanges and redrill them for our stock cars and never had a problem, but bear in mind we were on a track and not on a public road, liability and all that. From the looks of the flange you are wanting to use, 4 hole, and the knuck is a basic 3 hole there is not going to be enough meat there to drill your other holes, not all of them anyway. In addition to this the center shoulder of the mounting flange MUST pilot into the center hole of the knuck snuggly, this is what holds the upward forces and keeps everything aligned , a must. CNC fab from billet is way to costly because of the above mentioned comment, the size of the start chunk. I just purchased an 8" round piece only 2" thick rem from Ohio and it was $100 by the time I got it, see where this is going. Do not comprimise the knuck; take it to a machine shop and see if the mounting flange can be disassembled from the drive hub, wheel flange if you will, and have new billet mounting flanges made from the billet that will match your knuck bolt pattern and reassembled. That would be the proper manner to approach this one in my opinion. Good luck , interesting project.

[wellis77]

Thanks for the feedback Junkyard Johnney. I have solved the dilemma and what I'm going to do is simply use Viper knuckles. I'm not sure if I can use the control arms or build my own but using the Viper knuckles will eliminate many other nuisances, like mounting brake calipers since I'm using Viper brakes as well.