CNC lightweight front spindles

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plohl
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Re: CNC lightweight front spindles

Postby plohl » Mon Sep 12, 2016 2:58 pm

Nevermind, turns out there were more posts I missed

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Re: CNC lightweight front spindles

Postby madjak » Mon Sep 12, 2016 3:02 pm

I wasn't really planning on selling these, unless there is a big need within the community. I'm doing all this so that I can run them! I do like designing parts to be future proof though as I don't know which direction my car development will take me in the future.

The issue with the Keisler spindles is the change in geometry from the drop causing all sorts of issues with suspension setup. My design doesn't incorporate a drop for that reason, or if I do, it will be minor.

In terms of the steering arm tie rod, I was planning on running a rod end that threads onto the steering arm rather than the tie rod. This way I can pack the distance from the arm to the rack to alter bump steer. Also in terms of brake caliper... I am currently running Dynapro caliper but it would be cool to fit up AP or Stoptech calipers. If I make the caliper mount interchangeable though I could switch it out when I want.
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hks_kansei
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Re: CNC lightweight front spindles

Postby hks_kansei » Mon Sep 12, 2016 3:22 pm

I thought the point of drop spindles was to allow. Ride height drop while leaving geometry intact?

Since the mounts etc stay the same, just the wheel center point is higher on the knuckle.
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zossy1
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Re: CNC lightweight front spindles

Postby zossy1 » Mon Sep 12, 2016 3:42 pm

The Keislers do 4 things, in order of importance:

1. Build ideal caster/camber adjustment into the central areas of the alignment window (ie. You get pretty much perfect alignment numbers at the middle of your alignment pills, giving much better adjustability)
2. Lower front roll centre
3. Reduce bump steer
4. Reduce camber gain on bump

The rears do similar - but are even more of a pain to get right than the fronts.

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Re: CNC lightweight front spindles

Postby 97 MXV » Sun Apr 09, 2017 1:01 pm

These comments may be past use by date but am fascinated today by the innovative ideas presented.

Option 1:
Image

Option 2:
Image

I like the combined bolt on pitman arm and lower ball joint mount of Option 1.
It would need some decent bolts as long as possible and thick joint faces at the bolts to keep the joint under the bolts locally very stiff but both items need to be chunky in this area anyway and thickness can wash out quickly away from the bolts.
Suggest pitman arm be rotated through 90 degrees so its depth as a cantilever beam is in the plane of the steering loads.
Look at using say 3 pitman arm bolts...2 on the right and 1 on the left as right side carries approx twice steering load as the left side. Add a 4th to ensure friction grip for vertical loads.
The joint should be designed friction grip so no bolts in shear. Removable dowels for first up locating only. Maybe the assembly could bolt up from underneath also.

I caution against the twin annulus structure separated by little webs in Option 1. I think the Option 2 structure is much simpler and stress gradients through the structure much easier to determine. You know all the loads are more directly connected so stress paths not broken up into traversing through a maze of different paths fighting each other because of Poisson's Ratio and Hooke's Law determining load paths.
May be better to have the outside annulus for brake ducting a separate lightweight attachment.
I cannot imagine Option 1 structure being efficient with a lot of potential for hot spots and cold spots in an FEA, both annoying for different reasons. Much easier I think to sculpt Option 2 into a structure having metal where it matters to achieve an FEA all the one colour. :D


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