2G Let's build a Front UCA

[Black95TSIawd]

Wow!

 

[99gst_racer]

Wow, awesome modeling work Samuel! I like the serrated plate - my concerns with it are that I don't even know where to begin to get those manufactured, and I have concerns of excess weight. In that design, what would prevent balljoint shifting fore and aft?

I got some great jig building ideas from a co-worker today, who builds circle track a-arms. I assume 1/4" increments for length options will suffice? What increments should be available for fixed/built-in caster changes? I'm guess I'm just not sure how fine to make them...

 

[Black95TSIawd]

The more caster the merrier as far as fixed is concerned. If there can be some adjustment ie +- 1 degree to adjust for differences from side to side should work great.

 

[ileagleracing]

Wow, awesome modeling work Samuel! I like the serrated plate - my concerns with it are that I don't even know where to begin to get those manufactured, and I have concerns of excess weight. In that design, what would prevent balljoint shifting fore and aft?

I got some great jig building ideas from a co-worker today, who builds circle track a-arms. I assume 1/4" increments for length options will suffice? What increments should be available for fixed/built-in caster changes? I'm guess I'm just not sure how fine to make them...

I sent a model of the ball joint serrated plate to eMachineshop.com and got a quote of about $75 per part for an order of 10. I've tweaked my model a bit to allow for symmetrical parts, so only 2 unique parts would need to be machined. I figure a group buy of 20 arm sets could reduce the cost to around $200 per set for the machined parts.

It is hard to see from the original pictures I posted, but the outboard serrations are oriented 90 degrees to the inboard serrations. thus controlling the increments of caster. When I sent in my part for quote I included a dimensioned drawing as well, the serrations are based on a standard thread profile with a .05" thread pitch.

In 6061 AL those 2 parts weigh .2 lbs per side.
I didn't quote the cost to do them in steel, but steel would weigh in at .55 lb per side, you could then weld the base plate to the arm instead of rivets, but I'm not sure there is any advantage to that.

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[deth2u]

Neato design, man. I made a set of upper and lowers front and back from encapsulated spherical bearings and heims seven years back from 4130 chromoly

Here's mine:

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Edit: yeah, i know it's generally frowned upon to end a suspension arm on a threaded heim. Your design is certainly a better choice

If I recall correctly, the front lower arm bushings actually rest at two different elevations on the subframe. We moved the roll centers, and it took a LOT of jigs and measuring to complete. My GSX is a targa top with a hilariously overbuilt roll cage (14 points) and front K bracing, and sawing off the roof of the monocoque did absolutely no favors to the suspension beforehand.

This had to be the biggest and longest pain in the ass fab job my friend and I have ever done. It was a spur of the moment thing as my buddy was doing a lot of custom sand rail chassis build stuff, figured hey we should do this to the DSM too! Double A-arm fronts! It'll be quick and easy! Durr.

At this point my DSM pretty much has a custom everything. Can't think of one thing that hasn't been dicked around with or modified

 

[greengoblin]

Interesting. So you switched over to a single style lower arm . That is what Mitsubishi did on the 3G cars. Cool to see what you did.

 

[deth2u]

Delrin plastified and PTFE dry spherical motion control compoents offer the smooth, supple ride of a higher end shopping cart, which is then combined with the luxurious sensations experienced when the back of your airline seat is reapeatedly kicked by a five year old.

Trust me, I don't regret a thing.

 

[spyderdrifter]

Neato design, man. I made a set of upper and lowers front and back from encapsulated spherical bearings and heims seven years back from 4130 chromoly

Here's mine:

You must be logged in to view this image or video.

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Edit: yeah, i know it's generally frowned upon to end a suspension arm on a threaded heim. Your design is certainly a better choice

If I recall correctly, the front lower arm bushings actually rest at two different elevations on the subframe. We moved the roll centers, and it took a LOT of jigs and measuring to complete. My GSX is a targa top with a hilariously overbuilt roll cage (14 points) and front K bracing, and sawing off the roof of the monocoque did absolutely no favors to the suspension beforehand.

This had to be the biggest and longest pain in the ass fab job my friend and I have ever done. It was a spur of the moment thing as my buddy was doing a lot of custom sand rail chassis build stuff, figured hey we should do this to the DSM too! Double A-arm fronts! It'll be quick and easy! Durr.

At this point my DSM pretty much has a custom everything. Can't think of one thing that hasn't been dicked around with or modified

Does this offer a tighter turning radius?

 

[kmetiuk]

Neato design, man. I made a set of upper and lowers front and back from encapsulated spherical bearings and heims seven years back from 4130 chromoly

Here's mine:

You must be logged in to view this image or video.

You must be logged in to view this image or video.

Edit: yeah, i know it's generally frowned upon to end a suspension arm on a threaded heim. Your design is certainly a better choice

If I recall correctly, the front lower arm bushings actually rest at two different elevations on the subframe. We moved the roll centers, and it took a LOT of jigs and measuring to complete. My GSX is a targa top with a hilariously overbuilt roll cage (14 points) and front K bracing, and sawing off the roof of the monocoque did absolutely no favors to the suspension beforehand.

This had to be the biggest and longest pain in the ass fab job my friend and I have ever done. It was a spur of the moment thing as my buddy was doing a lot of custom sand rail chassis build stuff, figured hey we should do this to the DSM too! Double A-arm fronts! It'll be quick and easy! Durr.

At this point my DSM pretty much has a custom everything. Can't think of one thing that hasn't been dicked around with or modified

Super interested in the front lower single A arm....how did that affect feel and handling?

 

[MattHDSM]

I don't have anything to contribute to the design process, I wish I did, but just curious if there has been any progress made behind the scenes?