LCA pivot

[bjkadron]

Hello all!

Does anyone have the measurements of the lca pivot? The metal rod that goes into the lca bushing? I don't have mine out and I need the measurements so I can turn some stronger ones. They need to be pretty accurate.. Like about +/- 2 thousandths dia. and 10-15 length. If you have the capability to measure the threads that would be nice too.

Thanks all!

Benjamin

 

[bjkadron]

Hmm.. Nobody has their lca's apart? Or nobody has the equipment to measure to that accuracy?

 

[70Hardtop]

I'd say you'd need to give the guys some more time for that one

 

[bjkadron]

I'd say you'd need to give the guys some more time for that one

Yeah I was kinda thinking the same thing...

Just wanted to make sure so I would know if I need to take mine apart. 'cause that is a pretty tall order. :-D

 

[6pk2goDemon]

Do you need the dimensions of this pin?

 

[bjkadron]

Do you need the dimensions of this pin?

Yes! That one! all of the dimensions! Inside the bushing and out... But very accurately on that part where it fits into the K-frame. Because that is what holds the load.

 

[6pk2goDemon]

See if these help you......let me know if you need more or can't read the mic.

 

[bjkadron]

Yeah that would be perfect but I can't read the dial in these pics... It might be the computer screen though... Can't tell.

 

[bjkadron]

If you can just tell me the reading that go with what pic I should be able to go from there.

 

[6pk2goDemon]

Let's try this for you.........Keep in mind that a couple of these surfaces are tapered. I'm not sure how you can machine one of these, but go for it and make a couple extras while you're there

 

[bjkadron]

Could you possibly get the lengths too? Yeah I know they are tapered.. Just have to do a little trig to figure out how much... Unless I can get solidworks to figure it out for me! I was planning to turn one out of Aluminum first (faster) until I got it perfect then Make the good ones. And Yeah I was planning to turn a few. Thanks for doing this!

 

[6pk2goDemon]

Best I can do for you +/- a few thou:sith:. This thing is a bi*ch to measure.....

 

[duster360]

Hate to add more to it but, what about width and height of the shoulder in the middle of the shaft.

 

[bjkadron]

Best I can do for you +/- a few thou:sith:. This thing is a bi*ch to measure.....

That is great! like I said the length isn't as important. I'll draw up the plans tomorrow afternoon and see if it calculates the angles. If so I should have the first aluminum test piece by tomorrow night!!! I'll be sure to post pics and more info so others can benefit from all your hard work! Yeah I kinda figured it would be a pain... That is why I wanted to get it from someone else!:cheers: Well, that and I don't have a press to get mine out right now.

Hate to add more to it but, what about width and height of the shoulder in the middle of the shaft.

HAHA! Actually that isn't all that important as it is just a stop. I can get it just by subtracting the other measurements from the total length. But if he wants to measure it then by all means!

 

[bjkadron]

Here you guys go...

This is the aluminum one to make sure everything is perfect before I turn them out of steel.

By the way.. The tapers are .2* for the long one, and 1.0* for the short one. :read2:


Here it is! Will test fit this afternoon hopefully!

 

[clhyer]

You said you are doing this to get stronger ones? I've never heard of one failing. Surely the bushing would fail before the spindle?
Just asking.
Thanks,
C

 

[autoxcuda]

Why bother making this to fit stock rubber or over the counter poly bushings. Firm Feel/Just Suspension allready sells one?

How about making one to take a very high load spherical bearing. A plain bearing (poly) doesn't really technically work as the path of the LCA is not perfectly up and down due to the strut rod. There is an off the shelf low angle spherical that comes close to fitting that stock pin I.D. and LCA O.D. I found. ;)

That would be a NEW part that would take this to the next level.

They do offer something like that for the drag guys, but it's big bucks. And IIRC, it's a plain one axis bearing.... So you could sell it to the drag guys too.

-Steve

Here you guys go...

This is the aluminum one to make sure everything is perfect before I turn them out of steel.

By the way.. The tapers are .2* for the long one, and 1.0* for the short one. :read2:


Here it is! Will test fit this afternoon hopefully!

 

[bjkadron]

Why bother making this to fit stock rubber or over the counter poly bushings. Firm Feel/Just Suspension allready sells one?

How about making one to take a very high load spherical bearing. A plain bearing (poly) doesn't really technically work as the path of the LCA is not perfectly up and down due to the strut rod. There is an off the shelf low angle spherical that comes close to fitting that stock pin I.D. and LCA O.D. I found. ;)

That would be a NEW part that would take this to the next level.

They do offer something like that for the drag guys, but it's big bucks. And IIRC, it's a plain one axis bearing.... So you could sell it to the drag guys too.

-Steve

Either great minds think alike or we are both just nuts. that is pretty much my exact plan. I was just planning on making one with a nylon or "del-a-lum" for the people wanting zero deflection but still concerned about NVH and stuff. I just needed to make sure I got the tapers right so it would bolt up to the stock k-frames.

 

[autoxcuda]

Either great minds think alike or we are both just nuts. that is pretty much my exact plan. I was just planning on making one with a nylon or "del-a-lum" for the people wanting zero deflection but still concerned about NVH and stuff. I just needed to make sure I got the tapers right so it would bolt up to the stock k-frames.

For nylon or delin I don't think you need to make a new pivot. Just a nylon/delin bushing that fits. Problem is the LCA shell is totally varible diameter for the OD of the bushing. And the housing the bushing presses into is usually gouged and not a precision machined for a good bearing surface for the nylon or derin. Do you have some ideas to overcome the OD bearing surface? Like you own shell/sleeve to press into the LCA?

I think Firm Feel makes a nylon bushing insert.

 

[bjkadron]

For nylon or delin I don't think you need to make a new pivot. Just a nylon/delin bushing that fits. Problem is the LCA shell is totally varible diameter for the OD of the bushing. And the housing the bushing presses into is usually gouged and not a precision machined for a good bearing surface for the nylon or derin. Do you have some ideas to overcome the OD bearing surface? Like you own shell/sleeve to press into the LCA?

I think Firm Feel makes a nylon bushing insert.

Yes, Firm Feel does but it is more along the lines of a "poly" busing made out of nylon. Think more along the lines of a nylon bearing for what I'm thinking. With the inner and outer shells. I cant' seem to find a picture but Herb Adams talks about them on P. 23 of his book "chassis engineering" and has a picture. if you have that book. but yes, pretty much a pressed in sleeve.

the main reason I am making a new pivot is because one of mine is bent. and if it is bent then it isn't really strong enough for my needs.

 

[autoxcuda]

Yes, Firm Feel does but it is more along the lines of a "poly" busing made out of nylon. Think more along the lines of a nylon bearing for what I'm thinking. With the inner and outer shells. I cant' seem to find a picture but Herb Adams talks about them on P. 23 of his book "chassis engineering" and has a picture. if you have that book. but yes, pretty much a pressed in sleeve.

This is like what we used in our Circle Track cars because sperical are not legal. Can't find the exact one, but...

http://www.speedwaymotors.com/AFCO-Low-Friction-IMCA-and-UMP-Modified-Suspension-Kits,23503.html

the main reason I am making a new pivot is because one of mine is bent. and if it is bent then it isn't really strong enough for my needs.

Did you know it was not bent and then it got bent. I know people that road race with mondo 1.24" T-bars and not had an issue.

 

[bjkadron]

This is like what we used in our Circle Track cars because sperical are not legal. Can't find the exact one, but...

http://www.speedwaymotors.com/AFCO-Low-Friction-IMCA-and-UMP-Modified-Suspension-Kits,23503.html

Exactly! No metal to metal contact, super low friction, zero deflection, and ease of maintenance. What is not to love? And better for street driving than sphericals.

Did you know it was not bent and then it got bent. I know people that road race with mondo 1.24" T-bars and not had an issue.

Actually I'm pretty sure it was wrecked when I got it. which is why I found it where I did. But I figured I'd go ahead and make some better ones while I'm re-doing everything else. Any other ideas of things that could stand improvement while I'm at it?

 

[6pk2goDemon]

Here you guys go...

This is the aluminum one to make sure everything is perfect before I turn them out of steel.

By the way.. The tapers are .2* for the long one, and 1.0* for the short one. :read2:


Here it is! Will test fit this afternoon hopefully!

:thumbup: Wow, wow......nice work there. Does it fit?

 

[bjkadron]

:thumbup: Wow, wow......nice work there. Does it fit?

Thank you! Well... Yes and no... It is the right taper. But the tolerances are not quite to my liking. I measured one of mine and it is slightly bigger. The only thing I'm not sure about is that that one fits a little better.. I think I'm going to make it a couple thousandths bigger.

 

[3406pk]

That original piece looks like it is a forged steel. So you should use some good steel.