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Bebop said:
I'm surprised the end of the upper arm doesn't completely wrap around the cup. Obviously it seems fine, but that still surprises me.
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No need, that cup is anchored very well inside that arm, then with those wraps on either side, that cup is going no where.



mobil1syn said:
the more you dive into other forms of motorsports you realize how much rock crawlers over build things.
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God forgives, rocks don't.
 
I was blown away when I got into the roundy round world and single shear everything was the norm, even on things with lots of spacers and tons of leverage (steering bolts at knuckles with bump steer spacers. Though they know they're going to be out of the race when they hit the wall hard, so they're cool with breaking components acting as crumple zones absorbing energy. We aren't fortunate enough to have that freedom haha. Like these guys I'd be concerned about the cup's connection to the rest of the control arm, but if you're worried about the cup physically ripping in half, just have cups cut with heavier wall thickness.

I recall that Gomez failure where he had a front spindle flopping but still attached as he limped toward the finish. I thought I saw a shoutout to Elrods Prostraps with the video later because that's all that held it together, but I still can't find it.

I did stumble across this pretty sweet Gomez Bros walkaround from RCV with some perpectives you rarely see though

https://www.youtube.com/watch?v=UmBo...RCVPerformance

 
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Bebop said:
m sure that Marcos Gomez doesn't share that particular thinking, since he lost the upper arm and any chance of winning with it.
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sent out the bat signal to some people in the know and it appears he sheared the shank (actually text read "It's snapped the stem") on a 7/8" rod end. arm and chassis were fine.
 
mobil1syn said:
sent out the bat signal to some people in the know and it appears he sheared the shank (actually text read "It's snapped the stem") on a 7/8" rod end. arm and chassis were fine.
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Proof that overbuilding isn't always a bad idea...
 
patooyee said:
I can chuck a spacer up in my lathe and shorten it, make the hole size bigger, and a few other things. But I'm no machinist and turning a proper radius by hand is beyond my skillset. I guess maybe I could mill or grind a radiused tool for the lathe but it would be so much easier to just buy proper spacer from the get go.

The guy at Kartek said that the WSSX series is the "standard." Most of what they sell is WSSX. No one to this point has said anything about WSSX bearings breaking. So I question if the added strength and limitations of the FKS is necessary.
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"Proper" radius is not going to kill your joint. The loads will before that has any effect. Email me you CAD drawings and I'll show you what I mean.
 
Weasel said:
"Proper" radius is not going to kill your joint. The loads will before that has any effect. Email me you CAD drawings and I'll show you what I mean.
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they wont rip the liner out the joint, but they will remove contact surface area and you could spit the liner out
 
mobil1syn said:
they wont rip the liner out the joint, but they will remove contact surface area and you could spit the liner out
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don't run liners, they just wear out and start click clacking. :flipoff2:

We tried liner vs non for many years and ended up running no liners on the smaller joints. They made no difference other then wore out sooner and started making noise.

Local guys came to the same conclusion on larger joins in their crawlers.
 
Weasel said:
"Proper" radius is not going to kill your joint. The loads will before that has any effect. Email me you CAD drawings and I'll show you what I mean.
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You should have my files now.
 
Yeah, my concern on having high misalignment spacers that don't actually have the matching radius/circumfrence is what mobil mentioned, the amount of contact surface area that is being removed at high misalignment angles. When they're matched, some of the load can actually be transferred from the hoop of the heim directly into the spacer

IMG_5808.JPG


IMG_5809.JPG
 
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Those EMF joints do seem like a decent deal after you price out expensive high-mis spacers for the FK stuff. They don't list angularity measurements though. Am I missing those somewhere?

EMF used to never stock anything and took forever to build stuff. Is that still the case?
 
Sorta, they show what they have in stock on their website and then do have more regular stock ups. Their lead times are pretty accurate that I've seen lately.

Don't know on the angle, what do you need? I know for awhile we were set on having the spacers and then realized with a bit more design work we wouldn't need the misalignment and could run normal spacers.
 
Weasel said:
Sorta, they show what they have in stock on their website and then do have more regular stock ups. Their lead times are pretty accurate that I've seen lately.

Don't know on the angle, what do you need? I know for awhile we were set on having the spacers and then realized with a bit more design work we wouldn't need the misalignment and could run normal spacers.
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FK lists total possible misalignment on all their joints. I would think that would be a pretty important thing to know and I don't see it listed on EMF's joints.
 
Breaking parts is usually driver error or a weak design . Wearing out parts is another story. I actually can't remember breaking anything on Jason s's car but lots of stuff has bent. (What CroMo is supposed to do) Unhardened arms, uprights, and etc usually only last one race for bending. Hardening can make stuff last a year or allow you to hit stuff with faster speed. Almost all wear is due to braking forces.

Because IFS cars have no diif to catch on rocks, they can, and are, driven like missiles. They winch much faster and better also. A SA car usually wiggles thru the rocks more and with recent upgrades in their steering control (Dez) and steering speed (rocks) are more competitive today. Either can go portal......But I digress.

7/8 UCA heims are so "old school" for 4400. I was surprised when I heard that. I bet they are 1 -1.25" now. Which has been the new normal for years. (6+)
 
patooyee said:
FK lists total possible misalignment on all their joints. I would think that would be a pretty important thing to know and I don't see it listed on EMF's joints.
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Not really. It's only important if you need that movement. If you don't even better. call or text and ask him. I know I've seen it before just dfon't seeing it now.
 
question regarding the bearing on the UCA from the Jason shereerreerer picture:

is the bearing housing what is actually welded to the arm and serviceable or is it set into something else?

IF that were a milspec aircraft part for instance, the UCA would be built with a bearing housing in it and the bearing itself would seat with a press fit, let's say .0005-.0015" press fit and be pressed in from the bottom. that way when the large forces from the bump stop come in to play, the bearing housing would be forced into the UCA and not able to press itself apart. when the bearing get's sloppy from dirt or whatever, just press the old bearing out and press in a new tight one into it's place. limit strap would keep the whole thing from falling out the bottom so it wouldn't really need much staking or anything to keep it in place from that direction, but sure, and impression stake would be easy added insurance. then a cheaper bearing without a liner to fail or anything could be used and play could be easily measured to replace it as often as needed.

maybe i'm seeing it wrong but it seems odd to weld the bearing housing into the arm and rely on just being able to replace the ball or the whole arm to service the bearing.
 
Provience said:
is the bearing housing what is actually welded to the arm and serviceable or is it set into something else?
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yes. bearing housing is welded to arm. i think you are missing the cup portion of the equation.

i pulled the arm off and use a press to get the old one out. new one i could install with a dead blow after freezing the bearing and giving the arm a little heat. copper based antisieze went on the outside of the bearing AND inside of the housing.

or you can get fancy and buy the tool
https://youtu.be/TKbv4XSCs50

how-to-assemble-uniballs-into-cups.jpg


48413950.jpg
 
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thank you! the cup is absolutely what i was missing :)

personally I use some allthread and a "pusher cup" and a "catch cup" with a nut/washer on each side. only ever bother to freeze any when i've got tons of time or a stubbornly tight fit.

antisieze or some other similar coating is always important as well.
 
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