Interest: Bolt on X-Link

[Walking Eagle]

How much twist that needs? maybe there is a way to run it behind the axle.

Search "v-link"

 

[Walking Eagle]

Will an x-link work? Yes, obviously it does if you check out cranky-link's project.

Can you sell it in the US? Don't know - check for patent infringement I was pretty sure that Dobbins Engineering had a patent on it

home

Is it any better than going to a Y- radius arm set-up ala Jeep.? That's certainly debatable. They've been getting good flex out of those for some time now, and the one 80 here with it seems pretty flexable. Certainly the X-link is a big chuck of metal in front of the axle - but really, how much in front of the axle is it? I'd be hard pressed to believe that the x-link would handle any better on road than a Y set-up. I would actually venture to guess it'd be worse just because it would apear at first glance to have less roll resistance.

All that said, I don't think bolt on is a good idea. Try it, test it - I'm willing to be wrong.

As far as the Nay Sayers who think the front of the 80 flexes enough - WRONG!!!! Won't rehash previous debates, but the lack of flex in the front can create some pretty scary situations where added flex would have helped.

Heath

 

[Walking Eagle]

I'm planning on running a 1/4" I beam as the arm itself. Considering how well my 1/4" sheet has held up for my skid plate, I think that should hold up okay..

O.K. I've written three different rather biting and cleaver responses to this, and I'll just leave it at - Bad logic. What is good for a skid plate is not necessarily good for suspension parts. Look at the size of the cranky link, and the x-link, and the radius arms, then reconsider....

 

[Ebag333]

Can you sell it in the US? Don't know - check for patent infringement I was pretty sure that Dobbins Engineering had a patent on it

Yeah...don't get me started on people patenting things and then not bringing them to market.

But no....our patent system encourages innovation!

Certainly the X-link is a big chuck of metal in front of the axle - but really, how much in front of the axle is it? I'd be hard pressed to believe that the x-link would handle any better on road than a Y set-up. I would actually venture to guess it'd be worse just because it would apear at first glance to have less roll resistance.

Once it's pinned in place it will handle exactly as the stock would. There will be no movement to it at all, so there will be the same amount of roll as you would have with the stock mounts.

That's the whole idea behind it.

As far as the Nay Sayers who think the front of the 80 flexes enough - WRONG!!!! Won't rehash previous debates, but the lack of flex in the front can create some pretty scary situations where added flex would have helped.

Booooooo. Bad pun.

O.K. I've written three different rather biting and cleaver responses to this

Cleaver response is right after the way you butchered that last pun!

O.K. I've written three different rather biting and cleaver responses to this, and I'll just leave it at - Bad logic. What is good for a skid plate is not necessarily good for suspension parts. Look at the size of the cranky link, and the x-link, and the radius arms, then reconsider....

I've had a relatively in depth conversation with CrankyCruiser about his setup. He uses 1/2" (or close enough to it) plate, that's been reinforced.

What I'm starting with is 1/4" I Beam, which will resist twisting/bending much better than 1/2" plate (even reinforced).

I agree what's good for a skid plate isn't always good for suspension parts, but my point was that if a sheet of 1/4" can hold up to 6.5k lbs coming down on it without bending, it's not likely to bend when used for suspension parts.

The closest OEM suspension part to what I'm looking to do is the control arms, but those are subject to a lot more force than the X-Link arm will be. For one, a (OEM) mount will remain on the axle, which will take a lot of the force involved.

I've done a bunch of research on the various strengths of different material and configurations. 1/4" I Beam will be stronger than 1/2" plate in multiple dimensions, hands down.



For rock damage I'm considering boxing in the open side of the I Beam (side opposite the axle and brackets). This will do two things, one it'll increase the overall strength of the arm, and two it will help prevent the I Beam from getting bent up should you whack it on a rock. (It'll also make it look a bit cleaner.) Another advantage is that it's more likely to slide, than get hung up like an open end would.

 

[Waggoner5]

Ebag333, if you haven't realized it yet, you will not be able to build this without getting hammered from all aspects from the design to the liability. Everyone is an expert on suspension design and even though they haven't built or tested what you are doing, they will tell you whats wrong with your design, materials, and how you market it. I would build it the way you want it and run it. When its done and you want to sell some, do it, and be proud that you actually designed and built something yourself rather than following the mainstream. Its a cool idea.

 

[CreeperSleeper]

Ebag333, if you haven't realized it yet, you will not be able to build this without getting hammered from all aspects from the design to the liability. Everyone is an expert on suspension design and even though they haven't built or tested what you are doing, they will tell you whats wrong with your design, materials, and how you market it. I would build it the way you want it and run it. When its done and you want to sell some, do it, and be proud that you actually designed and built something yourself rather than following the mainstream. Its a cool idea.

I agree. And this is coming from a guy who builds some of the nicest Cruisers I have ever seen.

 

[Atticus]

Ebag333, if you haven't realized it yet, you will not be able to build this without getting hammered from all aspects from the design to the liability. Everyone is an expert on suspension design and even though they haven't built or tested what you are doing, they will tell you whats wrong with your design, materials, and how you market it. I would build it the way you want it and run it. When its done and you want to sell some, do it, and be proud that you actually designed and built something yourself rather than following the mainstream. Its a cool idea.

best advice so far

 

[Dusty]

Re-engineering the front of an 80 to get better flex has been done several times before and most of these guys would not do it again. It did not allow the truck to go any farther up/down the trail than the stock design, and body lean and drivability were sacrificed as well. The 80s are just too large and top heavy to make them like a slinky. By the time you address the body lean with shock valving, spring rate, and sway bars, you will see what I mean.

I dont know about that first statement Gary. Ask the guys who 3- linked their 80's or the guy who did the better radius arms if they did better on the trail. Once you drive an 80 with a front that is as loose as the rear you begin to appreciate how limiting and bound up you are with the factory front suspension.

So Nay and others are wrong with regard to rockcrawling and the front of an 80. The Facory front suspension does not make the 80 safer on the rocks-it makes it less. I know. I have driven it. the 3 link, 4 link, flexy radius arms in the front (and even the silly x link) make heavy 80 more predictable.

But my 3 linked 80 does suck on the road. sways all over the place if i need to turn. But in a strait line ive had her over 90mph

 

[Tools R Us]

... Once you drive an 80 with a front that is as loose as the rear you begin to appreciate how limiting and bound up you are with the factory front suspension. …

X2.

In every flex thread the “it’s going to be a floppy jalopy” FUD, (fear, uncertainty and doubt) argument comes up. I agree that the lifted ‘80 is a top heavy rig, so if street driven, softening it too much isn’t a good idea, can be uncomfortable or even dangerous at highway speeds. But there is a big range between the, stiff as a board stock and floppy jalopy setups. Depending on design, it can be setup in the middle, by using bushings, stiffer sway bar w/disconnect, etc, it can be tuned to have good trail flex/ride and acceptable highway ride. I doubt that this has much to do with the x-link, my guess is it won’t soften it enough to get into floppy jalopy territory.

I have been running the 3 bushing arms for +3 yrs, very happy with them. There is more cornering body roll, (more flex, lower flex spring rate = more body roll) for me it’s a good trade for the trail ride. Every time I ride in a standard radius arm ‘80 on the trail, I remember how mine was, no way I'm going back to that!

 

[Walking Eagle]

Once it's pinned in place it will handle exactly as the stock would. There will be no movement to it at all, so there will be the same amount of roll as you would have with the stock mounts.

That's the whole idea behind it.
.

I think we're talking two different rolls. Are you talking it rolling as in the axle rotating under torque? I'm talking about it rolling more in corners - cause you will have less sway resistance, I mean, that's kinda the whole idea behind it right? Trying to get rid of the axle trying to stay parallel to the body, right? Obviously alot more going into to that like sway bars and springs and shocks, but all other things constant, it's going to sway more in corners. How much more - that you'll have to try to find out, might not be much, might be alot, never done it myself, so all I can say for sure, is it'll be more.

The I-beam - guess I forgot since you were talking about a 1/4" I beam since you were using 1/4" plate to rational that it was strong engouh Certainly could estimate what directions it'll be stressed in and do analysis on the moment of inertia, or could just try it. Course you also haven't said enough about the 1/4" I beam to really state that it's stronger. If the I beam is only 2" tall, and beams only 3/4" wide, vs. 1/2" plate that is 6" tall - well, you get the idea. Mostly I was just teas'n a bit on the weak rational, more than the choice of material

I look forward to seeing it. It's an interesting design, interesting enough that I came up with the V-link, which is esentially same thing mounted behind the axle.

Hopefully you don't think I'm hammering you. I mean, you wouldn't have posted up if you weren't open for discussion right?

 

[Ebag333]

I think we're talking two different rolls. Are you talking it rolling as in the axle rotating under torque? I'm talking about it rolling more in corners - cause you will have less sway resistance, I mean, that's kinda the whole idea behind it right? Trying to get rid of the axle trying to stay parallel to the body, right? Obviously alot more going into to that like sway bars and springs and shocks, but all other things constant, it's going to sway more in corners. How much more - that you'll have to try to find out, might not be much, might be alot, never done it myself, so all I can say for sure, is it'll be more.

We must be talking two different rolls.

Off road (and unpinned) I agree that you will have more movement of the axle, and more body roll. This may be a negative for the high speed runs folks do, though I doubt it'd be much worse than our poor man's 3 link (hitch pin mod). Worst case scenario, simply pin it in place for the high speed run, unpin it after (if needed).

On road the handling should basically match stock. The X-Link bar will be pinned in place (or should be, unless you like the body roll? ), and the X-Link bar will not move at all. If the X-Link bar isn't moving, then the radius arms shouldn't be moving any more than a stock truck. Springs, shocks, and sway bars should be the same, so apples to apples there.

Am I missing something that would cause more body roll in corners?

The I-beam - guess I forgot since you were talking about a 1/4" I beam since you were using 1/4" plate to rational that it was strong engouh Certainly could estimate what directions it'll be stressed in and do analysis on the moment of inertia, or could just try it. Course you also haven't said enough about the 1/4" I beam to really state that it's stronger. If the I beam is only 2" tall, and beams only 3/4" wide, vs. 1/2" plate that is 6" tall - well, you get the idea. Mostly I was just teas'n a bit on the weak rational, more than the choice of material

Yeah yeah, I figured as much.

The I Beam is 3" high, 2.4" wide, 1/4" thick.

The radius arms are 3" high, 1.25" wide, 1/2" thick (that's at their tallest spot, they're much shorter than that near the frame).

The axle is 4" tall.

I mention the axle because most of the pics you see, the X-Link arm is roughly the height of the axle. Most of them are either in a V shape or cut out, to save weight. So that means you have a roughly 3" to 4" tall sheet of 1/2" steel.

For strength, I'll put a 3"x2.4"x.25" I beam up against 4"x.5" sheet any day.


I'm probably shooting myself into the foot for any plans to sell it, but I got just over 5 feet of that I Beam for $26. 1/2" sheet ends up being far more expensive, because you need far more material to have the same strength. A bit over 5' is enough to do two X-Link arms.

Best mod under $100?

I look forward to seeing it. It's an interesting design, interesting enough that I came up with the V-link, which is esentially same thing mounted behind the axle.

I seriously considered something like your V-Link, but I just couldn't see a way to really make it work. Too much stuff back there to get in the way.

I'd much prefer it being behind the axle than in front.

Hopefully you don't think I'm hammering you. I mean, you wouldn't have posted up if you weren't open for discussion right?

Pffft, this ain't nuthin'. Let me introduce you to some real forum trolls, then I might have a cause for complaint.

Seriously though, I don't mind the feedback or even the hammering. Web wheeling is cheap, right? I'd rather have someone point out a serious flaw before I go and do it, than after.

 

[Walking Eagle]

We must be talking two different rolls.

Off road (and unpinned) I agree that you will have more movement of the axle, and more body roll. This may be a negative for the high speed runs folks do, though I doubt it'd be much worse than our poor man's 3 link (hitch pin mod). Worst case scenario, simply pin it in place for the high speed run, unpin it after (if needed).

On road the handling should basically match stock. The X-Link bar will be pinned in place (or should be, unless you like the body roll? ), and the X-Link bar will not move at all. If the X-Link bar isn't moving, then the radius arms shouldn't be moving any more than a stock truck. Springs, shocks, and sway bars should be the same, so apples to apples there.

Am I missing something that would cause more body roll in corners?

I think I'm misssing something. You're pinning the x-link in place? Since on the ones I've seen the axle brackets are cut off so they don't interfere with the arm moving, I'm not getting where you're pinning the x-link in place.

 

[Ebag333]

I think I'm misssing something. You're pinning the x-link in place? Since on the ones I've seen the axle brackets are cut off so they don't interfere with the arm moving, I'm not getting where you're pinning the x-link in place.

Just have some tubing that you put a hitch pin or something through, where one side is attached to the axle, one side to the X-Link. No big deal.

 

[Walking Eagle]

Just have some tubing that you put a hitch pin or something through, where one side is attached to the axle, one side to the X-Link. No big deal.

ah - well you mentioned pining it once or twice, but never really said what you ment by that. It may be a bigger deal than you think. It won't be exactly like stock, cause even pined it's going to flex slightly differently.

 

[Ebag333]

ah - well you mentioned pining it once or twice, but never really said what you ment by that. It may be a bigger deal than you think. It won't be exactly like stock, cause even pined it's going to flex slightly differently.

The only spot that will add flex will be the pivot point, but it's not going to be much. Couple of mm's maybe. Pinning it should eliminate even most of that.

I really don't see what else would cause flex. And even if you're talking about adding a few mm's here or there, it's still going to be nothing like a 3 link, or even removing a sway bar.

 

[-Spike-]

IF you could pin it so the x-link stays perfectly stationary to the axle, it should drive exactly like stock. The problem I see is that without some kind of double-shear pin setup, that pin is going to move back and forth, and get galled- allowing more movement and more deformation of the pin. Especially if you use a rubber bushing as the center pivot instead of a bearing or other rigid point. And I don't see any way to make the pin double-shear and still allow the x-link the movement it will need without the pin. But, I haven't seen any of your ideas, so maybe you've got that one figured out.

 

[Ebag333]

Well, the motor mount isn't going to allow all that much deformation of the rubber. It's pretty solid, so that will help limit the amount of flex in it.

My plan is to use as big a pin as I can get away with, and some 1/4" wall tubing for the sleeve. If it fits tight enough, it shouldn't be any worse than using a hitch pin in place of a front bolt.

Worst case scenario could "pin" it with a bolt and nut. Bit more difficult to put on or take off, but would really lock it into place and totally prevent movement.

 

[-Spike-]

The hitch pin is double shear.

The motor mount is going to allow deflection in all axis (Axia? Axii?), which is why I think the pin won't hold it perfectly. Even my hitch pin is wobbling out the holes in the axle mount, and it can't move much. I think it'll move more than you think, and even more as the pin, hole, sleeve and motor mount all wear. I'm not by any means trying to dissuade you, just pointing out an area that might need more consideration. I also think the Aussie guy who made the original spent a lot of time figuring out that center pivot, and IIRC had a couple of ideas fail before he came up with what he uses now. I'm more concerned with that than the pin. The axle side of the center pivot also concerns me, I'm afraid you're underestimating the amount of force that will be exerted there- but again, I have no idea what you have planned and I hope you prove my concerns unfounded as I really like the idea.

 

[Ebag333]

So I finally got off my duff and started working on this.

My old welder was a little 80 amp gasless MIG that could make very pretty welds on the 1/4" steel I have, but that's about it. Well it recently had an "accident" (my own stupidity killed the motor to feed the wire), and I needed a new welder as I was making a box to hold Bigfoot remains for my brother.

Found a 225 amp Lincoln arc welder on Craigslist, and snapped it up.

After doing my brother's box (out of 12 gauge metal) I figured I had gotten decent enough to give it a shot at welding up my X-Link. Worst case scenario I grind it out, right?

Well, it went something like this:

First pass:
"Oooooh! Pretty weld! This one is my best weld yet, great penetration, looks pretty...."

Second pass:
(I only put a second pass to fill the gap between the I Beam and the round stock.)
"Hmm, not very pretty, but good penetration. I know, I'll do a third pass and just make it pretty, not worry about penetration."

Third pass:
"OH....YOUR...GOD.....WHAT HAVE I DONE!"


So yeah, if my welds look horrible and ugly, it's just because they're hiding my nice welds. I guess I still have a thing or two to learn about arc welding.

Anyway, on to some pics.

Here's what I'm starting with. This is a 1/4" I-Beam, which is probably way stronger than I need. The shape of the I-Beam should keep it from twisting, which is a problem when using tubing (square or round) or just simple plate.

The pivot point. Honestly I wasn't worried about it breaking by just welding the round tubing straight to the I-Beam.....but I tend to do things overkill and so took some quarter inch plate and welded that on top.

Shot of the whole thing. Not much to it, really.

Here's the X-Link cross-member roughly in position. The pivot point will go roughly in the center of the axle (exactly in the center side to side, roughly up and down ;p ), and some brackets will go from each end of the X-Link bar to the front of the control arms.

While the bottom of the X-Link bar will be a bit below the axle, it'll still be higher than the pumpkin and the control arms themselves, and it's not that far below the axle (it's a bit lower than it needs to be in the pic). You're really not losing much clearance.

(And my knuckle really isn't that bad. Weird shadow making it look bad.....)

View of the X-Link from the sides.

For those worried it hangs out too far in front.....it's actually behind the two bars you already got in front. So it's really not any more exposed than anything else there.


One thing I am considering doing is taking some relatively thin metal (maybe 1/8") and boxing in the open side of the I-Beam. This would be primarily to prevent bashing it against a rock from bending the edges of the I-Beam, and creating a weak spot.

Honestly with 1/4" metal, and how (relatively) short the levers are there, I doubt it'll be an issue. But I'll probably do it anyway.


Larger photos can be found at:
http://picasaweb.google.com/ebagola/XLink#

 

[donutfj80]

Your center pivot looks damn close to the panhard bar. Will it touch flexed either way?