Not sure if I'll go that way, but I updated with the double tube, flat oriented cross member and the axle center tower.
CK5
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Rear Links - And so it begins - finally!
- Thread starter BadDog
- Start date
Whatever Russ...... just post up some more pics!!! 
Don't forget to take some "long" shots along with all the closeups. It will help the rest of us understand the overall suspension layout, and will better clarify the more close-up, detailed shots.
That is all.
Don't forget to take some "long" shots along with all the closeups. It will help the rest of us understand the overall suspension layout, and will better clarify the more close-up, detailed shots.
That is all.
Nothing there is thicker than 1/8" and it's all essentially sheetmetal pieces cut & welded together.
The problem I have with the basic arched tube design is that there are three 'hinge points' in it. One at each join of the round tube(s) to the square tubes, and one in the round tube(s) it/themselves (opening/cosing the existing bend).
The flexing of the driveshaft arch is not going to go away until one of the current design constraints is removed. It can be mitigated somewhat though. That is why I wondered about moving the link mounts closer to the rails.
Bring triangulation down from cage structure to the center of the top of the driveshaft arch. That will considerably strengthen it no matter which design you opt for, though it will still be a point of flex. But perhaps we can move the load required to flex it beyond what is reasonable to expect to see there.
Overkill, who, ME?
The problem I have with the basic arched tube design is that there are three 'hinge points' in it. One at each join of the round tube(s) to the square tubes, and one in the round tube(s) it/themselves (opening/cosing the existing bend).
The flexing of the driveshaft arch is not going to go away until one of the current design constraints is removed. It can be mitigated somewhat though. That is why I wondered about moving the link mounts closer to the rails.
Bring triangulation down from cage structure to the center of the top of the driveshaft arch. That will considerably strengthen it no matter which design you opt for, though it will still be a point of flex. But perhaps we can move the load required to flex it beyond what is reasonable to expect to see there.
Overkill, who, ME?
Greg: It's kinda hard to get long shots due to where the buggy sits. It's sorta like it's got walls all the way around.
ntsqd:
I know what you mean about the arch. I can fix 2 of them (on each side) with a simple triangulation a few inches out on the cross member. But that arch top is what worries me a little. I'm just not sure how critical it is. Yes, it will flex, but to the point of failure or compromise? Not sure...
And I know what you mean about the constraints too. That "no good solution I'll be happy with" feeling is one of the things that's kept me from getting moving for so long. I guess I could get some 1/8 x 8" flat steel to build the cross member you designed, but then piercing it for all the stuff is going to require a LOT of effort to keep it stable, and I'm not really sure how much internal support would be needed to support in the areas of the link mounts to keep them from distorting it. Frankly, I'm afraid I would screw it up. Through tubes, laminates, internal bracing around the link mounts, and so on. I've also been considering a composite of yours and mine where I would build only the center section your way (instead of tube arches) and allow the bending moment of the 2 x 3 to control the forces (basically, just try to keep it from all going to the arch).
Looks like it's going to be raining AGAIN, so I'll have more time to mull it over I guess. What's up with this, I thought this was the freaking desert? It's rained almost every single day that I have had to work on this since I decided to force myself to get on it.
Thanks for the suggestions.
ntsqd:
I know what you mean about the arch. I can fix 2 of them (on each side) with a simple triangulation a few inches out on the cross member. But that arch top is what worries me a little. I'm just not sure how critical it is. Yes, it will flex, but to the point of failure or compromise? Not sure...
And I know what you mean about the constraints too. That "no good solution I'll be happy with" feeling is one of the things that's kept me from getting moving for so long. I guess I could get some 1/8 x 8" flat steel to build the cross member you designed, but then piercing it for all the stuff is going to require a LOT of effort to keep it stable, and I'm not really sure how much internal support would be needed to support in the areas of the link mounts to keep them from distorting it. Frankly, I'm afraid I would screw it up. Through tubes, laminates, internal bracing around the link mounts, and so on. I've also been considering a composite of yours and mine where I would build only the center section your way (instead of tube arches) and allow the bending moment of the 2 x 3 to control the forces (basically, just try to keep it from all going to the arch).
Ding ding ding! Hadn't thought of that! I can do that relatively easily, there is a big cross bar almost directly over it (in pics, behind the seat). I've got some hard bushing assemblies I could use there, and I could pull the bolt as an experiment to see just how much it does move for future reference. Hmmm, I think I like…
Looks like it's going to be raining AGAIN, so I'll have more time to mull it over I guess. What's up with this, I thought this was the freaking desert? It's rained almost every single day that I have had to work on this since I decided to force myself to get on it.
Thanks for the suggestions.
The $64 question. W/o being overly anal-retentive about it I say build it as stiff as you/we can figure out and see what happens.BadDog said:
If you're going to do that, I'd use the bent round tubes and plate to their centerline normal to the plane of the bend. Turn the bent tubes into the "U" shaped piece of my design.
Yep, thought of that too. Already figured on welding the 2 tubes together. Problem is, I have no way of making a bend in flat stock of the right radius. Maybe time to build a ring roller... And a "bend the hard way" arch to go between them is definitely outside my capabilities. I guess I could cut an arch instead of bend it, but I would need to find a piece of plate steel big enough. Shouldn't be too hard, might even cut up my replacement skid plate material for it. Would be nice if I could get the arch between the tubes in 1/4" or something, then plate over the top of all 3 like a "T" bent to run over the hoop. With the tubes welded inside that, it would be very rigid I think.
Realistically, it's probably going to be the 2 tubes welded together with a bushed support to the bar above and some buttress gussets on each side. Seems a decent compromise of easy and sufficiently strong (guessing of course). Second runner up (and not out yet) is a more constructed arch that we've been talking about. I'll have to go out and look at the steel I have and do some pondering…
Realistically, it's probably going to be the 2 tubes welded together with a bushed support to the bar above and some buttress gussets on each side. Seems a decent compromise of easy and sufficiently strong (guessing of course). Second runner up (and not out yet) is a more constructed arch that we've been talking about. I'll have to go out and look at the steel I have and do some pondering…
Oh, I misunderstood. I thought you were talking about a composite of the 2 designs with improvements to the rigidity of the arch alone (which is really the only potential problem area in my mind). I do like that change though.
But if built with the 1/8" stuff, that gets us back to piercing (along with tubing the holes through to maintain integrity) and internal structure to support the link brackets. I don't think it would hold up as a simple box design with the link brackets mounted to the surface. I like the design, I just think it would be beyond my ability to carry off successfully. I think the only way I would tackle something that much more complex and time consuming (by the time you work out the inner structure and at least 3 piercings) would be if I knew (or strongly suspected) that other simpler designs would not be up to the task, or if I really needed the strongest/lightest design possible (like for a baja truck). I don't see anything right now that suggests the need for that level of design, especially when this is probably not the final product that must hold up for many years (still considering future buggy).
But if built with the 1/8" stuff, that gets us back to piercing (along with tubing the holes through to maintain integrity) and internal structure to support the link brackets. I don't think it would hold up as a simple box design with the link brackets mounted to the surface. I like the design, I just think it would be beyond my ability to carry off successfully. I think the only way I would tackle something that much more complex and time consuming (by the time you work out the inner structure and at least 3 piercings) would be if I knew (or strongly suspected) that other simpler designs would not be up to the task, or if I really needed the strongest/lightest design possible (like for a baja truck). I don't see anything right now that suggests the need for that level of design, especially when this is probably not the final product that must hold up for many years (still considering future buggy).
I can see those points.
What I would do for the link mounts is to pierce the xmember for square or rect. tube and weld them to both sides of the xmember. Then maybe cap the mount tubes if I felt like it.
For holes like the exhaust might need you could likely use muffler moly for the sleave. The loads on it won't be very high, just want to keep the sides from caving in.
Updated the pic above.
Got a glimpse of why things happen VERY slowly around my place?
What I would do for the link mounts is to pierce the xmember for square or rect. tube and weld them to both sides of the xmember. Then maybe cap the mount tubes if I felt like it.
For holes like the exhaust might need you could likely use muffler moly for the sleave. The loads on it won't be very high, just want to keep the sides from caving in.
Updated the pic above.
Got a glimpse of why things happen VERY slowly around my place?
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LOL, tell me about it! I been talking about doing this for about a year or so, see how far I got?
Thanks for the pic, that's pretty much exactly what I had in mind.
Looks like more rain so nothing much is going to get done in the next few days. I'll update when I have something to show. Thanks for all the discussion, some people consider this "too much talk", but I love this stuff!
Thanks for the pic, that's pretty much exactly what I had in mind.
Looks like more rain so nothing much is going to get done in the next few days. I'll update when I have something to show. Thanks for all the discussion, some people consider this "too much talk", but I love this stuff!
Updated the progress page.
Check out these spring mounts.
Check out these spring mounts.
Just so that it can't be said that I should have mentioned it b4 it's too late, have you considered using coil-over coil springs? You don't have to have the damper to use them. They come in a huge range of spring rates, directly interchange with each other, and are $50 to $70 a pair. Most of the dez racer vendors will exchange unblemished pairs so that you can dial in the spring rate w/o having to buy 67 pairs of unneeded springs.
Food for (more) thot......
Also, SpiderTrax uses these springs on their front Sami link kit and they hold the spring in place, top and bottom, with little U-bolts. A pair on each end of the spring. Each spring plate has 4 holes drilled in it. Simple, easy, and cheep.
Food for (more) thot......
Also, SpiderTrax uses these springs on their front Sami link kit and they hold the spring in place, top and bottom, with little U-bolts. A pair on each end of the spring. Each spring plate has 4 holes drilled in it. Simple, easy, and cheep.
Thought never crossed my mind. Never looked into them, what diameters and lenghts available? Guess I'll be doing some sniffing (googling) today. Thanks.
Thanks for the suggestion, it was a good idea. Unfortunately, nothing local can match that price, and none support the free exchange even at that. I'm looking at $85 to well over $100+ per pair with no exchange option. To get that price requires mail-order with associated shipping and delays. So, ever the tightwad, I guess I'll continue with the V8 ZJs for now. If it won't work acceptably, it should be easy enough to switch to the commercially made springs by simply reducing the size of the coil locator tube. The top bump stop tube is 2" exactly anyway, so removing the top and bottom 3" tubes and replacing the bottom with a 2" should get me into off the shelf coil-over spring territory easily enough. And I'll also have a better idea where I need to go to avoid extra coils and/or round tripping.
Time to put another mark for me in the "Well duh!" category.
I was just under the truck this evening looking at what to do for the front cross member. Not really happy with the "sure thing" stability of my solution but not wanting to deal with the new problems of better solutions. Then it hit me, THE ANGLES ARE DIVERGING! Frame is going down at 12*, and the drive shaft is going up at about 16*(estimate). AND I had been looking at the point I had marked for the center of the rod end eye as the back side of the cross member (double Duh! and OOPS!) So all I really need to do is add about 2" to my links to get the cross member clear at static height. Then kick the 3" wide tube down horizontal (12*) to pick up another 1/2 or so of clearance, which should be almost enough that close to the pivot u-joint. And if testing reveals that it is too close, maybe french in the corner of the square tube right under the drive shaft if I need to for a bit more clearance. Basically just cut the closest corner off, about 4" wide and right in the center, then replate with some 1.5" strap or something at about 30* down slope.
So, I've got almost everything cut except the actual link bracket plates for the cross member. I'll probably cut those tomorrow, and drill lots of holes, plus some bevel clean-up to help deal with limitations of my welder on this heavy steel. Some of it is 1/2" to 1/2" which is a bit much for my little MM175, first time I've really wished I'd gotten a 210. No big deal, just some multi-pass and a little pre-heat required, so it wouldn't really justify the extra cost, but a 210 would be sweet just the same.
Supposed to rain tomorrow, but I'm hoping for a sunny Saturday for a change. If so, I might just get it all welded together...
I was just under the truck this evening looking at what to do for the front cross member. Not really happy with the "sure thing" stability of my solution but not wanting to deal with the new problems of better solutions. Then it hit me, THE ANGLES ARE DIVERGING! Frame is going down at 12*, and the drive shaft is going up at about 16*(estimate). AND I had been looking at the point I had marked for the center of the rod end eye as the back side of the cross member (double Duh! and OOPS!) So all I really need to do is add about 2" to my links to get the cross member clear at static height. Then kick the 3" wide tube down horizontal (12*) to pick up another 1/2 or so of clearance, which should be almost enough that close to the pivot u-joint. And if testing reveals that it is too close, maybe french in the corner of the square tube right under the drive shaft if I need to for a bit more clearance. Basically just cut the closest corner off, about 4" wide and right in the center, then replate with some 1.5" strap or something at about 30* down slope.
So, I've got almost everything cut except the actual link bracket plates for the cross member. I'll probably cut those tomorrow, and drill lots of holes, plus some bevel clean-up to help deal with limitations of my welder on this heavy steel. Some of it is 1/2" to 1/2" which is a bit much for my little MM175, first time I've really wished I'd gotten a 210. No big deal, just some multi-pass and a little pre-heat required, so it wouldn't really justify the extra cost, but a 210 would be sweet just the same.
Supposed to rain tomorrow, but I'm hoping for a sunny Saturday for a change. If so, I might just get it all welded together...
yunit
1/2 ton status
Anyone planning to run the new 2.5 Fox Shox when they come out? I think that I may go this route to make mounting the suspension a little easier.
I was thinking about them, but for the cost, necessary support equipment, and drawbacks described on PBB as well as talking with some of those who have run them, I just don't think it's a good path. If I was going that far and that expensive, I think I would just have to buck up and go on to coil-overs. And you guys know how cheap I am, if that tells you anything...
I updated the progress page with the latest rendering of my (hopefully) final cross member. You can read the description there, but here is a pic for the lazy (upper bracket bracing not shown).
I updated the progress page with the latest rendering of my (hopefully) final cross member. You can read the description there, but here is a pic for the lazy (upper bracket bracing not shown).
sled_dog
1 ton status
yunit said:
Look in Pirate Gen Tech. There have been a few threads about them. Like was noted, you can only really support as much weight as the seal will allow. Too much pressure on the seal it doesn't matter what size the shock is its gonna fail. I forget who it was, one of the vendors selling them seems to really hate and look down on airshocks. I'm going coil springs in the rear and whenever I have the funds I will coilover the front and replace the coils with coilovers.
Well, in spite of 3 days of rain (did someone move me to Seattle and not tell me?) I've got everything cut out and drilled. Should start the main welding tomorrow. But I have one more question.
As you can see from the images on my progress page (and here), some of my link brackets are rather tall, others are not so tall. Each of them has at least 2, and one has 3 link mounting positions. For each of them, I'll be making a spacer to bolt into the unused position to help lend 3D rigidity to the piece. Easy enough, it just cost me 4 extra 3/4" G8 bolts and nuts and some tube.
I'm also planning on welding some bits of strap/plate across the parallel brackets anywhere it won't interfere with the rod ends to act as shear planes. But I'm wondering, which of them really needs it, and which ones will be over-kill. I'm getting fairly tired of cutting plate, and I'm sure I'll be getting tired of welding before it's over with. The upper brackets on the axle and on the cross member are very tall, and I've already cut out shear plates for axle towers as well as one to go between and tie them together. And I'm definitely adding them at least on the back of the cross member uppers, and maybe on the lower ramp coming up too.
Finally, considering triangulating those tall upper-outer cross member brackets back into the frame to reduce torque load on the 2x3x0.188 cross member. Sort of like those shown in the image (which are no longer in the plan) but moved up near the top of the brackets. But is it really needed since they are so close to the ends that are mounted to the frame? The actual cross member to frame mate will be done with a 7" piece of 2 x 0.250 angle iron that is bolted twice through the bottom lip with 1/2" G8 bolts and once through the vertical wall of the rail also with 1/2" G8.
As you can see from the images on my progress page (and here), some of my link brackets are rather tall, others are not so tall. Each of them has at least 2, and one has 3 link mounting positions. For each of them, I'll be making a spacer to bolt into the unused position to help lend 3D rigidity to the piece. Easy enough, it just cost me 4 extra 3/4" G8 bolts and nuts and some tube.
I'm also planning on welding some bits of strap/plate across the parallel brackets anywhere it won't interfere with the rod ends to act as shear planes. But I'm wondering, which of them really needs it, and which ones will be over-kill. I'm getting fairly tired of cutting plate, and I'm sure I'll be getting tired of welding before it's over with. The upper brackets on the axle and on the cross member are very tall, and I've already cut out shear plates for axle towers as well as one to go between and tie them together. And I'm definitely adding them at least on the back of the cross member uppers, and maybe on the lower ramp coming up too.
Finally, considering triangulating those tall upper-outer cross member brackets back into the frame to reduce torque load on the 2x3x0.188 cross member. Sort of like those shown in the image (which are no longer in the plan) but moved up near the top of the brackets. But is it really needed since they are so close to the ends that are mounted to the frame? The actual cross member to frame mate will be done with a 7" piece of 2 x 0.250 angle iron that is bolted twice through the bottom lip with 1/2" G8 bolts and once through the vertical wall of the rail also with 1/2" G8.
