Just a little peek at the sliders
- Thread starter concretejungle
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concretejungle said:
"...will it really explode": I wouldn't know. Could it explode? Absolutely.
There have been many instances of compressed air vessels, designed by engineers to hold compressed air, failing explosively. The common causes are defective materials, defective construction, corrosion, physical damage, and over pressurization. Usually there are several independent mechanisms to prevent over pressurization, but sometimes simultaneous failures occur, and then the excitement happens. Sometimes the vessels fail even when not over pressurized. I would expect that the most common failures result in leaks, and not explosions. While I am not up on the details, I am aware that there is a substantial amount of codified engineering practices, based on past experience of failures, as to how compressed air vessels should be designed, manufactured, and tested.
If I wanted to carry compressed air, then I would use a proper air tank, preferably ASME rated for compressed air storage, mounted in a location least likely to be impacted by the ground or another vehicle, ideally with protection from a skid plate. I would not place the vessel in a location intended to hit and drag over rocks.
- Thread starter
- #46
Sangamo said:
If i was guessing i'de say pink
O.K. so i've decided not to put air in them. Everybody happy?
Thanks for the concerns though, seriously.
Dead Horse Beatdown:
I wouldn't trust DOM or EW tubing to hold pressurized air. Ever seen it split at the seam? Look at your air compressor, big round tank with fat welds and hemispherical ends/caps. Mine has a cutout at 135psi, think it was certified to 200psi, assuming that has big safety factor margin.
Pressure vessel design is a specialized field for a reason.
Sliders look good, keep in mind those thin, narrow gussets only help if they are loaded in tension.
tony
I wouldn't trust DOM or EW tubing to hold pressurized air. Ever seen it split at the seam? Look at your air compressor, big round tank with fat welds and hemispherical ends/caps. Mine has a cutout at 135psi, think it was certified to 200psi, assuming that has big safety factor margin.
Pressure vessel design is a specialized field for a reason.
Sliders look good, keep in mind those thin, narrow gussets only help if they are loaded in tension.
tony
Boy, are we bunch of pansies
For our sake, I hope none of us are:
- using the home grown front caster washer mod (no stress test or magnaflux for stress cracks or xray your welded beads)
-home made upper rear control arm adjustors (better have that welding xrayed)
-drive around w/o the front driveshaft/ABS(wasn't in the original design)
-add spacers in the wheel hubs (ever calculate the added leverage/stress on your bearings?)
-adjust the LSPV w/o using the proper pressure gauges
-weld on various skids and protection crap straight to the chassis frame (perhaps weaken the frame at the welding area? Better have it magnafluxed and xrayed)
.....
For our sake, I hope none of us are:
- using the home grown front caster washer mod (no stress test or magnaflux for stress cracks or xray your welded beads)
-home made upper rear control arm adjustors (better have that welding xrayed)
-drive around w/o the front driveshaft/ABS(wasn't in the original design)
-add spacers in the wheel hubs (ever calculate the added leverage/stress on your bearings?)
-adjust the LSPV w/o using the proper pressure gauges
-weld on various skids and protection crap straight to the chassis frame (perhaps weaken the frame at the welding area? Better have it magnafluxed and xrayed)
.....
I did my sliders off of George's design as well. There is one thing that I would do differently. I went ahead and built a bracket that mounts to the captured nuts on the frame alongside the cat. Getting this bracket to match up to the drilled holes was a serious pita. I bolted that outrigger on, tacked the out rigger in place, pulled the slider off to complete the welds and thought I was fine until I went to bolt the finished product back up. All of that heat moved that outrigger plate that matched to the captured nuts just enough to screw up my fit. Maybe it would be easier on a 93+, but for me ( I'm in an FJ80) I did cat back exhaust and raised the cat up out of the way and tried to use those captured nuts. I probably wouldn't do that again. Although, as I think of it, when I was looking for alternatives this seemed to be the best spot for the outrigger as far as strength goes. Don't plan on doing them again any time soon. For me, it was a lot of work. Then again, I was using a stick welder and a torch. The wire feed and plasma cutter that I use now would have made things much easier.
alia176 said:...
For our sake, I hope none of us are:
...
-weld on various skids and protection crap straight to the chassis frame (perhaps weaken the frame at the welding area?
...
Since you bring it up, that is actually a significant point. There are rather precise requirements to adhere to when welding vehicle frames if one intends to minimize weakening the frame.
At one point in time I reviewed an engineering document from Ford vehicle engineering, intended for third party firms that modify Ford vehicles (I.E. install custom truck bodies, beds, equipment, motorhomes, ambulances, etc) and it was very interesting to me to be aware of the various detailed considerations that exist regarding what portions of the frame were suitable for welding, the length of weld beads, the direction of the weld beads, which areas should have no welding, and the type of welding that should be used.
It really doesn't matter much to my what type of modifications others do on their vehicles. I do presume that some would like to a least understand what are the possible consequences, and equally importantly, what could be done to accomplish their objective and at the same time mitigate or eliminate adverse consequences. In other words benefit from wealth of engineering knowledge that has been accumulated over time, in many cases as a result of adverse consequences to others in the past.
- Thread starter
- #51
JB80, i know exactly what you are talking about on the captured nut plate for the slider that goes under the cat. I had it perfect, tacked the outrigger to it, removed it and finished welding it. When i put it back up there it had deflected about 2mm due to the heat. I used two VERY thin washers on the top nuts to compensate for the convex type surface.
By the way, i should have finished mounted and un-mounted pics by the weekend.
By the way, i should have finished mounted and un-mounted pics by the weekend.
Mike,
Same thing happened to me as well! Boy did my wife hear me cuss like a sailor when the last two bolts just wouldn't line up.
Does anybody have any creative but effective method of protecting the cats? This is on the two cats back to back vehicles, not side by side. I thought I saw a design where the front part of the cat skid uses the rear radius arm mounting bolt. Can't remember where the rear support goes to.
Ali
Same thing happened to me as well! Boy did my wife hear me cuss like a sailor when the last two bolts just wouldn't line up.
Does anybody have any creative but effective method of protecting the cats? This is on the two cats back to back vehicles, not side by side. I thought I saw a design where the front part of the cat skid uses the rear radius arm mounting bolt. Can't remember where the rear support goes to.
Ali
- Thread starter
- #53
Update
so here is a couple of finished pics. Thought i would need them this weekend but didn't. Came close a couple of times. Now, i have a little vibration issue with them. Not sure where, but i think i'll have that solved by the end of the weekend.
so here is a couple of finished pics. Thought i would need them this weekend but didn't. Came close a couple of times. Now, i have a little vibration issue with them. Not sure where, but i think i'll have that solved by the end of the weekend.
- Thread starter
- #54
few more.
- Thread starter
- #55
last few.
These look great ALex...I'd be interested in seeing pics. of in-action use, or post-action use and some analysis from you on how they handled...good stuff man--they look sharp.
Best.
-onur
Akron, OH
Best.
-onur
Akron, OH
- Thread starter
- #57
beno, i tried to use them this weekend, but to my surprise the cruiser was just high enough to miss the rocks. I was going to run at Kodak rock, which i'm sure i would have used them then, but with all the other crap that went down didn't have a chance to. I will for sure get some more pics and pics of them in use. My digi camera crapped out on my also this weekend........just to add to the list.
I gotta say that thinking a tube under 150 psi will explode when that tube is going to be expected to support a 6000 lb. vehicle teetering on a rock is pretty silly. Yes, my air tank in the shop is round and built to some engineering specifications, but it is built to take twice that pressure and is made of very, very thin steel. Even so, when i have seen air compressor tanks fail from rusting out from the inside, they leak. They do not explode.
i would not expect a slider to be able to fill a tire. i would be expect one to run ARBs or airbags though. I suspect you could air up a ways as well.
i will be cutting off my side bars shortly. They do not stick out nearly far enough and they don't have the Allpro-type kickout on the rear. After helping Bryon build a set, i need one for me. They are awesome on the trail. i will also be cutting off my cat skid plate. It's a big heavy mud catcher.
i am also a big proponent of the sandwich plates. Much easier to slide under the brake and fuel lines than a u-bolt and I take my sliders off a couple of times a year for repaints and modifications. there is no way i'm welding them on. i will happily weld to the frame. My 40 has stuff welded all over it. that's not a problem. i just want to be able to take them off when i want.
Just my opinion and experience, nothing more.
i would not expect a slider to be able to fill a tire. i would be expect one to run ARBs or airbags though. I suspect you could air up a ways as well.
i will be cutting off my side bars shortly. They do not stick out nearly far enough and they don't have the Allpro-type kickout on the rear. After helping Bryon build a set, i need one for me. They are awesome on the trail. i will also be cutting off my cat skid plate. It's a big heavy mud catcher.
i am also a big proponent of the sandwich plates. Much easier to slide under the brake and fuel lines than a u-bolt and I take my sliders off a couple of times a year for repaints and modifications. there is no way i'm welding them on. i will happily weld to the frame. My 40 has stuff welded all over it. that's not a problem. i just want to be able to take them off when i want.
Just my opinion and experience, nothing more.
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- #59
Gumby said:Even so, when i have seen air compressor tanks fail from rusting out from the inside, they leak. They do not explode.
i am also a big proponent of the sandwich plates. Much easier to slide under the brake and fuel lines than a u-bolt and I take my sliders off a couple of times a year for repaints and modifications. there is no way i'm welding them on.
Gumby i agree about them not exploding. Just not worth the trouble any dealing with it now.
I hear you loud and clear on the sandwich plates. I might switch to that. I don't like the bolts running under the brake lines. These sliders are very nice, but they are also kind of experimental. They will evolve as my ideas for them do.
I did destroy a cat bashing it on rocks, but much more frustrating has been smashing the under frame part of the exhaust right after the cats. If i keep the exhaust running under there and not over the frame, I will be building a slider for that part as well.