Home built independent suspension?

[JPK]

We do steam power generation, typically co-gen.

We also do air exposed high pressure welds as well as shielded welds. Stainless, aluminum, they need sheilding, but not carbon steel. When our guys do shielded welds they don't use nitrogen though, they use helium, which can be stored at ambient temps. The sheilding is to prevent oxygen from fueling burn.

I think using nitrogen lowers temp differential by limiting the heat to a very small area and not allowing the larger "body" of the pipe or pressure vessel to get hot, or even warm, to prevent warping. Think of it this way: Everything is close to the temp of the liquid nitrogen, except the relatively small area actually welded.

But like I said, I'm no expert on welding.

JPK

BTW, they also nitrogen it to freeze hot/cold water and condensate (highly treated water) so they can weld without shutting down a system. But that is a different topic.

 

[JPK]

Our guys speak in terms of thousands of lbs of steam/hour, many zero BTU's, grossly huge HP numbers too.

I'll ask our superintendent who oversees our welders what's up with the nitrogen today, and what they do with it to reduce/minimize distortion.

JPK

 

[UK4X4]

really as long as the arms are held in place securely and welds are done -properly


Tack all components in place first then wled in short spurts rotating arround the job, ie 1 end then the other reducing heat on the whole item to a minimum

Trailer wheel alignment is not a huge issue lake a front wheel drive car.

toe in and camber can be adjusted if the mounts bolt onto the frame.

good idea is to make the two arms while the axle is in one piece then cut out the middle.....

ie its easier to make a large one piece accurate rather than try and make two pieces the same

Most landy frames can be about 1/4 to 1/2 " out from end to end diagonals.....but they still drive ok !

 

[Paladin]

I can tell you right now, in the automotive industry, if tight tollerances need to be held on weldments, the weldment is not the finished product. It either gets bent or tweaked in some way, or the important points are machined after welding.

 

[reece146]

really as long as the arms are held in place securely and welds are done -properly


Tack all components in place first then wled in short spurts rotating arround the job, ie 1 end then the other reducing heat on the whole item to a minimum

Trailer wheel alignment is not a huge issue lake a front wheel drive car.

toe in and camber can be adjusted if the mounts bolt onto the frame.

good idea is to make the two arms while the axle is in one piece then cut out the middle.....

ie its easier to make a large one piece accurate rather than try and make two pieces the same

Most landy frames can be about 1/4 to 1/2 " out from end to end diagonals.....but they still drive ok !

This ^^^

Just apply good shop practice and get on with it.

You are building a trailer, not a replacement for the space shuttle.

 

[Martyn]

really as long as the arms are held in place securely and welds are done -properly


Tack all components in place first then wled in short spurts rotating arround the job, ie 1 end then the other reducing heat on the whole item to a minimum

Trailer wheel alignment is not a huge issue lake a front wheel drive car.

toe in and camber can be adjusted if the mounts bolt onto the frame.

good idea is to make the two arms while the axle is in one piece then cut out the middle.....

ie its easier to make a large one piece accurate rather than try and make two pieces the same

Most landy frames can be about 1/4 to 1/2 " out from end to end diagonals.....but they still drive ok !

I agree with you on the land Rovers :sombrero:

We have found major improvements in towing when toe in and camber is adjusted correctly. It's one of those things that you won't notice if it's correct, but on a responsive trailer you will notice it when it's off.

 

[Bluewater Australia]

Just if it helps anybody, I built a custom trailer using a known manufacturer's swing arms (local here - and from what I've seen of how they manufacture them there's no way I would try to replicate that in the shed!); and these airbags, these shocks (remote reservoir and 8" travel), limiting straps and hydraulic jounce shocks, which I haven't seen anybody else use on a trailer yet. They're in front of the straps out of sight in the paint-stage photo. So far so good, been over some rough country in the last year and all good. Still figuring out the ideal air pressure for the bags but so far it's lower than I thought, then a bit lower again, and maybe still lower than that. The trailer weighs around 1200kg loaded (2600lb)ish.

 

[Bluewater Australia]

Another pic from the front tells a bit more:

 

[wannabridin]

Looks good!! Do you have anymore info on those swingarms?? They are quite interesting!

 

[Greenmonkey]

So UK4x4, how long did it take for your poly bushings to show sings of wear? What type of bushing would work better? Does any one know what AT uses for bushings? I'm currently in the process of trying to design my adjustable trailing arm suspension, so this thread is awesome. There are a lot of great ideas and input here.

 

[Bluewater Australia]

Do you have anymore info on those swingarms??

Made in Western Australia - see http://www.trailerparts.net.au/pamphlets/Gaffa_Suspension__1_.pdf

and http://www.trailerparts.net.au/pamphlets/GAFFA_POSTER.pdf

 

[fxk142]

Too bad their kit is $1900 AUS and then shipping would kill you too.

 

[UK4X4]

The bushing are'nt worn yet- they just deform slightly

which i suppose they are meant to do

I take the whole trailer apart for shipping and re-assemble in each country we visit

they just get greased and put back in

They just deform about 2mm or a 1/6th of an inch - the inner one

same as the set of arms that failed the inner hinge point gets more stress.

lots have used just bolts and relied on the steel -steel connection

I used bushings as most suspension systems use them !

I can always replce with a bronze bushing or more solid nylon if required but I'm almost four years in and no damage

 

[JeepDork]

which is the best?

So which is the best? As well as not $2000 to build. I think the live axle with a min weight leaf spring with an air bag as the main means of suspension should work great. Use all the positive aspects of the live axle leaf spring set up without the draw backs. Live axle leaf spring to locate the axle and hold the empty weight of the trailer as well as control axle wrap with braking. Then use airbags to adjust for the load. This would also give you ability to level side to side even with the solid axle. I have 1600# springs on a 1400# empty trailer. If I ever get this thing done we'll see if I'm right! Any idea's??

 

[ntsqd]

What is right in one use can be wrong in another. I'm biased against using more than one type of spring in a suspension system because that makes getting the damping correct a near impossible task. Some might say that ride quality in a trailer isn't that big of a deal and I will disagree. It's true that a trailer need not ride like a Cadillac since presumably there are no humans in it, but it is equally true that a trailer must ride smoothly enough to not beat up it's contents. (Broken eggs in a cooler pretty much suck.)
If you think about it, the mounts needed for leaf springs are not much different from the mounts needed for linkage. Both need to be robust enough and have enough support structure to handle the loads imposed on them. The only linkage consideration above and beyond building leaf spring mounts is setting up linkage that doesn't lock-out suspension motion while under braking.

No matter what a solid axle will share a bump at one wheel with the other wheel. True independent suspension disconnects one tire from the other unless the bump is great enough to send an impulse thru the chassis. How important this is to a trailer I do not know, but I do know that it is a ride quality consideration.