off road tear drop trailer build

[colemancooler]

I have been planning this for a while now and do not have a job, but recently came into some $ and am itching to get started. the first issue I have run into is the trailer will most likely be under 1,500lbs and the only way I can buy a pre made axle with 6 on 5.5 bolt pattern, is to buy a 3,500lb axle, the over kill would be ok, but the ride would SUCK!, I am also considering an independent custom air bag suspension



which might nickle and dime me to death

[colemancooler]

[TJDave]

That is cool!


You should bring it to the Dunes and jump it before you build the bed!!

[79chevy39.5's]

How are you going to relate the pressure in the bags? 2 lines from the truck like glad hands on a sure brake trailer?

And won't the uphill side unload something fierce without constantly messing with one side out the other author done serious shock valving?

[benw]

You can just get the 3500 pound axle and use some lighter springs. The axle itself isn't going to affect the ride.

If you want it to ride smooth I would suggest using some nice long toy ota or jeep springs instead of the super short trailer springs.

Use a drop axle flipped upside down for better ground clearance.

[tobyw]

Exactly what Ben said... Find yourself some longer/softer leaves and proceed. It's a TRAILER. Independant air bag suspension seems just a tad over the top, with no real benefit... If you find yourself arriving at camp with your fine china and wine glasses all busted up, do a better job packing it.

[colemancooler]

I was thinking self leveling, with a tee to connect both bags for even adjustment, and can be closed for individual adjustment, the bags I am looking at Have 9.7 inches of travel where trailer springs ( very short) springs only offer 2. the above pics are not mine just the style I want to build

[colemancooler]

more info here
http://www.adventuretrailers.com/suspension.html

[Grumpy]

I am by NO means an expert on this stuff, but Ben and Toby have a point. Stick to the K.I.S.S. theory

[White trash]

Bags that are connected will push all the air to the high side bag. Only way to keep it equal on offcamber situations is to run a single fill/dump solenoid and a single open/closed solenoid on each bag. That complicates it, I'd K.I.S.S. it and just run coils if you are dead set on being independent. If not a trailer axle with mazda leader would do it all and be simple.

[benw]

If not a trailer axle with mazda leader would do it all and be simple.

Whut?

[White trash]

If not a trailer axle with mazda leader would do it all and be simple.

Whut?

My phone is so smart I look dumb half the time.

I meant mazda leaf springs.

[colemancooler]

you guys are making this way more complicated than it is



highly technical drawing

[Wrench]

Independent suspension can get very complicated with the alignment issues you will have. I think the solid trailer-specific axle with air bags is a much better idea, combined with your simple schematic above.

The good trailer axles implement some positive camber built in. You will see this as the axles look like they were jacked up in the center and bent slightly.

Make it even more simple, though. No need for two valve stems on the air bags. Just close the center valve to lock the air transfer when in use.

[colemancooler]

without the valve stems there is no leveling for sleeping flat

Shock, Absorption, and Rebound: A trailer equipped with leaf springs shock absorbers, and a solid beam axle will tip sideways, shifting the trailer contents, when one tire goes over an obstacle. The tipping is a result of both the left and right sides of the trailer being connected by the axle, the spring's lack of articulation, and stiffness.

After the tire cleared the obstacle the shock resulted in rebound as the leaf springs tried to dissipate the energy and the shock absorber tried to dampen it.

some of the info from the link i posted earlier in regards to ifs suspension vs single axle suspension

in the second photo i posted, they used a normal trailer axle placed where they wanted it, built the suspension to it, and then cut the axle after the suspension was built, alignment problems solved as long as you don't skimp on your suspension design

[Wrench]

without the valve stems there is no leveling for sleeping flat

Shock, Absorption, and Rebound: A trailer equipped with leaf springs shock absorbers, and a solid beam axle will tip sideways, shifting the trailer contents, when one tire goes over an obstacle. The tipping is a result of both the left and right sides of the trailer being connected by the axle, the spring's lack of articulation, and stiffness.

After the tire cleared the obstacle the shock resulted in rebound as the leaf springs tried to dissipate the energy and the shock absorber tried to dampen it.

some of the info from the link i posted earlier in regards to ifs suspension vs single axle suspension

in the second photo i posted, they used a normal trailer axle placed where they wanted it, built the suspension to it, and then cut the axle after the suspension was built, alignment problems solved as long as you don't skimp on your suspension design

Though the airbag leveling system sounds like a good idea, I think you will find it to be the opposite. Leveling jacks are a much better idea, because they will also prevent the bouncing and rocking that happens when you shift or move while sleeping, but airbags will not. I know it drives me crazy even in a full-sized travel trailer that does not have the jacks lowered.

As far as the rocking situation goes (solid axle vs independent), I dont think the design will make a whole lot of difference, though I believe spring rate and proper shocks will make a world of difference.

I really like how they solved alignment issues. Sounds really good, as long as the pivot points dont wear and move the alignment off, and hope that nothing ever gets bent. Those side-loaded swingarms need to be very STOUT to prevent any twisting, though!

[colemancooler]

i decided to keep it simple
i got tires and wheels for $40, and mounted them up, measure 29.5"


the axle is on order, and should be here in a week or so

[Livin4Today]

Bags that are connected will push all the air to the high side bag.

Actually it would be the low side that the air would go to, least resistance... The trick here would be "the right pressure" obviously based on weight. After reading alot on the AT site, I wondered how you were going to manage the rebound as their design eventually worked through to a point the actually used a shock within the bag...

[colemancooler]

any good trailer suspension uses a shock

[White trash]

Bags that are connected will push all the air to the high side bag.

Actually it would be the low side that the air would go to, least resistance... The trick here would be "the right pressure" obviously based on weight. After reading alot on the AT site, I wondered how you were going to manage the rebound as their design eventually worked through to a point the actually used a shock within the bag...

Ok this I gotta hear. How would the air be forced into the lowside bag on a side hill? If that were true the trailer would self level.


They make what they call an airstrut that essentially an airbag around a shock. Priced out of reason for this application though. Adding a pair of shocks to the suspension is never a bad idea.

[Livin4Today]

Ok this I gotta hear. How would the air be forced into the lowside bag on a side hill? If that were true the trailer would self level.

Simple Mechanics, sure you have 1 pressure throughout the system, as the low side drops more space or volume is created, and as the high side is compressed the air should like liquid follow the path of least resistance...

Hey, I ain't no scientist, just a redneck with his first Jeep, however, I've had past toys that had some engineering ingenuity within...

[tobyw]

Ok this I gotta hear. How would the air be forced into the lowside bag on a side hill? If that were true the trailer would self level.

Simple Mechanics, sure you have 1 pressure throughout the system, as the low side drops more space or volume is created, and as the high side is compressed the air should like liquid follow the path of least resistance...

Hey, I ain't no scientist, just a redneck with his first Jeep, however, I've had past toys that had some engineering ingenuity within...

Paitiently waiting for the other shoe to drop here...

[Grumpy]

[White trash]

Ok this I gotta hear. How would the air be forced into the lowside bag on a side hill? If that were true the trailer would self level.

Simple Mechanics, sure you have 1 pressure throughout the system, as the low side drops more space or volume is created, and as the high side is compressed the air should like liquid follow the path of least resistance...

Hey, I ain't no scientist, just a redneck with his first Jeep, however, I've had past toys that had some engineering ingenuity within...

You've never played with water balloons have you? Fill it halfway so it is flexible and hard to pop. That is your nominal pressure. Now holding it with both hands squeeze with one hand and observe that the hand applying no increased pressure now has a larger volume of water in the balloon vs the aide you compressed. The hand you compressed the balloon with is the low side of the trailer that has more weight on it due to a sidehill. Generic basic 6th grade science in action.

[Livin4Today]

Ok this I gotta hear. How would the air be forced into the lowside bag on a side hill? If that were true the trailer would self level.

Simple Mechanics, sure you have 1 pressure throughout the system, as the low side drops more space or volume is created, and as the high side is compressed the air should like liquid follow the path of least resistance...

Hey, I ain't no scientist, just a redneck with his first Jeep, however, I've had past toys that had some engineering ingenuity within...

You've never played with water balloons have you? Fill it halfway so it is flexible and hard to pop. That is your nominal pressure. Now holding it with both hands squeeze with one hand and observe that the hand applying no increased pressure now has a larger volume of water in the balloon vs the aide you compressed. The hand you compressed the balloon with is the low side of the trailer that has more weight on it due to a sidehill. Generic basic 6th grade science in action.

You are clearly a thinker, and I am mechanically minded, we simply have a difference in how we visualize the same reality... Mechanically speaking the high side would be the that in which the tire is buried in the well, and the low side would be that with massive clearance of the well.

I get the whole squeezing 'ballons' thing (I am nearing 50, and done that a time or few), but you might wanna re-read your example, I think if you look at it (or read it really slow), you'll see we are just looking from different perspectives, yet in agreement on the science...