Boat tail project based on a single wheel trailer...

[COcyclist]

Originally Posted by aardvarcus

It is hard to tell from the pictures, but how close is the shock mount on the hitch side (not trailer side) to the pivot point? The further the shock is from the pivot point (in the front/back direction) the more the shocks will travel with respect to the angle. If the mount is close to the pivot from a front/back perspective, you may want to move it closer to where the hitch mounts. I would hate to see all that work to not have the shocks travel enough to provide adequate damping.

Also, you will probably want to make sure that at the normal resting position on flat ground the shock is roughly in the middle of it's travel. That way the shocks won't over extend/compress if you drive over a sharp change in slope on the road.

I agree. It looks like the top of the shock should be lowered as well making it more horizontal and giving better shock travel and damping as the trailer rotates on the pivots.

[BamZipPow]

Originally Posted by aardvarcus

Looking good! I am assuming the PVC was just for mockup and will be replaced with a bolt and some washers.

It is hard to tell from the pictures, but how close is the shock mount on the hitch side (not trailer side) to the pivot point? The further the shock is from the pivot point (in the front/back direction) the more the shocks will travel with respect to the angle. If the mount is close to the pivot from a front/back perspective, you may want to move it closer to where the hitch mounts. I would hate to see all that work to not have the shocks travel enough to provide adequate damping.

Also, you will probably want to make sure that at the normal resting position on flat ground the shock is roughly in the middle of it's travel. That way the shocks won't over extend/compress if you drive over a sharp change in slope on the road.

Yes, the PEX pipe was only fer mock up purposes and not fer road use. I'll have to hunt down some 5/8" OD tubing and see what bolt will fit through that tubing. I know I want to have some spacers welded to the 2" to 1.25" adapter so it will be better able to handle the associated stresses. The tubing will then be passed through the adapter and welded in place. A grade 8 bolt will keep the shocks secured on the mount.

I measured from center of the pivot hole to the center of the shock hole on the rear tongue of the hitch and came up with ~3.75" If I were to have mounted forward on the main bar of the hitch, I would have issues with the tailgate...that is I would've have to disconnect/air down the air shocks any time I had to access bed via the tailgate...which isn't something I was gonna look forward to if I had to get things in/out after I hooked up the trailer.

I understood that the further away from the pivot point, the more dampening action I would see on the shock. Extending the tongue to the rear seemed like the best compromise with my requirements.

The 2" to 1.25" adapter that I cannibalized fer the top shock mount can be mounted at any vertical point along bulkhead so I can adjust fer the range of the shock(s) to allow fer maximum clearance and within the range of the shock. If you look further back into this thread, you'll see where I was testing the maximum range of the end of the trailer and when it would contact the truck/aerocap. I think the shock will be well within this range.

[BamZipPow]

Originally Posted by wyatt

How do you compress the shock to it's midpoint so you can attach it to your vehicle?

Originally Posted by COcyclist

It should be fairly easy to compress by hand if you do it before you fill the air shock with air.

For mock-up with old gas charged shocks, drill a hole if they are already junk and let the gas pressure out.

As far as compressing the old gas filled shocks, I will use the tongue of the hitch as leverage to compress them down fer the current test setup. I will eventually go to air filled shocks so I can easily compress them, mount the one end, and then fill them to the proper pre-load.

I don't want to loose the pre-load of the old gas shocks fer my testing just yet. I have to see how viable this setup will be before I move on to air shocks.

[BamZipPow]

Originally Posted by COcyclist

I agree. It looks like the top of the shock should be lowered as well making it more horizontal and giving better shock travel and damping as the trailer rotates on the pivots.

I looked at ways to maximize the dampening effect from the shocks as much as possible while keeping the complexity to a minimum. I understand that top mounting point should be on the furthest point away from the hitch pivot point as possible to capture the maximum amount of travel as the trailer oscillates. I'll have to see how well my current design will perform and will make adjustments if I need to in the future.

[BamZipPow]

I just measured the amount of travel if the trailer ever maxed out to the pivot range of the hitch...8.25" which would put the trailer at ~65° down and ~80° up. The shocks contacted the crossbar in the maximum up position. The compression range of the current gas shock is (23" fully extended to 15.5" fully compressed) 7.5". If the trailer were ever to be in that position, I think I would have a more serious problem than worrying about the hitch or shocks.

[BamZipPow]

There wasn't any tubing locally that would fit exactly the same way as the PEX tubing did so I went with a 5/8" bolt solution. I'll have to build out the proper support later on after I test this setup and the reinforcement.

[BamZipPow]

Success! All bolted in place and hooked up. I didn't have to build up any extra reinforcement behind the bulkhead.



Went fer a quick run and then checked all my connections. No adjustments or tightening required. Whew!

Small bumps are definitely dampened. The bigger bumps don't feel like they are dampened enough. At least I know it works well enough to move on to the next step.

Time to hunt down some air shocks fer a decent price. I'm looking at the Gabriel Hijacker air shocks model number 49151 for the Toyota Pickup (and fer many other vehicles). Looks like eBay and Amazon has them fer about $70 plus shipping.

[aerohead]

Congratulations on passing another technological hurdle!
Those oscillations are on the run now!

[BamZipPow]

Pulled the trigger on a pair of air shocks. They should be here in about a week. I guess I should work on the rest of the trailer in the meantime...

I was thinking about dropping the top mount to git more compression on the shock but would mean I surrender some of the unusable range on the shock. Hmmm...

[aardvarcus]

Looks good, I see from your explanation and the newer photos that you have the hitch angle and shock travel figured out. Hopefully getting the newer shocks installed will increase the damping factor to where you want it.

Oh, and did I mention it's looking good!