Removable teardrop progress!

[daytimer]

I've been working on a removable Big Woody. I wanted to still be able to use the trailer for general cargo. I have made great progress, but I've reached a stump. I'll save the long description. You can see in the pic how I'm managing it. But, when I lift it, it swings backwards into the hydraulic cylinder on the hoist. How can I reconfigure how I'm lifting it to keep it from swinging backwards? I thought I could adjust the lengths of the chains, but that didn't help.

20190225_135644 resize.jpg (192.88 KiB) Viewed 2050 times

[John61CT]

Longer arm, or winch it from a pulley

lift point needs to be over over longitudinal COG

[GTS225]

What John said. Your lifting point is aft of the center of gravity of the TD body. No matter what you do with the chains, it'll still swing toward the porta-crane until the weight is balanced below the hook, or it runs into an obstacle.
If your TD body is less than 1,000 lbs, you could fab a longer sliding lifting arm to get the hook out further, but you'll also lose a little in working height.

Roger

[daytimer]

Well crap. That's kind of what I was thinking, but I hoped there might be an easy fix. I do have to finish the back end yet. It's been too cold for any woodwork. We'll see how much more weight gets added to the rear when it's done.

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[iggy3860]

Here's a thought.

As most of the weight is at the back, the centre of gravity [CoG] is towards the rear.

Why not move the pick up points so that it balances around the CoG & pick it up from 'behind'?

[tony.latham]

We'll see how much more weight gets added to the rear when it's done.

Where's your battery going?

T

[swoody126]

a simple method to locate the true center of gravity(COG) is to place a 6' piece of pipe(not plastic) cross wise under the tear w/ it on the floor

roll the tear fore n aft until it balances

mark boldly w/ sharpie

this point will change as construction continues and items are added

any time you lift with a boom that pivots the arc of the lifting point moves aft/nearer to the pivot point

the above suggestion to create a longer arm may be your only potential solution unless you can rig a lifting point in the rafters

a second hoist in the front could also be a potential solution since the trailer tongue is only bolted in place the trailer frame could be rolled in place from the side then pivoted for alignment

a child's swing set( A-frame ) is another possibility for lifting point #2

having 2 lifting points can solve your issue

sw

[John61CT]

The ideal is a design that lets the axle placement fore vs aft be easily adjusted.

Gives maximum flexibility for ad-hoc layout adjustments as the design evolves,

locking the axles in just behind CoG, tongue weight at 10% becomes a final tweak, rather than a hard constraint.

[ae6black]

When I do this I just slide with a paired set of ratchet winches. Normally takes about 1/2 hour from start to finish once I remove the bolts that anchor my tear to my trailer. I also tend to use gravity to help either putting my tear or the tow vehicle up on a set of 2 X 6 blocks, nothing complicated, nothing fancy, it has just worked for me one or two times a year for the past six years that I've been doing this. The td is simply winched on or off to a take down cradle of three frames that are held together by 2 x 4 or 2 X 6's. the 2x 6 is on the top to help guide the removal by serving as a guide that stands proud of the cradle that i slide on to . Sorry I never took any pictures, not really that complicated.

Art

[daytimer]

Battery will probably end up on tongue of the trailer.
The lifting points can't be moved. They are 2 inch hitch receiver tubes that are built into the base of the teardrop.
Guess I'll have to wait and see how it goes once the rear is finished.

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[bobhenry]

I was going to do something similar and had planned to simply lift the shell slightly and place a few rollers ( heavy wall pvc) under the shell and roll it onto a waiting platform on casters that is almost the same height. Now with the rollers then removed the rolling "deck" could be moved about as needed with little effort should the stored shell be in the way.

[Tomterrific]

Run an attachment from the tip of the hoist boom to the front of the trailer. A simple rope, if you know knots, or a ratching tiedown will be enough. This will pull lightly on the front to keep the teardrop from rocking. I'm sure it is that simple, try it.

Tom