Expedition trailer made from FJ40 tub

[Volcanic Iceberg]

I decided to focus on the lift mechanism because that is the one thing that stands in my way of actually being able to use the trailer. So after consulting W/ MRPEPPER (mechanical engineer) on my lift design I began building the legs. I just have the one leg fabbed so far. Im still not finalized on the hinge. The springs and cables are not yet inside, but the pullys are. The pully axles are flush with the outside of the tubes so that the cables will be centered in the tube and not come in contact with the tube walls. The tubes are 1 1/4" OD which allows 1 1/16 th" ID for the 1" OD trampoline springs to hide inside. I also chose round tubes as oposed to square since they are a smoother surface and may come in contact with me in the night.

With the legs installed the top will sit aprox. 35" above the tub with an additional 10" or so of head room inside. - Plenty of room to sit up in, but not much more. I really didnt want to make it much taller. The bed area is only meant for sleeping in & changing clothes. The trailer already sits tall with 33" tires and I have to be able to reach the cap from the ground to lift it. Plus, once the tent material is installed I didn't want to create any more of a wind sail than I had to. It can get pretty windy in the desert. Looks like final maximum hieght will be around 7'-6". Perfect hieght for mounting a hanibal awning (or my home built version) .

I took a few pics to show the hinge progression.

just need to build 3 more and install the mounting hardware and the top should raise straight up hopefully with some significant mechanical assistance from the springs.

 

[Volcanic Iceberg]

One last one showing closed position. Pullys are actually the 1 1/4" wheels that sliding glass doors ride on found at the home depot. They have ball bearings and are quite stout. (See post #214 for original design)

 

[Volcanic Iceberg]

Ive been plugging away at the lift mechanism. Ive got all the legs welded up and am starting in on the mounts. Here are a couple pictures of one of the legs attached. (My hoist wont go any higher, thats why the top isnt level) In the verticle position you can see that the leg is not quite straight. This is intentional. I wanted it to swing slightly more than 180* to create a cam action holding the leg in position the hinge is slighlty off set to increase that cam action.

I have climbed up in there and there is the perfect amount of ceiling hight to sit up and move around.

 

[womacje]

Well done on the lift. I thought thru folding but couldn't quite work it out in my head, so I went with the gas struts instead.

Great work all around.

Jeremy

 

[croozy]

How did I miss this thread????

 

[The Jade Bean]

Wow, all I can say is AWESOME and great job! Subscribed.

 

[kling-on]

Wow nice

 

[Volcanic Iceberg]

I really wish I had made more progress on the expedition trailer over the winter, but something about the short days and the cold weather sapped all my energy. Its hard to get motivated when its dark and cold after work. I accomplished very little on the trailer. I know that this next camping season is close, and I love to go camping and exploring, so I have started in on it again.

First of all I needed to get the lift mechanism finished up. Although I would like to think that the hinged legs idea was brilliant, once I actually went about installing them I started seeing short comings. The biggest shortcoming is that the legs are too wide. There is no extra room for lift mechanism. Period. the trailer is too short. It is litterally the size of a queen mattress. there is really no extra room. So when I installed the first leg, it interfered with the mattress. I could see after several revolutions and bumpy dirt roads, the lift arms wearing holes in the mattress.

Second, while lifting the top the location and length of the leg forced the top to angle so far that it would fall off the side of the trailer before the hinge could lock into place.

I really needed to rethink how this top was going to raise. I could open it up like a clam shell length wise really easily. Tempting...... But that would mean I couldnt easily access the cargo hold on the lower end. AND that I would have to give up the awning over the kitchen area. What I have always wanted is for the top to lift straight up, and to be surrounded by tent material on all four sides. (like a tent trailer) with an awning.

Well before I could do anything lift wise, I had to connect the drip rail to the skirt piece. Up to this point I had them temporarily connected with welding clamps. The dilema here is that as precise as I tried to be with my measurements, what I am doing here is grafing together bits and peices from 4 different cruisers from 2 different decades and adding in a bunch of new material. Its a Frankenstien project. The boogered welds may as well be stitches. Stuff just doesnt line up......exactly. + Im no expert on fabricating. Learning as I go. SO the cap with the driprail had a pretty significant bow that we were never able to resolve, and the skirt piece was never entirely level. I knew that bolting it together with weather stripping sandwiched in was never going to end up working very well. So, I Welded it together. Clamping as I went, I was able to cure the majority of the gaps, and bows. the 16th of an inch gap left in places will be filled with some kind of body filler.

After all that clamping and welding, the fit on the tub is a little out of alignment. It still goes on but not as smoothly as I would like. At this point however, it is what it is. At least it does go on, Even if I have to smack it around a bit.

After welding the 2 parts together I propped up the rear end, Clam shell style, to ponder what to do about the lift mechanism. Lifting it length wise is much more secure and allow for a long leg without fear of the top sliding off. after a lot of thinking, I came upon an idea that I believe will work. The inspiration comes from a folding table in which you lift one end, swing down the legs that snap into position then go around to the other end and repeat. this design only allows for a 2:1 mechanical advantage since your only lifting one side at a time but it gets rid of the hinged leg and the springs and pullys which is more complicated and a weak point. The challange then is how to create shear value. with all the weight of the cap on top, and hinge points the top wants to come down.

the first design would have used cables strung diagonally for shear. I never really liked that. I imagined them getting tangled up, hanging out etc. when the top was lowered. With the table leg design I think I have it worked out so There will be no cables. Shear strength will come from a slot that a flange bolt on the leg will slide up into which will imobilize the leg once in the vertical position. As long as ther is down force on the roof it will not move in any direction. Down force will be maintained by the tent material on all 4 sides. The pictures are of the leg bracket prototype with the leg in the horizontal and vertical positions. The leg will actually be made of 1.5" 3/8" solid steel. at only 3/8" wide, it will not interfere with the mattress! The bracket will also be tucked up in the top skirt so the whole lift is super low profile.

It might be hard to visualize how this will work, so Im going to be buzy tomorrow building the brackets and legs and getting them installed. Pictures once installed should tell the story pretty well.

 

[The Jade Bean]

Well I to didn't do much on my trailer build this winter, so I understand. I applaud you for your resolve and although I don't completely understand the new design I am looking forward to seeing the new fab pics! Keep it up!

 

[waiting for time]

You can slide the bottom of the "table legs" over a tube and use gas struts to help them lift. You should be able to raise it at once like that.

 

[Volcanic Iceberg]

You can slide the bottom of the "table legs" over a tube and use gas struts to help them lift. You should be able to raise it at once like that.

Thats a cool idea, but the trailer doesnt have the depth to make that work. If it did, gas struts are weight sensitive, so any change in weight would affect how they functioned. Great idea though.

I worked on fabricating parts all day. Got everything built, but Im on babysitting duty tonight so legs are not installed yet. Maybe I can get some time in after kids go to bed.

 

[Volcanic Iceberg]

It was a long day......But the legs are done.

First picture: all legs in the upright position
Second picture: Legs folded position. Most likely there will be a big magnet mounted in the middle to hold them durring travel. They are very low profile only extending into the mattress area 3/8".
Third picture: This is what the mounting bracket looks like from inside the tent. I ended up using 2" x 1" X 1/8" thick rectangular tubing. The welds in the leg are the threaded ends of the flange bolts. First I drilled & tapped the holes then, I had to weld the bolts in the precise position depth wise, to allow the leg to function but without any wiggle room.

 

[Volcanic Iceberg]

Fourth picture: The leg is half way through rotation. You can see the bracket is slotted
Fifth picture: You can see the lower flange bolt on the back side. of the leg.

So the way it should work is that the legs are folded up next to the mattress durring travel. for set up I lift the back end of the roof up, and the legs drop down. when the weight of the roof is released the legs go up into the slots which make them ridgid in every direction. Then i repeat at the front end.....just like a folding table.

on the sleeping platform I plan to notch out the wood a little so the bottoms of the legs will sit on the angle iron that the deck rests on. This will further imobilize the legs. After that, snap on the tent material around the outside. this will work as an anchor against wind gusts and provide some shear value - Theoretically speaking.

Tomorrow its going up on the trailer to see wether my 12 hour day today paid off or was a huge waste of time.

 

[Volcanic Iceberg]

Got it up on the trailer. I need to trim the legs down 4-6" I did'nt realize it would be quite so high. There is over a foot of volume above my head sitting straight up. It is super exciting to finally have the top raised.

 

[Volcanic Iceberg]

Here is one of me sitting in it for scale.

 

[The Jade Bean]

Pretty awesome...when the top is loaded how will you get it up on the bars?

 

[Volcanic Iceberg]

Pretty awesome...when the top is loaded how will you get it up on the bars?

Good question. The roof rack will need to be there to have a place to mount the awning(s), but beyond that the things that will be on the rack will be things that will be offloaded before set up anyway I.E. Firewood, camp chairs, or an extra tent for the kids. Not planning on loading it up with much gear. Nearly everything will be contained inside the trailer below the mattress for security and a lower CG.

 

[The Jade Bean]

Good question. The roof rack will need to be there to have a place to mount the awning(s), but beyond that the things that will be on the rack will be things that will be offloaded before set up anyway I.E. Firewood, camp chairs, or an extra tent for the kids. Not planning on loading it up with much gear. Nearly everything will be contained inside the trailer below the mattress for security and a lower CG.

Right on!

 

[kling-on]

Here is one of me sitting in it for scale.

That hight looks good I would want to be able to kneel to do stuff and have head room.

Sent from outer space via my mind

 

[77TLCFJ40]

I would want to be able to kneel to do stuff...

Good call

Great build. Glad you're back on it.