Standing clam-shell mousetrip sleeper

[Pmullen503]

According to CLC's website they are looking at around $1500 for a "complete kit" which would include epoxy, cloth, and assorted hardware. BYO trailer however.

I built one of their kayak kits a few years ago. Very nice kit that went together easily. I thought it was worth the money vs trying to source materials and cut the wood parts myself. They use good quality marine plywood ($$$).

I still have issues with the design, hope they bring it to the paddle sports show in Madison, WI in March.

[Bluebunny]

Hello moderators and/or Demi-Gods of the forum! Like a pheonix, my thread rises from the ashes of neglect! I believe it is time to move this thread to the build section, or premature? Technically, I remain in the design phase, only working toward a scale model. In any event, I fully intend to pollute this thread with more photos and banter, leading up to the anticipated day of sawdust production! Onward! Through the fog! Kind Regards, BlueBunny..........

[Bluebunny]

My design/build thread revives! It is great to be back! All is rather well with me, in that amongst other things, that I ain't dead yet!. My project resurrection begins with a detail completion of the lower and mid (stationary) sections of the shell. In review, I stand at Revision 8:
wet weight: 1000 lbs
dry weight: 750 lbs
Northern Tools aluminum 5x8 trailer kit
Ultralight stich-and glue construction
8 sheets 1/4" marine ply (shell pcs)
2 sheets 1/4" underlayment ply (furniture pcs)
1 sheet 3/8" marine ply (rear walls and gussets)
3 sheets 5/8" marine ply (floor, bulkheads, stanchions)
uninsulated, except for 1/4" ply-under-foam-under-fabric P.M.F. roof panel (I'm interested in the latest opinions regarding PoorMansFiberglass)

............no galley ............no plumbing ............one little bunk ............


I'm not happy with the furnishings yet. Expect only to dress/undress etc, and make coffee and boil water for breakfasts, then head to the local cafe. Torn between nothing but stacked Rubbermaid containers and a top counter, to having additional shelves. Hmmmmnn...

[OP827]

It's great to see you back! My advise is to try finalizing your design before you start building. Refined design saves time and funds, such opinion is based on my build experience . Some design decisions in my build came from camping experience in a small manufactured trailer. In particular, I decided to have portable water and potty so I do NOT need to move the trailer during longer than a few days stay. When it comes to amenities, it is really a personal decision based what works best for you. It is always a compromise due to small trailer size and weight. I am following with interest! Best of luck with your project!

[Bluebunny]

Thanks OP! I think I have finalized the layout. Opting for a single counter without lower shelves, with four rubbermaid totes stored below. Only one narrow angular bulkhead box on port side along bunk (below the wrinkly shirts). Probably a few little shelves by the head of the bunk. Plenty storage below bunk, but my weight budget will require austere conditions. Should be super comfy for its size. Remember, it is functional as a standy or a crawly, depending upon whether the top is raised. The rear cabinet bolts in place, but it and the bunk are removable, as will be the rear walls, to allow the shell for use as a utility trailer...

[OP827]

Removable furniture is great, this will allow you to change configuration. Are you planning some hardware on the walls to accomodate that? This reminds me a space station ideas of utilizing limited space. Some wall stiffeners too?

[Bluebunny]

An example of intent to convert comfy standy into utility trailer. Shown is how I intend to remove the starboard rear wall / dutch door half, to allow the trailer to serve as utility trailer. Hopefully the photos are self-explanatory. the starboard rear wall, and the upper wall / upper dutch doorframe will deploy similarly...

in practice, will probably never happen, but has the ability for those extreme circumstances...

[Bluebunny]

I still do not have a clam top lifting mechanism. Consisting of a 5 foot wide by about 13 foot long top shell, 5 sheets of 1/4" ply stiched-and-glued, with 3/4" foam on top with the usual tight-bond/cotton skin. I expect a weight of 180 to 200 lbs, hinged at the front end. My alternatives are: electric screw actuators (need power); gas springs (big and expensive); a hand-cranked lifting winch (slow and laborious); or this - a garage door torsion spring/bar mechanism with lifting cable - it has adjustable tension, is inexpensive, lifts evenly, and should be reliable. I'm just not sure how all of that wound-up potential energy will behave in a moving vehicle. The clam top will be locked in place at both the top and down positions. Thoughts?

[Pmullen503]

Lots of trucks have roll up doors that use torque springs. You might want to beef up the mounting hardware, or at least use locking nuts and or Locktite on all connections.

But how will you rig it? I can see it working just fine using the kind of corner cable lifts a pop up uses. But if you plan to try to swing the top at it's pivot point, I don't think the spring can generate enough torque.

[Bluebunny]

Thanks Pmullen! good insights. good to hear from you again. My plan is to mount the torsion spring/bar mechanism to the reenforced underside of the decking, just inside of the rear trailer frame crossmenber. It will be a tension cable arrangement similar to my sketch here of the hand-cranked lifting winch. The improvement is that the bar will lift evenly at both rear corners, helping to avoid twisting and binding. The advantage over all of the methods considered is that both sides of the upper clam shell are locked together in even displacement. I'll have to choose a torsion unit to give a nominal lifting force of about half of the ~190 lb shell weight (the other half of the weight is on the hinge at the forewardmost point), adjusting the amount of torsion from there. The downside is that the torsion bar method is one of the heaviest. I have a severe weight restrictive budget if I wish to use my VW golf deisel as the tow. I have good experience towing my 18' Mud Hen sailboat with the VW; the boat has about a 1000lb wet weight, and I can stop OK. I'll have to travel with my cooler and my water and any heavy toys in the tow...

[Bluebunny]

But how will you rig it? I can see it working just fine using the kind of corner cable lifts a pop up uses.

P, I am not very familiar with pop-up lifters, except that I have the impression they are limited to about a 30 lb force limit? Can I get some with say 90 lb force, and adjustable? I'll search the threads for an education; thanks!

[OP827]

BB, if I were you I would consider two lifting points in back corner using webbing. They require much less radius of roller than steel cables and the rollers can be easily made at home. The idea is similar to lifting bed. If you are interested, I have sketched it here in case you are not familiar with that mechanism.

[Pmullen503]

I like the idea of using webbing instead of cable but the attachment point travels through an arc. The roller on the fixed part of the trailer would have to be long enough to accommodate that. You'd want to check if binding or folding of the web would be a problem. You could always switch to cables if it was.

I think I would mount the torsion spring below the frame so I would have room for a larger pulley. The tension will change with the number of rotations and a larger pulley will give fewer rotations. You could mount the spring to a sturdy bench and pull out the cable to see how the tension changes over the length of web/cable travel you need and then decide.

[KennethW]

Just a wild ideal. Use the webbing with a lever under the camper and a foot pedal(replacing the spring and wheel). Put your weight on the pedal and a little lift on the top. Up it goes. Then set a locking pin or latch. To go down step on the pedal and pull the pin. The pedal will stay up when the top is down. Pulleys on the lever would double the lift. If you need more lift weight mount your battery on the lever.

[Bluebunny]

I have sketched it here in case you are not familiar with that mechanism.

Thanks for the thinks everyone! Other than the weight of the lifting aid, I'm getting confidence that the system will work OK (and yes, the beauty of it is that it assists EVENLY at each rear corner. I'll think about the straps, I worry a little about them walking on the pulleys.
And OP; awesome sketch; thanks for your thoughtful effort! I like the contrast between our sketching abilities