"TrailTop" modular trailer topper building components
- Thread starter jscherb
- Start date
jscherb
Expedition Leader
When I first started the TrailTop design process, I was thinking I might make molds for doors and door jambs - side doors and rear barn doors. But a quick search for "Teardrop Door" on eBay suggests there are already plenty of door options out there already. Here are some door images I grabbed from ebay. I've scaled them accurately for these drawings, so you should be able to get a good idea of what the choices I found on eBay look like.
If anyone has other good sources for ready-to-use doors I'd be interested in hearing about them.
I'm still thinking about whether or not it would be worthwhile to make mold for a fiberglass rear teardrop hatch though, haven't decided if that would be worth the cost to the average builder or if they'd rather build the hatch themselves.
If anyone has other good sources for ready-to-use doors I'd be interested in hearing about them.
I'm still thinking about whether or not it would be worthwhile to make mold for a fiberglass rear teardrop hatch though, haven't decided if that would be worth the cost to the average builder or if they'd rather build the hatch themselves.
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jscherb
Expedition Leader
Since unforseen circumstances have prevented me from molding the first TrailTop parts yet, I've been amusing myself by doing some anim drawings showing how the parts will assemble 
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The photo is of the "Extended Dinoot Extended" tub kit (7'5" long) in my workshop with 30's/40's-style fenders. In successive views, the following TrailTop parts are added - a 36" radius curve, a straight section (3'5" long), a 12" radius curve, and another straight section (24" long). A plywood skin is added, and a window installed.
When building an actual TrailTop (instead of a digital Trailtop like this), you'd probably assemble the TrailTop framing parts flat on the floor, add the plywood skin and the window while the framework is still on the floor, and then erect the completed walls on the tub (or directly on the trailer frame, if you're not using a tub as I am in this example). So not only are the TrailTop parts modular, the assembly sequence is intended to be modular as well.
Depending on how long circumstances prevent me from doing the molding of the actual parts, I may expand this anim series to include the complete shell (the other side and the roof), and some interior components as well.
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The photo is of the "Extended Dinoot Extended" tub kit (7'5" long) in my workshop with 30's/40's-style fenders. In successive views, the following TrailTop parts are added - a 36" radius curve, a straight section (3'5" long), a 12" radius curve, and another straight section (24" long). A plywood skin is added, and a window installed.
When building an actual TrailTop (instead of a digital Trailtop like this), you'd probably assemble the TrailTop framing parts flat on the floor, add the plywood skin and the window while the framework is still on the floor, and then erect the completed walls on the tub (or directly on the trailer frame, if you're not using a tub as I am in this example). So not only are the TrailTop parts modular, the assembly sequence is intended to be modular as well.
Depending on how long circumstances prevent me from doing the molding of the actual parts, I may expand this anim series to include the complete shell (the other side and the roof), and some interior components as well.
jscherb
Expedition Leader
Here's another TrailTop assembly animation. Since I don't have 3-d drawing software, I'm doing these animations in my 2-d drawing program, so they may be a little rough in spots, but I think they're good enough to illustrate the main points. Also this particular animation file is pretty large, so it may take a while to download if you don't see it right away.
This time I drew a "breadbox" shaped camper rather than a teardrop, and it's got a rear barn door. The driver's side wall is going up first; it's got a 1/4" plywood outer skin, a layer of foam insulation, and the inside of the wall is covered with 1/8" plywood. Also notice in frame 8 a sill piece is secured to the bottom of the wall; this is used to bolt the wall to the Jeep tub, in the same way that a jeep hardtop bolts to the Jeep. Similar sills would go on the front and rear walls as well. The rear door is 3' wide, which is the size of the Jeep tailgate opening.
As with the last animation I posted, even though the animation shows all of the parts being assembled in place, what probably would be the best assembly plan would be to fully assemble each side panel, install them on the tub (or on the trailer frame if a tub wasn't being used), and then assemble the roof and ends to the installed sides.
For people who would want to still be able to use the Jeep-tub base trailer for cargo without the camper on top, this TrailTop would unbolt and lift off.
This one uses straight rail pieces, 12" radius curves in the front and a fiberglass 12" radius curved roof section, and 3.5" radius 90-degree corners in the back.
This time I drew a "breadbox" shaped camper rather than a teardrop, and it's got a rear barn door. The driver's side wall is going up first; it's got a 1/4" plywood outer skin, a layer of foam insulation, and the inside of the wall is covered with 1/8" plywood. Also notice in frame 8 a sill piece is secured to the bottom of the wall; this is used to bolt the wall to the Jeep tub, in the same way that a jeep hardtop bolts to the Jeep. Similar sills would go on the front and rear walls as well. The rear door is 3' wide, which is the size of the Jeep tailgate opening.
As with the last animation I posted, even though the animation shows all of the parts being assembled in place, what probably would be the best assembly plan would be to fully assemble each side panel, install them on the tub (or on the trailer frame if a tub wasn't being used), and then assemble the roof and ends to the installed sides.
For people who would want to still be able to use the Jeep-tub base trailer for cargo without the camper on top, this TrailTop would unbolt and lift off.
This one uses straight rail pieces, 12" radius curves in the front and a fiberglass 12" radius curved roof section, and 3.5" radius 90-degree corners in the back.
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jscherb
Expedition Leader
Here's another assembly animation... this time it's a teardrop shell on a Harbor Freight frame.
The frame is a 4x8, but I've made the shell 8'7" long. I've done this for several reasons - by doing this I can round the corners of the floor framing and drop the curved TrailTop vertical pieces down so the side panels will hide the Harbor Freight frame. Also it's nice to have an additional 7" to work with when planning the interior, and because of the 3.5" radius on the TrailTop framing pieces, the side panel inserts are still only 8' long for an 8'7" shell, so it's easy to add those inches and still use standard-sized 4x8 sheet material for the sides.
I've painted the TrailTop fiberglass side rail parts red on this one to complement the red of the Harbor Freight frame tongue. The side panels are aluminum-clad luan, which are available commercially. I painted one TrailTop part gray to blend with the aluminum - the 12" radius roof/side transition piece.
The frame is a 4x8, but I've made the shell 8'7" long. I've done this for several reasons - by doing this I can round the corners of the floor framing and drop the curved TrailTop vertical pieces down so the side panels will hide the Harbor Freight frame. Also it's nice to have an additional 7" to work with when planning the interior, and because of the 3.5" radius on the TrailTop framing pieces, the side panel inserts are still only 8' long for an 8'7" shell, so it's easy to add those inches and still use standard-sized 4x8 sheet material for the sides.
I've painted the TrailTop fiberglass side rail parts red on this one to complement the red of the Harbor Freight frame tongue. The side panels are aluminum-clad luan, which are available commercially. I painted one TrailTop part gray to blend with the aluminum - the 12" radius roof/side transition piece.
loren85022
Explorer
They should give Oscars out to best trailer fab guys
jscherb
Expedition Leader
What design would you build with those parts - one of the ones below or something else? Would you base your build on a jeep-tub trailer like the ones below or would you build on a plain frame? If what you plan is different from those below, maybe I could do up a drawing of your design for you.
jscherb
Expedition Leader
Most people I've talked to say the curved galley hatch is the hardest part of a teardrop to build, so I've been working on several potential designs to make it easier. On the easist end of the scale would be a full fiberglass hatch, but that would also be one of the most expensive ways to go due to manufacturing cost and shipping cost. I'm trying to balance the following:
- Cost to manufacture/selling price
- Shipping cost
- Easy of assembly
The goal is to come up with something that's very affordable and easy for an average DIY-er to assemble, something that takes the complexity out of making a hatch from scratch from wood.
Here's a design I think meets the goals... it uses two curved fiberglass ribs, several pieces of ordinary 1x3 lumber, and a piece of 1/4" plywood. In the drawings below, the ribs are shown in gray. They're curved in the proper radius to match the TrailTop curved side rail pieces, and they've got roughly a "Z" shaped cross section. The bottom of the Z provides a foot for bonding the plywood to, and the vertical and top of the Z provides a pocket for the 1x3 cross-ribs. Everything isn't necesarily to exact scale and proportion in these drawings, they're just quick sketches to convey the design concept.
Here's how it would go together. The first illustration shows just the fiberglass ribs:
Then the 1x3 wood cross-ribs are bonded/screwed in place. Epoxy would make an excellent bond between the wood and the fiberglass, and screws are added for extra strength. I've only showed screws on one side in this illustration, but they would be used on both sides.
Once the epoxy bonding the wooden cross-ribs to the fiberglass curved ribs had cured, the plywood skin is epoxied to the completed framework. Clamps are used to hold the plywood in place, but finishing nails can also be used through the plywood and into the wooden cross rails. The bead of epoxy is shown in yellow.
Because the curved outside of the hatch measures about 5' from the top edge to the bottom, two pieces of plywood would be needed to span the distance. The joint would be lined up with a cross-rib so nails could be put in along the joint line.
Summary for the DIY-er: the only operations he/she has to perform are cutting some 1x3 wooden ribs to length, epoxying/screwing the wooden cross ribs and the fiberglass curved ribs together, and epoxying/nailing/clamping the plywood to the frame. No curves to cut. Hopefully that's within the capabilities of the average DIY-er.
In production, the two fiberglass parts would actually be molded as one and cut in half along the center line, so there's only one fiberglass layup operation, which would make these parts very easy to mold and hopefully result in a very reasonable selling price.
- Cost to manufacture/selling price
- Shipping cost
- Easy of assembly
The goal is to come up with something that's very affordable and easy for an average DIY-er to assemble, something that takes the complexity out of making a hatch from scratch from wood.
Here's a design I think meets the goals... it uses two curved fiberglass ribs, several pieces of ordinary 1x3 lumber, and a piece of 1/4" plywood. In the drawings below, the ribs are shown in gray. They're curved in the proper radius to match the TrailTop curved side rail pieces, and they've got roughly a "Z" shaped cross section. The bottom of the Z provides a foot for bonding the plywood to, and the vertical and top of the Z provides a pocket for the 1x3 cross-ribs. Everything isn't necesarily to exact scale and proportion in these drawings, they're just quick sketches to convey the design concept.
Here's how it would go together. The first illustration shows just the fiberglass ribs:
Then the 1x3 wood cross-ribs are bonded/screwed in place. Epoxy would make an excellent bond between the wood and the fiberglass, and screws are added for extra strength. I've only showed screws on one side in this illustration, but they would be used on both sides.
Once the epoxy bonding the wooden cross-ribs to the fiberglass curved ribs had cured, the plywood skin is epoxied to the completed framework. Clamps are used to hold the plywood in place, but finishing nails can also be used through the plywood and into the wooden cross rails. The bead of epoxy is shown in yellow.
Because the curved outside of the hatch measures about 5' from the top edge to the bottom, two pieces of plywood would be needed to span the distance. The joint would be lined up with a cross-rib so nails could be put in along the joint line.
Summary for the DIY-er: the only operations he/she has to perform are cutting some 1x3 wooden ribs to length, epoxying/screwing the wooden cross ribs and the fiberglass curved ribs together, and epoxying/nailing/clamping the plywood to the frame. No curves to cut. Hopefully that's within the capabilities of the average DIY-er.
In production, the two fiberglass parts would actually be molded as one and cut in half along the center line, so there's only one fiberglass layup operation, which would make these parts very easy to mold and hopefully result in a very reasonable selling price.
What design would you build with those parts - one of the ones below or something else? Would you base your build on a jeep-tub trailer like the ones below or would you build on a plain frame? If what you plan is different from those below, maybe I could do up a drawing of your design for you.
Probably similar to the first one but without a flat rear. Built on a custom trailer, not a tub. See this link for the type of rear I am thinking perhaps. http://sawtoothent.com/?page_id=32 Havent had a chance to see how the rear could/would work with 60 and 30 degree pieces.
jscherb
Expedition Leader
What would you like to build? I'm thinking I might make a few sets of parts available to people who would to build interesting examples to showcase the capabilities of the TrailTop parts.
Other than that, I'm not in business to sell anything, so the parts would only be generally available if a company is interested turning them into a commercial product.
yj-hank
Observer
Jeff if you really do look for people to build an example I would gladly like to throw my hat in the ring. I would love to build the teardrop style trailer on a flat frame not on a tub. I would be happy to pay for all parts and set up a build thread or continue on with it on this thread. Please PM me if I happen to make the cut and I will give you my contact information. Great work as always. Glad your arm healed up so well.
Henry
jscherb
Expedition Leader
Henry,
Thanks. I'll probably decide what I want to do with the TrailTop stuff in a few weeks. I plan to mold the first set of parts this week and I'll assemble them into a teardrop to sit on top of the fiberglass Jeep-tub trailer kit that's set up in my workshop. Once I get assembly underway, I'll probably make a few molds for some additional pieces, such as the teardrop galley hatch curved ribs, so it'll be a little while still before I have a full set of molds for every piece I plan to make. During the process I'll decide how far I want to take the TrailTop concept and if I want to see it become a commercial product or not (have had some interest from 2 companies). If I decide to move forward with it, I'll likely be looking for a few people to assemble their own prototypes as showcase examples.
jeff