introducing T-Shell

[T-Shell]

It's obvious to me now that I should not have offered the polyiso foam panels without testing them. I've removed them from the website.

-Karl

 

[rruff]

It's obvious to me now that I should not have offered the polyiso foam panels without testing them. I've removed them from the website.

I'm sure I've seen these (or similar) used on some custom RVs and they are probably used for other boxes as well. If they are holding up in similar applications, that's probably the best "test". Just gotta keep users from hard mounting them to flexy chassis...

 

[T-Shell]

Back to the fun stuff . . .

Custom extrusions would save time but we joined panels in two steps. First, one panels is recessed to form a rabbet joint and the adjacent panel is adhered with SIKAFLEX 255-FC in the joint. Then angle wraps the joint inside and out. We used formed aluminum on the non-ninety-degree angles and pultruded fiberglass angle everywhere else. Clearance light wiring was routed through grooves in the edges of the panels during assembly.



We prepped all the panels and then started assembly from the floor up.

 

[T-Shell]

Cutouts in the panels need a generous radius to avoid stress concentrations and cracking. This is simple with the Tern Overland doors and windows that are designed with a nice big radius. The cabover overhang is a bit more complicated because you are joining three orthogonal rabbetted panels orthogonal but need a radius on the wall panel.


The trick was to relieve the corners of two panels to nest into the radiused rabbet of the wall panel.


This left room to nest in right-angle pultrusions covered by a custom tig-welded corner.

 

[T-Shell]

Here's a few pictures of the panels going up and the camper coming together.

 

[T-Shell]

The shell is amazingly stiff at this point just joining the panels but the primary structural strength actually comes from the fiberglass and aluminum angles that tie the stress skins together.

Forty-nine angle pieces close out all the seams, inside and out. All the 90-degree joints are Strongwell fiberglass pultrusions and the custom angles are formed aluminum.


TIG welded aluminum corner caps finish it out.


Now it's ready for finishing touches.

 

[T-Shell]

Caulking is tedious but it sure comes out nice when you precisely mask both sides of each joint and finish with steel spatulas.


Tern Overland doors and windows are easy to install and everything I hoped they'd be.

 

[ExpoMike]

That is coming along nicely.

 

[ITTOG]

It is looking great. How are you attaching the fiberglass angle extrusions to the aluminum corner pieces? Also how are you attaching the fiberglass angle extrusions to the camper?

The connection where the front wall and cabover come together with the side panels looks like a neat design.

Sent from my Pixel 5 using Tapatalk

 

[T-Shell]

Everything is bonded with Sikaflex 255-FC (similar to 252). Most surfaces are also primed with Sika Primer 207.

This Makita cordless caulking gun is sweet.


-Karl

 

[dirtnadvil]

very cool, I will follow along with your progress. I have a couple of questions ;
What is the ball park cost for a flatbed 6.5' ?
How are they mounted to the truck?
Are you a resource for parts and building out advice after one buys the empty shell or are you on your own to source windows, doors, etc.
Thanks.....John

 

[T-Shell]

Sorry, I missed your comment on this thread. Unfortunately, all sales are on hold due to supplier shortages - specifically panels. I’m hoping to change that in a few months, possibly by manufacturing my own panels, but that’s where things are at the moment.
That said:

• As of mid last year, a 13' cabover was about $23,500 with a door but no windows, but obviously doesn't have much meaning now.
• By default, we bolt through the edge rails of the flatbed. There are steel inserts with a captured nut along the bottom rails of the camper. Glad to work with you to customize something else.
• We offer Tern Overland doors and windows, and Rieco Titan jacks. You're free to leave that out if you have something else you'd like to use.

The prototype shown on our website is for sale so I can fund further development. It’s 7’ W x 7’ H x 16.5’ L and fits an 8.5’ L by 7’ W flatbed. Asking $26,000. I’d could sell the flatbed too if that helped make things simpler. It's specific for a 2012 Ram 3500 but I think we can make it work with any long bed (8') platform.

-Karl