Over-family-landing composite F-550 build

[ben_j_c]

What do you do for a living and what is your background?

Thanks for the kind words. I have a bio-electrical engineering degree and mostly do engineering & business management these days.

Working on projects like this helps me keep my hands busy and learn new skills. I enjoy doing it all myself, it makes me understand all the systems that could break when I am out using it, and hopefully gives me good insight into fixing them when they eventually break.

As to the skills and knowledge, it is mostly attitude and self confidence. You can do it too! This was my first time with serious aluminum fabrication (I built a few rafting tables before this to learn on), TIG welding, automotive painting, LASER cutting metal, differential work, insulated composite sandwiches, and more. Just take the time to research it and give it a try!

We see so many camper CAD builds that end at the CAD design.

I certainly have more time into the CAD design and material selection than the fabrication. So much to think about when building a rig like this. For instance our entire rafting setup is designed to fit inside the camper, that alone took probably 30-50 hours of planning to make it all fit in CAD and I am working on the fabrication now. I went through probably 100 variations of the nose, hundreds of hours of work to hopefully hit my head less than I do in my Grandby!

I also have a graveyard of unbuild design iterations that I rejected before settling on this one. My favorite reject idea is a hard sided popup with linear actuators (link here: https://cad.onshape.com/documents/4...renderMode=0&uiState=6260e786a0700c52f6b1bebd )






I might build it some day, but it requires thinner panels than I had, the folding sides get too heavy to manage practically if there was ever a malfunction when they are 2.5" thick. Additionally the thick panels make the a fairly tall popup, but still a few inches shorter than the current design.

I am still shorter than most real RVs with the current design, so I figured it would work and keeps the first build simple. The down side is that I cannot fit in a shipping container assembled currently, so the camper has to come off the truck to all fit in a high cube container (and it only clears by 1.25 inches through the door) so I will need to rig up a special container with the gantry setup to facilitate fully enclosed overseas transport.

Anyway, if you ever decide to build one like this, let me know I will walk you through more of the decision making I went through and you are welcome to the CAD files.

 

[mk216v]

Can't wait to see this color combo Ben!!

 

[Jonnyo]

this build is amazing!!!!! a question for you if you dont mind?! i m at the stage of ordering the sikaflex and primer sika flex for a structure of similar size as yours. if you had to guess, how many tube of 310ml sikaflex did you use? and how much ml of sikaflex primer? thanks!

 

[ben_j_c]

if you had to guess, how many tube of 310ml sikaflex did you use? and how much ml of sikaflex primer?

So for the panels glued to the aluminum to the I used:

32 x Sikaflex 252, White, One Component, Elastic Adhesive, 300ml Cartridge
2 x Sika Primer 207 AGR Pigmented, Solvent-Based Adhesion Promoter 250ml Bottle (for the aluminum)
1 x Sika Aktivator 100, 250ml Bottle (for the fiberglass)

You can probably get away with just one bottle of 207 Primer if you are more careful than me and don't spill it ever, but I had to order a second one.

You will also want to get a handful of those magic eraser sponges and cut them into wedges to spread the primer. Make sure to ask for the full length caps for the 252, some places send precut ones, I prefer to cut my own notch in them. Also the Milwaukee M12 caulking gun is a life saver for this job.

I just finished putting a 1/4 round bead of Sika 521 (in grey) to seal up all all the aluminum to the fiberglass, I used about 7 tubes of it. If you need some of that let me know, I ordered too much!

 

[reddrum]

Probably the first expedition vehicle built with agile kanban. lol. Great idea!

If you are looking for encouragement in your own build, I recommend a Kanban board. I don't know why, but it is super satisfying moving a post-it note into the done column!

View attachment 638680

 

[ben_j_c]

Well the painting has been interesting! I hired a guy to help me paint it and paid him for the paint, but he ran off with the money. So I decided I was just going to do it all myself. I have never done any automotive paint before, so it was a bit daunting!

I started with lots of sanding which is in one of the older posts, then I did some body work to remove a few dents. There was one under the rear driver door that required a bit of pulling to get right. I ended up welding washers onto it and then using a chain and skid steer to pull it all out straight. It worked pretty
well!





I then got the everything prepped in the shop


And we started painting! First we did a DTM epoxy primer, then Omni+ base coat, then a clear coat.






Next step painting the box!

 

[reddrum]

+1 for creative dent pulling. Looks very nice! Painting is really all about sanding. Well done.

Well the painting has been interesting! I hired a guy to help me paint it and paid him for the paint, but he ran off with the money. So I decided I was just going to do it all myself. I have never done any automotive paint before, so it was a bit daunting!

I started with lots of sanding which is in one of the older posts, then I did some body work to remove a few dents. There was one under the rear driver door that required a bit of pulling to get right. I ended up welding washers onto it and then using a chain and skid steer to pull it all out straight. It worked pretty
well!


Next step painting the box!

 

[ITTOG]

Well the painting has been interesting! I hired a guy to help me paint it and paid him for the paint, but he ran off with the money. So I decided I was just going to do it all myself. I have never done any automotive paint before, so it was a bit daunting!

I started with lots of sanding which is in one of the older posts, then I did some body work to remove a few dents. There was one under the rear driver door that required a bit of pulling to get right. I ended up welding washers onto it and then using a chain and skid steer to pull it all out straight. It worked pretty
well!

View attachment 726056
View attachment 726057


I then got the everything prepped in the shop
View attachment 726059View attachment 726063

And we started painting! First we did a DTM epoxy primer, then Omni+ base coat, then a clear coat.

View attachment 726064
View attachment 726065
View attachment 726066
View attachment 726067

Next step painting the box!

Hey you missed some spots.


But seriously, it looks good and the washers were a good idea.

Sent from my Pixel 6 Pro using Tapatalk

 

[mk216v]

Friggin' swindlers!

But the result looks awesome Ben, well done!

 

[ben_j_c]

Well it is time to catch you all up, expect a few posts in the next few days!

One of the big challenges with a rig like this is the spare tire, where does it go?! How do you change it, how do you make it get out of the way when you put a flatbed back on for farm work.

I decided to use 2x4 3/16 box steel to make pockets in the bumper.



Then I framed it up with some 2x2 box.



Then properly spaced it and welded on a plate with matching holes for the wheel.



I added a 2x2 stub coming out of the top to allow for a "L" bracket to be made to lower the tire from and welded on a pipe to center the wheel and pressed in some left over studs from a hub replacement project.




I think it turned out pretty great!

 

[getout]

Nice work!

 

[ben_j_c]

I feel I became on with the sander... Painting prep takes forever on something this big!

Here it is all prepped and I am just about to spray the back of the solar mounting rails



Then we moved it inside and started spraying the epoxy primer on all of the freshly abraded aluminum.




Then a 2k build primer



Then a top coat (and later a clear coat)



It turned out pretty great!

Here I am cutting the crawl through out of the freshly painted box!


It was quickly inspected and approved!


And mounting the camper to the truck. (Four wheel grandby camper for scale)



Getting closer!!!

 

[ben_j_c]

The next on the list was getting the roof to shed water. Due to the aluminum exoskeleton and glue/foam tape, the actual roof was about 1/4" below the rim. I do not want a giant chunk of ice flying off the roof someday and wanted to decrease the potential for leaks with a pond on top of the camper.

We decided to cut foam and glue to to the top. We built a hot wire cutter to make an arc in the foam to help better shed water.



Then glued it to the roof



Then we sanded it all


Then we cut a giant piece of fiberglass to put on top of it all



Then lots more adhesive! (no good in progress up top shots)



We also got the front bumper put back on



and replaced the headlights with DOT approved projector style (the truck came with some illegal HIDs, they might have been legal in Canada, but not in Oregon). This new ones required a bit of trimming of the fiberglass carrier board.



I am pretty happy with how they look and perform!

 

[ITTOG]

We decided to cut foam and glue to to the top. We built a hot wire cutter to make an arc in the foam to help better shed water.

I would love more info on this. I have been thinking of doing the same but for a hot tub cover. Would you mind sharing more info and pictures about your hot wire cutter. Also, how did you keep it uniform across the foam? Just by tightness?

 

[ben_j_c]

I would love more info on this. I have been thinking of doing the same but for a hot tub cover. Would you mind sharing more info and pictures about your hot wire cutter. Also, how did you keep it uniform across the foam? Just by tightness?

Sure, I made the foam cutter using 18 AWG nichrome wire (sourced from my local electronics hobby shop Norvac) and a (hastily) home made wood tensioning device. I used some left over surgical tubing to keep it tight as you can see on the top. That could easily be a bungie or some other stretchy material. I then attached a regular power cord with one wire going to each end of the wire and used some bolts to clamp all of that together. DO NOT PLUG THIS DIRECTLY INTO THE WALL. I used a variac transformer and started from 0 and slowly worked the winding ratio up until the wire started to cut the foam cleanly. You can also use this calculator and figure out exactly what voltage you need and create it some other way.



I then made a jig that held the uncut foam. On the edges I put rails that the nichrome wire could run on to make the appropriate arc cut. I used 1/4"x1" aluminum bar stock, you need to be very careful using a conductive material as the voltage between the two bars is close to the output of your transformer and can hurt/kill you. I didn't have anything flexible, nonconductive and heat resistant, so I made the aluminum work, but we were very careful with it.


Then it was just a matter setting up the foam in the jig and dragging the hot wire cutter through it. Run a few tests on some scrap foam first and be in a well ventilated area! Be careful to keep a consistent speed and even progression from each side. Stopping is also a big no-no as it burns the foam.

This was my first time doing it this way, so I am by no means an expert. Youtube "nichrome hot wire foam cutter" and you will find lots of other (better) examples! Good luck with your hot tub cover.