1st Gen Toyota Tundra Aeroshell Build
 

Fairly recently I decided to set up my truck for overlanding/road trips. And since I needed a place to sleep and I don't want to mess with setting up/taking down a tent every day during trips, I decided a camper shell was probably the best way to go. And since camper shells are expensive and it is hard to find used ones for appropriate vehicle specific models, I decided it would be fun to make my own. And since I am making my own camper shell, I figured I might as well try to make it aerodynamic and squeeze as much fuel efficiency that is reasonable in an overlanding type vehicle.

Just for reference, the best economy I have gotten out of the truck (2005 Toyota Tundra Access Cab 4x4) is about 22 mpg (highway @ 60 mph). It used to average about 18-20 mpg highway/freeway. Then after the installation of a home-made deer-resistant front bumper and larger than stock meaty all-terrain tires (285 75r16), the economy dropped to about 15-16 mpg highway/freeway. I have since dropped to a smaller (265 75r16) and much more highway oriented tire, so I bet that will give me a little bump, but I haven't driven enough miles to know the effect. My hope is to end up back around 20 mpg with the aeroshell mod and new tires. The desired gains are not extreme by any means, but will definitely be beneficial.

Anyways, on to the build... Basically I am making a cedar strip shell using similar construction techniques as the cedar strip canoes. I started by taking a picture of the back of the truck cab to get the profile, converted it to a vector graphic, and then imported it to Fusion 360. From there, I did a bunch of CAD work to get the frame of the shell designed.

I then cut all the frame pieces on the CNC out of poplar. The bit was a little smaller than nominal so some of the joints didn't fit very well. Overall it turned out pretty good though.

After that, I assembled the frame... pictures to come soon..

Now that I have 5 posts, I can start adding pictures.. Here is the CAD drawing: https://lh3.googleusercontent.com/tv...=w1597-h899-no

Here is the frame in various stages of construction: https://lh3.googleusercontent.com/yU...=w1597-h899-no

https://lh3.googleusercontent.com/R_...=w1597-h899-no

Finally, here it is mocked up on the truck: https://lh3.googleusercontent.com/-Q...=w1597-h899-no

https://lh3.googleusercontent.com/Lg...=w1597-h899-no

https://lh3.googleusercontent.com/zF...=w1597-h899-no

I messed up a little bit on the contour at the cab. It doesn't line up perfectly and has a shallower more rounded curve at the corners. I should have checked it before making everything, but I didn't and this is where I am at. I keep telling myself that since the cab corners are kinda rounded the airflow will follow them a little bit before separating and this point is probably exactly where my camper shell starts. So this is really a feature and will make it more aerodynamic. Yeah, probably wishful thinking.. Oh well..

That's really nice work.

What is the purpose of the two slots on the front and rear ribs?

Is the angle of the shadow on the back of the cab because the cab slants forward?

Thanks. The slots are for air vents. Eventually they will be covered with screens. I am not sure what shadow you are talking about, but the cab does slant forward a couple inches. I am going to extend the cedar strips past the end ribs to make eaves. The front eave will follow the cab slant. There will be a uniform 1" ish gap between the shell and cab when all is said and done.

Great work! Where about in Texas are you? ;)

I am in San Marcos.

Awesome!!!! You Nailed It!!! (or is that glue and screws? hahaha!) You have really built something that is as close to optimized as I have ever seen built. You should get very close to the best Cd you can achieve with a cap, but you have nailed getting the best CL. Your truck is going to feel like yer driving an arrow down the road. If your travels take you to snowy places, you'll really appreciate the stability.

How may I ask did you figure this out???

Great Job!!!

http://i53.tinypic.com/zyhi6s.jpg

BTW, I use Tiny Pic to upload my pictures to and I use the "Insert Image" thing above, or, I grab the "IMG Code for Forums & Message Boards" on the image page in TinyPic and paste it right into the post. You may wanna limit your image size to 600 pixels wide in order to avaoid sort of crashing the page.

Huge Welcome To You as well!!! As long as you don't consider adding golfball dimples or vortex generators to your exquisite creation :eek: ...you'll be very well received here.

Haha, thanks. Yeah, it's glued and screwed... well at least the ribs to bed rail pieces are. The longitudinal piece at the top middle is just glued. I will be using glue and brad nails on the cedar, which I have started cutting up.

I appreciate the confidence but I can't really expect too much overall. I am mostly just hoping to offset the aerodynamic downgrades in the front end. The truck is set up for better off-road capabilities and with that comes maximum approach angle. You can see the entire wheels from the front. I'll take some more pictures of it tomorrow to show you.

As far as how I figured it out... I started by playing with the streamlined body picture overlay thing on this site to get a rough idea of the shape I wanted. Then I took some pictures of the back of the cab to get the profile, which I should have done more carefully in hindsight. I converted the image to a vector graphic so I could import it into CAD, which I use Fusion 360. I scaled the vector graphic based on known dimensions and traced it with a spline to the centerline of the cab outline and then mirrored that so the two sides were perfectly symmetric. I then took measurements of the bed rails and drafted those up. From there, I made an offset plane at the end of the bed rails parallel to the cab profile. On this plane I drafted the back end profile, basically winging it. I knew I wanted it more rounded with a steeper angle coming in from the sides. I also made it as short as I thought would be reasonable for entering and exiting the bed area figuring that I will have a slightly raised platform that holds the mattress. I also wanted to maintain usage of my rear view mirror. From there, I ran a curve from the cab profile to the rear profile. Again, I was sorta winging it, but I made the curve tangent to a line sloping down 1 degree from horizontal at the cab and tangent to a line sloping up 10 degrees from horizontal at the rear profile. I then used the loft command to make a body from the cab profile to the rear profile along that curve. I intersected evenly offset planes with the body to get the rib profiles. There's a bunch more after that, but that was basically the crux of the CAD work.

Oh, and thanks for the welcome. I'll also look into making the pictures smaller as you suggested.

That is some beautiful work, there!

I would suggest adding in a provision for a detachable Bonneville-type spoiler. It might help even more.

I take it this desine is for fixed, likse a standard shell.. I made my shell open to ease Ingress and egress, As I'm 6'3".
Looks like it will help more than anything off the shelf.
Good work so far

Thanks. Yeah, the design is just like a standard shell, just hopefully more slippery. I went with the KISS principle on this project.

I like your aerocap. How much of a difference did it make for your vehicle?

Thanks. Are you thinking the spoiler would extend rearward behind the shell or sit on top of it? If it is to the rear, maybe I could make it into a cargo pod that mounts to the rear bumper or slides in the receiver hitch.

Before I forget, here is a picture showing the front end of the truck. https://lh3.googleusercontent.com/_q...w=w800-h450-no

As you can see, it won't win any low Cd contests. I probably won't be doing any mods here, as the current setup makes a huge difference in off-road capability. I might consider doing some sort of removable air dam (maybe made out of some sfiff rubber) that hooks over the bumper. And I will probably get rid of the round lights or swap them out with a light bar.

Anyways... Today was spent behind a table saw converting 2x6 (1.75"x5.75" actual) rough cut cedar into 3/4"x1/4" strips. This is basically the least expensive option I could find for getting the strips. You can order them online for about $5 a piece, but that gets real expensive when you need like 120 of them. You can get about 30 strips out of an $11 2x6 from Lowes. I ended up getting 6 boards so I would have extra figuring for waste. I will probably end up with a bunch left over though as the boards were surprisingly clean and knot free.

I started by ripping the boards into 1/4" strips:
https://lh3.googleusercontent.com/Fw...4=w800-h450-no

Then I ripped those in half to get the roughly 3/4" wide strips:

https://lh3.googleusercontent.com/Vl...A=w420-h745-no

I also started throwing together a makeshift router table for the bead and cove cuts: https://lh3.googleusercontent.com/YP...4=w800-h450-no

https://lh3.googleusercontent.com/-z...4=w800-h450-no

Went from~18.xx(290pmi) to 23.xxmpg(10,000mi) 60-65 with an average of 22.5. (1000usg 22,500mi) this 22.5 includes the 2900mi naked. Have had 5-6 100mi runs over Continental Divide @ 28. and 1 @28.95mpg @cruise set to 55mph. As compaired to 23.01 best naked. Plans are in motion to smoke test me and Aeroheads caps at DARCO in Ogden Ut sept9,16 I will be posting on that later. As well as a baby template. Im about 3000 mi behind on my fuellog right now.
Looks good so far . I will suggest a Kam back on tbe trailing edge .be tiped in 12.5° tord the center (down ontop 'in on both sides) of the last bow probably 6-8" in length . Make the edge a single smooth raidi ...sounds like you have some plains in this direction. With the rain over hang. .
To address the mishap on the cab just add a Corection pice with some Dalles or Woodruff keys.the 2nd bow may need some persuasion as well ,buyt might get lucky and only 1 . Or roll with it the small step will cost a small % reduction in mpg gain
. Gumby Stay Flexible
Dreem big chisel down to reality.

What is the difference in length along the curve on the first and last rib? How does that compare with the number of strips required?

Will you lay them from the sides up or center out?

Damn! That is a lot. Was that just from the cap or were there other contributing factors as well?

I appreciate the the suggestions. Feature creep is a dangerous thing so I think I'll probably just stick with what I have planned. It won't be ideal, but I will get it done way faster this way. Then after I test this one and find all of the flaws, I can re-evaluate the design and make a new one implementing some of the ideas flowing in. I am really curious what data you get from your upcoming wind tunnel test.

The length at the front rib is 90" and the rear is 75". Each strip should span about 0.75", so I should need a minimum of 120 strips. 20 of those strips will be partials.

I am planning on going middle-out on the strip layout. If I have learned anything from the show "Silicon Valley" that is the most efficient way of doing things. I think it will be easier to construct this way as I will have better access to the final strips, which will be the hardest. Also, I designed in a groove on the bed rail pieces for the strips to fit into. This way, I won't have to be uber precise on my cuts to get a really clean seam.

The spoiler should extend behind the aeroshell, kind of like what ccrider did for his Tacoma -> http://ecomodder.com/forum/showthrea...p-11271-6.html

http://i964.photobucket.com/albums/a...aerocap007.jpg

Here's my current aerocap, as of a couple of years ago. I've been meaning to attach a spoiler on it, as well as make an articulated hinge for it.

http://tom-viki.com/spgm/gal/Cars/1B...1408240000.jpg

Ok. I see what you are saying now. I think the eaves I have planned should do the trick. It should be similar to the picture of the red truck.

Today I finished up prepping the cedar strips. The little router table I made worked beautifully. I added a couple aluminum tabs to guide the strips so the bead and coves were consistent.

https://lh3.googleusercontent.com/Nb...o=w600-h337-no

After finishing up the strips, I picked the nicest ones and laid them out and played around with patterns between the light and dark.

https://lh3.googleusercontent.com/wD...Y=w600-h337-no

Then I set down a layer of plastic in the bed of the truck and then the frame.

https://lh3.googleusercontent.com/hM...s=w600-h337-no

After some glueing and nailing, this is where I ended up.

https://lh3.googleusercontent.com/-G...0=w600-h337-no

https://lh3.googleusercontent.com/yR...s=w600-h337-no

https://lh3.googleusercontent.com/7l...g=w600-h337-no

Oh, that's going to be pretty!

I hope you're not going to paint over that when you're done, are you? Because a nice sanding/glassing/resin job would look beautiful.

https://usercontent1.hubstatic.com/3905310_f1024.jpg

Looking good!

As for the shell, you could probably add a flexible air dam on the front of your truck under the steel bumper and get some of your front end aerodynamics back. I put a conveyor belt air dam on the front end of my 2005 Tacoma, which I use offroad quite a bit, and haven't had an issue. If you hit something, it just pops right back into place. Here is a link to my build thread in case you hadn't seen it.

http://ecomodder.com/forum/showthrea...tml#post438755

Looking at your bumper, If you didn't want to commit to a air dam all the way across, you could do two smaller conveyor belt tire spats mounted to your steel bumper to push the air around your tires, which would also help diminish tire noise and front/rear lift at highway speeds.

Thanks. Yeah, my plan is definitely to make it look like the typical cedar strip canoe/kayak. Of course, I have never done this or fiberglass before, so if I screw up too bad somewhere a long the line, I may have to paint it. I really hope it doesn't come to that though.

Thanks. I like that idea of a flexible air dam, maybe easily removable as well since most off-roading occurs at speeds where aerodynamics is not a concern. Depending on how well the aeroshell works out and depending of if I get itch for more aeromods, I may just rebuild the front bumper with aero in mind.

I like your Tacoma. It looks like you provided lots of good information. I'll have to spend some time reading through your posts.

Today I got a bunch of stuff ordered to finish the shell. I ordered the fiberglass cloth, epoxy, varnish, a sheet of polycarbonate for the windows, and a bunch of miscellaneous hardware to put everything together. I am pretty sure this will end up costing me about the same as a new basic model camper shell, but doing it this way is a lot more fun though.

I also finished laying out the cedar strips on the passenger side of the shell. Here is the progress:

https://lh3.googleusercontent.com/cr...A=w600-h337-no

https://lh3.googleusercontent.com/0H...c=w600-h337-no

https://lh3.googleusercontent.com/kO...w=w600-h337-no

https://lh3.googleusercontent.com/Uv...E=w600-h337-no

https://lh3.googleusercontent.com/vY...A=w337-h600-no

Beatiful work.
I am confused a bit about your order of fiberglass cloth. Do you want to cover the shell with fiberglass? In my opinion just clear coat should suffice. Do not cover this nice woodwork. Or is fiberglass for other reasons?

I am doing the fiberglass in a way that will make it completely transparent when done. Pretty much all the cedar strip canoes have fiberglass over them. It will basically just look like a thick clear coat. I probably don't need it, but I think it will be worth doing.

Aha, I didn´t know. Thaks for clarification.

Custom work for the price of a commercial product IMHO is a win.

With the flexible air dam, take care against the air pushing it out of shape. Curved outer ends would help. The straight center section could be shallower for less bending, and to clear high centers and form spats in front of the wheels.

Very well done
The shape is accentuated by the slats. Nice
Anxious to see mpg results...
Careful of water inflation at bed cap joint /stake pockets at speed .
I'll be able to comment about the square dual step at the edge of the bed soon. As I think that it causes turbulence on my cap. Maybe router the corners down to an angle or at least radi. them.maby even convex.

Agreed, I am a big fan of custom work as well.

Good ideas for the air dam. I'll keep that in mind when the time comes.


Thanks. What do you mean by water inflation? I am planning on smoothing out the square steps on the bed rails. It doesn't seem like they would cause too much trouble though as they are parallel with the air flow.

I finished up laying out the cedar tonight. Next up will be trimming the excess and lots of sanding.

https://lh3.googleusercontent.com/YD...M=w600-h337-no

https://lh3.googleusercontent.com/Fp...g=w600-h337-no

https://lh3.googleusercontent.com/Cc...A=w600-h337-no

https://lh3.googleusercontent.com/v0...o=w600-h337-no

https://lh3.googleusercontent.com/gU...E=w600-h337-no

https://lh3.googleusercontent.com/Np...A=w600-h337-no

https://lh3.googleusercontent.com/n4...U=w600-h337-no

https://lh3.googleusercontent.com/Vk...g=w600-h337-no

Looking good!

Damn that's pretty.

How are you going to open/close it? Hinge near the back of the cab? Just a small door in the back?

Sam

Could you please post a very close up photo of a slat joint at the ends?

I'm imaging something like the below image which I found on the Internet.

MLCS Flute and Bead and Tambour Door Router Bits
http://www.mlcswoodworking.com/shops...nd_bead112.jpg
Excellent work, a thing of beauty.