My aero (hopefully) fiberglass foam truck camper
 

With lots of people on ecomodder building aeroshells , boattails,trailers,kammbacks etc. I thought i would try to build a truck camper and maybe incorporate in as much aero as I could since I am building from scratch anyway.

My goal is to maintain or maybe exceed the mileage I am getting with my old camper (14-16) and stay under 1000 lbs dry weight as well as include a small bathroom in the new one. I always wanted to try the fiberglass/foam thing like I have seen here on Ecomodder by 3-wheeler and others and since the camper needs to be lightweight I went for this method.


Any suggestions or comments or questions are welcome but please remember that certain things in the design are fixed like cabover height and the roof height at the very back.

I can still make some changes since the main panels are not glassed together yet.

Things I incorporated to hopefully help aero
Tried not to go past the windshield with the cabover.

Keep cabover to truck roof clearance as close as possible

Built in some taper when I glassed the sides. The front and back are 3 inches narrower then the middle. Not much I know but the windows still have to in and they are flat.

I am planning on a 6" or 7" radius where the sides meet the roof and the front cabover. Should be doable with foam. I am wondering about what radius should I use where the sides meet the rear panel should it be less ?

Going to build a hinged fairing to help with airflow at the truck rear door window area

I am looking for advise on the cabover length .I really would have extended further past the windshield but not sure how much it would affect drag.. I could still change this without too much trouble. Also the roof is really just a straight line as it is now as you can see in the picture . Is anything to be gained by giving it a curve ?

Hope the pictures show up
This is what I hope to end up with

http://ecomodder.com/forum/member-tu...-base-only.jpg

http://ecomodder.com/forum/member-tu...de-profile.jpg

http://ecomodder.com/forum/member-tu...lamps-duct.jpg

http://ecomodder.com/forum/member-tu...e-clamping.jpg

http://ecomodder.com/forum/member-tu...icture-056.jpg

http://ecomodder.com/forum/member-tu...retty-good.jpg

http://ecomodder.com/forum/member-tu...ate-camper.jpg

Like your project! :thumbup:

I don't think the aero template is going to do you much good in that situation.

You can keep the sides and top to rear junctions absolutely square. Then you should put a folding boattail on the back like the semi-trailers have these days. That's what I want to do to my ginormous Lance which is only good for 10 mpg on the ol' '76 Chev. :mad:

I'd also say that if the height at the rear is fixed, that it be the max height throughout thus cutting some frontal area out... but I know it's awful nice to have some height above the cabover.

Radii on those vertical edges right behind the cab would be good too, to the extent they stick out from the cab sides.

Radii on those vertical edges right behind the cab would be good too, to the extent they stick out from the cab sides.

Which could be added later. Maybe as separate pieces for when taking camper on/off, but clean it up (smooth transitions) when installed.

Folding, removable boat-tail makes real sense.

.

Looks very nice. I anticipate you going below your weight goal.
DO you fly the thrush?

As you were building from scratch, could you not have considered making it a pop-top to reduce frontal area?

It does look a very nice shape however...

I've always hankered over a small tear-drop shaped trailer/caravan, that we could tow easily and over-night in.

Seeing your method of FG over foam has the wheels turning and thinking maybe I could build my own...

http://www.365campingcaravanning.com...d_trailers.htm

Thanks slowmover, Maybe I will do something like this out of foam and hinge it to the camper so I can open the rear door.
Attachment 10438

Attachment 10439

Big outside and roomy inside.

Bigger than what I would have done, but nice.

Too Complex?
Automobile 2 - Odds and Ends pictures by kach22i - Photobucket
http://i184.photobucket.com/albums/x...o-Camper-2.jpg

Kachi, push it on up to the original front height, see what that looks like. Give the guy some headroom in the bunk.

Thanks, So far the shell looks as though it will come in at less than 0.8
lbs per sq ft. or about 320 lbs or so (just the shell, no paint ,windows, or interior) ....and yes I fly the thrush. Its one of the first turbine models Ayres made. You fly?



Thanks...I thought about a popup believe me but since this fiberglass and foam thing is new to me it seemed a little easier to build a hardside. Maybe down the road I would like to try a hardside popup.

I am really pumped about this method of construction .It is incredible the radius you can do. All you need is a tablesaw. Here is ordinary Home depot foam in 2" Attachment 10440

and 1"
Attachment 10441
You can even make compound curves if you kerf it both ways with the tablesaw. If you are kerfing large panels like I was you should make a simple plywood throatplate splitter for the table saw.

Thanks so much for the detail pics. I have a leetle projeyct of my own......

Very nice job you have. Yes, I fly a straight tail 310 (skyking) and used to fly banner tow before 9/11.

You must be back east somewhere, nobody is doing a really cool project within driving range.

Yea, kind of tight up there in the old bunk. Little kiddies only, no room for adults doing adult things.:p

Thanks for the input kach22i . It is easy to see that you have some good ideas. I just need more headroom in the bunk like skyking said. My old camper had 35" bunk to ceiling and that allowed a short person to sit on the edge of the bed and that is good when space is at a premium. I do like the rear pop-up idea to reduce the wake.
Got me thinkin...Thanks

Re: behind the cab radii: I was thinking you'd cut those in, same as you'd do above, rather than add something on that comes ahead of the back of the cab.

I'd like to offer some advice. Reading this report http://csus-dspace.calstate.edu/xmlu...pdf?sequence=1 gave me some information I think you might find useful. It's about testing pick up trucks and aerodynamic bed configurations. These are the drag coefficient figures for aerodynamic toppers simply cut at an angle downwards, instead of a suburban like back end or a pick up truck bed.

Baseline 0.3453
Traditional canopy 0.3157
5degrees 0.2957
10degrees 0.2894
12degrees 0.2892
15degrees 0.2987
18.7degrees 0.3091

Now as you can tell the 12 degree slope has the lowest drag coefficient, however it isn't much lower than at 10 degrees or 5 degrees.

This suggests to me that in this case, instead of following the template as you would do on a boat tail, you may want just a slight taper on the top and sides. Even just a few degrees. That way you end up with a fairly significant drag reduction, without impeding the usefulness and spaciousness of the topper.

If it isn't going to be a huge engineering challenge I think the pop up design would be very useful.


Whatever design you do choose I'm looking forward to seeing it all come together.

Good point. What you suggest makes the most sense rather than dealing with hinges and fairings but i am going to put the jacks in a hollow tube "receiver" in that area so I can remove them easily for travel. The green square in the pic.Attachment 10443

Can those front jacks go back 4-5", right behind the radii?

Wow lots of stuff .Was not expecting such good results at 5 degrees.Thanks a lot

Cool. Never did any banner towing. I'll watch for your areoshell thread. And yep East Coast

Excellent project. I can't wait to see more. Rock on!

Still wondering about the cabover length and will it affect the cd ?
I now have a copy of Hucho's book and I refer to his roof load info..Now it appears to me that if my camper overhangs the windshield even just a little as in #3 , it has a definite effect on the Cd. Attachment 10530

So since I don't have the major panels fiberglassed together yet I thought I could move the side panels rearward and fill in the rectangles behind the cab and live with a slightly narrower bunk... and at the same time try to get a 5 degree roof angle as Yugomodder suggested. In blue below

Attachment 10528

I may also incorporate a small molded-in 10 or 12 degree Kammback on the rear if the rear door permits ( I need a drip edge anyway )

On a side note since I hope more people use this glass/foam method . I am on my last big piece and I found you don't need any clamps at all ...just duct tape. It works great in shear. And I didn't even use the 3M stuff .What you do need is a dead flat table which you can make out of old recycled hollow core doors from Habitat Restore joined together with biscuits (no glue) Use gauge blocks or a long straight edge to keep them straight and winding sticks to remove all the twist. Mine was 13' long at one point and setup takes only minutes .Works like a charmAttachment 10529

Advice, comments and suggestions always welcome and thanks to all those who replied so far

Turbo, on the cab-overhang have you considered rather than shortening the whole width instead radius the front edges in top view? Air splash creates a bow wave which increases drag. Hucho's section on trailers shows this clearly and Cd reduction as a result of edge radius. Food for thought?

Keep up the great work!

overhang
 

I'm very late to the party.Sorry!
With respect to the overhang,I suspect,that if you cantilever out beyond the windshield header,that the underside of the overhang will begin to act like an inverted splitter,directing some air under and to the sides rather than up the sloping nose of the camper.
Some of the centerline flow will displace far in advance of the shell/cab roof intersection and just go on up over the top.Streamlines below there will be directed sideways around the A-pillars and up into the void between roof and shell.
The hard edges as many members have mentioned,are sure to produce immediate separation.Hucho will have two formulas you could look at,one based on a single dimension (say width),the other,on the squre-root of the frontal area of the shell.
These would offer 'minimums' for attached flow at zero-yaw.You want as much radius as you can stand to build.In crosswinds,this is where you'll save big time.I realize it cuts into interior space so you're the boss of that.
If you do decide to push the camper out past the windshield,I would recommend that you 'soften' all the edges around the 'splitter' area.There's gonna be some wicked transverse flow,a lot of shear,a mixture of velocities attempting to marry one another,and it's a breeding ground for vorticity which may cause so much wind noise,the weather stripping and seals around windows will be overwhelmed,making a loud stressful driving environment.
If you absolutely must use the hard edges you might get some relief with VGs,used just to break macro eddies into micro eddies,altering the frequency to something you could live with inside the cab.
I used to drive a 35-ft moving van with cantilever box.You could clearly hear the sheet metal tin-canning as the turbulence was beating the s--- out of it above my head.Very stressful.:p

My understanding of his plans was that he was always going to radius those leading edges.

There is another way to fix the flow on those leading edges and that is to attach curved edges of the appropriate radius to the sides, that stand proud of the front face. Aerohead, you remember those?

attached edges
 

Frank,I do remember.Dr.Paul MacCready got a US Patent on such a thing.
Hucho has a depiction of such devices back in the commercial vehicle chapter on the face of a trailer van.
The fella with the dump truck was doing this with PVC pipe sections.
It would be way out ahead of nothing,and maintain some interior space otherwise lost.Especially where the jackstands are going.

Sorry guys I was away for a few days and didn't get to respond until now Thanks Aerohead and Kamperbob. OK no overhang for me .. Like Frank Lee mentioned I'll for sure radius the edges ( sides to roof and sides to front ) I am planning a nice 6 " radius in those areas and will do a mock up and post a picture later to show how I did it in case someone else wants to give it a try for their own project.

Are you guys talking about these?

On the front corners at the same height as the Mercedes badge?
http://www.emercedesbenz.com/Images/...252_08A982.jpg

Nope.

these?
 

No.MacCready came up with a half-cylinder device which attached to A-pillars and the windshield header,providing some radius where none existed.Dead air would pool inside the the inverted basin with the outer flow spilling over the new edge without separating.Way our ahead of nothing!

Hey Turbo, what's new w/ your project? Any updates?

+1

Inquiring minds want to know. :)

Nice camper !
 

I am in the designing stage of building a foam board fiberglass pop up truck camper. Can I ask what thickness your foam board is and how you did or will attach the boards together? Glue epoxy etc. ?

Also what does your framing look like ? Aluminum or steel etc.

Thank you in advance
Tommy

Any update on these projects?

I know old thread. I haven’t been on the form in a long time.. but i took a few pics of the camper I was working on a few years ago then it sat in the corner of my garage unpainted. Well I did get it painted

Looks great.

How does it sound out on the highway?

It is more quiet than my previous camper (Northern Lite 6’10”) which I thought was pretty good.

It looks great - nice work! I'd love to see it in person some day if our paths ever cross. (I full time RV all over the US. :)

So how did the dry weight come out?

That would be great...

Finished shell weight with door and windows is 473 lbs. But that does not include the remote jacks which are another 125 lbs. I will be under 1000 lb dry for sure but not sure by how much. I put in lifepo4 cells just too make sure.

Love this thing. Have a few questions.

How many layers of glass do you use?

Could you give a rough price per square ft of construction? This is foam, cloth, resin, paint.

I own a Toyota Sunrader, which is a C class fiberglass clamshell construction RV.

Absolutely love it, but would love it more if I could bump the good (for an RV) mileage up from 17ish to something the other side of 20.

As the kids are grown, we don't need the extra bed provided by the aerodynamic train wreck of the cabover.

I would like to build a very sleek, lightweight B Class Toyota motorhome on an existing toy RV platfom.

There are literally thousands of old stick and staple Toyhouses out there that have suffered the fate of most, which is they are structurally shot due to water intrusion. Many of them have perfect frames and low mile 22RE drivetrains.

These things can be picked up for a pitance. I looked at one a few years back. 40K miles. It had an Onan 2800 generator that was optional on these and can bring 800 bucks in good shape. I could have bought the whole thing for 800 bucks! Maybe less, but I didn't have a shop to work on it.

I would have the dinette/bed forward, galley midship and a V shapped wet bath in the boattail rear.

I really thing such a rig could make 20 mpg with the 22RE, maybe 22-23 with a manual trans.

Give it a tdi re-power and we're talking Vixen RV mileage! Without all the Vixen headache that come when you use Renault in any part of your drivetrain.