Bullet Tear

[C5shark]

Hi all!

I just got registered last night so I thought I'd stop in and introduce myself. I'm new to the camper realm, but after seeing a friend's teardrop a couple weeks ago I got inspired to build one. The intended use is going to be for traveling to various SCCA and pro sportscar races where I generally have access to facilities, but am just getting lazy about setting up a tent.

The tow vehicle is primarily going to be a 2014 Chevy Cruze, 1.4L turbo with manual trans, although it may occasionally get hitched to the GTO. The Cruze doesn't have gobs of power, so my goal is to keep things pretty bare bones in order to stay light. I'm also trying to incorporate some aero-efficiency into the design (using my limited knowledge of the subject) to aid the Cruze in towing. What I've settled on as far as requirements are, roughly 60"W x 48" H x 96"-108"L. I'll be building a trailer to suit the camper so i can maximize weight savings and place the axle properly to keep the tongue light. And of course, it will be a foamie!

I've never built something like this before, but I am just going through some various designs to see what will work best for me. Here's something I began drawing up last night, maybe this is a little crazy/ambitions/impractical, but again I'm just brainstorming.

The dome is 48" at its highest and 60" at its widest points. The domed section is 2 feet deep with a storage cabinet/seat designed in. The main body section is 7 feet long, tapering to 36" x 36" at the rear. The problems I have with this are 1.) The door would be small, maybe 30x30 at best. Is this too small? 2.) The curved sides and rear door make adding in any additional storage space nearly impossible. I may end up going with a more traditional shape just because it's so much more piratical. Also, my apologies for the somewhat half finished pictures and lack of the sketchup file. I can add better images when I get home from work. Let me know what you think!

[Mary C]

Welcome, You have ambitions!!! I have been on here for about a year and a half and I have read practically the whole forum so might I suggest that you read the Foam Stream build and through the foamie sections above and the other builds and perhaps some the lightbulb sections above were highlighted above not for questions but so you will get some of the information we have found through our builds. please read them, Our Thread here is Thrifty alternatives.........Notice Thrifty is the operating word. and remember we have proven certain things..........read above!! So now to answer .........looks like your plan might work, my thought is about the height vs width as our main caution in the design phase. Other than that we are not overly concerned in approaches to builds. You might want to check and find out what your vehicle can pull and be mindfull of that when you get your building supplies. To me a 4 cylinder manual suggest at the most 1000 pounds and that is pulling weight. I may be wrong but definitely a light weight TD.

good luck and welcome

Mary C.

[juanrc24]

Hi all I'm also new to the camper world, will be assisting the C5shark with his build in order to learn from his mistakes so I can build mine next year.

[Mary C]

Welcome to the foamie section, read over my build Grits and the Foam Stream builds Where are you building this build (in a hut, garage,barn,driveway yard or like me all over my house and porch and barn.and what are your names your first will do. I just like to know where you are so I can send you to people who know where to get stuff, also it helps others in your area to be able to help you out. And having a name keeps us from calling you by different things, and we are famous for giving you names like: Homer, Fert, Mabel, Augustus, and to what some can find any number of initials including jt rj bm p- just give us a name please. I don't care if its your brothers name or your next door neighbors Just a name. Look under the user control panel to insert your location . And we love pictures Lots of pictures. and Bears are , and we dont like flying frozen turkeys, I suggest the Thrifty Alternatives thread, yes its long and really filled with off the subject talking but you will get to know us and this will give you an Idea of how much we think we know.

Mary C.

[mezmo]

Hi C5shark,

Welcome to the forum and the Foamie section!

Here's a link to the Foamie 'aero' thread. It has a lot
of info to consider.

viewtopic.php?f=55&t=49036

Maybe the biggest help in aero is to size the front
cross-section of the trailer to be at least no bigger than
the ending or the max cross-section of the tow vehicle -
i.e. try to match the shapes, and to have some taper to
the rear [in all planes] for the Kamm effect. Your starting
design looks to be close. The idea is, that since the tow
vehicle has already "punched" a "hole" through the air, keeping
the trailer within that "hole' allows you to not have to push
any additional air out of the way. Keep in mind this is not an
exact science in the Foamie Aero thread,but a collection of
principals, that if applied should give you aero benefit. E.G., If
the tow vehicle is a van or a PU with a cap then the front
of the trailer doesn't really need to do anything other than fit
within the the tow vehicles end cross-section. If the tow
vehicle is a sedan or fastback car then some aero shaping on
the front of the trailer, at least starting at the top height
of the car trunk end should help some too as it has to redirect
the air flowing off of that to go around the trailer. Your design
looks good for that too.

The other thing that always helps and should always be done,
is to radius all the edges where any body planes meet. Even the
smallest of a radius helps.

Insofar as wondering about how hard it's be to fit storage in
a non-box shape, one approach could be to do a series of shallow
cubbies along the walls created by using some deeper ribs along
the walls, having the space between them forming the cubbie
areas. If I can find the two examples I'm thinking of, I'll post
them this thread later.

Cheers,
Norm/mezmo

P.S. I found them much faster than I thought I would:

My post about a youtube video:
How to build a teardrop trailer (Bonneville Style)
His technique is interesting, and could be tweeked for
less weight.
viewtopic.php?p=1061696#p1061696
http://www.youtube.com/watch?v=VrBvbXH6DSY

This was a homebuild on seattle CL from a couple years ago:
[Click on the pic for a larger view.]

[rowerwet]

you are taking on a challenge building with that much curved foam, while in theory it is easy, (just heat to 190 F and it bends like a wet noodle) in practice getting a sheet of foam to that point is a bit harder. kerfing is you best bet, or using blocks of foam and shaving them down to the shape you want (check out the foam stream thread)
the big thrifty thread has lots of info, the best I can say is to skin the outside of the curve with fabric, then the foam will tend not to snap as the fabric will take the tension stress.
Whatever you do, I would recommend testing the construction methods you will use ahead of time (I'm building a small boat before starting my big foamie build) to avoid any surprises.

[GPW]

Then , there is the thought of using the bead board foam , that can be bent , unlike the Blu or Pink extruded foams ... especially if it has a tension safe backing, applied before the bend is initiated.
Big blocks of the same can be easily carved to any shape ... but it’s Messy !

[C5shark]

Thanks for the input. I still have a lot to read here regarding construction methods, when I dreamed up that shape I was imagining it would be done by applying some type of light adhesive backer paper (pre-skinning with canvas might be a good alternative too) to the foam and then kerfing it. The dome would obviously be the biggest challenge because it would have to be done as wedges and then assembled, but with a little practice I think it is do-able.

[GPW]

Or if you‘re mathematically inclined , done in slices , progressively smaller half circles, and then stacked and smoothed ...

[KCStudly]

For me, a 30 x 30 door would be too small. I think I recall measuring about 30-32 inches from my seat to the top of my head.

I think my doors are 32 wide x 40 tall, IIRC.

Mary's reference to height vs. width is a precautionary tale. Being so light weight, and depending on the windy conditions of certain regions, it is entirely possible to have your trailer blown over while driving in a cross wind! It has happened, and is a known phenomenon with tractor trailer vans, tall campers, etc.

There was a thread somewhere that explained the math to compare the moments about the far side tire contact patch from the equivalent wind force applied at the centroid of the side profile vs. the opposing reactionary force of gravity at the near side tire contact point.

It may have been in Catherine and twins Penguino build thread (she had the unfortunate flop over), or it was a spin off thread from that discussion. I can't remember for sure at the moment.

[GPW]

KC, I think Catherine’s incident was a turning point for all of us , when the Foamie part survived so well .. and the Steel was the part that was bent ... Up till then , no one really knew about Foamie’ durability ... An unfortunate and precautionary tale , but a confirmation of the structure and concept ... For which we are grateful !

[KCStudly]

Oh gee, I hope that didn't sound negative at all. Just something to be aware of so as not to commit a faux pas and have a blunder. Perfectly avoidable and navigable, so long as we are all aware and take appropriate measures.

Solution No. 1 = 500 lbs of beer (or one 500 lb. bear? ...I can't remember which ).

[GPW]

Brick floor might work ... Actually we’ve watched the FS in the wind in the yard ...(like last night ) The FS wasn’t even moving ...the wind seems to blow over it ... must be the rounded top ...

[GPW]

Couldn’t help myself but to make another self-explanatory drawing ... re: the dome roof thing ... Although I used a more Primitive (eyeball-TLAR ) method on the FS , I’d certainly use this method next time ... Much easier (save the math) and more accurate ... Easy to translate to thicker foams too ...just more math

[lthomas987]

GPW... I think you just got calculus in my trailer building. Not as good as getting peanut butter in my chocolate.

Actually that would work great. And using techniques for making stacked wooden bowls you could probably cut way down on material waste and removal.

http://m.instructables.com/id/How-to-make-a-bowl-from-a-flat-plank/step7/Stack-the-rings/