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DIY Tandem Travel Case

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Old 04-17-14, 08:55 AM
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DIY Tandem Travel Case

My poor wife injured her foot yesterday hitting a wayward rock on her morning run. She swore that it jumped out of no where. Now she is hopping around on crutches and barred from running or biking for the next month. The good news is that it should heal in time for our trip in June, and I am in possession of some newly found free time.

Looking at my bike, I am pretty happy with it as is - for now anyway. So I thought I would look into building a better way to pack my bike for the trip.

The traditional 2 SS cases work OK, but I have to completely disassemble and wrap the bike each time. I do like to tinker with my bike, but I rather not spend a few hours of my vacation time packing and unpacking each way. I am thinking that if I design the case just right, I can pack the bike with minimum disassembly hopefully reducing the packing and tuning time to less than 15 minutes. This would also make travel from hotel to hotel easier without a car rack.

So, are there anyone here who built their own cases who can guide me through this build?

Thanks,
CJ
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Old 04-17-14, 08:21 PM
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with your skill it will be impressive for sure. Check out this triathlon forum link for some ideas. I would love to replace my S&S cases with carbon just for weight savings but the cases have proven to be very stout and have held up extremely well under many many trips

Slowtwitch-think Bike Case: Triathlon Forum: Slowtwitch Forums
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Old 04-17-14, 09:23 PM
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This is what we did with our uncoupled Speedster:
https://www.bikeforums.net/tandem-cyc...rked-well.html

The hinged top is simply taped down with duct tape, replaced by TSA no problem.
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Old 04-18-14, 06:24 AM
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Great looking box Carbonfiberboy. How many times have you used it since building and have you run into any problems or possible redesign ideas since your initial post?
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Old 04-18-14, 10:22 AM
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Carbonfiberboy,

Very nice bike case! That thing looks indestructible. I am envious - your packing time must be less than 5 minutes. I also like the wheels. I can imagine my kid ridding that thing around the airport.
Any advise on the design and build of the case?

I made something similar in the past, but was not very happy with their dimensions and weight (24lb each).
Everything fit, but it took a long time to pack and unpack. Also fully packed at 50lb each and without wheels they were very awkward to handle.



This time, I think I'll attempt a case similar to what AKexpress suggested - fiberglass with intergrated wheels and handles. Toying with my bike dimensions this morning, I came up with this preliminary drawing:



The right case is standard 26x26x10in needed for the wheels. It should also hold the bike's mid section.
The left case is 28x22x12in and will fit the front and rear sections. Both cranksets will stay on along with the chain, derailleur, brakes, and cages. The DI2 essentially eliminated the need for post assembly derailleur cables adjustments. Not removing the brakes will eliminate the brake cables adjustments. The things left are the timing belt, eccentric, handle bars, saddle posts, and pedals. I am aiming for a 15 min. packing/unpacking time.

I'm off to learn about fiberglass.
Any issue with this material for luggage?

CJ
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Old 04-18-14, 10:51 AM
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For a much easier method of packing a coupled tandem that does not require full disassembly, here is an example of a Tri All 3 Sports - Velo Safe Pro ISP case model. 51"L x 16"W x 39"H (includes casters) and weighs 39 lbs. They have other size cases too, but this one is tall enough to allow leaving the the rear wheel installed (this particular tandem has a Rolhoff rear w/belt, so leaving the wheel installed was a key factor in packing it this way):


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Old 04-18-14, 12:03 PM
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Originally Posted by waynesulak
Great looking box Carbonfiberboy. How many times have you used it since building and have you run into any problems or possible redesign ideas since your initial post?
I could have made it a hair lighter by using 1/2" X 1/2" stiffeners instead of 3/4" X 3/4". It was stronger than it needed to be, but not much. Serious rough handling by the cargo crew drove the captain's seatpost (w/o saddle) partway through the box top, but nothing damaged. They picked the box up and threw it ~8' onto a pile of other bikes. Too bad for the other bikes, which had also been similarly thrown. Rigid case good. We've only used it twice, but would love to use it again! We'll be driving down to CA for a century instead of flying, so won't need the case this year.
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Old 04-18-14, 12:14 PM
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Originally Posted by chojn1
Carbonfisherboy,

Very nice bike case! That thing looks indestructible. I am envious - your packing time must be less than 5 minutes. I also like the wheels. I can imagine my kid ridding that thing around the airport.
Any advise on the design and build of the case?<snip>
It's made of 1/8" mahogany exterior doorskins. 3/4" thick cleats in the corners. Stiffeners every 12". Thick wood blocks at the ends of the bottom to take the caster mounting socket. Grainger parts:
Stem Caster Mounting Socket,PK5
Item no: 5VT35
Swivel Stem Caster,13/16"W,2"D
Item no: 4X948

Piano hinge for top is epoxy bonded in place, not fastened. Case is glued together with epoxy, fastened with air staples.

I weighed everything before I started building to get an idea of the possible: 70 lb US limit, 30 kilos foreign, 114" total of H+W+L, w/o casters if necessary. But the box was never weighed or measured by the baggage folks.
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Old 04-18-14, 01:23 PM
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I have a full size traveling case that looks like a LARGE Sampson suitcase with beefy locking clasps. The wheels pack in the foam lined lid. All you do is remove the seat post, and turn the handle bars sideways. Wrap the tubing in foam and strap down with valcro straps attached to case. Total weight is around 75lb.
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Old 04-18-14, 06:27 PM
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Ludkeh,

Love to see your case picture if you have one handy. What is the dimension of that case? Even with two cases, I cannot arrange my frame well enough to leave the handle bars attached.

Twocicle,

The advantages of the two 62 in. cases are that each are lighter and more manageable. Both easily fit into a rental car or taxi and travel free on flights. This project, for me, is also about the joy of solving a puzzle and the challenge of creating the solution.

CJ
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Old 04-19-14, 11:53 AM
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Light and strong, rigid foam such as Divinycell core with Kevlar and epoxy covering the foam. Should be able to be far lighter than wood, plenty strong and easy to reinforce in local spots as needed. With additional foam stiffeners, with Kevlar bonding them in place, it should survive rough handling with no problems.

PK
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Old 04-21-14, 10:40 AM
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Originally Posted by chojn1
Twocicle,

The advantages of the two 62 in. cases are that each are lighter and more manageable. Both easily fit into a rental car or taxi and travel free on flights. This project, for me, is also about the joy of solving a puzzle and the challenge of creating the solution.

CJ
Yes, I do understand the benefits of the standard S&S cases. I was only providing an alternative answer to the OP question regarding a reduced disassembly packing method to avoid "completely disassemble and wrap the bike each time.".

We have traveled with both a full size Bike Pro case (uncoupled tandem) and the standard S&S cases with our coupled tandems. The latter obviously allow more flexibility in choosing transportation means.

So you have a choice of case options to consider: full size, mid-size, compact. The larger the case the less disassembly required, but the more troublesome for extensive traveling abroad - it's a known fact regardless of whatever "worked fine for my trip" posts are provided.
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Old 04-21-14, 12:24 PM
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Carbonfiberboy,
I looked into ordering the casters from Grainger, but decided to use some wheels I am liberating from a set of in line skates instead. Any problem with your wheels surviving the baggage handlers? Seems like anything sticking out is fair game for their destruction.
Also, do you think they treat your baggage better when you make it look better and tougher?
Bill McCready of Santana seems to believe that hard cases get more abused than their soft sided cases.
My current homemade cases get so many scratches, and they never made it out of any airport without a TSA inspection. I think I'll make these cases look as much like normal luggage as possible. Maybe, they will have more mercy on carbon fiber luggage.

PK,
Kevlar and divinycell would be the ideal materials for this project. But, I don't think I want to spend that much on these DIY cases. I have some left over carbon fiber from the bike build which I would like to use. I don't have enough for the complete build, so I'll use some fiberglass for the base layers. Also, I am not as concerned about weight as I was with the bike, so I may forgo the vacuum bag technique and just layer on the carbon fiber sheets. Do you think that would be sufficient?

Twocicle,

I guess I am trying to have it both ways: the convenient of smaller cases and the ease of minimal dis-assembly. Here is what I have so far:


The boxes are the final size. The packing is pretty close to what I had envisioned on the drawings. As I had hoped, both cranks can stay on along with the chain. But, I cannot figure a way to leave the handle bars on.
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Old 04-21-14, 10:22 PM
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Carbon over glass should work well enough. The added expense of Kevlar gives the better physical properties of elongation rather than cracking.

If it were me and Glass was one of the materials, I would glass the cases, no carbon and paint it black, done.

I assume you will use a Balsa or styrofoam core with epoxy resin, thinner plywood will work well also but gets heavy.

PK
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Old 04-22-14, 07:01 AM
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How many layers of glass should I use?
Also, ridges or no ridges?

CJ
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Old 04-23-14, 04:27 AM
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Originally Posted by chojn1
How many layers of glass should I use?
Also, ridges or no ridges?

CJ
Explain more, glass over what wood? Ridges to add stiffness, as in internal to reduce external dimensions pr something else?

If room permits, I would add internal stiffeners such as an X from each corner to corner of each panel. Make this all from wood, then go two layers of glass on each side, one ply aligned and one at 45. Do the 45 as the second ply so the fabric bias is laid more easily over the stiffeners. I would do the carbon as a layer on the cured glass, wrapping each edge with overlap onto the other carbon by 1 inch past the edge. This edge could also get a protective trim to save the carbon. If the carbon or fiberglass splinters and goes into someone fingers, you will be headed to europe a
nd the bike will be going to Fiji with no paperwork.

PK
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Old 04-23-14, 08:45 AM
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The foam cores are finished this morning. I made them using a single sheet of 3/4" insulation foam.
When I get time this weekend, I'll start layering the fiberglass.



Once that is done, I can either leave the foam in place for padding and support or melt it with acetone and add alternate support structures. I am thinking of using Styrofoam strips rather than wood covered with several layers of glass. Do you think that will be strong enough?

I am also toying with the idea of pour-able foam for the support and packing of the frame. If it adhere well enough to the inside of the case, I may not need any additional support. The foam will also conform to the frame, eliminating any movement and need for wrapping. What do you think?

Exposed carbon fiber and fiberglass edges will be covered with hard rubber weather strips. Don't want my bike in Fiji unless I'm there.

Once again, thanks a lot for your help PK.

CJ
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Old 04-23-14, 09:43 AM
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Originally Posted by chojn1
Carbonfiberboy,
I looked into ordering the casters from Grainger, but decided to use some wheels I am liberating from a set of in line skates instead. Any problem with your wheels surviving the baggage handlers? Seems like anything sticking out is fair game for their destruction.
Also, do you think they treat your baggage better when you make it look better and tougher?
Bill McCready of Santana seems to believe that hard cases get more abused than their soft sided cases.
My current homemade cases get so many scratches, and they never made it out of any airport without a TSA inspection. I think I'll make these cases look as much like normal luggage as possible. Maybe, they will have more mercy on carbon fiber luggage. <snip>
Those casters are very sturdy, as are their mounting points. They did fine. I did set them up so I could have pulled them off if I'd wanted to - they weigh about a pound - but I didn't. Looking at bikes coming off the plane from Germany in Seattle, the hard sided tough cases were the only ones that survived. Everything else was pretty much destroyed, including having the wheels broken off our suitcases. Plastic wheels, plastic mounting.
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Old 04-23-14, 01:11 PM
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CJ,

It looks and would seem like you already know what you are doing... what help could we offer?

Your idea of foam for stiffeners instead of wood echos my thoughts. Looking at your foam work it appears you already understand the need for round rather than square corners. Glass does not like to go around square corners or joints and needs some curve to transition. Any stiffeners will also have to follow the rounded corner and seam rules. Given that I would expect that you can make foam core stiffeners plenty strong enough without wood cores. The idea of internal ribs is a pretty decent thought.

As to removing the foam from the inside, I would be inclined not to do that unless you absolutely have to. In fact I would glass the inside of that foam shell so you have glass on both sides. This will create a very strong structure and may not need any stiffening ribs. You could probably do some localized cuts in the internal side for just a bit more room here and there if needed.

Since you are using foam core/form I presume you are using epoxy resin?

Pourable foam inside around bike parts will add a LOT of protection and strength so long as you do not allow it to wrap around anything and trap it in there. With all the irregular shapes on bike parts and foam expansion I would think that a very large risk.

One of the real advantages of composite construction is you can tailor the structure to the requirements. In this case with your rounded corners I would not think rubber would be as useful as a couple extra plys wrapping around the corners inside and outside. This is similar to the wooden cleats used in corners of wood boxes.

One of the tricky parts is how you plan to handle the joint between box and lid?
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Old 04-24-14, 06:14 AM
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Originally Posted by Carbonfiberboy
Those casters are very sturdy, as are their mounting points. They did fine. I did set them up so I could have pulled them off if I'd wanted to - they weigh about a pound - but I didn't. Looking at bikes coming off the plane from Germany in Seattle, the hard sided tough cases were the only ones that survived. Everything else was pretty much destroyed, including having the wheels broken off our suitcases. Plastic wheels, plastic mounting.
CFB,
I think you have the advantages of a very sturdy case and a solid mounting point for your casters. Mounting the same wheels on my thin fiberglass/carbon fiber case would be a recipe for disaster.
Also you don't have to worry about the dimension of your case. I am at the 62 linear inch dimension limit. I am not sure, but technically I think they do count wheels.
So, I am designing a wheel well that is mounted inside the box with only a small portion of the wheel showing.

CJ
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Old 04-24-14, 06:56 AM
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Vroom,

Thanks for the vote of confidence. This project is a series of experiments for me - I've never done it before. I do enjoy experimenting; but, I like it more with more knowledgeable and experienced people watching. That way I don't deviate too much toward the wrong direction. Also, I am very open to new or different ideas and ways of doing things from other people's perspectives. My ideas are constantly changing based on the experiments and your feedback. So, keep it coming.

I do have to remove big chunks of foam to install the wheels, the pull handle, and the hinges. It may be easier just to melt the bottom foam and replace it with pourable foam afterward. The lid foam will probably stay. I played with the pourable foam that arrived yesterday. It is rather stiff when completely expanded. While this will provide great support, it does not provide as much cushion as I had hoped.

I am using epoxy resin, just because that is what I have left over from the last project. Glad I "picked" the right one.

The rubber weather stripping is for the edges between the lid and the box. I am still playing with ideas on how to align and weather seal the seams in the close position. It should be water resistance to withstand a little rain. Piano hinge like CFB's case would work fine.

CJ
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Old 04-24-14, 10:36 AM
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Cushioning... controlling movement is most of the battle here. You do not really need cushioning as much as you think.

Yes epoxy is the right choice for use with foam... polyester resin will melt the foam and generally NOT work the way you intended. I have successfully used polyester resin with foam, but I mummified the foam with duct tape first. I have heard of folks painting the foam with latex paint to seal it as well. Those techniques are most applicable to removing the foam core.

The removal aspect... the wheels was what I was thinking when I mentioned only removing what you have to. With a sanding drum on a drill you should be able to produce some nice arches matched to the wheel circumference and still keep the foam sandwich construction on most of the box. The foam sandwich is typically what is used in aircraft composite structures due to its combination of light weight and strength. By moving the structural elements further apart you get much better strength, glass or carbon fibers are best in tension/compression and poor in bending. A single layer of fibers puts most of the stress in bending where the fibers are weak. In bike terms think little tubes versus big tubes: big tubes light and strong BTW this is also why I thought stiffening ribs would be beneficial.

There are a couple directions you could try going on the seam between box and lid. One is to do the layup as one piece and then cut them apart. A fine tooth jigsaw could do this but even better would be one of the vibrating saws that have been the rage the last couple years. Those have suitably fine teeth and do plunge cuts. Woodworkers have been known to run a cube through a table saw to create a box/lid. The other direction is layup one side and then use as part of the form for the other layup. Saran wrap between layups will keep them from gluing together. Same for duct tape with the advantage of a bit of thickness for future clearance. Using this technique you could create a bit of an overlapped seam.

And speaking of saran wrap... on a flat panel layup like this plastic like saran wrap is fabulous to put over the top of the layup and work the resin around under. Can get almost vacuum bag quality that way. You might find some very interesting videos on the subject at the Expiremental Aircraft Association (EAA) web site. They have one using a baggie to create a pre-preg of sorts for hand layup.

And one last thought... do not mix resin types. I made this mistake years ago putting polyester over an epoxy joint and had a devil of a time getting the polyester resin to kick off over the epoxy. So once you start with epoxy you will have to stick with epoxy. You *may* be able to put epoxy over cured polyester but definitely not the other way around.
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Old 04-25-14, 03:03 AM
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Chojn, FWIW, I would skip the hinge idea and do a two piece case like the molded black one shown earlier. With your experience with the couplers, consider something on that basis, a slip fit. It will add a reinforced band around the case even if just a lid. The novelty of doing this is that with foam core, you can build the latches into pockets and have them below flush.

A snap latch that is spring loaded to seal but remains overcenter will be fine if recessed.

Remove the foam in those areas to ensure a solid mount for the latch on both components.

Not saying this latch but it gives you an idea what I mean.

TL - Over-Center Series Latches - Southco

PK
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Old 04-25-14, 08:28 AM
  #24  
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CFB,

I drew up my wheel mount yesterday:



It is designed for a roller skate wheel and will be recessed into the case. I'll print it up on my 3D printer later today.

Vroom,

Do you think fiberglass over the foam core would be sufficient? I either have to remove the core to add the internal support structures, or leave it and and skip the additional support. I could add external support, but I am trying to keep the design clean.

Great idea on the saran wrap. That is what I'll use on the frame for the pour-able foam.

No worries about the resin. It is the only one I got.

PK,

I think the piano hinge along the entire back side of the lid would give better support than two latch points. You are right about the need for a reinforced band around the case though. I was going to use rubber weather stripping at that site, but I think I need to come up with a better support and seal.

The latches from the old cases are similar to the one you showed but with out the spring load. It will be reused to save money and reduce waste.

What do you think about rivets, versus screws, versus epoxy for mounting hinges and hardware?

CJ
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Old 04-26-14, 02:07 AM
  #25  
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Originally Posted by chojn1
CFB,

I drew up my wheel mount yesterday:



It is designed for a roller skate wheel and will be recessed into the case. I'll print it up on my 3D printer later today.

Vroom,

Do you think fiberglass over the foam core would be sufficient? I either have to remove the core to add the internal support structures, or leave it and and skip the additional support. I could add external support, but I am trying to keep the design clean.

Great idea on the saran wrap. That is what I'll use on the frame for the pour-able foam.

No worries about the resin. It is the only one I got.

PK,

I think the piano hinge along the entire back side of the lid would give better support than two latch points. You are right about the need for a reinforced band around the case though. I was going to use rubber weather stripping at that site, but I think I need to come up with a better support and seal.

The latches from the old cases are similar to the one you showed but with out the spring load. It will be reused to save money and reduce waste.

What do you think about rivets, versus screws, versus epoxy for mounting hinges and hardware?

CJ
Expansion fasteners in composites can always compromise the hole and work loose compared to a tension or tension / expansion fastener. Closely sized holes and wide area washers may prove best for this application with threaded fasteners. Id you are installing this in the core areas, you wil need to densify those areas. Easiest way is to drill your holes. Then use a tool such as an allen wrench and work through the hole to remove the foam. You are doing this to prevent crushing when the fastener is tightened. Fill the area with a milled fiber / epoxy mix and cure. Use tape to keep the mix from running out. Once cured, redrill through the location, using the now visible filled hole as a guide. Wide area washers or full size doubler plates will minimize any disbonds or tear out.

As for the latches and piano hinge, the hinge is easy, but will require a true surface to fold without binding. The slip fit top, may or may not be best, but is easily molded from the first half.

As for internal support with no increase in size, you can add ribs to the foam. In simple terms, envision the letter W. If this is the side panel of the case, you can remove foam from the valleys. Apply fabric to follow the valley contours. Next fill the remaining valley, now covered in cured fabric / epoxy, with foam, then add a fabric poxy to cover this new foam. Done this way you will have internal ribbing with angled support.

The above can be tied into wheel locations of add reinforcement to open panels.

I do have a question, in regards to the foam, are you using low density styrofoam from Home Depot or Lowes?

FWIW, whenever possible, bevel all the foam edges 45 to allow the fabric to lay easier and provide a better load path. If you need to bond, foam to foam, always splice it with a Microballon / epoxy slurry, cure, shape them add fabric. Epoxy without Microballons to foam is not always best, it can give an inconstant bondline.

Curious if you have started making panels yet.

Let me know.

PK
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