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Hey I came across these guys while doing research on Radon. They seem to certainly have the creds to help us with this issue.
Two of them have a PhD's in mechanical engineering
One was an Assistant Professor of Mechanical and Aerospace Engineering at the University of California
One has a ton of composite experience.
http://www.technq.com/Personnel.html
I think they'd be more than qualified to help us with our problem.
Jimmy
I believe Kevlar is as slippery as it is tough. The blades need to be serrated.
Can it be properly bonded to polyester resin? I'm assuming the Kevlar requires epoxy resin.
Brian
Quote:
Originally Posted by jimh3063
Weren't you the guy just asking someone else to leave the Radon out of it?
Quote:
Originally Posted by HazelNut
Do you have the experience to prove me wrong? I think I can do an adequate job backing up my opinion with hard facts. All you have to do is look at the evolution of chassis design from aluminum monocoque through composite tubs of today. You obviously did not understand the example I provided in my earlier post. That example should be within you experience, the belly pan on any FF or FC if it is riveted and/or bonded.
Steve I think Brendan's question is fair, what experience do you have with hybrid construction?
You've given examples of several cars back in the late sixties that had riveted skins that were outlawed then.
Knowing cars from that era, they probably had aluminum pop rivets at best as well.
Given that hybrid construction was outlawed back then instead of being fostered, who has built and tested a real hybrid car using modern materials that has been properly engineered?
I doubt retrofitting cars with safety panels would be an across the board solution.
If the panels don't add anything but safety, cost and weight, no one is going to install them unless they are mandated. I think we can all agree that is probably not going to happen anytime soon.
Given a new FC is north of 85K, this sport is not for the faint of wallet for anyone wanting to drive a new car.
If we are truly committed to safer race cars, it's going to take a generational change to new rules and designs.
Quote:
Originally Posted by jimh3063
Quote:
Originally Posted by jimh3063
That's my other brother Daryl (what was the name of that stupid show?).
Oh, and that's Teeter, not Tweeter. I'm insulted, take a time out....just kidding.
I'm way behind on this thread, also getting ready for PRI. As far as your question regarding the best method to fasten a panel, there are a lot of ways to put skin on the bones. Composites aren't very good in bearing strength or point loads (think holes with fasteners). Neither is wood, but they make things like roller coasters and bridges out of the stuff with proper design. One can't make blanket statements about materials because it is possible to make any material unsafe through poor design. We make lots of carbon panels that fasten to things like airplanes, unmanned vehicles, etc. and through the miracle of proper analysis and design techniques, they don't fall off. Increasing the bearing area by using larger diameter holes, adding flanged/bonded bushings, countersunk holes, metal or composite doublers, embedded shear plates and a host of other techniques can be easily done to transfer the point load to the rest of the panel. These can all be done in your garage if you like.
I can't see a simple way to attach an anti-intrusion panel of sufficient thickness without stiffening the chassis to some extent, but I'm not sure that's really a concern given the 6" rule. In the recent Radon project we compared three chassis designs: a tube frame with no panels, a tube frame with carbon panels, and a tube frame with aluminum panels.
All were designed to give the same target torsional stiffness and meet the F2000 rules. Surprisingly, at least to some of us, they all ended up about the same weight. The solution with the carbon panels was not the lightest, but it was by far the safest, and also happened to be the cheapest, most elegant solution. Whoever came up with the 6" spacing rule was either very smart or very lucky.
In general, if you want to add a side impact panel, it first needs to be thick and rigid enough to keep from wadding up like a dish-rag when that halfshaft comes knocking. It must also engage enough of the rest of the structure to distribute the load, just in case there is another car attached to said halfshaft. Two plies of Kevlar won't stop much more than a stray lugnut. You will need quite a bit more, say 1/8" minimum.
That's about 12 plies of 5 oz Kevlar. (BTW, Kevlar is about twice the price of other para-aramid equivalents and many carbon fabrics.) No matter how you attach this panel, it will be MUCH LESS STIFF than attaching similar clearly legal aluminum or steel panels, but MUCH MUCH safer.
In any case, adding any additional safety panels to your car is a moot point unless the recent COA ruling is overturned.
Darrin
Kevlar & some other ballistic fibers lose some of their properties when exposed to humidity, heat or UV light.Quote:
Originally Posted by racecr
Zylon was the miracle fiber until some officers down south left their vests in the trunk & the combination of heat/humidity was fatal. That has resulted in a roughly $30M settlement & the product being pulled from the market. Zylon is still mandated in IRL & F1 for side impact protection I believe.
In a composite panel using these fibers, you need to overdesign a bit & it is a good practice to seal any exposed edges with resin. Kevlar & other para-aramids are not very good in compression either, so that should be considered in structural applications.
[[FONT=Verdana][FONT=Verdana]Steve,[/FONT]Quote:
Originally Posted by S Lathrop
[/FONT]With all due respect, that is a very generalized statement. A joint can be the "weak link" but properly designed it can be the strongest link as well. Using your “properly designed” tube frame example, a poorly designed weld can just as easily be the failure point. You do not tack weld the tubes and expect the joint to hold. Similarly, panel attachment points have to be engineered properly (although it's not rocket science, at least not for the past couple of decades).
I don't see anyone claiming that the riveted and bonded floor pans used in most cars (Citations included, I believe) are a dangerous failure point and have to be replaced several times a year.
Airbus, Cessna & others use very similar "hybrid" construction with composite panels attached to metal frames in their aircraft, and they don't seem to be falling out of the sky. :)
Despite all this talk of "hybrid" versus "pure tube frames," all the FC cars I've seen at the race track use "panelized" construction: stressed floor pans, riveted front bulkheads, skinned main bulkheads, bolted-together bell housings. If the rules really did require "pure tube frames" then all modern FC cars would be illegal. And you couldn't stress the engine, either.
[FONT=Verdana]
[FONT=Verdana]Darrin[/FONT]
[/FONT]
Wren:Quote:
Originally Posted by Wren
I'm dead serious. They're probably more than qualified to help. Those guys are pretty knowledgeable people who could be considered subject matter experts in their respective fields. If they can help me with my VD what do I care where they're from. I care what they know. Whats wrong with asking a knowledgeable person his thoughts on a subject. I do it all day everyday. I find is makes my life a lot easier. I'll take help where I can get it. If there are others on this board with those level credentials, I'm all ears to them as well. I will listen to anyone who can help me who knows what they are talking about. I think at this point to solve my immediate problem, I'm going to look into what it would take to implements Jay's recommendations. I don't think it's the best solution but it is the best I can do right now. I'd like to see the reg's changed to make the area around the "cockpit" open as it applies to rigidity caused by intrusion panels, if that means a safer car. I thought someone had mentioned the not so rigid part of a VD was the rear of the car anyway. That's not the part I'm trying to change.
Jimmy
Quote:
Originally Posted by S Lathrop
cool your jets turbo. I'm not trying to "prove you wrong", no need to get defensive.
I'm just asking a question.
I like the idea of a hybrid design, but I don't know if it's up to task or not. I've clearly stated I'm not an engineer. You've plainly stated that hybrids aren't up to the task. I want to know if that's your opinion or if it's fact. If it's opinion your very entitled to that, however it can't be passed off as a "fact". If it is fact please provide the proof (objective, repeatable, verifiable, test results) so that we can move our conversation forward.
As for belly pans. I'm a pretty ****ty mechanic and I always worked on my own cars and I've been known to offroad plenty. In fact going airborne launching off the rumble strips at the exit of the esses at road atlanta gives me a bit of a "happy tingle" in my pants. And that's pretty much like dragging the belly across an asphalt cheese grater lap after lap after lap. I was always able to keep the belly (aluminum or steel) on the car for at least a full season. The car goes down to a bare chassis every winter anyway so if I need to do a floor so be it. It's only an extra few days work.
After sleeping on the problem, I may have come to a viable solution Brendan.
Crazy glue the road kill trapped in Charles car after a long trip to RA on the sides pf the cockpit.
Quote:
Originally Posted by Dennis McCarthy
Dennis;
I am not certain that Brendan intended the question to be fair.
But more to the point, I have spent decades engineering in FA first and then Indy Lights. Most of my work has been with the T97 Lola, and the Dallara. I have worked on some very competitive cars and have wins on both oval and road courses. I think that qualifies as experience with composite cars. Building cars does not pay all the bills.
Directly related to this issue, I spent time in 2004 working on a Stohr DSR for a customer in Chicago. We won the divisional championship and qualified finished third and the run offs. I ran a torsion test on the Stohr when I started that project. That experience was a big help when I started the FB/F1000 Citation.
I have done torsion tests on most of the cars that I have engineered. I use the data for setups.
I think the Stohr qualifies as a true hybrid chassis?
On another subject, you put your finger on the real issue, $85K cars. The customer pool for cars that expensive is very limited. I don't have any customers that can afford or want to afford that expense. The only way FC survives is through having competitive cars that are available for half that. People can get on the track with good equipment for under $20K. I believe that this is why FC still survives.
If you really want to do something that is more modern, then why not go to F3 chassis but use FC engines, wheels, and tires. A new F3 chassis is about $85K especially if it were built for the F2000 market. Used cars are available for half the cost of new. I think that with the F3 aero rules and narrow track, the cars might make a very good match for the current FC. Something like this is a logical way for the class to go forward.
Short of doing a slow transition to F3 type cars, why change the way we build cars just so we can sell a few new cars and may be loose more existing competitors?
Improving safety is an other subject as well and I tink that is what we are discussing here.
Steve:
I do actually own of the chassis you speak of. I am more than willing to take photos of it or any part of it anyone has the desire to see.
I will say that those cars are very expensive to fix after a crash. I don't think that our class is ready for that expense at the non pro level to run this level of car. I think the mere level of expense to fix one of them will actually change peoples driving styles.
I will say, I feel VERY safe in it. It's built at a level that I've seen no where else. Really afraid of ****ing it up though for reason stated above.
I will say though, once you take a close look at those cars, you will change your whole opinion on what's out there.
Jimmy
it's not roadkill, the dead animal on his car are protection idols that our team shaman places there during the sacrificial blessing. It's the final step to prep the car, set corner weights, then call this guyQuote:
Originally Posted by jimh3063
You have stumbled on to a truth. If we keep the side panels as non-structural then we avoid the high cost of repairing composite tubs. Elan has panels for a very reasonable cost.Quote:
Originally Posted by jimh3063
Darrin has the experience to help here. It appears that there are some real possibilities. IRL added panels to the outside of the IPS cars. That is something we might discuss.
Darrin; the 6 inch fastening rule was from David Bruns.
Steve:
As I has mentioned before, I had left a vmail yesterday concerning their panels.
If anyone has hooks into Elan and can get pics and pricing, please do and post.
Jimmy
Brendan did intend for the question to be fair. If Brendan meant to be snarky he's just be snarky. Brendan is interested in exploring options. If hybrids are a cheaper, better, safer, more modern solution we should be looking at them. If they aren't we need to prove that they aren't, kill the concept and move on. I want to see FC thrive, I want to see racing thrive, instead we're watching it die on the vine.Quote:
Originally Posted by S Lathrop
And yes Brendan is aware that Brendan is referring to himself in the 3rd person.
SWEET!!! can we see this data and how it compares to similar pure tube frame sports racer? I'd also like to see some kind of comparative testing on saftey factors as well as cost of maintenance (chassis wear items) and chassis repair items.Quote:
Originally Posted by S Lathrop
40k you say? I'm highly doubtful of that. Were you able to build and sell a highly competative car for FC (or equivalent class, I was 5 in 1985, so I wasn't up on my legacy class designations) for 20k back then?Quote:
Originally Posted by S Lathrop
http://www.dollartimes.com/calculators/inflation.htm
Quote:
Originally Posted by S Lathrop
the concept is cool but the full tub (based on my readings, we should also gather empirical data to back this up as well) does seem to be an issue in terms of repair and maintenance, especially post big crash. If we had data to say otherwise and they turn out to be serviceable and cost effective and adaptable to the class and adaptable this is also something that should be looked at.
also baytos tried to float this concept for the cooper series and it was cool but proved to be unfeasable for whatever reasons.
I'm interested in survival and growth of the class (and open wheel in general). I'm not sure what that will take, but all the fighting and hair splitting isn't helping anything. We need to look to the future.
Steve:
I just want to make sure there is no confusion with people who read this thread, the Dallara F3 chassis is a full carbon tub. No tubes, no hybrid construction of any kind.
I think working in the confines of a tube frame with composite outer panels (cockpit) is what I've been trying to say all along. I personally don't' have the knowledge on how to pull this off but I'm sure one of the propeller heads on this board does.
As far as stumbling on a truth. It's truth I've know for quite some time. That's why the Dallara comes out of the garage only once in a while.
Like I said before though, it's at a build/quality level that I've seen no where else short of an ALMS prototype.
Jimmy
Brendan;
Two points:
1. The absolute cost of a car is not the issue. A better way to look at it is the cost of a car compared to US medium income. When cars cost about 50% of medium income you sell a lot. That was the case with FF in the 70's. I had several years where I sold over 20 cars per year. By comparison, Haas did 150 Lola's in one of those years. Cars such as Formula Atlantics that cost more sold a lot less. I will guess that the cost point for selling a reasonable number of cars for a class like FC is some place between 50% and 100% of medium income. Above that sales decline fast.
2. I have been doing my torsion tests since the late 70's when I built the Z14 FSV, an aluminum monocoque design. To the point here, the Stohr was about 20% less than the 94 FF/FC Citation. For comparison the Swift 008 was less than 3 times the strength of the same car.
Should we start putting everyone through metal detectors at the track so we can "feel safe"? Can you attach a number to "feel safe" that the car designers can target?
The fact is the Dallara "looks safe". There is no science describing how safe any race car is. No standard for the meaning of safe.
We do know that the errant half shaft coming through the cockpit side is an extremely rare event. It is simply not cost effective to prevent such events. We don't actually have any science telling us how to prevent them.
Brian
1. agreed
i'd be interested to see how the costs of FF from the 70s stacks up against its sports car contemporary (say a porsche 911) in terms of price VS the cost of a current FC vs it's sports car contemporary (say a porsche 911). Have race cars gotten cheaper or more expensive VS. a hot street legal sports car. Us ebing racers we're all pretty much into cars in general and most of us probably had some kind of sports car before we got into racing, and some probably had to decide, 911 or go racing in a open wheeler?
2. what exactly is your testing procedure?
is the issue with the stohr vs. your car that the stohr just isn't as well designed? Meaning that it's relative flexibility isn't as a result of an inherent flaw in the hybrid concept, but is an issue inherent to that specific design or perhaps just lee's construction method?
BTW i will be silent on this topic cus I'm traveling for the next while. Keep to discussion lively I look forward to tons of new info on the subject.
Brian:
The F3 chassis goes through some pretty rigorous testing by the FIA. I'm sure my VD would fail miserably. I think quality and safety of the Dallara shows in the construction. I've asked a lot of questions about fit and finish on things on my VD. I've gotten some pretty funny answers. The best one was why are there 9 and 10 tooth starters and the reply was "it depends on how ****ty the casting for my bellhousing was". I understand that when tubes get bent a little during welding as they heat up and then cool. Some of the chassis are so off there has to be something else wrong. NONE of this exists on the Dallara.
Maybe you haven't been lucky enough to drive a higher end Formula car. Try it and you'll know exactly what I mean.
Jimmy
Gents:
I just got this from Elan. The mounting looks shakey at best. I don't know enough about the composite Tegris that it's made of. They're 1800 a pair.
Take a peak. I think I'm about done after this post. I know what I need to do for me.
I FEEL like I'm about done although I have no empirical data to back that statement up.
Jimmy
I can't speak for your VD but the new RFR chassis passes all the F3 crash tests. I think everyone involved was surprised how well the tube frame car did in the F3 test.Quote:
Originally Posted by jimh3063
Side penetration was the only test not perfromed. That is the discussion at hand. How do we bring the tube frame up to some standard that makes sence.
The Elan panels look like a good idea. The mounting system should work well. The panel needs to stay put.
Jim;Quote:
Originally Posted by jimh3063
Why do you think the mounting not effective. It seems to me that it would do exactly as intended...hold the panels in place. It would also provide the benefit (in FC / FF terms) of not adding to the structural rigidity of the chassis.
SteveO
Steve:Quote:
Originally Posted by SOseth
I would feel (no data to back that up either) better if I wasn't drilling holes in tubes that are going to be used to take an impacts. I liked Dennis idea of welding something to hold them on and not drilling holes if I can avoid it. The brackets look like if they were hit the would break. Brian I have no empirical data to back that up. Just trying to head off a comment at the pass. They look like electrical conduit brackets. I'm sure we could find better brackets than that. I also don't know a whole lot about the composite it is made of, how many layers is it composed of and how much it weighs. I'm sure those questions can be answered.
Jimmy
Not most elegant looking hardware but looks to me most of the impact would be spread out over the surface area of the frame tubing. If the brackets break, I don't see the big deal as long as panels stayed in place.Quote:
Originally Posted by jimh3063
As allowed today looks like you can have something like this, plus Kelvar in bodywork and a cleaver seat to protect from bone on frame impact.
There are a variety of possibly methods to mount these sorts of side panels that do not entail hard bolting, riveting, bonding, etc. The question that remains for each of them is their effectiveness in keeping the panel in place correctly.
Such methods include:
1 - U-straps such as shown in the Elan pictures
2 - Wellnuts into steel taps welded to the sides of the frame rails.
3 - 2 panels similar to what Radon did, except that one is outside the rails, and one inside, bonded to each other, but with a loose fit around the rails.
4 - Exterior panels bolted at the 4 extreme corners, with u-straps or u-bolts at the center of each frame rail ( akin to the British requirements).
5 - Composite U-straps bonded to the outer skin, loosely captivating the frame rails.
Each of these may or may not captivate the panel correctly - we just do not know yet.
Each of these, while allowing the panel to perform to some decent degree, may only give us 20% of the potential of that panel if it were hard bolted at specific intervals. Again, we do not know.
Hopefully, we can somehow get some of these variations tested properly over the course of the winter.
With all this mending the rules, did I hear someone say that bead seats are now illegal:confused: The fiberglass seat that my VD came with, can not be that safe
noQuote:
Originally Posted by Peter Gonzalez
btw- no rules were mended. The rules clarification was withdrawn.
Richard:
I hope to use these panels or something like them. Are they illegal under the written rules, if they have fasteners closer than six inches?
Are they illegal under the recent extension of the rules by the COA, since they decided you can't have ANY additional cockpit protection unless it's steel or aluminum panels.
Trying to do my research "Look before I leap"
Jimmy
Wren:
So the none of this thread matters?
Jimmy
Quote:
Originally Posted by jimh3063
I can't even follow the leap from me saying that no rules have been meddled with to you asking whether or not the thread matters.
You are just making stuff up now.
Wren:
I think Peter meant to say was "amended" because the COA changed the rules from what
is actually written in the GCR. From their opinion:
"The opening paragraph for the FC rules (2010 GCR, page 180) clearly
declares that this is a restricted class and any allowable modifications
must be stated in the rules, and there are no exceptions. 9.1.1. D.7.b
clearly stipulates the materials that may be used for intrusion
protection and carbon fiber is not listed."
Bead seats provide intrusion protection, and they are not listed in the
rules specifically, so they are prohibited.
That also means you can't use any sort of protective seat unless it's
made from steel or aluminum. Am I not getting what was written in an effort to clarify? It seems very specific.
You can't make this **** up!!!
Jimmy
You are just trolling now.
Wren:
Not even a little. Just trying to understand whats allowed. I'm not sure why quoting rules is trolling.
If I misquoted something, please point it out and I'll stand corrected.
I would actually appreciate it if John could comment on my last post to this thread as to it's validitity.
Jimmy
What if some one poured a bead seat which went all the way up to the top frame rail and had a sheet of Kevlar or carbon fiber buried in the beads?
Some ballistic protection without illegally stiffening the chassis.
Just a wild idea. I will not be hurt if anyone who knows better explains why it will not work.
:)
No, mending is what I said...
But look at this, the opening paragraph for the FC rules (2010 GRC, page 180) clearly declares
that this is a restricted class and any allowable modifications must be stated in the rules, there are no exceptions. 9.1.1.D.7.b clearly stipulates the materials that may be used for intrusion protection, carbon fiber is not listed.
Bead seat material is not listed either. So I guess you can't use anything but aluminum or steel in the cockpit?
Peter
When the rules stipulate that no modifications are allowed, this simply does not cover absolutely everything you can think of but only those that are listed. Does this mean that you cannot have a seat in a car because a seat is not listed. Of cours not & it would be silly to think that seats are not allowed because they are not listed.
Thanks ... Jay Novak
Isn't selective enforcement of gray areas where a lot of this carbon argument started? I agree with Jay on the seat thing. I will say that the wording seems to lead to many potential contradictions though. Wren, thats what I was trying to get across last night. If someone really wanted to go the distance and protest based on the letter of the law, the seat could be deemed illegal.
Jimmy
Let's say for the sake of discussion that your VD was delivered with a seat, any seat or no seat at all. Are you supposed to sit on the frame.Quote:
Originally Posted by jimh3063
Jimmy, the carbon side panel issue was/is not a grey area st all.
Thanks ... Jay Novak
So what your are saying Jay that is if an item is not prohibited specifically it is allowed?
Steve,Quote:
Originally Posted by S Lathrop
Would you, or anyone else, know whether the RFR was actually crash tested or if the design was validated by analysis. I am having difficulty finding much on the Euro standards that it may, or may not be, certified to. I believe their website says “designed to comply with the FIA crash test requirements for 2009." On another post, someone said that Firman indicated the car “did well’ but did not pass all the tests. I do know that the RXXXX Rn.10 chassis meets the 2009 FIA roll cage standards WITHOUT the cockpit panels installed (per GCR 9.4.5.F).
We had set up a test rig to perform static crush tests (for energy absorption) for the nose cone & tailcone structure. (They were low-cost, very F1-like carbon fiber impact attenuation structures.) We also intended to set up a quasi-static FIA-like side impact test using the tapered cone method. I now have a sufficient pile of scrap to test, but not much motivation to do so :(
There was also a test plan in place to torsionally test the chassis & some trick methods for revealing any “problem areas” in the panels that may have crept up during initial track testing.
Darrin
Some of the inductive reasoning in this thread is beyond mind-boggling.
It was actually crash tested under FIA supervision. The FIA is actually developing standards for tube frames. This is what I was told in several conversations with Baldwin and Firman.Quote:
Originally Posted by Darrin Teeter
I did a lot of torsion testing on a frame when I was developing the Z16 FF. That was on a bare frame. It helped a lot as I finalized the design in 1978. More recently I have used FEA modeling (first on the 87 Citation and then extensively on the 94 model). Most helpful has been the testing I do to confirm and monitor a car once it is done. That is a test of the car as raced. And that is the same test I did on the Stohr and the Swift 008.
The interesting thing for me is the high correlation between the FEA analysis of my frames and the test of the finished car. The test is simply setting the car up without shocks and springs. One end is supported on the suspension and other on a pivot point. Then I load one corner of the pivot end with weight and measure the twist of chassis at each axel center line. If you add more measuring points you get a good idea of what a chassis is doing and where you might have a problem.
The 008 Swift was interesting because conventional wisdom proved to be wrong. The car had a bigger problem that most people missed at first. I did not work with the car very long but I understood that Swift had to address the problem I found.
Doug;Quote:
Originally Posted by Doug Carter
If you ciould boil down all the posts and skim off the slag, you might have a good book on race car engineering.
Off Season Cabin Fever must be spiking.Quote:
Originally Posted by Doug Carter
[FONT=Verdana]If the method has been shown to work in the UK (I can't find any evidence of that), then I would vote for option 4, but I would also leave room for some good ‘ol Yankee ingenuity and see if we could improve it.[/FONT]Quote:
Originally Posted by R. Pare
[FONT=Verdana]However, if the intent is to eliminate the possibility of stiffening the chassis, then option 4 wouldn't accomplish that. Of course, if you want to completely prevent side panels used for stiffening, you have to eliminate the currently allowed option of attaching steel or aluminum on 6” centers. In the analysis we did for the Radon project we found one with aluminum side panels to be the lightest (not safest) structure of the three we tried.[/FONT]
[FONT=Verdana]Changing the 6" rule would make some cars illegal, I assume.[/FONT]
It has got to be apparent to more than a few that there are areas where there is just "an accepted practice" whether the rules allow it or not. A fresh set of eyes takes a look at the GCR for what it says and doesn't say....upsets the status quo...panties get bunched.
If it really was that black and white we wouldn't have all these really long threads about the Radon, the Geartronix and wheel "covers". More to the point, the CRB and the COA would have agreed to begin with.
Do we really want to define a seat? Do we want to define how it may be attached? If you (generic) are going to stand behind the "If it doesn't say you can then you can't" type clauses in the rule book then you certainly need to give that some thought.
I'd say make a bead seat the goes from the roll hoop to the front bulkhead. Form the sides out of resin cured spider silk if you wish and then fasten it to every frame rail it comes in contact with 6" on center and declare it a "seat".