Cockpit Closeout Material

[volvo2f2]

Since we have departed from the composite monocoque, I am wondering how other teams do the cockpit closeout material on a tube frame. Underneath the frame rails or on top of them? More importantly, how do you normally fasten them to the frame. Thanks

[Pinkie]

In the past, we have used sheet aluminum to serve as the firewall/seat I am fairly sure it was held on by rivets, but this year we are trying to do something using composite material. The judges wanted to see more composites last year, and they didnt particularly like our 'lack of a definite driver position'.

[fade]

you might try something out of spandex like the pic shows. you might get laughed at though http://fsae.com/groupee_common/emoticons/icon_smile.gif

http://www.lightningbikes.com/f40.jpg

[Kyle Walther]

where in the hell do you find these pictures?

[carmaxxx]

what thickness of Al sheet do you use for the firewall? and what grade?

would 6061 and 3mm do?

Is it all right to have a (slightly) flexible floor made of Al sheet?

[Drew Price]

Are you guys riviting Al closeout directly into the frame tubing, and if so, are you worried about putting all those little holes along the tube? I have seen it done this way, but don't know how I feel about drilling holes all along my frame.

Trying to come up with a way to do it without composites.

Anyone do a series of small welds on steel closeout?

[BeaverGuy]

Before we did a combination seat and firewall we used aluminum riveted to the frame. It wasn't directly riveted to the tubes though. There were a series of tabs welded to the tubes and these were drilled for riveting to the aluminum. AS far as thickness, 3mm is overkill. Do you really want a 15lb firewall? We used the thinnest sheet we had and because we weren't bending it the alloy didn't matter. The only problem with a flexible floor is if you step on it. But ultimately it is up to what you are comfortable with.

[carmaxxx]

I'm talking 3mm because i plan to use the seat backing as a firewall. I'd need at least 3mm of aluminium for a rigid seat.

I also plan to use thin Al sheet for the floor, and due to the low thickness, it'll tend to flex. However, since there'll be ample chassis tube triangulation below it, it wouldn't matter.

What do you use for flooring?

[BeaverGuy]

3mm is still way thicker than neccesary. I want to say that we used 0.030" thick aluminum for our firewall, so a 1/4 as thick as your 3mm. Which in '03 was the seat back and in '04 was the mounting for the seat and it was plenty stiff. It did sag some but it was also stessed as it was intended to be a stressed skin in the chassis. Sag did increase when the car was warmed up and as the car aged. We used the same material for our floor closeouts.

[KU_Racing]

we used .030 aluminum sheet, fastened with threaded rivets for easy removal. I would not recommend welding the firewall in, as if you ever need to remove it you will have to cut it out. With rivets, it is very easy to drill the heads out and re-pop rivet the panel back in, and it can be done in a matter of minutes. The threaded rivets are a little heavier, but are even easier- just 6 or 8 screws held the firewall in.

[JerryLH3]

We've always used aluminum sheet held in place with tabs welded to the frame and #10-32 screws and nuts. It works well for us.

[Chace]

Over the past several years we have usually used a double layer of kevlar cloth with some sort of asbestos based heat shielding directly in front of the headers. We've never tested its fire-proofness, but the judges have never given us a problem about it. we usually just hold it in place with the same dzeus tabs that the seat is held in with along with a bit of speed tape.

[Steve Yao]

As discussed, close-outs vary greatly from team to team.

Some bond in composite panels for rigidity. Others will rivet in Al or composite panels. Others use aircrafts skins. Some fabricate complete body fairings. Many simply use a panel with holes punched in corners for zip ties. I'll note that Auburn won 2nd in design at FSAE-W with a few zip-tied panels. Cheap, light, no extra tabs, easily removable, dead-simple.

[GediBGU]

Originally posted by Chace:
Over the past several years we have usually used a double layer of kevlar cloth with some sort of asbestos based heat shielding directly in front of the headers. We've never tested its fire-proofness, but the judges have never given us a problem about it. we usually just hold it in place with the same dzeus tabs that the seat is held in with along with a bit of speed tape.

Hi Chace, what was the firewall thickness?
Did you handle the materials yourself or have a factory manufacture it?

- Gedi

[theTTshark]

Originally posted by GediBGU:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Chace:
Over the past several years we have usually used a double layer of kevlar cloth with some sort of asbestos based heat shielding directly in front of the headers. We've never tested its fire-proofness, but the judges have never given us a problem about it. we usually just hold it in place with the same dzeus tabs that the seat is held in with along with a bit of speed tape.

Hi Chace, what was the firewall thickness?
Did you handle the materials yourself or have a factory manufacture it?

- Gedi </div></BLOCKQUOTE>

You probably aren't going to get a reply from him considering the thread is over 5 years old.

[Charles Kaneb]

Has anyone tried really, really thin steel? 26 to 30 gauge, welded in? It might get loud but it might be really good for this.

[Z]

Charles,

Back in 2005 I suggested the "44 gallon drum chassis" (http://fsae.com/eve/forums/a/tpc/f/125607348/m/59910078621?r=93510309621#93510309621) (ie. a 0.5 to 1.0 mm sheet steel monocoque).

This is still my favoured solution for FSAE. The two main roll hoops as specified in the Rules. Side impact and other "Rules necessary" structures done as top-hat sections spot welded to the skin (should be fairly easy "Structural Equivalency" paperwork). No effort made to "triangulate" things, because the skins do that. No extra bodywork required, other than a pretty nose (combined with footbox access panel), and maybe streamlined engine cover. Much improved driver safety from cockpit intrusion of foreign objects (seatback also steel, and part of structure). Quick, cheap, and simple production car fabrication methods (ie. origami + spot welder).

And super stiff, very strong, and possibly less weight than conventional space frame.

Z

(PS. A sheet steel version of the WWU Twin-Tube (in abovelinked thread) would also work well.)

[Alex Lewis]

Two years running now we've used bonded carbon panels in a steel frame chassis - single layer of carbon either side of 3mm of reinforcing foam provides a nice stiff panel.

These are laid in triangular shapes that fit in the gaps of the side impact structure etc and a large square in the base of the cockpit serves as the floor, all bonded in with two part epoxy.