is foam core fiberglass enough strength to be chassis?

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KinFung
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is foam core fiberglass enough strength to be chassis?

Post by KinFung »

https://www.youtube.com/watch?v=QESyuZVBkJ8&t=55s

look likes it is very easy to make :shock:
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RichardSIA
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Re: is foam core fiberglass enough strength to be chassis?

Post by RichardSIA »

What I saw in the video I would say no, mock-up only.

Lots of discussion in this oldish thread,
viewtopic.php?f=39&t=18798&hilit=carbon+fiber

But I still plan to do a plywood/foam main structure for my Tatum-13B Suzuki build.
Major difference is in the use of foam only as a filler for the wood structure.
Engine cradle will be tube steel attached to the rear bulkhead.
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ngpmike
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Re: is foam core fiberglass enough strength to be chassis?

Post by ngpmike »

It would probably take some engineering, but could be done! Jim Hall's Chaparral 2 race cars were a fiberglass monocoque, and there are a lot of foam and F/G airplanes flying around now!
Mike - Read my story at http://twinlakesseven.blogspot.com/
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BostonWill
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Re: is foam core fiberglass enough strength to be chassis?

Post by BostonWill »

My ex-brother-in law had a company that built composite experiential planes for decades (including military drones)! It can be done, but you really need to know what you're doing. It would take some serious engineering

Thom
Thom
KinFung
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Re: is foam core fiberglass enough strength to be chassis?

Post by KinFung »

BostonWill wrote:My ex-brother-in law had a company that built composite experiential planes for decades (including military drones)! It can be done, but you really need to know what you're doing. It would take some serious engineering

Thom

if it really work, there are many things can do

e.g. 3d print foam core parts
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ngpmike
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Re: is foam core fiberglass enough strength to be chassis?

Post by ngpmike »

The experimental aircraft arena is probably your best bet for advice and inspiration! One of the best books that I know of is "Moldless Composite Sandwich Aircraft Construction" by Burt Rutan. There are others out there but Rutan is one of the pioneers with an impressive track record!
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benny_toe
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Re: is foam core fiberglass enough strength to be chassis?

Post by benny_toe »

I think all F1 and Indy cars are carbon fiber tubs these days. The carbon is stronger than GRP for a given thickness ut for stress points you can make the GRP thicker.

Often thought about this but I really don't know enough go any further than wondering.
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KinFung
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Re: is foam core fiberglass enough strength to be chassis?

Post by KinFung »

benny_toe wrote:I think all F1 and Indy cars are carbon fiber tubs these days. The carbon is stronger than GRP for a given thickness ut for stress points you can make the GRP thicker.

Often thought about this but I really don't know enough go any further than wondering.

carbon is more expensive than GRP :BH:
KinFung
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Re: is foam core fiberglass enough strength to be chassis?

Post by KinFung »

ngpmike wrote:The experimental aircraft arena is probably your best bet for advice and inspiration! One of the best books that I know of is "Moldless Composite Sandwich Aircraft Construction" by Burt Rutan. There are others out there but Rutan is one of the pioneers with an impressive track record!

it really quiet strong

https://www.youtube.com/watch?v=biZ2Sl63nr0
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Johnsinski
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Re: is foam core fiberglass enough strength to be chassis?

Post by Johnsinski »

The BEC book talks about aluminum honeycomb construction and bonding stuff together. I wouldn't trust my skills on that. Welding steel is relatively easy and reliable.

But that foam build video is very cool. Some serious skills that guy has. I may do a seat build thread for my BEC, I CNCed a foam mold for that, albeit one sided. But you could "fairly easily" CNC both sides to make a foam core. You'd need a BIG 3d printer to print part cores, but maybe it could be done.
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Driven5
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Re: is foam core fiberglass enough strength to be chassis?

Post by Driven5 »

That partially depends how you define 'enough strength':
Enough strength to survive the first drive? Easy.
Enough strength to survive 10's or 100's of thousands of miles of street and/or track abuse? Considerably harder.
Enough strength to survive an at-speed crash? Even harder yet.

There is a reasonably large body of knowledge regarding the strength, fatigue resistance, and survivability of welded steel tube car chassis. There is not for foam core fiberglass car chassis. Airplanes tend to be better shaped for composite use than most cars are.

Much like an aluminum monocoque, I'm not saying it can't be done to an acceptable (or even superior) level...Just that the standard of proof before I'd trust my own life to riding in one at highway (or greater) speeds would be much higher than for a tried and true steel tube frame.
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a.moore
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Re: is foam core fiberglass enough strength to be chassis?

Post by a.moore »

"Is it strong enough?" - the simple answer is yes.

Its strength and elongation properties put it at a disadvantage to carbon fiber since you will need more of it to get the strength but the extra stiffness will hurt its ability to absorb energy in an impact without failing (think brittle vs. ductile materials).

The design requirements to successfully build a composite monocoque are not difficult but definitely a few levels above designing a steel space frame. You need to worry about ply orientation, the number of plies, and how you handle things like lapjoints and high stress areas where suspension components, seats, seatbelts, and rollbars attach.
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RichardSIA
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Re: is foam core fiberglass enough strength to be chassis?

Post by RichardSIA »

a.moore wrote:"Is it strong enough?" - the simple answer is yes.

Its strength and elongation properties put it at a disadvantage to carbon fiber since you will need more of it to get the strength but the extra stiffness will hurt its ability to absorb energy in an impact without failing (think brittle vs. ductile materials).

The design requirements to successfully build a composite monocoque are not difficult but definitely a few levels above designing a steel space frame. You need to worry about ply orientation, the number of plies, and how you handle things like lapjoints and high stress areas where suspension components, seats, seatbelts, and rollbars attach.


Yet, the plywood Marcos 1600's were remarkably simple and more rigid than the space-frame design that followed.
Basic design criteria remains the same, create boxes and triangulation as much as possible.
Foam core can be useful, but so can a simple expanded cardboard spacer.
My Tatum build is still fairly far down the list but I have done a few very basic chassis sketches.
I will have to do them again as Paper & Pencil 1.0 does not post well. :wink:
If I must be a one-man PC free zone, so be it!
KinFung
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Re: is foam core fiberglass enough strength to be chassis?

Post by KinFung »

RichardSIA wrote:
a.moore wrote:"Is it strong enough?" - the simple answer is yes.

Its strength and elongation properties put it at a disadvantage to carbon fiber since you will need more of it to get the strength but the extra stiffness will hurt its ability to absorb energy in an impact without failing (think brittle vs. ductile materials).

The design requirements to successfully build a composite monocoque are not difficult but definitely a few levels above designing a steel space frame. You need to worry about ply orientation, the number of plies, and how you handle things like lapjoints and high stress areas where suspension components, seats, seatbelts, and rollbars attach.


Yet, the plywood Marcos 1600's were remarkably simple and more rigid than the space-frame design that followed.
Basic design criteria remains the same, create boxes and triangulation as much as possible.
Foam core can be useful, but so can a simple expanded cardboard spacer.
My Tatum build is still fairly far down the list but I have done a few very basic chassis sketches.
I will have to do them again as Paper & Pencil 1.0 does not post well. :wink:


is marcos 1600 mean this?
https://www.google.com/search?q=Marcos+ ... HK707HK707
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RichardSIA
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Re: is foam core fiberglass enough strength to be chassis?

Post by RichardSIA »

Yes, my old one is probably on there somewhere.
The main body did become the final chassis member.
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