Car Body Cost?

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#1

Medium size sports car body, doors, hood, dash and any inner body supporting structure. What would be a close estimate of what it would cost to build the plugs and molds for a kit car body? Not including R&D, or time - just materials cost.

A friend of a friend built a “Graber” car… from scratch he designed and built the molds and fiberglass bodies. It’s a 4 piece body, no doors on that one though, and no dash or inner support structure.

I’m thinking a chromoly steel tube frame with mounting tabs for the body to fasten to. Obviously it would need a dash, firewall, wheel tubs inside and i’m thinking those would be fiberglass.

How many gallons of resin for the molds? How many gallons of resin for the body and structure? How many yards of fiberglass? saying 14oz or so fiberglass cloth done in like 4 layers. I wouldn’t want heavy, thick bodywork. I think a total thickness of around .060" (1.5mm) would be good.

#2

GOT ANY CAD experience?
First, the Graber site is a great inspiration - including his CNC machine. (Mine’s much smaller - -for now.) And, he did it all in his 2 car garage - well, mostly I think.
I have on a back burner – a project car based on the Kawasaki racecar from the mid 60s. There is a link over at http://thekneeslider.com/archives/2006/01/25/kawasaki-factory-auto-racing/
I could give you an estimate from my CAD drawings of the surface area of the body work - no internals designed yet - but that would work out to the basic shape minus reinforcements – etc.
Its an open cockpit - CAN AM style and “smallish.” Perfect for a start up project I’d think, and easily enough powered by motorcycle engine - gotta think economy these days.
Not too unlike the Stoer SCCA DSports class. oops that’s STOHR
Let me know I’ll look for my drawings and calcs.
Cheers - Jim

#3

Here are a few ideas - rough and a lot of approximation too

12000 sq inches surface Area ----> 9.3 sq yards

      Using  your layup of  14 oz cloth (per sq yd)

130 oz cloth per layer ----> 4 layers 520 oz cloth 32.5 Pounds
50/50 Cloth Resin -----> 520 oz Resin 32.5 pounds (that is about 15 to 16 liters of resin - for your cost estimate)

SO the body minus reinforcements, attachments etc under 70 pounds!

An AUSIE built a formula car (powered by a 250cc motorcycle engine weighing 350 pounds full up! :smiley: (http://members.optusnet.com.au/~pwstone/jmw/jwstory/jmwstory.htm)
Did over 120 mph too. Not bad eh? Mind you - you won’t be very happy if you hit something very hard!:eek:

#4

I would like to see the CNC machines used for the foam cutting.

I have seena turret mill used and I have seen a 5 axis router for super precise stuff.
For smaller stuff, a 4 axis cnc router can be used.

#5

Heres one that works ok - its a router and certainly does the work!
http://www.grabercars.com/
AND - a car is the output!
Other choices are 3/4/5D foam hot wire machines – There are some Italian sites – interestingly enough much of that technology is involved in stagecraft/architectural work.

Other than the HUGE CNCs used for large yacht programs - mil - etc what were you looking for? Not my modest machine – I hope – he says blushing :wink:

Cheers - Jim

OK I just did a re-READ and maybe the graber cars site no longer shows his cnc – I’ll look for a copy I may have on file.