body work made by vacuum formin

[sharaf93]

hello guys,
I have been checking for materials and manufacturing techniques for the bodywork, and I have found a technique called "vacuum forming" which can be used to form thermoplastics such as ABS plastic
so I wanted to ask if anyone have an experience with this issue and is there anything in the rules that denies using ABS plastic for body work ! ? can anyone give experienced comparison between fiberglass bodywork and ABS plastic.

[Bemo]

I have never tried the technic you're describing. What did you find in the rules about allowed materials for non-structural bodywork? The answer is simple: Nothing. That means, you can use whatever you want ;-)

[MileyCyrus]

You might find this article interesting:

http://www.fstotal.com/thermoformed-...racing-team-2/

[SkeH14]

Hey Sharaf93

for the 2014 competition year our team ran with thermoformed ABS bodywork.

Although the bodywork was quick to make, ABS is tricky to work with in many ways. It is heavy, lacks rigidity, and doesn't guarantee a great surface finish. We had to invest lots of work into making molds that could be placed into a vacuum forming set-up, and had to use fairly thick sheets of ABS to ensure that we had half decent panel thickness at all points along our final parts.

Thermoforming is cheap if you're doing multiple sets of bodywork, which I guess is good for the cost report, but in my opinion it's not an ideal solution for competition winning cars.

[sharaf93]

Hey Sharaf93

for the 2014 competition year our team ran with thermoformed ABS bodywork.

Although the bodywork was quick to make, ABS is tricky to work with in many ways. It is heavy, lacks rigidity, and doesn't guarantee a great surface finish. We had to invest lots of work into making molds that could be placed into a vacuum forming set-up, and had to use fairly thick sheets of ABS to ensure that we had half decent panel thickness at all points along our final parts.

Thermoforming is cheap if you're doing multiple sets of bodywork, which I guess is good for the cost report, but in my opinion it's not an ideal solution for competition winning cars.

Thanks,
Regarding the abs ,
I want to ask you about the weight of your bodywork, and can you tell me about the main defects you faced ?
And if I can use the fiberglass composite, especially the wet layup method, how can I expect the weight since it is difficult to control the fiber ratio and resin content

[SkeH14]

with regards to the ABS, our weight was pretty high (I'm not gonna use exact numbers, but it was into the double digits). We had to pull our plastic over very large male molds, and as a results the company we used to make the panels specified a 1/4" thick sheet. I'm sure you could save weight by using a thinner sheet, but you run the risk of having panels that are too thin.

If you decide to make your bodywork out of fiberglass and resin then it would be best to avoid wet layup techniques. Although this technique is fine for making molds, it leaves a lot of resin in the final parts that you really don't need. In our experience wet layup pieces are almost always three to four times as heavy. If at all possible make your body panels using a VARTM process. That way you have only the amount of resin that you need in the final part.

[tgman]

I would argue against ABS being heavier, admittedly we went for a different design (less surface area) to our previous noses but it was lighter than the wet layup carbon fibre bodywork we have done in the past.

In terms of the molds the heat does mean you probably have to keep away from foam blocks but MDF isn't that expensive, we got enough surplus from a local timber yard to do two or three sets and its not that much harder to work with than foam if you have the correct tools (belt sander!)

In terms of defects / surface finish its no worse than composite panels done on a male mould. We did do a bit of post work in terms of sanding but nothing serious, before giving it a clear coat.

Two issues we though we would have are deformation from heat (muffler in side pod) and abrasion against the ground. It turns out neither of these was a serious problem and it actually fared as well or better than the carbon panels we used to use.

Basically do it, its an order of magnitude cheaper in the cost report and much easier in reality. Its not a perfect surface finish but its easy, light, cheap and quick. If you get along well with the vac forming guys they might even make a few sets for you (we may have an art car sooner rather than later)

Source - One of the two guys that made the moulds in that article