Team-BHP - Pics: Carbon Fiber Seat - How it was handmade for FSAE

Quote:

Originally Posted by Rehaan (Post 838398)

Hi Davis,

I think you might be right that we did not use all the CF for the seat (contents of the roll was 340sq.ft) - i wrote this thread quite a few months later. However, we did use more than 1 yard per layer (probably 2/layer, but still doesnt quite end up at 27 unless we really wasted a lot!)

We used West Systems epoxy.

For another (group) project i was involved in my classmates did a wet layup, but this time we got the mould CNCd and it was vaccum bagged as well. It was for a recumbant bicycle frame (i will try to post pics later).

I did also get a chance to see some large heated moulds (for car body panels) as well as the CNC cloth cutters, pretty cool.

Would love to see some info/pics of the work you do and have seen, especially what happens in india as i havent seen or heard of much! Do start a thread if you can.

cya
R

west systems is quite popular for epoxy, High quality stuff, the price says it all 100$ per quart. Which hardener did you use? 207? Vaccum bagging is clean, better than layup, and less resin in the part.

Quote:

Originally Posted by navin (Post 838562)

Davis you seem to be a pro at CF/ FRP moulding.

Does one need the mold release wax (any specs?) and the PVA. For FRP I have found that a plastic sheet sprayed liberally with PVA is adequate to act as a release layer.

Different people, different ideas, all we want is to take the part out of the mold.

Hi,
I am in the process of starting a Cf and CFRP products and automotive parts manufacturing unit in gurgaon. We have been doing sampling for over 3 weeks now and have been doing it using different resin systems. The coming week we will be starting to make parts by Resin infusion. Till now we have used wet layup and Vacuum bagging. Our goal is to be up and running commercially by 25 th of September. As, of now anyone who is offering to make custom automotive parts in india are way too expensive as there is no one to regulate costs, no real competition. If anyone has questions get in touch with me. We will also be offering starter kits with guides. Also, we plan to release a self help video every fortnight for education.

Regards.

Quote:

Originally Posted by Rehaan (Post 157534)

Okay,
...
So as you can see in the image above, the final seat was constructed in CAD. We then proceeded to cut the computer model into 2" sections and printed out the cross section of the seat at those 2" intervals.
We then cut 2" sheets of polystyrene foam along those profiles, and then glued them all together to form one big rough seat.

Then was the "fun" part of sanding it down. Keeping a close eye on symmetry. (Luckily i was out of town during this part of the mould making :) )
...
R

Thanks for such a detailed writeup! We are planning to make CF bodyworks this year. At the moment the frame is being build up. And due to limitation of human resources, space, as well as time, we are not sure if we would make bodyworks ourselves or get it made from a professional. Though, being designer myself, I am insisting on making it ourselves. I think it would be fun. We have had experience of making seat and small frontal nose using glass fiber and also using CF for all of our previous cars. We follow similar process in mould and choose second option for lay up.

Also it is interesting to know brown tape could be replacement to wax! Any highlights on problem faced using tape or recommendations ?

In 2013, we successfully made semi-monocoque chassis, rear space frame. So we required only a small nose to cover up impact attenuator from front. While making the nose, our then team leader decided to make one without using wax at all! :Frustrati It was messed up at the end, as the mould couldn't be removed as one would expect. The reason to omit wax was the cost. If we could replace wax with cheap brown packaging tape, it would save us some bucks for other spendings.

Just for information, Carbon Fiber was sponsored by TeXtreme last year, lot of which is still left!

If we choose to make on our own, I would be contacting you for help, if required, with the accuracy of moulds, lay-ups, etc

Also, it'd be great if anyone could share any contacts in north india who specialize in making such parts, in case we require to outsource.

Quote:

Originally Posted by moodswings (Post 3190672)

I have sent you a PM regarding the same.

Thanks

Quote:

Originally Posted by Ashir (Post 3655462)

Also it is interesting to know brown tape could be replacement to wax! Any highlights on problem faced using tape or recommendations ?

Any molded items pick up every single detail from the mold. In this case, you will see the lines where the edges of the tape are. I don't think this should be something to worry about in your case though.

There's also a big difference between a mold that you just use once and a mold you plan to use several times. The former makes things easier, because you can destroy the mold when removing the piece (if required).

I did this 10 years ago, so don't remember too many more useful details than what this thread says! :)

cya
R

Hello Everyone,
First of all I want to thank everyone who has contributed to this thread.

A bit of background, in 2013 our car's body was initially made out of Kevlar(don't know why this decision was taken as I was not a part of the team back then) by a fibre industry, but due to improper dimensions of the mold, the body didn't fit on the frame, so finally the body was made out of aluminium.

This year we plan to participate in FS Italy and want to make the body out of fiberglass. The reason for choosing fiberglass is because of its cost, also this will be our first time working with fiber so don't want to take too much risks. For practice we visited a fiberglass industry and after much pleading they allowed us to teach a thing or two about working with glass fiber. We made a test mold(picture attached) which very vaguely resembles a car's body. We used polystyrene foam to make our mold->applied a thin layer of POP for finishing and then sanded it->applied 3-4 layers of Waxpol->applied a layer of PVA->applied a layer of White Resin+Hardener->finally applied 2 layers of glass fiber with epoxy resin. The results were promising as the body seemed to have sufficient rigidity, the only problem we faced was that at some regions the foam had melted. This, we thought was because of improper application of POP. To counter the foam melting, we plan to modify our process by applying a layer of POP and then applying a layer of metal putty on the foam. My questions are- Are we doing this right? Can we modify our process for better results? Also, most of these chemicals are available in the open market and don't carry any sort of name or instructions, does anyone has an idea about the name or grade of the various epoxies and other chemicals available?

Thanks!

Participated in the event and what an experience it was! Although we couldn't clear the scrutiny because of some problems which couldn't be rectified there, but still got to learn a lot. Coming to our car's body, finally we made the sidepods out of glass fiber by making the pattern out of MDF board. We used three layers of glass fiber;two layers of 300gsm and one layer of 200gsm. The nose was made out of aluminium. The total weight of the body came to be around 12 kg although I would have liked the sidepods to be a bit more stiffer, probably another layer of fiber would have done the trick. The next step is to make the nose too out of fiber for the FS India event to be held at the BIC in January.

Quote:

Originally Posted by DetonatoR (Post 3822096)

Participated in the event and what an experience it was! Although we couldn't clear the scrutiny because of some problems which couldn't be rectified there, but still got to learn a lot.

Oh that's a bummer! But glad you still managed to make the most of it...

Quote:

Originally Posted by DetonatoR (Post 3822096)

The total weight of the body came to be around 12 kg although I would have liked the sidepods to be a bit more stiffer, probably another layer of fiber would have done the trick.

Rather than adding more material to give it strength, I'd suggest improving the structural strength (eg. adding ribbing, etc). However, that would be harder to do now that it's made.

The racing stripe/s look cool :thumbs up