DIY Carbon fibre parts

[necronomicon]

Hi all,

Gona try to make some wet lay carbon fibre sheet and then cut some one-off parts for my TT-01 and TL-01, nothing fancy but just a new project to see how hard the carbon fibre is to make and work with. Obviously wont be as stong as the professional pre- preg. stuff or sheet made with vacuum pressure etc, but should be OK for battery cover/ top deck/ other low stress areas.

Just been looking into how to do it and it looks reasonably straight forward- lots of safety considerations to think about as well.

Got my 300g/sm carbon fibre cloth (looks well cool) and resin, just need a nice day and gloves/ measuring cups/ glass plates etc and I'm away......wish me luck!- If all goes well i will do a tutorial on it so you guys can have a go, if its a disaster, will share that too!

 

[Mad Ax]

Good luck []

I've heard that carbon fibre resin is very

hard to work with - if you get the mixture wrong it will either be very

brittle or will simply not set, unlike fibreglass resin, which will

either set quicker or slower depending on the mixture.  I've also

heard that any moisture present in the air can cause the resin to go

misty, which looks very poor on the finished product and can't be

fixed.  I've read it's best to do it on warm, dry, sunny days only.

I've

also heard that a good way of heat-curing is to put the finished

product into a black plastic bin liner and put them on top of a car in

the sun for a day.  I guess for small-scale items like RC parts

you could use an oven to heat-cure.

Let us know how you get on []  

[necronomicon]

Well, got my first sheet of carbon fibre!- rushed it a bit and didnt get as good a surface finish as I had hoped for, its got a slightly rippled surface finish from the polythene sheet used as a release layer getting buckled a bit. Its light and strong though- 2 layers of Cf with polyester resin holding it all together. Just letting it cure now for longer, the next one will be better!!

[Rat Fink]

try using silicone mold release instead of the polythene, this is available from ceramic suppliers ( they sell clay and all that stuff) 20mm mdf to support the bottom layer of glass I used polythene pegs in the board to locate the top sheet and then the top sheet of glass, once again 20mm thick mdf and then 20kg of bar bell weights to top it off. you need to wait a little to allow tnhe air to get out before you put the top sheet and the weights on.

this worked well for me.

Gee

[necronomicon]

Thanks for the tips Gee, will try that, the polythene sheet seems to react a bit with the resin, making the surface wrinkle a bit. trying a 3 ply sheet now, just wai ting for it to cure.

The first attempt was ok and got some parts from it, but they seem a bit brittle.

cheers

Neil

[kingeddie]

cant remember who it is, but there is a guy on the net that sells off cuts fro helicopter parts of sheet carbon fibre, a mate of mine bought some bits big enough to cut chassis from for around £8 a piece, cuts real nice with a TCT router or mica cutter, then you just need to seal the edges with nail polish or super glue. I'll try to find out who it was and his email.

[DeeMiller]

If the mold is affected, you may want to use epoxy resin which is more expensive though but not as aggressive as polyester.

To speed up the proces (and stiffness) you can bake it in an oven at 80-100 deg. C.

Did this back in the days when I was making surfboards out of PS-50 foam. (not the baking that is...).

To clear out the air bubbles you can use a roller.

When stirring the epoxy resin, allow the air bubbles to get out (or store it in the frigde because it doesn't harden below 5 deg C.).

I also used an old vacuum cleaner to get them out...

 

Grtz Dee.

 

[necronomicon]

Hi Dee

Thanks for those tips, its a steep learning curve alright, an expensive one too!

Having problems finding large volumes of epoxy resin, polyester resin seems common enough though- i suppose main problem so far is parts seem a little more brittle than i was expecting- thats for 3 layers CF cloth compressed into a sheet about 1.6mm thick.

cheers for help

Neil