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carbon fiber weight saving

Posted: Sun Oct 09, 2011 10:06 pm
by knobs
A whole 50g!

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Pointless, I know.

Just need some tea strainers to finish them off.

Re: carbon fiber weight saving

Posted: Sun Oct 09, 2011 10:17 pm
by impmad2000
pointless ? Never !
I like :) !

Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 10:11 am
by smallspeed
did you mould those yourself or have you brought them?
im in the process of making some CF parts for my track car, so any tips and hints appreciated 8) so far have made a front door card which came out ok, and am starting making a mould for the rear this week

Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 11:03 am
by Bruce M
and you will be taking lots of pictures / posting a "how-to"?

please :bounce:

I've seen an example of making inlet trumpets. Involved using silicon foam to fill a metal trumpet, removing the plug and wrapping in CF sock and finally covering with a condom to press against the foam plug. Worked quite well.

Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 2:08 pm
by knobs
Ok, since you asked so nicely,

HOW TO.....

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I used an aluminium mould for the venturi - the part is only as good as the mould, so put all your effort in here. The carbon is prepreg, which already has the resin in it, far less messy than wet layup. Trial and error is used to work out the best template to cut your carbon to.

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The mould is treated with a virtually invisible semi permanent release agent, which maintains the polished surface. Next the carbon is applied to the mould by hand, with the resin already in the fiber the carbon is pliable and should be worked into the mould surface as tightly as possible.

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Next, 'bagging', the layup is wrapped in a plastic release film, followed by a breathable nylon layer then some heavyweight breather fabric to give a layer for the air to escape when applying the vacuum. The whole lot is then placed in a vac bag with a nozzle attached to connect to your vacuum pump.

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All the air is then sucked from the bag to press the carbon tight to the mould, using a vacuum pump.

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Then bake at 120deg for about an hour to activate the resin.

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With the baking done, the carbon releases easily from the mould - assuming you've applied the release agent correctly.

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Make 5 more

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Trimmed on a disk sander, then some bases were machined in aluminium.

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The bases were then bonded to the horns using a high temp epoxy.

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Bolt them to your carbs, and look at them for a while. Note: don't tell your wife that it took you nearly a week to make them, she won't understand.

Matt

Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 2:11 pm
by knobs
Oh, by the way, I make knobs too;

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Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 2:32 pm
by smallspeed
thanks for the reply, very informative! i'm going to be following a similar process except for the oven bit because i don't have one big enough.. ..plus most of my stuff is going to be non-structural cover panels and things

very neat job, and the surface finish on the inside of the trumpets is awesome from using that mould 8)

Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 3:56 pm
by Gary71
Lovely work :)

There is a bit more than 50g waiting if you make the air cleaner base plates from carbon as well!

Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 6:06 pm
by squirdan
if you were to make some carbon fibre stacks for slide throttle or high butterfly type applications ...ie like you have done but taller, I reckon you'd have q a few takers

carbon versions of these:

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Re: carbon fiber weight saving

Posted: Mon Oct 10, 2011 7:08 pm
by Mike
interesting stuff, thanks for sharing.

Re: carbon fiber weight saving

Posted: Tue Oct 11, 2011 9:37 am
by steve wright
pure automotive porn, lovely. :wink:

Re: carbon fiber weight saving

Posted: Tue Oct 11, 2011 9:04 pm
by Captain Ahab Jr
Excellent, good effort

Just a thought on the next set why don't you laminate in the bolt flange, it would save a few more grams, money, time and give a more accurate fit.

Looks like you already have a threaded hole in the end of the mould to bolt on a return plate, also stick some drill bushes in and you can drill off the bolt holes before demoulding.

Re: carbon fiber weight saving

Posted: Thu Oct 13, 2011 4:53 pm
by Andrew Dyer
Are the gear knobs for sale?

Cheers
Andrew

Re: carbon fiber weight saving

Posted: Thu Oct 13, 2011 9:39 pm
by knobs
Just a thought on the next set why don't you laminate in the bolt flange
Captain Ahab,

Quite right, next time I'll combine the flange. This was just a practice run.
if you were to make some carbon fibre stacks for slide throttle or high butterfly type applications ...ie like you have done but taller, I reckon you'd have q a few takers
Squiredan,

Yes, but those (GRP?) ones look more period. Happy to give it a go though - do you have any dimensions?

Andrew, you have PM

Thanks for the great comments!

Re: carbon fiber weight saving

Posted: Thu Oct 13, 2011 11:03 pm
by brembo
if you were to make some carbon fibre stacks for slide throttle or high butterfly type applications ...ie like you have done but taller, I reckon you'd have q a few takers
Matt,have a spare set of high butterfly trumpets. let me know exactly the dimensions you need,and I'll forward them to you.Can also send some photo's,if it helps.
Regards,