Ive been wondering how to go about making all carbon fiber blocks (different thickness) so they can be machined into different parts… ive researched on google and looked at 35+ pages on this forum cant find any info …
Any info would greatly help out.
Thank you very much for all the help. i look forward to learning more from everyone here.
Machining carbon probably doesn’t happen too often considering the cost of the material and the number of layers and labour needed to make it.
Carbon is strong so we can use less of it and minimise cost.
But if you need to create blocks then I would just layup as many layers as needed with a pre preg material.
You’re talking carbon fiber? Or just carbon?
You can purchase monolithic carbon but, I’m betting that will be very expensive. Making a thick laminate isn’t cheap either. I know of a friend who works at a company and they will make large sheets of carbon fiber layups, like .075" and bigger, then they machine the plates to shape. They use them for back up structures on large molds for commercial planes. Stuff is pretty awesome when it’s that thick and autoclaved at 100PSI. I have a few scrap pieces of it. Fun stuff.
Like Fasta says, you should design with intent. ANd not just design a metal part then figure that it should be carbon. The brute force method is wasteful. Take a look at the F1 cars… that is awesome stuff.
What’s the application?
Didn’t some one on here , get there hands on some thick carbon fiber blocks. At memory they where quite think like 50+ mm , and was happy to sell them
Tim
Found it.
http://www.compositescentral.com/showthread.php?t=10200&page=2
Thank you everyone for the responses.
Im looking to make some 1/4" thick parts out of solid carbon fiber… Being new to this i dont think laying up 16 layers of carbon at once can be done (could be wrong) thinking it has to be done in steps… can i just do a layup of 4 layers sand and wipe down and add another 4 layers and do it in steps ?
1/4 inch shouldn’t be a problem in one go. You’ll need to vacuum bag it if you are doing wet layup and you’ll need to use a slow epoxy to avoid exotherm
As Nc42 says 0.25" shouldn’t be an issue.
If you are using prepreg you could always add an intermediate dwell in the cure cycle to minimise the exotherm risk. Debaulk every 3 plies or so and it should be fine.
do you think vacuum infusion would be ok? Im totally new to all this so i appreciate all the help.
As Nc42 says, as long as you choose a slow epoxy and follow the cure cycle advice things should work out ok.
When you think of the thickness’s of boat hulls and wind energy blades that are successfully made by resin infusion the technology to infuse thick parts clearly exists.
People are doing this a lot nowadays to make rings. Talking over 1" thick plates!! Check out Turbocarbon on instagram as a start. He makes pretty thick stuff using infusion. I don’t know his process or resin, but you might be able to ask.
The main problem is yes, exotherm. Thick plates don’t have places to let the heat build up go. so it overheats and does BAD thing. Slower resins are better, because they don’t create the heat fast resins do.
https://instagram.com/turbocarbon/
turbocarbon74@gmail.com
CarbonWaves.etsy.com
I would bet as well some of the people that make thick plates for cosmetic reasons bond plates together. But that’s just a guess based on how I’ve made a few thicker items before.
If you’re using woven fabrics (good permeability) you should easily be able to infuse up to an inch without breaking a sweat. Just use an infusion rated epoxy (cps less than 300 at RT) in the lowest speed you can find to make sure your exotherm doesn’t kick too rapidly. Let it gel on its own and then post cure, don’t do a forced/snap cure to ensure things don’t get too hot. Just toss a bunch of 20oz 2x2 together (best permeability because there is so much space between the large 12k fiber tows) and you will have no problem. Added benefit is that 2x2 20oz is one of the cheapest forms of carbon available. Each ply yields .8mm in thickness at normal infusion fiber fractions, so you should be able to achieve 1/4" with less than 8 plies.
The 50mm and 55mm thick plates I have are bonded with 2 different thickness sheets. Thickest non bonded is about 30mm or 35mm.