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MikeD
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Hi, I'm planning to make some parts out of your carbon fibre sheet, what is the best way for me to cut shapes out of the carbon? also will normal drill-bits work to drill it? The parts I am making at the moment are just prototypes, if I want to make more (like hundreds) of parts I don't want to be doing them by hand , can the sheet be laser cut? Thanks. Mike
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Paul (Staff)
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Hi, You can use just about any tools to cut and shape carbon. The important thing when working with carbon fibre is to cut the part ‘too big’ and then use a sanding block to smooth and shape the edge. This way, even if the tool you use to cut the part chips the surface slightly, this will be sanded away by the sanding block leaving a nice smooth edge. The best tools for doing the cutting are ones that use an abrasive as their cutting surface, rather than something with ‘teeth’. Perma-Grit tools are good examples of abrasive tools. If you do use something with teeth for the cutting, always use something with fine teeth (like a metal cutting blade) rather than big teeth (like a wood cutting blade). Another very useful tool to use to cut straight lines is a slitting disc in a grinder (the type used for stainless steel) this makes light work of the material and leaves an edge with virtually no chipping. Here’s a link to the Perma-Grit tools on our site: https://www.easycomposites.co.uk/perma-grit-toolsHere’s a link to a guide about cutting and shaping carbon fibre: https://www.easycomposites.co.uk/learning/how-to-cut-carbon-fibre-sheet-and-tube Standard drill bits work perfectly well with carbon fibre; best results are achieved with high rotational speed and low pressure, and like with many materials it is best to have something behind the piece like wood to minimise the likelihood of a 'snatch' when the drill bursts through. There are a number of ways of cutting carbon using CNC machining, the most common are CNC routing and water-jet cutting cnc routing is generally suited to smaller components and ones with small drill holes, water-jet cutting is ideal for larger projects or cutting difficult materials such as Kevlar. Water jet cutting is generally faster that routing but it is very difficult to cut small diameter holes (less than 8mm) due to delamination caused by the jet 'piercing' the material. If you wish to get a quote on water-jet cutting there is a firm near to the Easy Composites facility that is familiar with cutting all of our materials you can contact the here: http://www.waterjetstoke.co.uk/Laser cutting can be problematic, we have known people to achieve good results, however, by the very term 'composite' having a sheet made up from more than one material each exhibiting different burning/melting characteristics it can be very difficult to achieve the right setting which will lead to a neat finish. Best of luck with your project.
Paul StathamEasy Composites / Carbon Mods - Technical
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Ledon Racing
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Group: Forum Members
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One thing to note if you're doing a lot of drilling in carbon it will very quickly blunt normal drill bits, I keep a set specifically for carbon, if you can afford it carbide drills stay sharp a lot longer, but a good comprimise are cobalt bits. Also its best to work up gradually to your final hole size, much like you would with metal.
www.LedonRacing.com
Professional motorsport services
& composite production / repairs.
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Carbon Tuner
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I have an adjustable speed Dremel and the "tile cutting" bits. I love it cause its a little 2" wheel that can cut through 6 plies of 12k like butter. I need A band saw though for the straights'
If Brute Force Isn''''t working your not using enough...
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malcsonar
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Group: Forum Members
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Hi,
I've purchased some rigid CF sheets for a project and have had them water-jet cut into shapes, as we've done on other projects. Unfortunately, we've suffered quite bad delamination at many of the small hole sites - which I now see is indicated as likely by Paul's post of 7 years ago (see above) - but also on some of the edges of the pieces which is perhaps not so expected a result. I'd like to find out your opinion, please, on water-cutting - has it come on any in the last 7 years, and are there any new techniques that greatly reduce the likelihood of delamination?
We are now looking at either CNC cutting or laser cutting of the pieces. Laser looks worth a go, judging from Paul's post above - but may not work to our satisfaction. Are any CNC methods or approaches better than others, in your view?
Thanks!
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oekmont
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Group: Forum Members
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You have to enter the part from the sides with every cut. Never start in the middle of the part. Because while it cuts the initial hole, the water builds up pressure against the sides, wich then causes the damage. once the hole is established, the water just flows through the part, without building up that much delaminating forces. Holes can be drilled or better routed first, to give the water jet a starting point.
Laser cutting isn't a good option for carbon, as the fibre has an incredible high melting point and great thermal conductivity, while the matrix is just the other way around. This means it's hard to cut through the fibres, and there is great thermal exposure to the resin near the cut, causing it to burn or degrade.
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malcsonar
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Group: Forum Members
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+xYou have to enter the part from the sides with every cut. Never start in the middle of the part. Because while it cuts the initial hole, the water builds up pressure against the sides, wich then causes the damage. once the hole is established, the water just flows through the part, without building up that much delaminating forces. Holes can be drilled or better routed first, to give the water jet a starting point. Laser cutting isn't a good option for carbon, as the fibre has an incredible high melting point and great thermal conductivity, while the matrix is just the other way around. This means it's hard to cut through the fibres, and there is great thermal exposure to the resin near the cut, causing it to burn or degrade. Thank you - much appreciated. That's a helpful description of what's going on with the delamination. I think, though, the cutting house did pre-drill the holes, but we still ended up with delamination anyway... All a learning process. I'm convinced now that CNC is the way to go.
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Matt (Staff)
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+x+xYou have to enter the part from the sides with every cut. Never start in the middle of the part. Because while it cuts the initial hole, the water builds up pressure against the sides, wich then causes the damage. once the hole is established, the water just flows through the part, without building up that much delaminating forces. Holes can be drilled or better routed first, to give the water jet a starting point. Laser cutting isn't a good option for carbon, as the fibre has an incredible high melting point and great thermal conductivity, while the matrix is just the other way around. This means it's hard to cut through the fibres, and there is great thermal exposure to the resin near the cut, causing it to burn or degrade. Thank you - much appreciated. That's a helpful description of what's going on with the delamination. I think, though, the cutting house did pre-drill the holes, but we still ended up with delamination anyway... All a learning process. I'm convinced now that CNC is the way to go. Waterjet cutting really should be perfectly possible; 'bursting through' carbon sheet with a waterjet is a no-no but if you start from a pre-drilled hole then it should be no different to starting at the edge of the laminate. We supply hundreds of cut carbon fibre components to companies which are all done on waterjet. It might be worth checking with the waterjet company to make absolutely sure that all internal cuts were started from a pilot hole. I'm not a waterjet expert but there are a number of parameters (jet width, abrasive grit, sacrificial bed) which will all affect the quality of the cut. Set up correctly, you should get a near perfect edge. CNC is of course also a great option. You've probably seen the video we produced on cutting carbon fibre sheet with a desktop CNC router, if not, take a look.
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malcsonar
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Group: Forum Members
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+x+x+xYou have to enter the part from the sides with every cut. Never start in the middle of the part. Because while it cuts the initial hole, the water builds up pressure against the sides, wich then causes the damage. once the hole is established, the water just flows through the part, without building up that much delaminating forces. Holes can be drilled or better routed first, to give the water jet a starting point. Laser cutting isn't a good option for carbon, as the fibre has an incredible high melting point and great thermal conductivity, while the matrix is just the other way around. This means it's hard to cut through the fibres, and there is great thermal exposure to the resin near the cut, causing it to burn or degrade. Thank you - much appreciated. That's a helpful description of what's going on with the delamination. I think, though, the cutting house did pre-drill the holes, but we still ended up with delamination anyway... All a learning process. I'm convinced now that CNC is the way to go. Waterjet cutting really should be perfectly possible; 'bursting through' carbon sheet with a waterjet is a no-no but if you start from a pre-drilled hole then it should be no different to starting at the edge of the laminate. We supply hundreds of cut carbon fibre components to companies which are all done on waterjet. It might be worth checking with the waterjet company to make absolutely sure that all internal cuts were started from a pilot hole. I'm not a waterjet expert but there are a number of parameters (jet width, abrasive grit, sacrificial bed) which will all affect the quality of the cut. Set up correctly, you should get a near perfect edge. CNC is of course also a great option. You've probably seen the video we produced on cutting carbon fibre sheet with a desktop CNC router, if not, take a look. Thanks very much, Matt - some great advice there! I hadn't come across your CNC video before, actually - excellent stuff. I was certainly surprised at the waterjet results - maybe you're right, that it was a set-up issue...
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