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Matt (Staff)
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Hi Everyone, Hopefully a few of you have noticed that we've been publishing a number of new video tutorials recently. I've now published the first two (out of three) of a new series which shows the end-to-end process for starting from a CAD design, CNC machining the pattern from epoxy block then sealing and preparing the pattern before taking a prepreg carbon fibre mould off the pattern. In the next video (not done yet) we'll finish off by using the prepreg mould to produce a carbon fibre part. Essentially, in this series what we're trying to demonstrate is the 'other way' to make composite parts, using technology and high tech materials to replace the more manual traditional methods. This is a topic that comes up every time during our training courses and so hopefully this is a process (and tutorial series) that people will find interesting (and maybe useful). The price of perfectly usable CNC equipment is coming down all the time and the quality and availability of 3D CAD systems (like Fusion360) is moving the baseline of what is achievable at home or in a small workshop or business. Our new products and tutorials aim to support this revolution. Also, in this current climate where people are very focused on the idea that 3D printers are the answer to everything, hopefully we can steer a few people towards the understanding that for most composites processes a CNC router is a far more suitable piece of kit to invest in. So, this first tutorial in the series we demonstrate how to CNC machine epoxy tooling board and then seal and finish it using epoxy board sealer.
I'd be very happy to discuss any of the topics raised in the videos including how these processes and materials might be used in your projects.
Matt StathamEasy Composites / Carbon Mods - Technical Sales
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Anders R
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Hi, Great tutorials, very interesting for a project I am working on. However, my pattern is already produced using PU600 and not EB700, finished off with 2K car paint. Will this work with the XPREG Tooling Prepreg? Best Regards, Anders
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Matt (Staff)
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+xHi, Great tutorials, very interesting for a project I am working on. However, my pattern is already produced using PU600 and not EP700, finished off with 2K car paint. Will this work with the XPREG Tooling Prepreg? Best Regards, Anders Mmmm, good question. The problem with PU modelboard is that PU inhibits the cure of epoxy at elevated temperatures. Having said that, you've covered your PU board with 2k car paint (which will be either acrylic or could be PU itself) and therefore the tooling prepreg would not be in contact with the PU board so you might be OK. I'd say the first thing to look into is what your 2k car paint is made from. If the paint itself is polyurethane then you might still have the same problem. If the paint is acrylic then it might be OK but I think I would have to suggest a trial to see if the paint itself inhibits the cure at all. Because the initial cure is done at a pretty low temperature (which should just about be OK for the paint) there is a good chance that the cure inhibition won't occur but it really will come down to the individual behaviour of that paint system.
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Hanaldo
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Interesting stuff... How about this one Matt:
The tooling pre-preg tech data says it should not be used on patterns with polyester matrix. But what about an epoxy compatible polyester top coat like Duratec?
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Matt (Staff)
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+xInteresting stuff... How about this one Matt: The tooling pre-preg tech data says it should not be used on patterns with polyester matrix. But what about an epoxy compatible polyester top coat like Duratec? Yes, it's a similar situation in that it would probably need testing. We don't have any experience of trying the prepreg on Duratec but we have done some initial testing on some other pattern primers/coatings and these seemed to show compatibility, particularly at a low temperature cure. Although we didn't concentrate on testing compatibility with pattern coatings we will do some R&D into this and try to come up with a list of the compatibility dos and don'ts. The datasheet discourages polyester because there's a risk that even at the lowest initial cure for the tooling prepreg you could be up at the top-end of what a typical polyester can take and that's likely to cause problems. Some polyesters have a higher Tg (and also subtly different chemistry) which may make them suitable for use with this tooling prepreg (at the low initial cure). If you get some results of your own, please share 
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Hanaldo
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I see! Well the Duratec has a Tg of 120C, so should handle the temperatures easily. I'll have to get some tooling pre-preg and give it a go. A pity I didn't ask this earlier, I would have got a bit of the tooling pre-preg with my order this week!
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Matt (Staff)
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Group: Forum Members
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+xI see! Well the Duratec has a Tg of 120C, so should handle the temperatures easily. I'll have to get some tooling pre-preg and give it a go. A pity I didn't ask this earlier, I would have got a bit of the tooling pre-preg with my order this week! 120'C; that's interesting. I'd say that's a great candidate for potential compatibility. I'll see if we can get some and do some R&D trials. Be sure to let us know if you get some results yourself, either way. Thanks Martin.
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rmaddock
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Hi Matt,
The videos are superb.
I’m busy prototyping a composite Canoe and am thinking about the hull fittings.
At the moment, there’d be very few pieces and I’m not fiscally in a position to buy the cnc equipment......tempting though it might be.
Will EasyComposites be offering a production service? I’m thinking about producing mould plugs from cad files mostly. If yes, what are the max dimensions you can work to? Most of what I’d need, end caps, handle brackets and the like are quite small but a Canoe thwart (a bit that goes across the top, between the sides) could be up to three feet long.
Cheers,
Robert (anything to avoid hand finishing plugs) Maddock.
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Matt (Staff)
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Group: Forum Members
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+xHi Matt,The videos are superb.I’m busy prototyping a composite Canoe and am thinking about the hull fittings.At the moment, there’d be very few pieces and I’m not fiscally in a position to buy the cnc equipment......tempting though it might be.Will EasyComposites be offering a production service? I’m thinking about producing mould plugs from cad files mostly. If yes, what are the max dimensions you can work to? Most of what I’d need, end caps, handle brackets and the like are quite small but a Canoe thwart (a bit that goes across the top, between the sides) could be up to three feet long.Cheers,Robert (anything to avoid hand finishing plugs) Maddock. Hi Robert, I'm afraid we don't have any current plans to offer a CNC service. I totally understand that investing in CNC kit isn't right for everyone or every project but this equipment is becoming increasingly accessible which is why we've started to do more tutorials aimed at people who do have these facilities. The fact that the prices of the machines is coming down does mean however that there are more 'makers' about who could potentially offer their machining services and so it's possible that if you ask around in various communities you could find a hobbyist who might be able to offer to do this machining for you. If you do jump up into the commercial world then I worry that you might still find that the prices charged for CNC machining, even for a relatively small part, might be prohibitive (and drive you into the arms of a cheap CNC machine!). All the best, Matt
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Anders R
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There are a lot of CNC routers at startups and small companies but since they are used for their own product development I guess it is difficult to get access to them. Maybe it could be an idea to start a forum section for this in the future? Even if you have the money for a small CNC kit you will probably soon find you will need a larger, more powerful and robust one. My new build will be ready Q1 2018 if you haven't found a solution before then
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