How to make this part/mould??

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How to make this part/mould??

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Darren	Darren posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 54, Visits: 916	Im looking for some advice on how to make the part below and mould? It is a cam chain sprocket cover on a small 160cc engine, Dead flat and 8mm thick.. Is this even possible with the heat/oil??
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Hanaldo	Hanaldo posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Absolutely, you just need to have a think about how you want to do it. It's a good idea to know exactly how hot it gets so that you can plan accordingly. If possible, get it up to the maximum temperature that it would see (probably sitting in the sun after riding through traffic?) and measure it with an infra-red thermometer. Then you'll know what Tg resin you will need to handle the heat. I'll take an early punt and suggest it's likely to get hotter than 110ish, so you will either need pre-preg or EC's high temp laminating resin. Oil shouldn't worry the epoxy, it's more ethanol that causes issues (which can appear in your oil if you're running something like E85). If you're not on ethanol then you should be ok. My approach would be just 2 pieces of flat steel sheet. 3-5mm thickness to handle the process. Apply release agent, then lay up your carbon on one of the sheets using EC's high temp epoxy. If you want to duplicate the 8mm thickness (unnecessary in my opinion, carbon will be much stronger than the original and it isn't a structural part, but I can understand the aesthetic appeal) then you will need either ~32 layers of 200g carbon or 8-9 layers of 650g carbon. Lay up each layer, then clamp the other piece of steel on top. Clamp it up quite tight to squeeze out the excess epoxy. Then it's simply the unenviable task of trimming up a slab of 8mm thick carbon and you're done! :p
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Darren	Darren posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 54, Visits: 916	The max temp it gets is 130 deg C so you wasn't far off. That sounds like a really simple process..will the surface be pin hole free? Should i oven cure , then post cure up to the 130 deg C?
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Dravis	Dravis posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	First off... do you know what the back side looks like? The "thickness" seems to me to be a different part then the metal cover? some of the engines I've seen with cam-chain covers use a fibre part against the engine block + a thin metal cover on top of that, usually the "fibre" part has cutouts to leave room for the internal moving parts.. You really need to remove the cover and take a closer look at it .. you may well have a more complex part than just a flat 8 mm thick cover .. I have managed to make quite nice cosmetic parts (End caps for Bike exhausts + exhaust shields) with the EC high temp resin .. It need a "stepped" postcure to reach the 180 degree Tg .. this can be found on the sheets for the EC resin. "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-) Edited 10 Years Ago by Dravis
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Darren	Darren posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 54, Visits: 916	On the back side of the part it has a 1mm recess, but i can get away with not needing that on the carbon part
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Dravis	Dravis posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	But, I am right in thinking the cover is in two parts? .. If thats the case I would get some filleting wax and round off the outside parts (where the metal meets the black material) Then make a flange /base board.. ( see the EC tutorial with the "epoxy mouldmaking kit" ) https://www.easycomposites.co.uk/epoxy-mould-making-starter-kit Then wax/ release coat the whole ting thoroughly and make a mould from it . "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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