30mm Thick Practical Vacuum Infusion Structural Part?

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30mm Thick Practical Vacuum Infusion Structural Part?

Author	Message
Fasta	Fasta posted 8 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	I have done 50mm thick fibreglass with infusion where we used the flow medium on each side of the stack. All went well, it was water jet cut to a profile after. If you need such a structural part then machining it from solid carbon may not really be the best way. I would assume your block is a uniform laminate of x? layers of possibly the same material? When you machine this you would be cutting through the fibres and layers at the surface of your new part whereas a moulded part can have some of the layers essentially wrapping it up in an unbroken fibres, then within this you can also lay fibres on the load paths and structural areas etc. This is the way to do it so you can minimize the amount of expensive carbon fibre you use and also make it stronger and lighter than a solid sheet would be. If you are up for CNC machining of a sheet material then why not machine a mould to make the part? Fastacraft Facebook page
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ChrisR	ChrisR posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 363, Visits: 3K	A number of questions there: 1) can you infuse 30mm+ : Yes, I've seen it done but you will probably do 4 or 5 test runs before you've got it right, materials and process are critical 2) If machine time is a concern then machining a block like that should be much cheaper and quicker than making the thing out of CF! 3) Stress flow would be critical to your layup 4) machining CF on that scale is fun /not 5) don't thread directly into the place, use a metal thread bonded or screwed & bonded into the laminate 6) 4140 steel will be rather weighty. If I were doing it, I'd be better picking a different, lighter alloy and machining it
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Duk	Duk posted 9 Years Ago HOT Topic Details
Group: Forum Members Posts: 7, Visits: 180	Another question that is a bit different. Would it be realistic to create 30+mm thick part via vacuum infusion? The idea here is to produce a large blank that a central bearing plate for a gearbox could be machined from. Final thickness is 30mm, so a bit of extra thickness during creation of the blank would probably be a good idea. Someone in some part of the world has produced a new bearing plate for this gearbox (It's an Alfa Romeo transaxle from the Alfetta/GTV//GTV6/75) and gained some improvements. But they still had some measurable (bench testing by applying torque to the input shaft with the gearbox in 1st gear) distortion. I'd suggested going for something like 4140, but the machine time is already a concern for the guy and I don't know about material availability. My logic behind this is 2 fold. The CF plate should be more rigid than the aluminium plate. And actually getting material like 4140 in the size that is required is, in my experience atleast, very difficult/impossible or just too expensive. Is such an idea viable? Would machined CF be durable enough to support bearing races? With the exception of the selector rod detent spring holder, no threads need to be in the bearing plate as bearings are held in place by separate, thru bolted retaining plates. Attachments 720.jpg (313 views, 245.00 KB)
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