I have started a few weeks ago to make by myself 3D printed moulds in PLA and later in PETG, for my carbon components (see examples attached, two moulds for bottle cages).
Due to the tight tolerances of 3D, compared with the fiberglass moulds I did in the past, does anybody know the thickness of a single carbon layer and so how many layers of carbon I need to apply to have my components?
Consider that the points of the moulds I have to build the piece from, has a depth of 2mm.
Thanks for the help
Well it depends on what weight fabric you’re using, what pressure you are consolidating at, what fibre:resin fraction you achieve etc.
If you are using vacuum consolidation with a fibre:resin ratio of around 60:40 then a general rule of thumb is that you will end up with a thickness relatively close to the fabric weight. So a 200g fabric will give you around 0.25mm, a 450 will be around 0.5mm etc. But it does vary slightly, so it isn’t super accurate.
Ok, thanks, I needed just a general rule. The carbon has a weight of 200gr/sq.m so, according to your advice, to fill 2mm I should give 8 layers of carbon (?).
Also, the pump supplies a pressure of -1 bar.
On the mould I have already brushed a layer of epoxy to give more stiffness and then the PVA
If it were me and this part doesn’t have super tight tolerances then I would do 9 layers of a 200g to get to 2mm thickness. So many layers tends to compact down a bit more in my experience. Realistically you probably need somewhere in between, but if 0.5 of a mm either way isn’t going to cause problems then 8 or 9 layers is about right.
That’s ok, thank you for your advice, I will apply those 8.9 layers.
On my previous fiberglass moulds I have applied between 5 and 6 layers.