Originally Posted by ml_batt@yahoo.c  Hi All,
I am embarking on the whole CNC thing for the first time and very interested to learn if there is anyone out there with experience in milling fibreglass laminates (Epoxy/Fibreglass) and plastics such as HDPE and Nylon,
Can I use a bench top style of Router or do I need a full blown workshop with 3 phase power and a mill that will tackle metal? I am mostly working on Fins and Rudders for water sports craft such as surfboards and sailing craft. so I don't necessarily need much Z axis but I do need enought o make moulds.
Blueline |
Assuming you are planning on vacuum bagging your parts, there are a lot of different materials that you can use to cut molds depending on how many parts you plan on pulling out of said molds.
For very low numbers of parts (1-10), you could cut a mold from a tooling foam, seal the surface with epoxy, sand it smooth, wax it up and pull parts.
For a larger quantity of parts, there are several varietys of Renshape that would be a better material. That would involve cutting the mold, sanding to an appropiate finish, waxing/ mold releasing, then pulling parts.
As far as using the CNC to trim the part, it is do-able. You will need to make a fixture to hold your part while the machine does it's thing. The propper tool bit is crucial for good results and they are not cheap. Personaly, I would not go through the trouble and expense unless I was planning on running over 100 of the same part.
You can cut foam on a fairly simple machine with a fairly basic spindle. Harder materials will require a more robust setup. Using foam molds, it is possible to make parts with a reasonable amount of detail and accuracy (+/- .010".) Rensape wiill hold much more detail with acrruarcy >.005". You should decide what sort of accuracy you will need and build towards that. Of course, more accurate = more $$$.
You will find that a good CAD program and CAM software and the knowledge/skill to use them will be crucial in order to have any success with this sort of process. After all, you gotta be able to draw the parts and molds before you can cut 'em.