[PaulMakesThings]

Hello,

A past professor of mine has asked me for advice on a machine for his lab. He probably asked me because I'm a mechatronic engineer now. But I don't work with mini CNC's and don't know which ones are good.

here is what he needs:

-Small footprint
-Can cut samples out of flat sheets of plastic and fiber composites including carbon fiber, doesn't need to cut metal
-6x6 inch work area at least
-he hasn't specified but I'm guessing he can afford something in the $5K range
-limit switches, other protections a plus

Since he just needs to cut little samples from sheets of composite, I'm thinking he just needs a little engraver/cutter, above all it must be easy to use. I can't teach his students how to use it, I might help install it but that's it. So the more intuitive and reliable the better. I'm familiar with sherline mills, but those don't even have limit switches or homing, and I'm certain the students would be crashing through the clamps and the bed constantly. I think something a little more narrow in its use which just cuts sheets would be better.

[Fastest1]

Possibly a Sherline. They are nice little machines if production isnt the object. They are accurate, relatively inexpensive and there are many modifications and parts available. IMO they wouldnt be the best if metals are brought into the equation but for sheet stock it should be great.

[mcphill]

I recommend you look at Microcarve. Very low cost and perfect for non-metal cutting. An area of concern is cutting carbon fiber, though. Extraction of particles will ne critical.

Hello,

A past professor of mine has asked me for advice on a machine for his lab. He probably asked me because I'm a mechatronic engineer now. But I don't work with mini CNC's and don't know which ones are good.

here is what he needs:

-Small footprint
-Can cut samples out of flat sheets of plastic and fiber composites including carbon fiber, doesn't need to cut metal
-6x6 inch work area at least
-he hasn't specified but I'm guessing he can afford something in the $5K range
-limit switches, other protections a plus

Since he just needs to cut little samples from sheets of composite, I'm thinking he just needs a little engraver/cutter, above all it must be easy to use. I can't teach his students how to use it, I might help install it but that's it. So the more intuitive and reliable the better. I'm familiar with sherline mills, but those don't even have limit switches or homing, and I'm certain the students would be crashing through the clamps and the bed constantly. I think something a little more narrow in its use which just cuts sheets would be better.

[LongRat]

Sounds like you need a small router. Carbon fibre sheet requires a high speed spindle, preferably at least 15,000 RPM. Something like a Kress router running at 25000 RPM cuts CF sheet exceptionally well.
Without the need for the rigidity that's needed for metals you can get away with an aluminium or even MDF framed router. Most routers have integrated vacuum extraction which is critical for fibreglass and carbon fibre. You don't want to breathe the dust in. Routers are a lot cheaper for a given working area which is also a plus.