[oknups]

How good is the 770, at doing very small moves on 3D parts?
Software to generate the tool paths not being any issue, rather how well the Mach controller moves the steppers in very small steps.

I need a machine that can make a mold for carbon fiber composite parts, finish straight off the machine is a big factor.

The best example of what I would like to be able to do with this machine is molds like this link.
http://web.me.com/walterberger/Merli...s/DSC04425.jpg

I ask because I have some doubts due to a recent post.

I considered outsourcing the work, but found it extremely expensive.

[cheetahcnc]

I have outsourced parts on a $60,000 machine which didn't have the finish you are looking for right off the machine, and that wasn't even 3D. May be why the cost is so expensive.

Jim

[tbaker2500]

It is exceedingly hard for any tool to create a perfect finish. Most cutting operations will leave a tool mark of some kind. That is why it is often better to do some hand finishing afterwords.

Also, creating the jig to hold that part will be a challenge.

[TXFred]

The mold in the picture has been finished by hand, probably with sandpaper.

There's nothing wrong with doing it that way. I've done 3D surfaces on my 1100 that sanded smooth with just a couple of minutes of work. The 770 should be just as good, if not better.

Frederic