[sudo-discuss] need help setting up high-precision CNC machine at sudo/CCL

[Jake]

On Tue, 7 Apr 2015, Patrik D'haeseleer wrote:
> 
> We should definitely not be collecting pieces of half-broken machinery 
> that nobody uses (see: acoustic microscope)...

hey, just because you don't know how to use a piece of machinery does not 
mean it's half-broken.

regarding the CSAM, that granite-based 3-axis CNC machine on the border 
between CCL and sudoroom, it is most valuable as a high-precision CNC 
machine for general-purpose milling and carving, or even laser ablation. 
But it DOES WORK as a CSAM, if anyone cares to use it for that purpose.

Unlike all the other CNC machines in the space, this one uses linear 
encoders to report back its position to the controlling computer, so that 
belt and gear slop are irrelavent to its precision.  This is called 
"closed-loop" CNC machine control and is as fancy as it gets.

The motion control system in it right now is a Parker Compumotor PC23 
system, which begins with a 16-bit ISA card inside a 486 desktop computer, 
running windows 95 / DOS.  The software on it is specifically for the CSAM 
(accoustic microscopy) function, WHICH WORKS, but it doesn't work for 
general-purpose CNC stuff like running G-code files.

To do that, we should replace the 16-bit ISA card with a Mesa Electronics 
Anything-I/O FPGA card such as the 5i23 (PCI) or the 7i60 (USB) both of 
which I HAVE ALREADY.  Mesa electronics products are all intended to be 
used with LinuxCNC and are fully open-source software (though not 
open-hardware) so it should be easy to upgrade the machine to FPGA-based 
motion control under linuxCNC.

If anyone wants to take on this adventure, it should be a small matter of 
RTFM, since this is the most common usage of the 5i23 board, as seen here:

http://www.automation.com/product-showcase/mesa-releases-5i23-io-card-for-the-pci-bus
http://www.mesanet.com/pdf/parallel/5i23ds.pdf
http://www.mesanet.com/pdf/parallel/5i23man.pdf

and the software for it:
http://mesanet.com/software/parallel/5i23.zip

the linuxCNC forums should be full of documentation about setting it up.

-jake