Engraver/Router Retrofit

This machine was originally run by some sort of printer driver for engraving. In hopes of turning it into a useful g-code CNC machine for our school, I retrofitted it with LinuxCNC using a 27" iMac for the main computer and a MESA 7i96 as the main i/o hardware.

Since I also wanted to reuse the original physical user interface which involved 20-some membrane buttons in a matrix arrangement and about as many LED lights, I added a MESA 7i73 pendant card. One additional hardware component is a pair of latching buffers, which I needed to handle current through the LEDs, and also used as multiplexing outputs. I ran out of outputs and didn't feel like adding another card, hence the need for multiplexing outputs.

The multiplexing logic is handled in HAL, which is something I don't necessarily recommend even though it was an interesting experiment.

I manufactured a custom panel for mounting the keyboard and manual controls. The panel also houses the 7i73 pendant card, as well as a USB-RS232 converter. The main i/o card is mounted inside the main enclosure, along with all the power supplies and e-stop relays.

Another interesting experiment was to use smt components on a single-sided perf board. This is done by splitting each pad under the smt component in half, which works out perfectly for .05" pitch components. Interestingly enough, smt resistors and capacitors are easier to install on perf board than the thru-hole variety. For wiring I tried a bunch of different methods but settled on using thin enameled magnet wire.

The spindle was originally run off a Toshiba vf-9, which I wanted to use but doesn't communicate via MODBUS, so I replaced it with an Automation Direct GS2.

The original axis motors were steppers, which I replaced with Teknic Clearpath SKSD integrated servo motors. These motors are intended to be drop-in replacements for steppers, and work using a step-direction signal. This turned out to be the most expensive part of the retrofit but the speed and smoothness is quite impressive.

Attached are some pictures of the final product. This project turned out to be more involved than I anticipated but it appears to be a nice little router now.

Included here are my .ini and .hal files. Feel free to ask questions or to provide suggestions.

Thanks to the many people on this forum and in the mailing list who helped me.

Ahh, the router.

Here's the router.

Something else that turned out really well is a dust brush I designed and 3D-printed for it. The unique thing about it is that the front part is hinged and held shut with magnets, and opens for handy access to the ER collet.

nice done
is this a ballscrew system or a belt driven mashine

Leadscrews and round recirculating ball ways. This is the weakest part of the system but its design intent is is engraving and light wood routing.

Elte, yes. Air cooled, 2kw, 18,000 rpm, integrated ER 32 collet.

A good trick if you have problem with the plastic pin of your wirring-pen is to take apart a cheap ballpen refill and use the brass pin after you got rid of the ball. I always fix the brass by winding some wire over the plastic.
Hope I expressed clear enough ;-(
Mike

I made a wiring pen out of a discarded lab pipette.