CNC Cheat Sheet

So my EMCO mill suddenly started working after months of stress and although I have become fairly familiar with operating it I quickly realized  that I know diddly squat about the important CNC milling stuff like G-Code or  how to work a CAD/CAM software to actually be efficient at milling. So I googled "G-Code cheat sheet", and to my amazement not a single high-resolution, colorful, to-the-point, well explained PDF file popped out. I was flabbergasted.

But, there were, after some digging plenty of black-text-on-gray-backround websites with comprehensive lists of G-Code that would be very useful. If only they were in printable format, to hang on the wall behind my machine...

So I decided to make one!

G-Code Cheat Sheet

Original files:

Download G-Code Cheat Sheet in .SVG format.

Download G-Code Cheat Sheet in .PDF format.

Please note that I am an absolute beginner, and I have made this sheet to learn this myself. I will not be held responsible if the information is wrong. Please do not hesitate to let me know if you find mistakes or if you have suggestions. Thanks!

Here are some sources I used:

• LinuxCNC G-Code reference
• CNC Cook Book G-Code Reference  (Has reference for both Mill and Lathe)
• Daewoo PUMA 450 Program Manual (Mainly for lathe, but still useful)

Other Cheat Sheets i made:

• Capacitor Cheat Sheet
• Resistor Cheat Sheet
• Ohm's & Watt's law Cheat Sheet

EMCO M1 update

I now have no less than 3(!!) EMCO controllers in my workshop. And most importantly, I have all 3 axes working in my original F1P!



After determining that my EMCO F1P CNC machine had some issues with the controller (more specifically a fried step-motor controller board), I was feeling the despair creeping in. I started googling frantically for spare parts and repair options online without finding anything reasonable. The very next day I struck gold. A full F1P system for sale at a resonable price and in "promised ok state". A few days later I suddenly had TWO CNC mahcines in my workshop. But I had bought a dead system, and the guy I bought it from just repeated his original lie when I called him.

Two EMCO M1 controllers side by side

Despair was yet creeping in. Then, by another happy coincidence I found a controller for one of the EMCO lathes (T1) which is based on the same technology as the F1P for sale at a bargain price (Thanks Torgeir G.)! After verifying that it contained the same step-motor board i was pleased to buy it.

R3D413000 Step motor driver board in EMCO M1 controller

And after some fiddling about I finally have a working controller! The idea now is to put the original machine back in order using parts from the second and perhaps sell it.  The rest second will the be retrofitted with new drives and a modern PC based control. So far, my searches have turned up the following parts that may be of interrest:

Control board

Motor drivers

This has become a bigger detour than expected for my original project, but really I had to protect my initial investment which was substantial. Now that it works it will at least maintain its price if not go a little up.

First impressions EMCO

Just a quick note on the EMCO CNC machine.

It looks kind of cheap the first time one lays ones eyes on it, but after tinkering with it for only a short period of time it has become apparent that is is of extraordinary quality.

Some of the engineering choices made during its design are truely free of comprimise.

For one, the computer has a sealed chassis cooled via a huge air-to-air heat exchanger that prevents dust to enter the electronics.

The electronics are spaced out with lots of clear to read maintenance instructions and lights to signify problems.

All the parts are of highest quality brand and make, such as the kraus & naimer switch with KABA lock system.

In the CNC machine itself, all the parts are made of quality steel, machined to perfection. Many clever solutions prevent dust and dirt to reach the contact points and ball-bearings.

The steppers have additional metal optical encoders to keep them in check, so does the spindle motor.

All cabling is masterfully arranged.

I could go on and on. In conclusion, this is a magnificent piece of equipment that I am looking forward to getting up to par.

EMCO in the workshop

Just a quick update.

I FINALLY got my EMCO CNC machine into the workshop. I have already started the work on cleaning it up and troubleshooting it. And here are some pictures:

EMCO F1P - being cleaned

EMCO Tronic M1 - without front panel

Moving 200kg alone takes time

In my car

My assistant working

Protobuf for embedded

I have recently had the opportunity to research potential binary protocols at work. The thought just occurred to me that Google's protocol buffers (a.k.a. protobuf) might be a good candidate for the serial communication that occurs between different components such as controllers and servos.

You might think that it has too high overhead, and that may very well be the case. On the other hand protobuf has a few advantages that may not be obvious before you start using it.

For one, it makes thinking about your protocol much easier. The .proto text file format is just brilliant for recording your latest and greatest ideas for a protocol.

Second, you can actually use the code that is compiled by the protobuf compiler, not only for transfer of data, but also as your internal representation of the data. This will save memory, and that is good.

Third, it makes changing and even managing versions of your protocol effortless. For an embedded hardware project you might think that is unnecessary, but at least in my project with 36 servos with custom firmware and probably a whole bunch of other little controllers responsible for other stuff, with protobuf you could just change the .proto files, rebuild the firmware binary, upload it to the right controllers and be done.

I will investigate what impact protobuf has on the performance of tiny controllers, and on the bandwidth and latency of the serial communications, and report my findings here.