CNC conversion

The mill is sold under different brands for instance Sieg X1 or Harbour Freight 47158

I have had my mill for almost 3 years now and there been times I wished I had a bigger mill but for most jobs it works just fine. Sometimes I want to cut irregular forms and that can’t be done manually in a mill so I decided to convert the mill to cnc. Before I started the conversion I searched the web for all information I could get on how to do the job. It is extremely valuable to read about the experiences from others. This is my small contribution to the subject.

Hardware

I bought a gas strut with 100 Newton to compensate for the weight of the quill (10 kilo).

A motor mount kit from cncfusion.

A driver board and stepper motors from Xylotex

A touch screen and a used Dell computer.

Software

Mach 3 from Artsoft

Lazycam from Artsoft

Vector engineer vectorengineer

Motor mounts and couplers.

I mounted the cncfusion kit according to their instructions. (See cncfusion homepage). It was a straightforward job. After my first cut I saw that I had some backlash. I found out that it was difficult to press the collars to the bearings at the same time as you tighten the collar. So instead I put a spring between the coupler and collar and first tighten the coupler and automatically the collar was pushed to the bearings.

Driver board and stepper motors

The motors from Xylotex are nema 23 with a Holding Torque of 269 oz.in. Now it was time to mount the motors. There was nothing to it just mount them to the motor mount.

The motors had double shaft so I mad a handle to manually work the mill. I am going to make two more for the other axis.

On to the driver board. A warning! Do not plug it in if your currency is 220 V. You first have to open the driver board and move a switch. When you opened the board you can see the switch inside a box with holes in it. Don’t try to open that box you can change the switch from outside with a small screwdriver. Connect the parallel cable to the driver board and the other end to the printer port on your computer.

Don’t connect the motors yet.

Computer and software

I bought a used Dell computer GX260 with Pentium 4 2.00 GHz and 512 MB ram. XP home edition. A licensed version of Mach 3. Since my workshop is rather small and I don’t want to have a mouse and keyboard there I installed an 8-inch touch screen to operate the system. I mounted the screen to the mill.

Now I started up the mach 3 program and configured the correct pins for the axis. I am not going to go in detail how its done you can check Artsoft website. Now it is time to connect the motors to the driver board and switch the driver board on. To jog without a keyboard. I had to use the virtual keyboard in XP. I found out that I had to put my Z-axis and X-axis in reverse to get the system to work correctly. I noticed that the stepper motor had no problem lifting the quill in the Z-axis so I decided not to mount the gas strut. The weight of the quill kills backlash in the Z-axis.

The first Cut

I am building a combustion engine the Panther pup designed by Bill Reichart so I thought it would be nice if I could cut something useful for the engine.

I decided to try to cut the support in this drawing.

Cad cam

I used Vector engineer to make the cad drawing. I bought a licensed version of Lazycam (Artsoft) to transfer the cad drawing in to g-code. And then it is time for the mach 3 program to drive the mill. The standard layout in mach 3 is not that good for touch screens so I downloaded a layout called simple 3 axis and this is how it looks.

If you click this link you can see a short clip of the cut. DSC26.mpg

The cut is finished. It was not perfect since I had some backlash in the X - and Y-axis.

I changed the way I mounted the couplers. You have already read about that. And now I got rid of the backlash. I made a test cut 25x25 mm and checked with the calliper. It is difficult to measure exactly but for sure it is less than 0.03 mm.

Another cut of the support and here it is mounted. It’s a perfect fit.

I have cut a letter for a boat in 2mm aluminium. Arial rounded MT 100 mm high.

Here is how I made the cut. I gloved an aluminium plate 120x120 mm to a piece of wood.

Then I fastened it with clamps in the mill.

Here is when the cut is finsished.

After some polishing.

I had set upp my cnc with 800 steps per revolution (400 steps per mm) but that was not correct with the Z-axis I had to change that to 1080 steps for the Z to work correct. Now after some tests it was time to put the mill back in the workshop again. When I have more experience with CNC I shall update this page.