This is a prototype 3D capable Mill. It has a possible resolution of 160 steps per mm. The bed size is just over A4 and the Z axis has a cutting depth of 25mm.
The Mill was constructed using Custom Wood(MDF). The lead screw
is 8mm threaded Steel, the slides are from Print head carriages (Wide Format
Dot Matrix printer parts, a palette of these from a local Auction cost $22.00).
The original bearings were made from tufnol. I have had a go with an adjustable parallel reamer to manufacture bearings for the Z axis out of brass to see if I can get a better result. The verdict after testing is good, but more work is needed.
The biggest problem is aligning the steel runners to parallel so that the bearings don't bind.
I have also added a vacuum bed, which will hold a piece of PCB material very well(I havn't tried plastic sheet yet but expect the same result). I gave some of the guys at work a go at removing the PCB (only one managed)
Top view showing Vacume table looking down Z.
The electronics came from Oatley Electronics in Australia, they have a kit MOSFET CNC STEPPER MOTOR DRIVER KIT. I purchased 3 of these kits @A$35.00 each (one for each axis).
Picture shown Electronics (note there are many Toroidal rings on the DC leads).
The artwork to mill was produced using Corel Draw, which was plotted to file using a HPGL printer driver. The Plot file was then interpreted using a shareware program called DANCAD 2.6 on a 486 which controlled the Stepper Drivers. Sample below used this method.
Kellyware has a very usable windows Mill driving program http://kellyware.com/,
this is much frendlier than the DOS DANCAD. You will need a PC that runs WINDOWS
95 though. And it is free at the moment!
Sample Engraved in MDF
More Pictures: MorePics.htm