As I live in an area where high-tech equipment is manufactured, the local scrap yards reflect this: you can find lots of scrap metal from CNC machining left-overs, and occasionally scrapped prototypes or older industrial equipment like pick & place machines, industrial printers etc. containing gears, linear guide rails, servo motors and other useful mechanical stuff.
The lathe is powered by a 3HP motor from an old tread mill.
This video
provides more info how I build this lathe. Although the lathe is relatively
small, the 3HP motor with tacho-feedback provides high torque, also at low
RPM. The base is not as rigid as the heavy lathes, so chatter will happen
more easily.
Please see below for some firmware design notes. The Pixaxe 28X2 firmware
.bas file can be downloaded
here
which can be read with notepad or the
Picaxe Editor.
In 2020, I added a vertical mill to the lathe, again using materials from the industrial scrap yard. This video describes how I made this mill.
Milling generates a lot of vibration, and I now understand why mills are made from heavy cast iron. My simple lightweight construction generates more chatter, so when milling metal, I need to make light cuts. Milling aluminium works well, and the surface finish looks good. The X-Y table lead screw backlash needs to be minimized, and every bolt needs to be fixed with Loctite.
I used the free
Google Sketchup 8 software for making the 3D CAD drawings. You can download
the complete lathe & mill 3D file here.
The drawing is 1:1 scale, so you can use the measurement tool for checking
all dimensions. Use the layer tool to show/hide specific parts.
The electrical speed control schematics and design notes are shown below.
The Picaxe 20x2 firmware .bas file can be downloaded
here.
For the OLED display I used the AXE133Y. It needs to be reprogrammed for
higher frequency. The firmware can be downloaded
here.
e
The PCB layout drawings are shown below. I made the double sided PCB by
hand, using the isolation routing method.
