In 2019, I build a metal lathe from materials that I found
at our local industrial scrap yard.
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.
Building a Vertical Mill
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.
Building a Digital Dividing Head for making gears
In 2021, I have made a Digital Divider Head for cutting spur gears. This video explains how I made this device, which can be used to cut all kinds of gears.
The key component for the digital divider is a 24V DC motor with a 278:1
gearbox.
I mounted a 500 pulse per turn encoder to the motor shaft. It gives 139300
pulses per turn of the output shaft, so a very high resolution for dividing.
The other components are:
An Arduino Nano V3 (Use the import one, for some reason the official Arduino Nano shows some strange behavior with my program)
A L298N Motor driver Module which can drive moderate size motors.
A 12 character 2 row I2C controlled LCD display for showing all user information
A HEDS5540 A12 500 pulse per turn quadrature encoder mounted on the motor shaft
The control box schematics and notes are shown below:
The Arduino program can be downloaded here. (Apologies to the real programmers out there, my programming skills are rather limited. For sure there are better ways to get the same functionality)
I used the free Google Sketchup 8 software for making the 3D CAD drawings. You can download the complete lathe & mill & Divider 3D file here. You can check all dimensions and components on 1:1 scale.