DIY epoxy CNC milling machine
Reading all the CNC & DIY forums I have grow up to building my own CNC milling machine.
Mill is designed to accomodate working envelope of X: 50cm Y: 50cm Z: 45cm
- epoxy granite gantry design with moving table
- scraping table as a solid base
- THK SHS20/HSR25 linear rails
- wather cooled "chineese spindle" 2.2KW with ER20 collet
- Servo motors
P3 Sanyo Denki750W SGDM-08 Yaskawa 200V
- servopack yaskawa step/dir SGDP-08
- controller ethernet based CS-LABS CSMIO-IPS
Gantry was created by mixing various sand grades (0.8mm and 2-3mm diameter) some micro spheres and epoxy (polish made Epidian 61) with slow hardener called PAC (also from epidian). Going slow is crucial if we do not want any srinkage or skey of parts. For PAC hardener setting time is 3-4 hours and it takes a week to fully cure. As for the ratio of expoxy to filler it was 15-20% expoxy to sand by weight.
Scraping table was choosen as a base for the mill. It is strong and hard with precision plate on top. Table dimensions are 100x60cm and it weights more than 300kg. Moving crane is a must!
Currently I am working on
improving the Y axis and designing and building the Z axis. Also wiring the control box is keeping me awake.
Done with improving the Y axis. It was expanded from 50cm to almost 90cm. It was needed to improve rigidity of Z axis by increasing the width between Y axis THK carriges. It was increased to 34cm making it pretty solid now. The working envelope in Y axis is still full 50cm.
After making room in my small shop I have assembled gantry with tracing table. Now all the time consuming alining and squarnes checking.
After table has been aligned propertly it was time to align gantry