MECHANICAL DESIGN, MACHINE DESIGN

For this week we have to design, fabricate, assemble and automate a machine. This week we have to work in groups. Our group is formed by two industrial designers (Wilhem Schütze and Luis Sierra) and an architect (Lucía Lucas). We have decided to make a CNC milling machine because Luis and Wilhem have special interest in this item.

Design
The authors of the machine are Wilhem and Luis. Lucía has designed the box for the electronics and has done the documentation and the video. The design is based in different DIY projects about CNC milling machines. It is easy to find all the components used in this project in anyone hardware store. The structure has been made in MDF boards with digital fabrication. We have used also aluminum profiles to make the x y movement easier and softer. The working area of the machine is a standard size of 600x900 mm. This size has been chosen because is the right area to fabricate guitars (body and mastil, separately). The chuck system is ER11 and the motors are stepped motors DEMA 23.

Fabrication
For fabrication we have used a ShopBot and MDF boards of 2,44 x 1.22 m. For all the pieces the machine has took 7 hours aproximately. We had to make 9 different toolpaths for the ShopBot because we had different ways to cut. The problem of that has been that some holes weren´t cut. Finally we fixed it ordering again the machine to cut the holes.

Machine drawings:

Electronics box drawings:

Assembly
The assembly between mdf pieces has been ok. We have hadproblems assemmbling mdf pieces with aluminum profiles. This union had to be almost perfect because the aluminium profiles are the basis for the movement in X and Y. Other problem has been the insert of other mechanical pieces for the movement. Finally we could solve all issues as you can see below.

Electronics
We're using an Arduino board loaded with firmware GRBL, this is connected to 3 drivers TB6600, which control 3 motors NEMA23. We designed anf fabricated a distribution board, to facilitate and order the wiring. As a source of power we are using a computer ATX switching power supply 12v for the drivers, the feeding for the arduino is via USB, and the feed of the head, that is a spindel 300w is apart with a 31v source

Final result
You can see in this video all the process and the final result milling a block of wood.