Week 7 - Computer-Controlled Machining

Contents

Draw

I want to make a Japanese coffee table so the idea is going to begin with Fusion 360. According to the size of Roland MDX-540 (500 (X) x 400 (Y) x 155 (Z) mm), it is really hard to make something "big" directly. So the design concept is that adding more joints to let it be big enough.

Using double layers to make table stable

Design result

I had no clue that how to export vector files on Fusion 360 so I exported my design to many pieces of STL files and chose 123D Make to slice them.

(Afterword: I recognised that we can simply export vector files on Fusion 360 with clicking chosen body face -> Sketch -> (right-click) Sketch-number -> exporting DXF)

I imported vector files to Dr.Engrave which could control Roland machines and mill with vector paths. Though there is a big issue that it could just follow paths which means it cannot just mill the right outline we want. Before milling, I had to generate the "outline" of my outline shape, and fill tool path with setting "pitch" in "drill bit radius".

Make

Sending to mill

Setting

Spindle RPM:       12000
Z Speed:           11    mm/s
Z Up Position:     0.5   mm
Z Down Position:   -15   mm

4mm drill bit, set pitch in 2mm. Here we have to use blue which we set to fill tool path.

Fixing it on the platform

Boom!

However, the edges look messy which are caused by up-milling drill bit. In this case, if I choose down-milling drill and I will get nice result instead. Also 12000 Spindle RPM is too high to mill. Following this tutorial (Spindle RPM and Feed Rate Calculations) would get perfect parameters to work.

Combination. It took me a quite long time to do because when I designed, I did not consider about any tolerance between them. It is better to set tolerance in ~0.1mm.

This is something wrong with final path milling so that my component draft and mill badly. After this tragedy, I fixed plywood with double-sided tape to platform.

The quality of plywood seems really bad because all pieces of wood made for building concrete forms.

(in words 混凝土 模板用合板)

For my dovetail joint, I used Roland default software to control.

Result

Files