Week 07: Computer-controlled machining¶

Ironing Stand¶

Ironing Board — Designed and milled an ironing stand. TBD.

Assignments¶

Group assignment:¶

do your lab’s safety training
test runout, alignment, fixturing, speeds, feeds, materials, and toolpaths for your machine

Individual assignment:¶

make (design+mill+assemble) something big (~meter-scale)
extra credit: don’t use fasteners or glue
extra credit: include curved surfaces
extra credit: use three-axis toolpaths

1. Group Assignment¶

We traveled 240km to FabLab Hamamatsu where we can borrow the big CNC machine.

FabLab Kannai group work page

I was first much intimidated by the large machine and the big noise, then realized what an amazing opportunity it was to design and build very large things, as long as you follow the safety procedures. Thank you Take-san of Fablab Hamamatsu for the very warm welcome and the training.

Safety procedures include:

don’t wear loose clothes
protect yourself with goggles, etc.
securely chuck the blade.
secure the board with nails before cutting.
know how to stop the machine with physical machine button as well as the software button
don’t leave your eyes off the machine while it is working
clean the debris

FabLab Hamamatsu

2. Individual Assignment¶

2-1. Design¶

I designed an ironing stand based on a design in a beginners wood working book, with the following changes

Unified the board thickness to 18mm
Instead of nailing the parts together, made the parts to press fit.
Made holes on the top table so that steam iron can be used (together with felt mat and cover sheet.)

First I made a Fusion model in 3D.

We went out for shopping and selected a nice laminated pine board of size 910 mm x 1820 mm.

2-2. Create CAM Toolpath¶

I received advice from Tamiya-san to use the dog bone technique considering the diameter of the end mill.

I made the design change after we arrived in Hamamatsu, but it took me more time than I had expected.

Before coming to Hamamatsu, I found a way to automatically arrange parts flat with Fusion Manufacturing mode, however, could not find a way to export the flat model in ai nor svg file format.

Tamiya-san taught me that the easiest and quickest way to export the paths is using Shaper utility on Fusion and exporting the faces one by one as SVG and place them on Adobe Illustrator. Saving the ai file in the old CS format is important to be used with the Cut2D software in the next step.

It was almost evening when we started cutting wood. First, we uploaded the Illustrator file to Cut2D. CUT2D

Then configured the pocket toolpaths, profile toolpaths, and drill holes, and then exported the toolpaths to Mach 3D, the machining controller.

2-3. Milling¶

First I drilled the holes to fix the workpiece. And then fixed the workpiece with the screws. fixing

Then, loaded the rest of the toolpaths to the controller. pockets done honeycomb

I found the pocket was too deep and there was a cut trace while the endmill is moving between cuts. Apparently z-axis setting was not optimal, so that we fixed the setting of the machine and cut some extra. Some trial and error, and it was 21:30 at night!! I decided to bring the work pieces home.

back home

And only after I tried to fit the pieces together I found that I totally forgot about the clearances....😱 The pieces do not fit each other!

does not fit

Since then, I have been filing the parts forever … I think I am almost there…

almost there

Reflection¶

Finish the design before the machining day, and need to be reviewed by the instructor beforehand
Don’t bother with automatic 2D layout feature of Fusion Manufacturing mode. Using Shaper utility and simply exporting faces as SVGs and placing them with the Adobe Illustrator is so much easier.
Don’t forget to incorporate clearance in your parametric design. To do so, you need to design parametric from the beginning.
For venting holes, making punching board with drilling would have been much easier and faster, rather than the honeycomb design.
z-axis adjustment of the machine is very important otherwise your pocket could be simply a hole.
z-axis adjustment starts with securing the chuck of the tool.
Having made all of the above mistakes, I discovered that filing and sanding can help save the project😃

Design Files¶

Checklist¶

[x] Linked to the group assignment page
[x] Reflected on your individual page what you learned of your labs safety training
[x] Documented how you designed your object and made your CAM-toolpath
[x] Documented how you milled and assembled your final product (including setting up the machine, fixturing, feeds, speeds etc.)
[x] Described problems and how you fixed them
[ ] Included your design files and ‘hero shot’ of your final product

Reference¶

Kantan Mokko Style (book: “Simple woodwork style”)