Week 7 – Computer-Controlled Machining – ShopBot!

Weekly Summary

For this week's make something big session the challenge was to design something that can only be made with the ShopBot. The limitation was that we could only use one sheet of 910 x 1820 x 18mm plywood - and it absolutely had to be finish in one day. I finally decided to make a console desk, I designed it during the Saturday Lab session in Kamakura, on Sunday we went to Enokido Lumber in Shin-Kiba (north east of Tokyo, not far from Disneyland) to use their ShopBot.

The final and assembled console desk.

Group Assignment

This weeks group assignment was to do your lab's safety training, and test runout, alignment, speeds, feeds, materials, and toolpaths for your machine. More details at the Group Page.

Individual Assignment

Setting

The individual assignment was to make (design+mill+assemble) something big (~meter-scale).

We were going to have access to a ShopBot - many thanks to Enokido Lumber in Tokyo for letting us use their ShopBot - and their workshop.

We had the following restrictions:

The plan was to do design on Saturday in Kamakura, and the go on Sunday to Enokido Lumber and use the ShopBot. Not only use, but finish!

Sketches and Ideas

This was the most fun. As Neil mentioned in his lecture, this week - unlike the electronics week - will have potential for expressiveness.

Here are sketches of my development journey, how I ended up making the piece I did:

My initial idea is to create play board for Plarail trains, which would also double as a table. I imagined the circular cutout to be a train turntable.
More sketches for turntables and switches for Plarail.
Expanding the Plarail play board to a combined chair, table, high seat.
Realizing that 1 sheet of wood will not be enough for the Plarail idea. Re-conceptualising to make a console desk.

Modeling the Console

I started by making a sketch of the side panel of the console.
Then I added a cross at the back - for stability.
Making sure the different parts fit together!

And here is the Fusion 360 Embed:

I started modelling with the side of the console table -and I choose the wrong dimension to start with. I will leave the mistake in the documentation as a reminder for myself and other.

Modeling still does not come easy for me. I need to deep dive into the tutorials.

Data Pathway

  1. Model paramedically in Fusion 360
  2. Export as DXF
  3. Clean in Illustrator/Inkscape
  4. Import to VCarve Pro
  5. Add Dogbone/T-Bones, Tabs, Pockets, etc
  6. Export from VCarve Pro
  7. Import to ShopBot Software (dedicated Computer connected to ShopBot)
  8. Run ShopBot

VCarve Pro

VCarve Pro is a proprietary software for Windows ($699 / £540 / €660), that is used to prepare vector files for the ShopBot.

VCarve Pro

Adding Dogbones and Pockets

Adding Fillets and Dogbones in VCarve Pro. Screenshots from the VCarve Pro 9.0 User Manual

As VCarve Pro is a proprietary software, we only had limited access to it. And I forget to document the process of adding dogbones & pockets in detail. The screenshots above are from the VCarve Pro 9.0 User Manual

VCarve Pro Automation needs improvement.

The Shop

Enokido Lumber is located near Shin-Kiba, an industrial area in the Tokyo Bay. Very Neo-Tokyo.

The ShopBot

Our Instructors Asako Okazaki and Tsuchiya Yosuke were on site to introduce the ShopBot, Asako-san has deep knowledge of ShopBots, as she is working Vuild which distributes ShopBots in Japan.

Health & Safety Instructions

Details of a ShopBot

Adding the Mill Bit

The tools for changing the mill bit are connected to a key, without which the ShopBot can not run. A brutal, but effective safety measure.

Emergency Stop Buttons

Emergency Stop Buttons are big and red. One is directly on the machine, the other one is one the extensions button, which also has a reset and a start button.

Zero-ing the Mill Bit

The zero-ing works semi-automatically. A conductive plate is put underneath the mill bit, the bit lowers until an electrical connection is made.

ShopBot Auto-zeroing.

The ShotBot Software

The ShopBot software is running on a dedicated Windows machine, connected directly to the ShopBot. (I wonder how much dust is inside that machine. After 1 day in the shop, my Laptop had already a fine, even dust cover.)

ShopBot Software

The software panel shows the position of the end-effector. The yellow icon on the right brings up the 'Go to Location' Panel, which allows you to move the end-effector manually - when adding a new plywood sheet or drilling holes.

ShopBot Software in Action.

Feeds & Speeds

More information about the recommended Settings at the Shopbot Info Page.

Cutting Preparation

The cuttings itself has 3 steps, that should be followed:

  1. Preview, if OK then
  2. Air Cut, if OK then
  3. Material Cut

Preview

A bit counter-intuitively, to do the Preview, you have to click the big, screaming CUT PART button - but the mode has to be in the Preview position.

If that looks good, proceed to Air Cut. Mode needs to be set to Move/Cut again, press the big CUT PART button. This brings up another settings menu:

Apologies for the Screen Photos - it was difficult - and I forgot to wrestle with screenshots on that Windows Machine.

Air Cut

To do an Air Cut, set the Offset in 2D or 3D to 3D and press START, which will result in this message:

This is another safety precaution. Before cutting starts, the physical START button needs to be pressed:

Test Air Cut

Cutting in Action

Observer the numerical values in the console!

Cutting!

Stop Cutting

Stopping the cut can be done gracefully by pressing the stop button - or the space key on the keyboard.

Stop Cutting!

Runout

Runout is defined as the rotation inaccuracy which occurs when the tool is no longer aligned with the main axis. *. Ideal a tool with 1/4 inch should leave a trace of exactly 1/4 inch.

Measuring the runout

The measured runout is between 6.30 and 6.40mm, 1/4inch is 6.35mm.

Cutting Videos

Quite relaxing.

MP4 Video, 2.1M

Long (25min) Version on Vimeo.

MP4 Video, 1.5M

Longer Version on Vimeo.

Post-Processing

Well, sanding.

Pre-Post-Processing

Ready to assemble.
Inspecting cuts.
Not yet sanded.
Rough Edges.

Why are there a Kamakura letters engraved on the table? Because I re-used the group board to make my table top. Otherwise we would have thrown it away (and my sheet was not big enough for all my parts!)

Re-using Material.
Milling large areas to 9mm is not recommended.

Post-Post-Processing

After sanding, assembling.
Connections are a nice, snug fit.
The X on the back makes the table stable - as expected

Hero Image

Hero Image!

Other ShopBot Places

Cainz is a chain of Home Centers/DIY places Japan, some of their shops have a ShopBot on site, which can be rented for 30min for ¥2,500. (TODO: find out details) https://map.cainz.com/map/289 (Tokyo, Tamasakai)

Design Files