Week #3 Computer controlled cutting

What I’ve done this week

  • learning and checking laser cutter in our lab.
  • cutting stuff using vinylcutter.
  • creating cardboard constructing kit by laser cutter.

Weekly Assignment Requirement

Group assignment

  • characterize your lasercutter’s focus, power, speed, rate, kerf, and joint clearance
  • document your work (individually or in group) Kamakura Group assignment

Individual assignments

  • Design, lasercut, and document a parametric press-fit construction kit, which can be assembled in multiple ways. Account for the lasercutter kerf.
  • cut something on the vinylcutter

Kamakura Group assignment

I was in charge of researching about focal point of the laser cutter in our group work.

Description of Assignment Work


create the logo of my final project. end make a sticker by vinylcutter.
The logo is needed to represent my final project concisely. While thinking it, I had to rearrange my idea and it made my mind clearer than before.

designed the logo roughly on Inkscape.

used envelop filter to add angle on fonts.

used SDX1200 by brother. it was super user friendly machine.

a piece of cutting sheet and the mount sheet for SDX1200
sticked cutting sheet on the mount sheet which had adhesive surface
there were two types of it (strong one and weak one). but both could be used for the sticker sheet. according to the manual

test cut

setting cut data

just before cutting my data, I found unnecessary vectors
the vectors would cut unexpected part so I must have had removed them
so I reedited the file on inkscape


spike means the shape of my final project. and net means networking. the spikes connects each other and give data from sensors to the users who accesses them from remote place.

press-fit construction kit

Using a laser cutter, I made a parametric press-fit construction kit from a piece of cardboard. According to Neil’s lecture, cardboard was a good material for prototyping because it was not expensive and easy to craft.
for this assignment, I wanted to make a 3D object from pieces of one shape because I do not want the kit gets complication to be composed of lots kinds of shapes.

first failure
Firstly, I tried to make a 2V geodesic dome inspired by Jun Kawahara‘s work. His kit was composed of 3 kinds of pieces. I tried to change it to be composed of pieces of just one shape.

Borrowing his parameter, I recreate his design and simply combined his 3 pieces into one.

In the first trial, it seemed the pieces interfere with each other because of direction of the connecter slot.

I changed its direction though the most of the extra part of the pieces come out outside by this change…

Then, I found another trouble. It was not controllable by the parametric way. It should have been changed its size when even only its dome size parameter was altered but it was not be done. It seemed that the piece had too much constrains because I combined 3 pieces without detailed design based on calculations.

second failure
For learning parametric design, I decided to start with simpler design. I found a good example from the Internet market site. Its shape seemed cuboctahedron(or vector equilibrium) whose faces were composed of only equilateral triangles and squares. And I could understand the shape of each pieces of this product must be based on the same size of the equilateral triangle because its length of sides(both equilateral triangles and squares) were all same.

image credit

So on Fusion360, I tried make the similar shape to equilateral triangle with the slot (one of the sketch menu) I set the parameter for length of the slot and constraints on each edge of the 3 of them to create triangle shape.

But when I change parameter, the shape was transformed unexpectedly and cannot keep the shape of triangle. (one of the slot in 3 wasn’t changed at all.).

third trial
Finally, I decided just to recreate the example from the internet.

At first, I drew an equilateral triangle and added slots for making the joint on each vertex of it.
To make the design parametric, I used formula as many as possible. it allowed to change the size of all the parts at a time if I changed the parameter of the length of the side of the equilateral triangle.
And also, I really cared about the constraints to avoid not changing situation by their setting.

the parameters for the object

narrowed the triangle shape by the auxiliary lines which were drawn as circle using parameter. and also make a hole in the middle.

turned all the extra lines to construction lines (broken lines)

slot was slightly changed to round off the sharp corner. it made the pieces durable after cutting as actual cardboard pieces

done! save as .dxf file.

laser cutting and assembling
imported to inkscape and ordered closely for wasteless cutting. I actually liked this stuff many pieces in one picture cause it seemed a kind of graphic design

lasercut some to check if the connecting part worked or not.

I used the prameter below to cut properly as reserched in our groupe assignment work.


connecting part was okay. so cut it a lot.
and assembled them.


possible next plan

make different sized shape by parameters. and add to the model already assembled. also could try on another materials.

Description of Important Weekly Learning Outcome

the notion of parametric design is quite useful. it helps us redesign the outcomes really quickly. I have to do prototyping a lot in the FabAcademy term. so this IDEA is going to be absolutely powerful tool for me. but setting of the parameter is much more delicate than I expected. I should be careful about the relation of each part of the shape of the design because they interfere each other easily. but, there is no reason not to make use of it.

and I learned two ways of machine cutting. vinylcutter is for only thin material. but its cutting trace is so clean because it doesn’t produce charcoal thing. on the contrary, lasercutter makes charcoal on the material edge. so we have to think about kerf which is burnt down while cutting. but its cutting is very speedy and powerful. so I would like to use them properly.

2D sticker design (.svg)

3D piece of construction kit (.f3d)


laser cutting using inkscape

envelope inkscape (Japanese source)

The Melnikov Press-Fit Kit