4. Computer controlled cutting¶

This week I worked on computer controlled cutting with the vinylcutter and the lasercutter. The assignments are below :

Hero shot¶

Vinylcutter¶

First, I started with the vinylcutter.

Vinylcutter description¶

The working width is 305mm and the length limited to 3m. There is a plotter option and some blade height automatic settings until 1mm. Otherthise, the blade is fixed at 2mm. The Silhouette Cameo 3 machine is the only machine compatible with Silhouette’s AutoBlade, a self-adjusting blade. With the full color LCD Touch screen, you can load your media and access the machine settings. You can put your files on the machine with a USB Device. You have to manage the speed and strength parameters regarding the king of vinyl you’re using. If the speed is too quick the vinyl can be torn off, if the strength is too weak the blade would not cut the vinyl and if it’s too strong it would also cut the support.

For this logo, I used a speed of 5 and a strength of 10.

Preparation of the file for the vinylcutter¶

I designed my file with Canva

I imported it on the software Silhouette Studio that I downloaded :

Use the mirror effect for the sticker you want to put on a fabric or the text would be upside down…

Vectorized it by clicking on the menu on the right and then choose the settings to improve the line arround the letters and once it’s ready, click on “vectorized”

Then select you vectorized form and delete the black part

And then you can send it to the machine by clicking on “Send” on the right top corner but before you can parametered your vinylcutter.

I did 2 products with the vinylcutter : one for a piece of fabric with thermal transfer vinyl ( purple) and one for a sticker with adhesive vinyl (orange). As you can see on the picture, I had more difficulties with the adhesive one but I replaced the letters after.

The thermal transfer vinyl is mat and goes with a transparent support whereas the adhesive one looks like paper and goes with a white support.
When you put it on the machine, put the mat side up. It would be the side in contact with the textile.
I chose the orange color and then placed the vinyl material in the vinylcutter by taking care to align the material with the line on the left

I started the machine, cut carefully the outline of the logo by starting by the internal contours of the logo like the space in the A and added a sticky plastic wrap on top

Finally I stuck it on my computer by removing the back, pressing the sticker to make sure it adhered well and removing the top plastic

Then I did another sticker to press on fabrics by using a similar method excepted that you need to heat the sticker on the fabric with a heated press or an iron so that the vinyl stick to the piece of fabric instead of the plastic. Indeed, the plastic is thermo resistant and helps for the vinyl to be well fix on the fabric. The temperature was 356 Fahrenheit during 180 seconds.

Final result on fabric :

Lasercutter¶

Lasercutter description¶

The machine is a MLlaser ML-W1290 150W chinese lasercutter CO2 model painted an rebranded under MlLaser name with a 150 Watt CO2 Tube. The cutting surface is 1200*900mm with a cylinder turn option.

There are :

a ventilation system (blue pipe) that is connected to the fume extractor placed outside,
a cooler system (ideal temperature : 22°C),
a compressor surrounded in orange that pulse air on the lens to avoid the dust or smoke to obstruct the laser beam and to push the flame close to the lens,
at the back there is a laser tube

You also have a lens and mirrors (surrounded in orange) to improve the light reflection

The laser is motion on the X, Y and Z axis thanks to stepper motors pushing the belts.

Security¶

Keep in mind that this machine can be dangerous so be careful of :

Toxic fumes inhalation so don’t put potentially toxic materials with varnish or other toxic components.
Activating the ventilation before lasercutting
Putting down the safety glass
Keeping watching in case a fire starts and keep an extinguisher (On this machine you have an emergency stop button to stop it)

Group work with Theo GAUTIER from Agrilab ¶

Kerf measures :

We started by measuring the kerf because regarding on the material used, the laser cuts wider than the line and that measure can impact your final kit construction if you don’t take it in your parameters design. So we tried to measure it with several materials : MDF (3 and 6mm), carton heavy duty (2 mm), poplar (4.8 mm) and plexiglass (3 and 6mm).

The first step was to choose the material :

Open the software Lasercut 6.1, design a 10 cm square with 10 lines inside, select the speed (15% or 60% for mdf 3mm, carton and poplar), the power (100%) and then select the “cut” action on the right menu and send the files to the laser by clicking on download

Place the material on the honeycomb and do the autofocus with a magnet place between the laser and your material and click on “Datum”. Once it’s done, remove the magnet, put down the security glass, active the ventilation and press on “Started” on your laser menu.

Take the final cut square after waiting view seconds to let the smoke being evacuated by the ventilation and measure the extremities by gripping it with a vernier caliper :

and do it again for the different materials :

The kerf is then calculated by making the difference between the initial value : 10 cm and the after cutting value. The values are below :

Kerf values

Materials	Side measure (cm)	Kerf (mm)
MDF 6mm	9.68	0.32
MDF 3mm	9.82	0.18
Poplar 4.8mm	9.78	0.22
Plexiglass 3mm	9.35	0.65
Plexiglass 6mm	9.52	0.48
Carton heavy duty 2mm	9.52	0.48

Thus, we can see that regarding the materials, the kerf value is different and must be taken into account in your design if you want your pieces to fit correctly together.
Focus test

The aim was to do a focus test of the lens manually in order to check if the line of the laser is as fine as possible.

First : put a papersheet on a MDF material, start to press on “laser” to make a hole on the paper and move to the right and dowm the laser to make manually the finest point.
Between each point you have to measure the distance between a point you choose on the laser and the surface of the paper sheet

Finaly, use the “Autofocus” button of your laser to compare the size of the point with those you made manually.
In our case, we found that the autofocus of our laser were not optimized because we made a smaller point. As represented below :

Speed and Power test

We tested the impact of speed and power on different materials with our laser. The first observation was that below a power of 11, nothing is happening.

Then we cut the different materials :

That’s the final result : (From the left top corner to the right : MDF 6mm, Plexiglass 3, Carton 7, MDF 3mm, Poplar 4.8, Carton 2, Paper 80g, fabric)

We can see that regarding the material, the speed and power required are different.
Joints test

We tested different kind of joints with the poplar 4.8mm material, regarding the tests previously done last year :

The dimensions between the joints were not large enough so the pieces didn’t fit. The mistake was the width of the polar, I noted 4.2 mm instead of 4.8 mm. We added an extra value of 0.1 mm to make it smoother.
Some pieces were to fragile and broke when we try to join it.

Preparation of the file with Autodesk Fusion 360 and Lasercut 6.1¶

Once you have prepared your file on Fusion 360, you can make a right click on your sketch to export it as a dxf.
I first trained with my logo (to see the engrave and cut fonctions together) that I imported on Lasercut 6.1 vectorized with an dxf format with Inkscape by saving your file with the “.dxf” extension.
Then I choose the size of my logo, the parameters of the laser cut like the power (100%), the speed (15%) and what kind of actions I wanted : engrave and cut.
After making the autofocus with the laser and tested the faisability of the logo on the material I choose, I launched the lasercutter. The result is below :

Then, I did the week assignment :

Design thinking : make a parametric maze kit for rabbits inspired by the Lapirinthe from Rabbits World

Image from the site Rabbits World presenting the Lapirinthe product

As I want the product to be used by my rabbits, I need the material to be harmless if swallowed because rabbits enjoyed gnawing… So I chose the poplar material.
Regarding the dimensions, I choose a height of 30cm and a length of 50 cm.
Thanks to the kerf test done previously, I know that the poplar kerf is 0.2 mm so I constructed my sketches in a parametric way to take into account the kerf.
First, set all your parameters in the “modify” > “modify the parameters” tab

Then, click on “d” to active the sketch dimension tool and then select the side you want to configure it:

Don’t forget the kerf that you need to remove to the joints and you can also add a little extra to make sure the pieces fit well. We call it a “Jeu” and put 0,1mm.
After designing your file, you can change its appearance by clicking on : “modify” > “appearance”