In the third week of Fab Academy, the plan was to design a press fit construction kit, using parametric drawing programs.
I was really interested in making a mini press fit chair
I thought that it would be a nice preparation for the computer-controlled machining week to make a mini press fit chair made of paper this week
My plan was to make a few different variations of a chair
I decided to stick with the program inkscape and draw my designs there
I started off by changing the default units in Inkscape from pixels to millimeters
To do that you click on file and the document properties window should appear
My next step was to make a simple rectangle with the width of 80mm and height of 40mm
And after that step i drew another smaller one with the dimensions of 20mm x 5mm. Then i changed the colours of them
The next step was an important one. I used the clone feature on the small rectangle
The clone feature makes the design parametric
To do so you have to click in your item, go to the edit toolbar, click clone and then create clone. Or simply use the shortcut Alt+D
A clone looks like a copy of the original object, but it’s more than that: a clone is a linked copy that changes whenever the original changes
My next step was to align the small rectangle, and it´s clone to the big rectangle, using the Align and distribute tool
To do so you click on the object toolbar and you will find the Align and distribute tool there. The shortcut is Shift+Ctrl+A
Next i wanted to draw the feet for my chair
I drew a another rectangle, now with rounded edges. The dimensions were 60x50mm
Next i stretched the rectangle to 55x85mm
Now i duplicated this shape, made it smaller and centered it to the bigger shape
Next i used the difference tool(Ctrl + -), selected both items and then my foot design looked like this
My next step was to cut this item in half by using the difference tool again
After that i created a small rectangle that would fit onto my first design
If you can do all the things above, i think the rest of my design should be very easy to do
When all my items were finished, i turned off the fill of them and turned on the stroke
To do so you have to select the items, go to the object toolbar and click the fill and stroke option, or simply use the shortcut Ctrl+Shift+F
On the image below are the parts for the chair
It´s very important to save your file as a pdf file for the laser cutter and make the page fit around the items you want to cut
The laser we have in our lab is an Epilog Mini
The material i used was a cheap cardboard
There is a nice tutorial on the Fab Lab wiki which i found very helpful
It´s necessary to switch on the ventilation and the air pressurizer, otherwise the printer won´t turn on
I turned on the machine
Next i took my material and placed it in the machine
On the machine, i pressed the X/Y OFF button followed by the green GO button for confirmation
Now i proceeded to move the laser by hand to where i wanted it to start cutting. The POINTER button helps you aim as you get a red dot on the lasers position
My next step was to manually calibrate the height and i clicked on the FOCUS button to do so
I used the arrow buttons on the machine (up) and (down) to lower the bed
The machine starts at the top left corner of design files. When i was satisfied with the position i pressed an SET HOME and that was the starting point for the cut
Next i opened my document in Adobe PDF reader on the computer and pressed the print button
After that i clicked on the PROPERTIES tab to set the laser cutter's options. Here i determined the settings that correspond with the material i am using
In the properties window i selected the vector setting. Vector means cutting only.My next step was to set the piece size
After my properties settings were complete i hit the print button and the job name appeared in the lasercutter
And then i hit the green GO button on the machine and the job started
And here are my parts ready after the laser cut
And here are two chair designs i made from the parts(i cut out on more kit)
The first one is a regular, majestic chair and the second one is a more funky, rocking chair
Neil also gave the students the task to make something in the vinyl cutter
I decided to make a sticker for the back of my phone, and decided to make a sticker out of the Fab Lab logo
I found thisimage on the internet and decided to use it
I copied the image to inkscape and there i used the trace bitmap option
The size of my phone is 14x7cm so i created a rectangle in inkscape to align the logo with it
I decided to have the logo 50x50mm
The vinyl cutter is a very simple tool. The one we have at our lab is a Roland GX-24
I decided to use orange material
The settings for the vinyl cutter are fairly easy. There are is a very useful tutorial for the vinylcutter on the fab wiki page
This is the tutorial i used long time ago
It´s on Icelandic but i hope people from other nations also find it helpful
This is what the design looked like after being put through the vinylcutter
I am fairly pleased with this sticker and i think it looks good on my phone