How to Make [Almost] Anything | Life + Times Of v.2020

Cody Paige | Ph.D. Candidate
MIT | Aeronautics and Astronautics

 

 

 

 

 

 

Projects

[01 Laser Cut Construction Kit and Vinyl Cutting]

This week we're learning how to use the laser cutter and the vinyl cutter. We are designing construction kits with a laser cutter and have been given free reign to design anything with the vinyl cutter.

Laser Cutting: Brainstorming

For our construction kits we need to create a laser cut parametrically designed construction kit that will account for the lasercutter kerf, which can be assembled in multiple ways, and for extra credit include elements that aren't flat. I really like the look of the live hinges and wanted to use these somehow in my design. I began by brainstorming some ideas of how to include all of the elements into one design.

Brainstorming ideas

 

Laser Cutting: Design Selection

I ended up combining two of my concepts - the computer stand and the purse - into one transformable concept. The idea is to have an old-school backpack that can turn 'inside-out' into a computer stand. Some of the challenges I found in thinking through the design were:

  • How will the backpack be wide enough to carry the computer but allow the stand legs to be inside the width of the computer?
  • How will the legs of the computer stand keep it steady with the backpack strap thickness to contend with?
  • What types of joints will I use for the two different types of side panels?
  • How do I design a live hinge with the right radius?
  • Backpack/Computer Stand Concept Sketch

    I did a more detailed sketch of what the parts would like to to answer these questions and to have an idea of the dimensions I would need before starting in on the CAD software (sketching is much easier for me by hand!).

     

    Detailed sketch of parts

     

    Laser Cutting: Modelling in Fusion 360

    Next up was putting this into a 3D CAD model. At first I tried using SolidWorks, since this is a program I am familiar with, however, I was finding that what I knew of SolidWorks would have had me make the design flat. This would have made it difficult to check my work without actually cutting it. I chose to use Fusion 360 mostly because I wanted to haave the timeline bar which allows you to move back to any point in time in your design and make changes. I learned in Fusion 360 as well how to use the sheet metal tool. This is great for a project like this that folds since it allows you to make your design it the 3D format but then to unfold it and create flat patterns out of your 3D design.

    Some key learning moments for me with this design were:

  • Define EVERY parameter: I ended up having almost no numbers in my design since I parameterized just about everything with defined parameters. This was great since I didn't have the thickness of the board when I first started designing, nor was I sure how many joints I wanted. But critically, this helped me to design an optimal living hinge.
  • Sketching is everything: A good sketch is all you really need for a good design, all the rest is easy. The first sketch I made was mediocre and this came back to bite me. Luckily I had the timeline bar and was able to go back and fix it!
  • Living Hinges take a lot of memory: I ended up only actually showing one of my living hinges in my 3D model. When I added in the cuts the model slowed down dramatically. Since I only wanted to make sure they worked as expected, this was fine with just showing the top hinge, and then just used my sketches for creating the cut paths.
  • Here is what I ended up with! I have the top living hinge shown here, bottom is only in sketch. The side panels are see-through so you can see the backpack panel is on the outside and the computer stand panel is on the inside. The back view here shows slots for the straps as well!

    Closed backpackSlots for all the panels and strapsOpening the living hinge

     

    Laser Cutting: Path Planning

    Next up I needed to turn this into a 2D image for path planning. The first thing we did was the group project which was to characterize the laser cutter, which you can find the results of that here. I then completed sketches of each of my parts. To do this so that I was taking advantage of space appropriately, I copied the panel parts and set them up flat next to the central panel of the backpack. I linked all of these panels and sketches to make sure that if I changed any parameters down the road, they would all update automatically (tested this out when I updated the board thickness).

    Laser cutting pattern in Fusion 360

     

    Laser Cutting: The Final Cut

    I used the laser cutting characterization that our group did to figure out the bet size to use for the finger joints, and the settings for the laser. The first run I did I found the gaps for the living hinge were too small. The cardboard started to lift and because the laser cut the ends of the hinge first, it made that even worse.

    Undersized hinge pattern

     

    I more than doubled the vertical gap in the hinge spacing and voila! It worked! Here's some pictures of it in action!

    Computer stand panel assembled.Backpack panel assembled.

    Backpack closed.Backpack open

    Computer stand in action.Backpack with straps.Finished backpack on my back, with button closures added.

    Vinyl Cutting: Design and Sketch

    Every year my family makes all of our Christmas presents for one another. I figured the vinyl cutting componenent was a great opportunity to make a present for my sister! Her favourite movie is Princess Mononoke (if you haven't seen it yet, go watch it now! Done? Ok, now keep reading). The Kodama are these super cute spirits that can twist their heads all the way around. I decided to do a sketch of a few of these Kodama to make as iron-on transfers. I'm going to make her a sweater and iron these on for ultra cuteness. Here is my sketch of the Kodama:

    Kodama

     

    Vinyl Cutting: Cutting Pattern

    I scanned in my sketch and used Adobe Illustrator to turn this into a vector drawing. This allowed me to smooth out the lines and delete the white background to have only the black line outlines remain. I had some issues getting the acutal vector anchor points showing up, so with some much needed TA help, Corel was used instead to turn this into the right vinyl cutting pattern - the top is from Corel, the bottom from Ai.

    Kodama vinyl cutting pattern

     

    Vinyl Cutting: Transfer Station

    Printing the pattern onto the iron-on-transfer went incredibly smoothly. Using Corel Draw, with Tom's help, I made sure that there were no 'white spaces' filled in. This meant checking that when I moved a set of lines, like the inside of his body, that that line didn't remain as part of the outline for the infill of the body. Once this was done, I picked a piece of iron-on-transfer paper (there was only a small piece of black). I cut the raw edge to make it nice and straight -- there was a corner cut out of it. I then put it in the cutter, shiny side down. If I had had writing in my design I would have had to make sure that the image was mirrored since the iron-on-transfer paper gets printed on the down-side of the paper. Using the 'Piece' selection on the machine, the size of the paper pops up. I took this size and put it into the Corel drawing and stretched my image to the full size of the page (a little bit of give at the edge). Then... PRINT!

    Next up I had to do the weeding. I found it was best to gently pull back the excess pieces and use a small hobby knife to help to cut any of the transfer that didn't quite get cut through. The eyes/mouth were a bit tricky to keep on the sticky paper while taking out the excess, but holding it down with the tip of the knife while gently pulling off the excess seemed to work fine.

    Kodama weeding done

     

    The final step was to cut out a section around the design and weed off the excess there. Now its ready to press onto my fabric!

    Ready to press!

     

    Source Code

  • Main Backpack panel (.dxf)
  • Side Backpack panel (.dxf)
  • Kodama Outline (.ai - openable in Corel)
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