Advanced laser cutting - Creating a pressure fit mock up
As a reminder of the work he has done in his lifetime the retired recipient of this gift is given a mock-up of the plasma cutter he has been working with. This present is built in fablab @ Waag, mainly by using digital drawing (see attachments) and the laser cutter. A short description with some key features of the design and building process is given, as well as a image overview of the whole process.
I started of with pictures of the machine to give me some inspiration of how I could tackle this built. I've also used them for dimension purposes. Here's a picture of the machine:
I started with making the the two sliders. I tried to use as much pressure fit parts as possible because this would reduce glueing time. It's good to keep in mind whilst drawing the components that the laser cutter is removing material, to be precise +/- 0.22 mm. So if you cut a square 5x5 mm then it will actually be 5.44x5.44. In pressure fit designs this is enough to have too much clearance, so keep that in mind whilst drawing your digital files and do a simple test cut with the material you'd like to use before completing your digital design. Next the process of cutting the 4 mm triplex (speed 0.8 power 100 PPI 1500) and the design of the sliders is shown (only the small u-shaped parts are glued):
Next the box that holds the material that has to be plasma-ed:
Then the beam that slides over the two sliders, with the cubes that represent the real parts that hold the electronics and create the laserbeam. The spacing allows the small boxes to grab the slider tight enough so it doesn't shear and loose enough so you can still move them:
Then I drew and cutted the control panel with the components engraved on them (speed 40 power 50 PPI 1500) and the laser pin (represented by a pencil so it can draw shapes on i.e. a cardboard piece) which moves also. A tip for parts that are cutted and engraved or parts that have cuts in cuts. Choose your colours in a way you engrave or cut the inner parts first and then cut the outline. This way there won't be any misfits when a part seperates from the material and falls at an angle. Finally the bottom plate (done last so the two sliders were definately parallel, otherwise sliding would be impossible):
And that's it. So next time consider a pressure fit design. It will take some more design time, but it saves you a lot of time and swearing whilst building, especially glueing. Kind regards!
