For my multimeter I needed to design a proper case, not just random slab. 3D Printing and design in general was covered in Week 5. Because of the features of the casing, it was printed with the large industrial printer, that was broken during the week 5 and most of the course. The Stratasys printer I used has the capacity for soluble support materials, allowing internal structures to be designed and printed, and I utilized that capacity for this. Industrially developed printers like the Stratasys or the Form2 usually have very extensively designed user interfaces, that really dont allow for too many problems in starting the printing.

For the purpose of my multimeter, I needed to elevate the board up about 10mm to give room for terminals, and the piezo speaker that would get hotglued to the bottom of the casing. Also this served an opportunity to anchor the board into place properly so it wouldnt rattle around inside.

To the side of the casing I made holes for the serial communications, and for USB. In the bottom I left room for the banana connectors and designed a small ledge that would hold the bottom plate in place neatly.

In the top I made room for the 9v battery, and its connector, also gave it a bit of a corner pieces to make sure it didnt accidentally move around. The covering for the battery tray has a small nook in the casing, enough to look neat but also to allow it to swivel around for replacing the battery without taking the whole lid off.

With the window is when things get tricky. If I designed the lid to have just an opening for the window it wouldnt hold in place, and the screws sticking out wouldnt look neat. This design does need two panes, one to go inbetween the casing and the hole, and the smaller main window that then would get superglued on.

Since the plexi I had for laser cutting was 3mm thick, and the screw top is 3mm tall. With this design I was able to sink the screw into the casing, giving it a nice professional look. Well that was the intention... The part of the lid holding the window in place on the inside also were placed so that when assembled they anchor the display in place so it doesnt get to move around and is placed properly for reading.

For extra complication, the button for switching around the features, is printed in place. While not entirely visible on the casing drawing, the button is separate enough that the printer fills the space in between with support material that then gets dissolved in the appropriate bath.

Also for the nice final touch the multimeter needed proper probes. These I designed in Inventor, and then milled out with the roland mill out of wax, then made a casting of silicone and them cast plastic with the cables within the mold to get the usable probes. I explained this in Week 12