Top and Bottom Hard Insulation Covers

We’ll use thin Delrin/Acetal for these parts. (Highlighted Blue for the top, similar plate on the bottom). Either of Delrin, Acetal, and either of the homopolymer or copylomer versions are acceptable. We had originally avoided acrylic because of its tendency to shatter and crack on impact, but this can likely be revisited.

Open

The part isolated is shown below:

Open

A few different thicknesses were tested in the earlier prototypes and 3/64” thickness was decided on as the 1/32” seemed a little too flimsy and the 1/16” was thicker than required.

Have a read through these 2 hackaday articles for some great info on laser cutting the material:
https://hackaday.com/2015/09/03/how-to-build-anything-using-delrin-and-a-laser-cutter/
https://hackaday.com/2015/09/22/drawbacks-of-lased-delrin-and-how-to-slip-around-them/

Ideally, we’ll laser cut them on the Epilog laser cutters in the Rapid Prototyping Center. The prototypes were cut by Tommy Tran on the laser cutter in the WatiMake Lab.

Revisiting this on July 18, 2020

We are revisiting the material choice here and hoping to potentially get some cost reduction, but we’ll go with whatever option is best for design.

We have only been able to find the 3/64” Acetal material from McMaster-Carr (https://www.mcmaster.com/8575K253/). We would need 5 of those pieces, and at $25 USD each, plus $15 shipping, would work out to around $200 CAD.

Cost reductions would be great here. Other materials, thicknesses, etc. are all on the table, but must be able to be quickly manufacturable. Laser cutting is great and likely preffered but it other options are available then let’s definitely explore them. Able to purchase material locally (Waterloo, Toronto regions, etc.) would be a great benefit as well.