E36 Cup Holders

A major flaw on E36s is the absence of cupholders, as BMW offered ashtrays instead. I decided to design and fabricate my own. My objectives with the design were holding the average drink size, looking OEM / fitting interior aesthetic, and not needing to drill or cut any part; leaving it fully reversible.

The most difficult part was mapping out the surface of the console to ensure a proper fitting insert. The surface had non-symmetrical fillets, draft angles, and a limited amount of space. To outline the surface, I began getting a rough estimate of the dimensions through my calipers, modelling a 2D sketch of the profile, printing a 1mm thick plate of said profile, checking the fitment, and iterating until it had a nearly identical 2D profile, both across the horizontal and vertical.

I was able to re-use the expanding rivet and the existing mounting holes of the ash tray to mount and secure the cupholders to the console.

For dark interior car parts, which can be exposed to the sun for a long period of time, ASA and ABS are preferred. I went with ASA since it has the best material properties, however the trade off is that it is much harder to print and is susceptible to warping. I had some trouble initially getting a successful print, but after some failed prints and finding solutions online, I pre-heated the bed and chamber, and added brim to get a valid print. These two steps were most effective on providing a satisfactory print.

I am pleased with the final outcome. The cupholder fits snug, remains stable, and meets my initial objectives. I believe it matches the interior aesthetic well.