Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5219767.

This a Large cup holder for a tray that attaches to a tray on a walker. The holder easily holds 12oz glasses and coffee mugs. It attaches quickly with a large nut. The holder itself, is printed using a TPU filament. You could try PETG or ABS but it maybe to rigid to work well. I don't think PLA would be a good choice, unless you can get FPLA+ which is available on Amazon. I printed the nut in PLA and the combo is great, and the nut tightens well against the TPU.