I needed these for my lawn tractor. So I drew em up. I was trying for basic, but kind of heavy duty(ish.)
No supports should be needed. The under side of the top of the big circles on the cup holder came out a tad fuzzy but tolerable. You can see it in the pic.
The cell holder fits my Moto G5 in its case. The opening in the top is 90 mm x 17.5 mm. Scale to fit yours if you need to.
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