Version 2 of my stroller cup holder. I also have a V1 that is more simple.
Inside radius of clamp is 40mm. Fits stroller handle from 38mm up to 50mm.
I have added a V3 bracket with inner diameter 36mm. this should fit better of V2 is to loose.
I have used 3mm closed cell EVA foam with adhesive on the inside of the clamp to protect the handle of the stroller and give the clamp more grip.

Hardware used:
1 x Hex M5x12mm
1 x Unb M5x35mm
2 x M5 nyloc nuts
1 x Hex M6x65mm
1 x M6 nyloc nut

I used some 3mm adhesive foam inside the bracket and cuphoder to protect mounting place and reduce noice from bottles.

Anycubic

i3 Mega S/Pro

Yes

Yes

50%