My daughter broke her piggy bank cap since it was made of really thin, cheap plastic. I finally have a practical use for some Ninjaflex! The hole diameter for her piggy bank was 33mm. Theoretically, you should be able to scale my model using that diameter to fit your needs. This is for Ninjaflex or other flexible materials only. I also made a tapered one, which should insert better but I never printed it since the regular one worked fine.

No

No

200 micron

20%

My Printrbot settings:

print speed - 10mm/sec
temp 230C
bed temp 40C
retraction distance .7mm (I use a Ubis metal hot end)
retraction speed 40mm/s
no fan on first layer

no raft or support needed