6/2/2020... If you are having issues with Cura and fitting this to your bed, maybe watch this video to get rid of the "keep out" area on some of the newer version of Cura.

https://www.youtube.com/watch?v=Il1sierB4Yk

4/3/2020... If you print the Flat version, I just added 2 prints to glue in the missing 14mm bottom chin pieces

3/27/2020... I added a picture of me wearing the helmet. I have a 23" circumference head and it fits snug.

I split this helmet in 2 using Fusion 360 then I resized it using Cura to fit on the Ender 3 and also fit a 9-16 year olds head (although it does fit mine). See the pictures, it sits on the bed at a 45 and Cura will slice it, you just have to sit it just right on the bed and do not select Brim or Skirt.

Use Supports Everywhere except put a support blocker at the very tip top, it's not needed and will save lots of time and plastic.

I used silk silver :) and love the results!

There are 2 version here. One has the entire point of the chin but doesn't sit flat on the bed so you when you turn on support, the back of the helmet will be entirely supported.

The easier version lies nicely on the bed and gives you a good solid base to build on. The draw back is you lose a little of the bottom of the chin (~14mm)

I have a normal fat head and it fits me. I really sized it for my 9 year old to where. Fits great!

Otherwise, .24mm layer height and 10% infill. Make that higher if you like, it may be stronger but will take longer to print.

Thanks.