How to draw a hollow center ball

vahan_dinihanian

Im new.   can anyone help me over the phone and walk me through how to make a file of a Round ball:

7" round ball that is hollow in the center. two inches thick from the outside to the inside surface. The interior void is 3 inches in diameter.  The ball would be 3d printed out of foam rubber and have 1.250 holes all the way around the sphere spaced equally from each other approximately .500.  I need an STL file so that this prototype can be 3D printed.  It needs to be made of foam rubber so that it can be squeezed into a 3 inch ball, then immediately expand to 7 inches.   

_Ðave_

See Link  Here>> 7" Hollow Ball & STL

andrew_troup

The equispaced holes are a bit more tricky. There was a thread recently about modelling a strainer

https://forum.onshape.com/discussion/comment/12764/#Comment_12764

which shows how to create hole patterns, but the difficulty is in the geometry of spacing the holes evenly over an entire sphere.

3dcad

Would it be easiest to create a sector with holes and use circular part pattern & boolean to create a sphere?

brian_jordan

Don't know if this helps. As part of my learning curve I have been modelling a ketlebell which involved producing a hollow sphere.
See https://cad.onshape.com/documents/91de9126f0c24d81b35d8a26/w/3f74fa95326b4236873250a5/e/aded0bf282664b24b717c822
Sketch 1 was simply rotated around the vertical axis through the centre.
As you can see, I am now trying to work out how to equip it with a handle but that's another issue.