Cutting spherical shape

john_leeman

Hi folks,

I'm wanting to cut some semi-spheres into a plate that will retain some ball bearings (see attached image). What's the most efficient way to do this in Onshape? In the past I'd made solid sphere entities and used a boolean, but since that isn't an option I am a bit lost as to how to do this. FWIW these are 0.5" bearings and the cut is 0.125" deep.

Thanks!

lemon1324

I had to do this on a part, and boolean was definitely the easiest.  Make a sphere, pattern the solid sphere, and then subtract, choosing all the spheres as the tools. Also for a non-uniform layout like that I'd definitely look at the point pattern script @mahir linked.


(This is the boolean tool, by the way)

michael3424

Assuming that the feature will be applied to the existing holes in your screen shot, can you use fillets?

coleman

Revolve remove. 

Boolean is an option btw.

mahir

@john_leeman, there is also a FeatureScript Point Pattern that will streamline the process, regardless of whether you use a cut-revolve or boolean.

lemon1324

I had to do this on a part, and boolean was definitely the easiest.  Make a sphere, pattern the solid sphere, and then subtract, choosing all the spheres as the tools. Also for a non-uniform layout like that I'd definitely look at the point pattern script @mahir linked.


(This is the boolean tool, by the way)

john_leeman

Thanks all. I was able to get a workable solution - feedback on how it was done is welcome. The document can be viewed here: https://cad.onshape.com/documents/12b88db9eab08322224df6b3/w/1a82690688b56903ba818e09/e/19a5f976656e69d0f7e24124

owen_sparks

john_leeman   Nice job

The only comment I'd make is the assembly is upside-down and offset in the "Tilt Plate Assembly" tab.  To fix, stick a fixed mate connection on the origin and your "part1"  plate  and you'll be all set.

Cheers,

Owen S.

john_leeman

Owen - Thanks! This part does actually sit with the bearings on a flat surface (granite plate). You place a tilt measurement instrument on the top of the flat, then use gauge blocks with the single ball bearing in different detents to create various tilts for calibration. In this case, full scale on the instrument is <1 degree, hence the long baseline.

owen_sparks

Hi John.

Ah-ha, that sound interesting.  (Sorry I'd jumped to the daft conclusion that this was part of a game, whereby the plate is tilted by the "player" with the intention of dropping the balls into the holes.  Showing my age...)  Your version sounds like much more fun.

Cheers,

Owen S