3 ms·

Thought this would be about the machining setup to make them, not the math of the CAD setup. To actually machine this, you would basically use a ball end mill

Thought this would be about the machining setup to make them, not the math of the CAD setup. To actually machine this, you would basically use a ball end mill (which has a roughly half-sphere end) and drill a bunch of offset holes according to the pattern outlined in this writeup.

machineroo 7y ago
Or you can load the CAD setup in something like SolidWorks and it will generate for you the required toolpath for a specific machine.
- cjsawyer 7y ago
  That’s what they said. The tool path here isn’t the hard part and if you used anything other than a ball end mill you’d waste a ton of time and come out with a worse result.
defterGoose 7y ago
A ball-end mill wouldn't be the best tool for this, they're meant more for 3d contouring. They've probably just used a normal endmill and interpolated each hole or used an appropriately sized drill. And at the volumes they're manufacturing, waterjet or laser-cutting (not as good for aluminum) are likely the method of choice.
- jacobolus 7y ago
  A waterjet / laser cutter makes no sense as a way to cut a hemispherical hole. It seems highly likely there is a ball end mill involved in getting the final smooth shape (maybe after roughing out the holes with a cylindrical tool). The main question is whether the ball is the same size as the hole, or a bit smaller (which would require it to move around in little spiral paths instead of just going in and out once).
  - defterGoose 7y ago
    A waterjet/laser makes plenty of sense if you're interpolating anyway. And ball Mills aren't designed for plunge cutting, so using two different tools would be a suboptimal solution. Since the holes have no features in the z dimension, there's just no reason to use one in this particular case. Edit: ok, looks like it is hemispherical, so you're right. I had thought initially that it was two layers of offset circular holes.
  - londons_explore 7y ago
    Inspecting a finished product should answer this question?

machineroo 7y ago

Or you can load the CAD setup in something like SolidWorks and it will generate for you the required toolpath for a specific machine.

cjsawyer 7y ago
That’s what they said. The tool path here isn’t the hard part and if you used anything other than a ball end mill you’d waste a ton of time and come out with a worse result.

defterGoose 7y ago

A ball-end mill wouldn't be the best tool for this, they're meant more for 3d contouring. They've probably just used a normal endmill and interpolated each hole or used an appropriately sized drill. And at the volumes they're manufacturing, waterjet or laser-cutting (not as good for aluminum) are likely the method of choice.

jacobolus 7y ago
A waterjet / laser cutter makes no sense as a way to cut a hemispherical hole. It seems highly likely there is a ball end mill involved in getting the final smooth shape (maybe after roughing out the holes with a cylindrical tool). The main question is whether the ball is the same size as the hole, or a bit smaller (which would require it to move around in little spiral paths instead of just going in and out once).
- defterGoose 7y ago
  A waterjet/laser makes plenty of sense if you're interpolating anyway. And ball Mills aren't designed for plunge cutting, so using two different tools would be a suboptimal solution. Since the holes have no features in the z dimension, there's just no reason to use one in this particular case. Edit: ok, looks like it is hemispherical, so you're right. I had thought initially that it was two layers of offset circular holes.
- londons_explore 7y ago
  Inspecting a finished product should answer this question?