how I held tetrahedron to finish last face.

[Jimsehr]

When I made tetrahedron I found it hard to hold to finish last side. Most of part was done on lathe . but I had a pip left on face where it was cut off. And all the edges were razor sharp. So I made a little fixture to hold part on mill while I removed the pip. The fixture holds part the faces a little bit up on the angle.

 

[JerryK]

That looks very small Jim, what
size is it ?

 

[Jimsehr]

I made it out of 1/2 dia stock. If you mic across the points it is about .430 Across. The edges are razor sharp.

 

[Tozguy]

Good work Jim, thanks for sharing.
What is that little pyramid used for?

 

[JerryK]

I made it out of 1/2 dia stock. If you mic across the points it is about .430 Across. The edges are razor sharp.

WOW! That is a small one Jim. (good job)
I have one around here somewhere made from 3" diameter.
I'll see if I can find it later

 

[JerryK]

This tetrahedron made from 3” dia. Delrin
I milled a opened end pocket with taper walls.
Lock it in from the bottom.