Hi guys
Where do you get spheres and semi spheres to align to mold halfes like in the picture?
thanks
Just use plasticine or wax and use a box cutter blade to cut 4 angled sides?
https://www.cytec.com/sites/default/files/files/TDS1004_Manufacturing_Procedure_Insets_Issue3b.pdf
Hope this helps.
For my personal use I use normal round head finishing nails from the hardware store. They push in easily like a thumb tack on a flange material. They work great when using wax or foam. Other wise you’ll probably want to make your own system on a lathe one afternoon.
I really prefer using knock out rounded dowels and bushings vs a bolt. The mold can essentially be dowel’d together and locked. Then you knock them out with a mallet and the mold falls apart when you wedge in a spot or two. That’s using a knurled bushing insert and a dowel pin. Easy to seal as well with vacuum tape.
Also dowels are cheap and bushings are very easy to make.
Ping pong balls cut in half. Marbles set in to the plug.
Those ones look like ping pong balls.
I have used these too, I cut a hole in my split flanges on the pattern work and set a whole ping pong ball into it half way deep.
I have seen people use rubber bouncy balls cut in half. Seems to work pretty well and they only cost $0.25 for 2 halves!
I use ball bearings as they offer better precision. I have a selection from 10-40mm in diameter.
Useful for split CNC’d tooling as you put the reference dimples on the file before the block is cut. Then after machining simply place the balls into the pre-cut dimples. You just select the correct diameter to match your chosen machine shop’s ball ended cutter ( often 12mm)
“Brammer” is where you can get them and they have a European network.
I’ve used a large drill bit (1/2") to wallow out divots into the flange of first half.
