I'm almost about to cnc mill my own planetary gearbox.
one question puzzles me.
For milling the outside ring, which is an internal involute gear (teeth are going "inside" the rind, not outside like a regular gear), I am faced with a classic "my endmill wont fit in the corners while later on another part must fit in there anyway"
kinda problem (sorry for lacking the proper vocabulary but i'm pretty sure most of you must know what i'm talking about.
In general, when i face such issues, I design the part in CAD so that later on the end mill will always fit whatsoever.
A typical example would be
But for the involute gear ring, i would rather avoid weakning the part or do pretty much anything that might endanger the desired fonctionality.
Here my approach is different. I am making drawing the inside teeth slighly deeper so that the extra clearance is enough so that the part that will remain after the endmill has done its job cannot collide with the planet gears
screenshot below. the ring in green. the circle corresponds to my 1mm endmill. As you can see it should be fine (i hope so)
My question is : would you have better tactics in such a situation ?
Any idea is welcome.