01-01-2013, 02:33 PM
(This post was last modified: 01-01-2013, 02:35 PM by Sunset Machine.)
About two years ago I needed to fix my lawnmower - the power drive transmission went kapooey. This is a little mower like you'd push around the yard, which is what I'm doing with it now. But I started a project requiring a worm and wheel, got as far as making the hob and for whatever reason put it on the back burner.
The next step was to cut flutes in the hob. I wanted to cut them helical (at right angles to the lead) and I guess that's what stopped me - no universal dividing head. The other day I ran across this picture:
Planer-spirals.png (Size: 159.84 KB / Downloads: 115)
It looks like the right-end of the slanted bar slides on the table, guided by the tee-slot. A follower rides the bar and gives a twist to the work as it goes. Realize that the work and table are moving, the bar and cutter are stationary.
I've since found more documentation, and a word of caution that it won't cut a true helix. So that's my question to you math guys - why isn't it a true helix?
The next step was to cut flutes in the hob. I wanted to cut them helical (at right angles to the lead) and I guess that's what stopped me - no universal dividing head. The other day I ran across this picture:
Planer-spirals.png (Size: 159.84 KB / Downloads: 115)
It looks like the right-end of the slanted bar slides on the table, guided by the tee-slot. A follower rides the bar and gives a twist to the work as it goes. Realize that the work and table are moving, the bar and cutter are stationary.
I've since found more documentation, and a word of caution that it won't cut a true helix. So that's my question to you math guys - why isn't it a true helix?