Here I am trying, after kicking this can down the road for a while, to make one of the missing gears for the Town Woodhouse notcher. I have a 38 tooth gear, so making the assumption that these will be 14.5 degree PA, i worked out that 38+2 over the dia, 3331.5 gives me a DP of 12.
The chart rivetted on the notches says I need a 20 tooth gear, so a while back I went and bought a 12 DP, 14.4 degree, 17 to 20T cutter from RDG. (This was before I bought a huge stash of gear cutters from @pressbrake1 ....
So yesterday I had a look at the job, put the large cicinnatti dividing head on the TW table to see if it would be possible to notch out the splines, then moved it over to the horizontal table of my Richmond mill. (Sounds easy but the bloomin cincinnatti dividing head is too heavy for me to lift off the floor, so a pulley block was involved).
Just for interest I thought I'd match up my cutter to the existing 38tooth gear, but it didn't go all the way to the root. Hmmm, strange thought I, perhaps something may be amiss? So that's when I decided to try to match up one of my stash of cutters to the 38t. And the result was this:
Pic to follow
The chart rivetted on the notches says I need a 20 tooth gear, so a while back I went and bought a 12 DP, 14.4 degree, 17 to 20T cutter from RDG. (This was before I bought a huge stash of gear cutters from @pressbrake1 ....
So yesterday I had a look at the job, put the large cicinnatti dividing head on the TW table to see if it would be possible to notch out the splines, then moved it over to the horizontal table of my Richmond mill. (Sounds easy but the bloomin cincinnatti dividing head is too heavy for me to lift off the floor, so a pulley block was involved).
Just for interest I thought I'd match up my cutter to the existing 38tooth gear, but it didn't go all the way to the root. Hmmm, strange thought I, perhaps something may be amiss? So that's when I decided to try to match up one of my stash of cutters to the 38t. And the result was this:
Pic to follow