Posted by Bill S on May 13, 2005 at 10:57:23:
In Reply to: worm and worm gear PD changes posted by Charley on May 12, 2005 at 10:09:51:
I couldn't get the .045 CP and the angle to match up on the worm for the given OD, so I made an assumption that the .045 must be Normal CP. Then I was able to get a close match to normal CP (.045), helix angle (16D 7M), and OD (.230). Using CPC-TMILL, I found the following for the worm:
Normal CP: .045
axial CP = .045832
Normal DP = 71.35
Addendum=.014
Pitch Dia=.202
MOW = .23055 over (3) .02279 pins
I can't quite agree with the lead of .1817. I think it should be 4 X axial CP, or .183328
Looks like the gear specs stayed the same except for the OD. Since the pitch and angle stayed the same, then I must assume that the pitch dia is the same as before. This tells me that the addendum is .006 larger than standard.
If these conclusions are correct about the worm and gear, then the
setup change gears to cut the gear will be the same.
If the worm data calculated above (Esp. PDia) are not as specified on your print, then let us know.