Question about making worm gears
I just had a question while we're somewhat on the subject, and as I can't seem to figure out how to start a new thread, I thought I'd ask it here. I'm building an indexer, and I decided to make the worm and worm gear. I ordered a 1 1/8 6 acme tap to cut the gear with. I need to figure the exact diameter of the gear for 90 teeth. I've googled it, I got one formula but it's clear as mud. Now simple math tells me for 90 teeth at 6 tpi I'd need a circumference of 15, diameter of 4.774. But that's PITCH diameter, right? Not the od of the blank? So do I add 2(.3183) or how do I go about getting that dimension? Not trying to hijack a thread here, I apologize in advance for any inconvenience.:nervous:
I just had a question while we're somewhat on the subject, and as I can't seem to figure out how to start a new thread, I thought I'd ask it here. I'm building an indexer, and I decided to make the worm and worm gear. I ordered a 1 1/8 6 acme tap to cut the gear with. I need to figure the exact diameter of the gear for 90 teeth. I've googled it, I got one formula but it's clear as mud. Now simple math tells me for 90 teeth at 6 tpi I'd need a circumference of 15, diameter of 4.774. But that's PITCH diameter, right? Not the od of the blank? So do I add 2(.3183) or how do I go about getting that dimension? Not trying to hijack a thread here, I apologize in advance for any inconvenience.:nervous: