Originally Posted by HuFlungDung Geof,
Is the 'pitch' you are referring to in your examples a regular thread tap pitch, not a diametral pitch that would be more commonly referred to in a gear catalogue? 6 diametral pitch would have 1 inch of diameter for every 6 teeth on the gear, hence a 4" pitch diameter gear would have 24 teeth. |
Tap pitch. My machine generated a 60 tooth wormgear and I think the pitch diameter of the gear was somewhere close to 3.86". I can no longer recall the details but I needed a worm gear for a tilting mechanism on a desk I designed. I intended to make the gear from leaded steel and the largest diameter I could part-off in my big turret lathe was 4". So a played around with different worm pitches and gear tooth counts until I happened onto this combination. Diametral pitch confused me then and it confuses me now so I ignore it.