These are my metric conversion gears for cutting short metric threads on my Craftsman 109!
These gears are a diametral pitch of 24, like all the other gears on the 109 so they can mesh right in on the quick change gear box.
(speaking of change gears, if you want to replace your 109 quick change gears with all 3D printed gears, here is a link to a set of change gears from another awesome designer! - https://www.thingiverse.com/thing:2770529)
The best combo for change gears to get metric is a 127 and 100 tooth combination to get a 1.27 ratio (Converting inch to metric) but with that diametral pitch they were way too large for the lathe, so I found out these are a close range from this article here: https://conradhoffman.com/metricthreading.htm
47/37 gives a 1.27027 etc, which gives a rough equivalent to the 127 and 100 tooth gears while making it suitable to fit in the 109. For reference the leadscrew on the 109 is 8 TPI so that gives you a roughly 2.5mm pitch! (which can be divided/multiplied for your wanted pitch from there)
I have included the STEP files in case anyone wants to adjust, measure, etc
Thanks for checking this out! Hope it can help someone out there!
| 37_Tooth_Gear.step | 896.5KB | |
| 47_Tooth_Gear.step | 940.7KB | |
| Craftsman_109_37_Tooth_Gear.stl | 158.7KB | |
| Craftsman_109_47_Tooth_gear.stl | 144.6KB |
