Herless Lathe SSB-MK5 Threading Dial

thingiverse

I bought a Herless lathe from a friend but it had no threading dial. A discussion on Facebook showed that it is a clone but I could not find a replacement dial component anywhere on eBay and other websites. The manual showed that it has a Metric leadscrew - and my threading indicator showed a 3.0mm pitch. The manual also showed that I needed a couple of gears to handle metric threading - I chose to make a 24T gear for this device, as I will need others later. I built a redesign of the original Threading Dial using Fusion360 based on some rough sketches shown in the parts manual. Initially sketched the lathe apron using calipers and measured bolt hole locations and general geometry. A quick test print with 1mm accuracy showed if it all fit. I then extruded the 6mm base plate to ensure bolts are evenly attached to the apron body, and extruded a guess of the thread body depth (30mm - turned out correct). I learned how to make a 24T metric spur gear using YouTube tutorials. Set the gear height to 6mm and the pitch diameter came to 12mm. I added an approximate of my leadscrew, and lined up the spur gear, giving me the location of the shaft hole (thankfully - all centered). A couple of test prints in ABS grey 0.4mm showed some tweaking was needed for hole locations. I didn't have a 6mm shaft, so I turned down some 8mm aluminum bar (maybe I could have made all holes 8mm?). I super-glued the spur gear to the shaft and inserted it into the body. Then I attached the top dial with superglue. Left to dry for a few minutes and attached the hole thing with 6mm cap screws to the apron. Future: I will probably reprint this in green (to match the lathe) and print it with 0.25mm nozzle for better quality - but the 0.4mm print came out well and was quick to print (~2-3Hr). I will have to re-print it with PTFE because I think ABS won't handle the oily environment of the lathe, but for now - I can just reprint. It works - and having never used a threading dial before, I still have some learning to do. But for a few hours of Fusion 360 learning, I'm very happy with the outcome! Hope this helps someone else.