08-10-2021, 03:32 PM
I have to cut some M10-1.5 threads in some 1215 steel for a new QCTP mounting stud. I bought a 1ft piece of 10mm stock from McMaster and was going to cheat and use a die to cut the threads but I couldn't find one at a cost I was willing to pay. So I decided to bite the bullet and cut the threads using my mini lathe. I set up the gears for the 1.5 thread and powered on the lathe. It made too much noise for my liking so I investigated the source and found two gears rubbing. I needed to make a spacer to make some room between them to prevent the rubbing. I had a 1/4" oversize flat washer that was the perfect OD and thickness, I just needed to enlarge the ID to 12mm.
I filed some round notches on the washer so I could screw it down to a piece of wood for drilling it out. Worked good. Then I filed a square notch in the ID for the key.
Put it together and no more noise and the spacer also fixed the alignment issue with the mating gear. But then I noticed the screw holding the gears on was coming loose. I tried re-tightening it and running it again but same problem. WTF!
The screw needs to be able to be tightened right up to the end of the shaft the gears mount to and when I added the spacer it pushed the gear out slightly past the end of the shaft. So I needed to make another spacer. I found an oversized #4 flat washer that was the perfect OD and thickness. I just needed to drill out the ID so the screw could pass through it. Got that done and now I can tighten the screw to the end of the shaft and it stays tight.
All ready to cut some M10 threads after lunch.
Ed
Gears rubbing and gear offset:
Spacer work:
Gear rubbing and offset fixed:
Shaft end spacer (prior to being drilled out):
I filed some round notches on the washer so I could screw it down to a piece of wood for drilling it out. Worked good. Then I filed a square notch in the ID for the key.
Put it together and no more noise and the spacer also fixed the alignment issue with the mating gear. But then I noticed the screw holding the gears on was coming loose. I tried re-tightening it and running it again but same problem. WTF!
The screw needs to be able to be tightened right up to the end of the shaft the gears mount to and when I added the spacer it pushed the gear out slightly past the end of the shaft. So I needed to make another spacer. I found an oversized #4 flat washer that was the perfect OD and thickness. I just needed to drill out the ID so the screw could pass through it. Got that done and now I can tighten the screw to the end of the shaft and it stays tight.
All ready to cut some M10 threads after lunch.
Ed
Gears rubbing and gear offset:
Spacer work:
Gear rubbing and offset fixed:
Shaft end spacer (prior to being drilled out):