Slightly off-topic, but I need some change gears for my Barnes #5 lathe, Odd-ball pitch, 14DP, when all the contemporary and newer lathes use 16DP. I have found a couple sizes I need off eBAY, but not all of them. I used openSCAD to configure a sample gear, and used 3d printer, CNC router, and conventional machining to make a sample 20T gear.
The big gear is a 100-year old Barnes steel gear. Yellow is 3-d printed PLA, white is CNC-machined nylon, last one is 6061 aluminum.
The PLA is very good, tight to dimensions, but I'm not sure how durable it would be. I don't have any other filaments, I'm sure if I could use PETG or another higher-strength filament it would be quite useable.
White nylon is a disaster, a lot of burrs and poor surface finish. My settings for feed & speed came from generic websites, I'm guessing I could spend some time tweaking values it would probably produce better results. A zillion offshore lathes using nylon gears proves that the material is suitable.
Aluminum for the win. Took a piece of 6061 plate, on the band saw to rough cut to o,d,, bored the centre hole to size, made an arbor, then chucked arbor and blank in the lathe and turned o.d. to size. Took arbor and blank and chucked it into a spin indexer. 14DP cutter set off eBay. 1 hour of manual machining on my RF30 mill.
Ignoring programming time, PLA took about 1.5 hours, nylon about 1.5 hours, aluminum about 2 hours. The only real advantage of the automated manufacturing is I could do something else while the machines buzzed and clicked to themselves. But, I got 2 hours of enjoyment running the lathe and mill that I didn't get running the 3DP or CNC.
