- Joined
- Jul 18, 2020
- Messages
- 13
I recently broke the 2 speed selector combo gears in my Grizzly 7x14 lathe. I successfully replaced them with new plastic gears.
This got me thinking. These gears are very amenable to 3D printing. I can easily reverse engineer the gears and my CAD program has a tool to produce gear profiles. It needs the number of teeth, the diametrical pitch, and the pressure angle. Obviously I know the pressure angle. But I am not positive of the diametrical pitch because the teeth on the original gears appear to be very similar to that produced by my car program, but not identical. The teeth on the original gear are a bit taller (or conversely cut deeper) than those produced by the CAD program.
As long as the teeth mate properly, I believe it is not critical to have a certain specific profile. So, I need to make the sum of the pitch diameters (calculated from the number of teeth and outer diameter or vice-versa) equal to the center-center distance of the spindle to the intermediate shaft.
Of course I didn't measure this when I had it apart, and I may have not been able to measure it accurately enough anyway.
Does anybody know this distance? How about the diameter of the intermediate shaft. I think it is 12mm, but I could easily be wrong. Again, I didn't measure it when I had the thing apart.
Once I have the data, and create the 3D printable file for the gears, I will post them on Thingiverse, and here too if possible
Thanks in advance for the info!
This got me thinking. These gears are very amenable to 3D printing. I can easily reverse engineer the gears and my CAD program has a tool to produce gear profiles. It needs the number of teeth, the diametrical pitch, and the pressure angle. Obviously I know the pressure angle. But I am not positive of the diametrical pitch because the teeth on the original gears appear to be very similar to that produced by my car program, but not identical. The teeth on the original gear are a bit taller (or conversely cut deeper) than those produced by the CAD program.
As long as the teeth mate properly, I believe it is not critical to have a certain specific profile. So, I need to make the sum of the pitch diameters (calculated from the number of teeth and outer diameter or vice-versa) equal to the center-center distance of the spindle to the intermediate shaft.
Of course I didn't measure this when I had it apart, and I may have not been able to measure it accurately enough anyway.
Does anybody know this distance? How about the diameter of the intermediate shaft. I think it is 12mm, but I could easily be wrong. Again, I didn't measure it when I had the thing apart.
Once I have the data, and create the 3D printable file for the gears, I will post them on Thingiverse, and here too if possible
Thanks in advance for the info!