Posted by Jim Pollock on April 20, 2012 at 22:12:17:
I have an old Barber colman #12 hobber that has no differential. I have never cut a helical gear before but I need to make one now and I have one to duplicate but I am not sure about how to get an accurate measurement on the helix angle of my sample gear. I did roll it on paper up against a straight edge and then measured the angle of the marks left on the paper and I got 35 degrees. Would this be accurate enough? This gear has 12 teeth and I believe it to be 7dp. The od measures 2.530"
How big of a night mare would it be to cut this on my old hobber? I have the manual for it but it does seem quite complicated to gear it properly to cut this gear. I think that I would have to make some new gears for my index and feed as I don't have a complete set.
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