Posted by BillS on November 02, 2011 at 11:56:29:
In Reply to: Re: Question for Tom Ramsey about calculating final cut posted by tom on October 30, 2011 at 08:21:19:
Hi Tom,
Thanks for showing the Lorenz pages for Span Measurement.
Also, I might mention that the Lorenz example for 70T Spur gear on the 2nd page is wrong as I read it - the span over 8T for 4Mod and 20Deg PA is 92.485mm, not 104.29mm... or since I can't read German did I miss something?
I ran their formula to be sure, but only to confirm that my Span calculator was not deceiving me. Our Span Calculator (it belongs to us all) confirms the formula, just not the value printed in their example. The other examples confirm the calculator and I'm always glad to see that.
The span calculator is in the FAQ page for anyone to use, free of charge. It's easy to use - just click the link above, enter what you know and skip the rest, then click the 'calculate span' button. It will take any PA, Helix angle, shift coefficient or backlash.
If anyone is interested, I could add an option to render change in depth as a function of (Actual - Print Spec) Span Measurements, but I'm kinda busy right now. Besides, it may be more common to need to work from a print MOW. What do people think about that?
I think the original question was to find the formula, chart, etc. that shows how much to change depth of cut when making a Measurement Over Wires, and comparing that to print MOW.
I guess the same question would apply to a span measurement if the print shows the desired span measurement.