Adapted from an article "Spur Gears and Pinions" by John A. Cooper in "Machinist's Workshop", 4/99, Volume 12, Number 2, pg.8
John Cooper wrote one of the best articles on homeshop gear making I've seen. For those of you who haven't seen it yet, the reference is:
"Spur Gears and Pinions" by John A. Cooper "Machinist's Workshop", 4/99, Volume 12, Number 2, pg.8
I've never made a gear but I have several projects on the burner that require same and his article was so well written and complete that I'm encouraged to undertake what has always seemed a most challenging task.
John includes all the required calculations in his article and really nothing more seems to be required. Despite his thoroughness, I thought it would be nice to write a program to implement the calculations. Not only does the program simplify things and minimize errors, but it writes a nice data file that one can print and carry to the shop for reference. It's another good example of the computer helping to save time and avoid mistakes.
Operation of the program should be self-explanatory. It's programmed with a set of defaults that correspond to the example that John used in his article. For those of you who may not completely comprehend all the values computed, John has provided a most explanatory diagram on pg. 11 of the article. Your shop notebook should definitely contain a copy of this article!
DP = diametral pitch = teeth/pitch diameter (in)
Mod(ule) = pitch diameter (mm)/# of teeth
Therefore:
DP = 25.4/Mod