Posted by BillS on September 06, 2012 at 16:56:58:
In Reply to: i don 't know cutter posted by bilal on September 06, 2012 at 14:07:41:
OD x NDP = 2 + Teeth/(cos(HA))
I calculate these possibilities:
NDP = 9.6618
NCP = pi/NDP = 0.32515
Module = 25.4/NDP = 2.629
Depending on the gear's original design, it could have been enlarged in OD to improve the profile. If we assume enlargement by 1 tooth, the previous formula becomes:
OD x NDP = 3 + Teeth/(cos(HA))
NDP = 9.988
Coincidence? Maybe, but is close enough to 10 NDP to try rolling a 10 NDP cutter (or gage) to see how smooth the roll is.
You also should check your estimates of HA, OD, etc. You may need to adjust one or more (are you sure HA=25?) and recalculate.
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