Gear Tech Tips


	Gear Tech Tips Technical Information For The Gear Industry	by AMERICA
	This Edition is Sponsored by: Wenzel GearTec	Tech Tips Edition #2
"Add A Friend" To Receive This Newsletter Hob Life and Shifting Strategy (Part 2 of 2) *"Calculation of Shift Amount"* Once the usable length (UL) of the hob is known (discussed in Part 1 of 2), the number of usable teeth (UT) can be calculated. *UT = (UL / p_x) Gashes in the hob (p_x is Axial Pitch) The number of usable hob teeth is used to estimate the parts that can be hobbed per sharpening. This is calculated by using general tool life factors (LF) which are as follows: - Uncoated High-Speed Steel (HSS) tool = 80 lineal inches of part per hob tooth - Coated HSS tool = 125 lineal inches of part per hob tooth (assumes re-sharpened and not recoated) - Multi-Gash (>15 gashes) tool = 200 lineal inches of part per hob tooth - always coated - Coated Carbide tool = 350 lineal inches Using the above life factors, the parts per sharpening is calculated by: Life / sharpening of hob (in inches) = UT * LF -or- Parts / sharpening = (UT * LF) / (N * Face width of part), where N = number of teeth in part Once the number of parts per hob is established, the shift amount per piece can be calculated. Shift / part = UL / parts per sharpening Other useful formulas: Axial Pitch (p_x) = p / P_nd Add E-mail Addresses: Want to make sure that someone else you know is receiving "Gear Tech Tips"? Please click here to add additional e-mail addresses. Opt-Out Option:** If you would not like to receive future editions of "Gear Tech Tips", please click here or just "Reply" back to this e-mail and ask to be taken off the e-mailing.