If you think of Gear Expo as only a machine tool show, you're not seeing all of its potential. You may be tempted to skip it this year, especially if you're struggling to fill your current capacity. I've heard too many stories of canceled orders, falling profits and slashed budgets to believe that great numbers of you will be attending Gear Expo with buying new machines as your No. 1 priority.
Even with some segments of the gear industry facing economic uncertainty, Gear Expo exhibitors and potential visitors are looking forward to this year's show. Instead of focusing on buying and selling, many of those involved with the 2001 show have chosen to focus on the show's value as a marketplace for knowledge.
Users of gear-cutting tools probably do not often consciously consider the raw material from which those hobs, broaches or shavers are made. However, a rudimentary awareness of the various grades and their properties may allow tool users to improve the performance or life of their tools, or to address tool failures. The high-speed steel from which the tool is made certainly is not the only factor affecting tool performance, but as the raw material, the steel may be the first place to start.
Base helix error - the resultant of lead and profile errors is the measured deviation from the theoretical line of contact (Fig. 1). It can be measured in the same way that lead error on a spur gear is measured, namely, by setting a height gage to height H based on the radial distance r to a specified line of contact (Fig. 2), rotating the gear so as to bring a tooth into contact with the indicator on the height gage, and then moving the height gage along two or more normals to the plane of action. The theoretical line of contact on helical gear must be parallel to the surface plate, which is attained by mounting the gear on a sine bar (Fig. 3).
Face-milled hypoid pinions produced by the three-cut, Fixed Setting system - where roughing is done on one machine and finishing for the concave-OB and convex-IB tooth flanks is done on separate machines with different setups - are still in widespread use today.