Dec 18, 2015 | Tool Time
The effects and causes of hob flute lead error. In previous issues, we looked at several types of hob errors: flute spacing error, rake error, and runout. Another important type of error can be found in the lead of the flute, also known as the gash. Flute lead error...
Apr 15, 2015 | Tech Tips
Hobs mounted without precision. Consider the following two gear tooth profile inspection charts (these have been simplified for illustrative purposes from what one would see in practice): Inspection charts such as these plot the geometric variance normal...
Nov 3, 2014 | Tech Tips
Gear tooth lead variation caused by wobble. In this issue we will consider the problem shown in the following gear tooth lead inspection chart (Figure 1). This chart is a measurement along both the left and right flanks of four teeth of a gear. This is an...
Mar 10, 2014 | Tool Time
Identification, Measurement, and Correction of this Error. In Issue 2 of “As the Gear Turns,” we investigated the effects of hob rake error on the gear tooth profile. Rake error is only one of several possible factors leading to tooth profile errors. In this issue, we...
Dec 11, 2013 | Tool Time
The importance of hob rake. In order to produce high quality gears, it is important to use hobs of AGMA Class A or better. Equally important, these hobs must be properly sharpened in order to maintain the correct hob tooth geometry. Improper hob sharpening introduces...
