K Diagram only for mean value diagrams

[[Ow...]]

Would somebody care to elaborate on this and also explain how the diagram alignments work on the K-charts?

I looked in the manual to no avail, and while it seems fairly intuitive, I'm looking for some examples with explanations. 

Hoping somebody has some documentation on them.

TIA

 

[[Ch...]]

Owen,

 

 Howdy, sure, these are mainly to tell Gear Pro how to align the K-Tolerance Band to the actual data, there are a few ways. By default with a K-Chart I think the general rule of thumb is the 'highest point of the trace/measurement' typically aligns to the top of the tolerance band. What is shown as upper tolerance option above. There is also the option to align the trace/measurement data of the lowest point which will then 'become' the lower tolerance band alignment.

Reference Line is to any arbitrary 0 line to attempt to center the trace I presume.

Zero point I think is to start the band where the trace starts at zero it appears.

You can also restrict the alignment range allowed so as it looks for a hi point or low point of trace, you can restrict the area it searches for, this is typically reduced to the main profile area around the center /PD allowing for some end relief etc.

In most cases unless otherwise specified - upper tolerance should be fine, if unsure consult your Engineering Dept.

Good luck !

 

[[Ow...]]

Dear Chris Gear Rotolo,(middle name meant as a compliment)

Thank you for elaborating on the subject. 

I'm currently in the early stages of a functional analysis that is focusing on using chemically accelerated Isotropic SuperFinishing to remove Micropitting from case/induction hardened gear teeth and prolong the life of the gears. A lot of the older gear nomenclature on the gears I'm using are controlled with K-charts.

Even though the New AGMA 2015-1-A01 established in 2003 no longer recommended using the "K" chart for profile and lead evaluations, it is still being used in the automotive and agriculture field I work within, seen a 2024 print the other day using it.

The problem with the “K” chart is that any profile or lead within the defined “K” area could be an acceptable gear. Some of the newer prints restrict the alignment to be with the high point tangential to the reference line, and defines allowable pitch and index deviations, the older prints do not.

When checking worn gears, short of topographical evaluation, having the diagram alignment selections is imperative. I just wanted to make sure there wasn't anything affected that is not intuitively implied.

I am struggling with K-charts appearing on leads and I haven't updated to Gear-Pro 2025 yet, but I hope it fixes the lead K-charts.