"K-Charts"

[[Ed...]]

Hello my friends,
I have new project at work, need to measure helical spur gears. And the problem is that I need to use "K-charts"
I haven't use them before and don`t know nothing about them.

Could someone provide me with some information about "K-charts"?

Thank you... 😉

[[Ch...]]

Hi,

I believe the post above needs some help with K Charts as well. I'll try to keep it as simple as possible :

The 2 lines are tolerances bands, high and low. In a standard 'typical' K-Chart, the high tolerance line is -0-, Zero. The highest point of actual traces becomes the zero line, the software should align /line-up the K Band tolerance to the high point of actual trace with this -0- REF line. The rest of the profile will all be below the high point and should fall within the band line tolerances. If the trace/actual measurement crosses out of the band and comes back in to the end, it is still considered out. The entire trace should be within the "K Band". The middle of the band is typically referred to as the "neck" and is the smallest tolerance sometime only .0001" in to pass through. In some cases ,the drawing will allow the high point of trace ("touch" point) to only occur near the middle. In Gear Pro the 'diagram alignment' allows you to set where you will allow this high point to be. Diagram 1 of the K chart input is the lower tolerance line - or the line that makes the K shape or V shape. (Remember to enter negative value for tolerance in Diagram 1 as it is below the zero line). Diagram 2 in Gear Pro is the top line usually straight line with 2 points only both at 0. You can input the location points in diameter or roll angle. Roll angle is a bit more common for K Charts. You can change the inputs in Gear Pro on the first window in profile, the eval tab in the bottom right corner.

On the report, if the actual trace goes out of band anywhere it should show up red (assuming you leave K-band activated in tolerances tab). It will show you how much under the chart. You will have to look closely at the chart to see where exactly sometimes, as sometimes it appears to be border line or on the line. Other software will report the location underneath the chart where it goes out. Gear Pro does not as I'm aware, you will have to read it on the chart.

Good luck, if you need further help please post a copy of B/P K Chart and results/input screen if you have any.

Happy Gearing !

[[Ed...]]

Hey..
thank you for info, but where I can find more info, some .pdf or videos with examples?
The idea is clear, but I need to achieve deeper knowledge's 🙂

[[Ch...]]

Try AGMA specs , Ive seen them in 390.03 - very old.

[[Ma...]]

The ANSI/AGMA 2000-A88 standard document has some info on "standard" K-charts in the body of the standard, and information on "modified" K-charts in informational Appendix C.
Truthfully, most of the gear inspection community has been trying to move away from the use of K-charts for many years as they are thought to be better suited to manual rather than modern CNC instruments. K-chart evaluation is also a pass/fail type thing and typically doesn't yield any numeric results for SPC analysis etc.

[[Ow...]]

I don't deal with them often enough but, it seems like I almost always end up having to mirror or flip the chart in gear pro to get it to read right after interpreting the way it's supposed to read from the drawing.
I suspect those who work with them all the time might say different but, if you had a proven Master gear or a proven part measured on another system with the K-charts, it would make it easier to verify the chart.
Here is one example.
.

[[Ow...]]

Attached is a document an individual sent me on how they generate the chart initially before fine-tuning.

K Chart illustration.docx