Calibration shaft for diamond quill

[Kaitsu]

Not sure if this idea is introduced already earlier. The accuracy of diamond quill scales comes up for discussion every now and then. I have promised for many people to make a sketch of a simple shaft that can be used to calibrate, for example, Blademaster and Wissonta machines. The sketch is quickly made and only roughly describes the idea. Machinists do understand what is wanted from the sketch and they can certainly measure the missing dimensions if you have the parts shown in the sketch with you.

[Bill_S]

That would certainly work for a very precise calibration. My Wissota includes an adjustable pointer for reading the engraved ROH scale on the quill. Something like this would simplify checking the pointer for accurate calibration.

[marc]

yes it is of course a very good idea, but for the moment I am doing it with a vernier caliper, because the graduated measurements are not precise

[Query]

To what extent does a diamond quill wear down with use? Is that a significant issue? Or does the tip eventually chip off?

I have a very stupid question: Does your device hold the diamond quill itself, or is it a type of radius gauge that checks the radius after the wheel is ground to shape?

I guess more consistent radius achieves two goals:
1. The edge shape is better controlled, so the skater doesn't have to change the way they skate as much after sharpening.
2. Less metal is wasted during sharpening, so the blade lasts longer. The lifetime lost with each sharpening of high end figure skate blades often costs more than the sharpening itself, so that matters a lot.

[Kaitsu]

Signification of the diamond tip wear is far from the machines scales inaccuracy. I do not know what kind of calibration they do in the factory, but there seems to room for improvement. Another case where calibration is good to make is, when you need to change the diamond. In Wissota, scale is sticker which position can vary. For this reason they have made adjustment screw which can be used to adjust "zero point".

So to summarize main idea of calibration is ensure that we all would make same ROH.

I have seen so many times that skate tech has marked certain radius to the skate, but real ROH is 2-3mm different. Its problematic for the skaters whom uses different skate techs. You ask them to do certain radius, but in reality you may get something else. Whom´s ROH is correct? In worst case they add "bonus" to you by making edges uneven. So its not only ROH which can vary. Even more severe error can be made by making edges uneven. If these two varies every time you sharpen your skates, I can assure that you need longer adaption time than if skate tech would ensure that ROH is always same and edges are as even as possible. Repeatability and accuracy are key factors to the good sharpening.

[Query]

I have seen so many times that skate tech has marked certain radius to the skate, but real ROH is 2-3mm different.

3 mm is about the difference between 3/8 inch and 1/2 inch. That's really, really bad.

It's one more reason skaters shouldn't keep switching skate shops. Not only do they have to adapt a lot, but they will sharpen away their figure skating blades in just a few sharpenings.

Does the Wissota machine make it easy to set the zero point correctly?

Your calibration shaft sounds like a good idea! There must be many professional skate techs who don't understand this issue, and don't try to adjust for quill length.

This may sound extreme, but maybe skating organizations should certify skate techs' knowledge and skill, and publish the results.

Of course individual skaters can buy a set of radius gauges, and while they are at it, level checkers, to check how their techs are doing. It's not all that expensive. But that is a lot of knowledge to expect of them.

[Kaitsu]

Does the Wissota machine make it easy to set the zero point correctly?

Please check
https://wissota.com/wp-content/uploads/2022/02/Diamond-dresser-inch.pdf