I have a programming / IT background too, so I know where you come from as far as over thinking goes. How does velocity impact the testing? What about media tension, temperature, etc.?
What it comes down to is that the PT50’s are amazing, easy to use instruments. Just slowly push the blade against the media until it breaks. It’s really as easy as that. Unless you are talking about super low readings, 50 or less, and worried about single gram increments, I’m sure what you are doing is just fine. Trust your readings.
And really, we’re talking about woodworking tools and knives. 5, 10, or even 20 grams one way or the other is not really all that significant. Readings of 150 gf or less is very sharp. I doubt that for all practical purposes that you could tell the difference between a 150 edge and a 170 edge when you are using the tool. 20 grams is the wight of 4 U.S. nickels (5 cent piece). Consider adding that amount of weight to the end of a chisel. Could you tell the difference when pushing it through some wood?
I believe that with woodworking tools a smooth, polished edge is what you want. Knives are a whole different animal with the choice of varying degrees of a toothy edge, how to get it and not ruin it when deburring. That is much more difficult to really understand and achieve.
Personally I always use the test media fixture rather than the clips. That way I don't have to worry about conversion factors or detensioning the clip, etc. The fixture works great.
Considering that you sharpened to a 105 gf reading, you are doing great as far as sharp goes! Soon you will trust the results of your PT50 too. So, yes. You can relax.
You are doing it right and everything is fine. It’s funny; after a while you just do a test and don’t really even think about it much. It’s really that easy, and produces reliable results every time.
What it comes down to is that the PT50’s are amazing, easy to use instruments. Just slowly push the blade against the media until it breaks. It’s really as easy as that. Unless you are talking about super low readings, 50 or less, and worried about single gram increments, I’m sure what you are doing is just fine. Trust your readings.
And really, we’re talking about woodworking tools and knives. 5, 10, or even 20 grams one way or the other is not really all that significant. Readings of 150 gf or less is very sharp. I doubt that for all practical purposes that you could tell the difference between a 150 edge and a 170 edge when you are using the tool. 20 grams is the wight of 4 U.S. nickels (5 cent piece). Consider adding that amount of weight to the end of a chisel. Could you tell the difference when pushing it through some wood?
I believe that with woodworking tools a smooth, polished edge is what you want. Knives are a whole different animal with the choice of varying degrees of a toothy edge, how to get it and not ruin it when deburring. That is much more difficult to really understand and achieve.
Personally I always use the test media fixture rather than the clips. That way I don't have to worry about conversion factors or detensioning the clip, etc. The fixture works great.
Considering that you sharpened to a 105 gf reading, you are doing great as far as sharp goes! Soon you will trust the results of your PT50 too. So, yes. You can relax.
You are doing it right and everything is fine. It’s funny; after a while you just do a test and don’t really even think about it much. It’s really that easy, and produces reliable results every time.