Trying out new PT50A

[Larrin]

I got my new edge on Up sharpness tester and was very excited to try it out.

First test: Spyderco small Persian in my pocket. Sharpened on sharpmaker up to extra fine rods at 15 dps and then used on random things the past few weeks. Result: 300

Second set of tests. Byrd Cara Cara (1?) that I reprofiled on the Edge Pro to 11-12 dps with 140 grit diamond plate. I then moved to the standard edge pro waterstones

180 grit: 471
320 grit: 230
600 grit: 157
1000: 179
0.5 micron diamond paste on bovine: 137

It looks like I need some more work on fine grit sharpening as the 1000 was worse than the 600. Either that or I got lucky on the 600 or tested a wire edge.

The low grit stones are a little different than the ones that are currently included, I think. I looked at the Edge Pro and it says “Ben Dale 3-99.” It’s been around a while.

[grepper]

The very first time I used my PT50B I was amazed at how informative it was and how well it worked.  It’s actually addictive and I use it with every blade I sharpen.  Combined with a microscope I learned more about sharpening in a month than had in years wallowing in supposition and speculation.  

I suspect the variation in sharpness data you present has more to do with burr, or lack thereof, than incomplete grinding of the apex.  Grinding is quick and easy.  Burr removal, especially when trying to preserve a toothy edge is far more demanding in my experience.  

FWIW, and I am no expert, I have found that unless the object is to duplicate a DE razor type of edge, grit has less to do with sharpness than edge finish.  I’ve been able to produce 60-70 edges using only a 150 grit belt for the grinding.  Very sharp but still nice and toothy.  

Anyway, please keep us informed of your further testing!

[EOU]

Good deal Larrin! Please keep us abreast of your progress and findings.