USB Microscopes question.
- This topic has 21 replies, 5 voices, and was last updated 09/08/2019 at 11:10 am by
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For the price you can’t go wrong! Even if you didn’t use for sharpening (which you will) it is worth having as you will fine other uses. On the low power setting it works great for removing splinters!!!
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Marc, the knives I’m talking about are Wuesthof knives. We have had this set for many years and they have mostly been sharpened on the hand held ceramic sharpener that Wuesthof sells. I’ll try to get some pics and post them. I ended up going with a Dino-Lite USB Microscope. I hope it does the job. 🙂
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Tommie,
I’ve added some pictures to show what I look for in the reflected light when shooting straight down onto the edge. I used my pluggable scope at the highest magnification.
The first set is my Spyderco PM2 I sharpened two weeks ago. I drew a red line where I tested the edge and then shot three pictures of the bevel – Right, straight down, left.
The next set of pictures is our kitchen work horse. I sharpened it last weekend and the BESS score was around 150. Tonight it tested at 316 but it gets used every day for almost every meal. I took the same pictures – right, straight down, left.
I did the same thing, drew a line at the test point and shot the microscope pictures there.
Not sure these pictures do justice to the visible difference between the edges I see on the computer screen. Just realize that the ultimate goal is to not have any light reflected from the edge when looking straight down with the scope.
Ed K.
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These are the pictures of the kitchen work horse.
Ed K.
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Tommie,
There are many variables in setting a bevel angle. Your question goes to the science of sharpening. Steel quality, blade geometry, and knife usage all need to be considered. Because the kitchen knife in the picture above sees lots of usage and is used for slicing bread as well as chopping raw carrots, I have settled on 17DPS. I’ve added the last picture I took after sharpening. You’ll notice, I don’t spend a lot of time going for super polish.
In the pic from January, I only went to 600 grit and the BESS numbers are under 200. This last weekend, I only used my new 2200 stones to break them in. I spent about 20 minutes at 17DPS before I got to the apex and quit.
I hope some other forum members who do a lot of kitchen knives will weigh in with how they choose a bevel angle.
Ed K.
While I have time, I want to post some pictures of my pluggable scope. Since I hold the scope tight to the edge and rotate looking at the sides as well as straight down, I’ve worn a groove in the clear plastic shield. Base on a post from tcmeyer, I now wrap the shield with UHMW TAPE 19-20A-.5-18 Tape.
Once the new layer of UMHW tape is in place, I wrap it tight with blue painters tape.
https://www.amazon.com/gp/product/B01N5G0Z8Y/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
For those just starting with the scope, you might want to take preemptive measures.
Ed K.
Tommie, 20 degrees per side, (dps), is a good average bevel angle to start with. I believe this is tcmeyer’s mainstay. After beginning with this bevel angle you can monitor the edge durability, longevity and knife performance to guide you to tune the bevel angle more to your liking and expectations.
New knife science applied studies suggest that a knife may be able to do just as well with a narrower bevel then we once thought. This is part of the reason that Ed K utilizes 17 dps as his mainstay angle. I follow this new theory direction, too.
Some users follow the path using a marker to determine the existing knife’s sharpened bevel and match this angle as their starting place. That way you’ll simply be sharing the edge that’s there as opposed to removing more steel as you low-profile the bevel.
You can do web searches and sometimes find the factory recommended angles. There is a user submitted chart in the W.E. Knowledge Base with suggested sharpening knife settings that W.E. sharpener users have utilized and shared.
Basically, thinner knives with harder steels can support more acute bevel angles. There’s a balance to be attempted. The wider the bevel the more applied edge pressure is necessary to push the knife edge through what it’s cutting. This extra applied force needed in turn wears the knife edge down easier. Thinner more acute knife bevels can penetrate and pass through what they’re cutting with less applied force. The balance that must be struck is, is the steel hard and tough enough to support the thinner narrower more acute bevel with out folding or rolling over under knife edge use. Harder steels are more brittle and this steel usually breaks or chips off as the knife edge wears as opposed to rolling or folding.
What ever angle you choose to apply, be sure to record the clamping and sharpening settings to more easily facilitate touch ups and bevel angle profile adjustments you may decide to try.
Marc
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