Opinions and advice on my sharpness tester idea.

[Blade Banter]

I recently started to work to figure out an effective way to test sharpness of a blade.  During that time I started with a Lyman pull gauge before coming across the Edge on Up.  I reached out to Mike Brubacher on the use of their device for edge testing for reviews on the "Blade Banter" channel.  He said that I would be able to make a posting here to get some suggestions.

    I tried to put together a fixture type of system and initially I was playing with the use of dental floss sticks initially, then using fishing line currently.  I may pick up a roll of the BESS to see how that works with the unit as it seems well tested and can be a consistent media.  I'm still working with the Lyman pull gauge as a measurement tool and actually made use of a fidget spinner for the media.  

    I put together a device to work to have repeatable testing for knives through reviews and was looking for feedback and advice on the set up. 

[Ken S]

Welcome to bessex, Blade Banter.

This is actually my second reply. I had my first reply 95% complete during my quiet early morning coffee before my wife and grandchildren arise. I checked UPS tracking from an email and inadvertently lost my reply. No problem. It gave me a chance to mull over a new reply and watch your video a second time.

High marks for your video. Well organized and technically fine. (refreshing  

I was confused by your 14.2 reading. You don't mention your measurement units. It appears to be ounces. Correct? The BESS crowd work in grams, although we are not adverse to other measurement units. I suggest a short audio editing tweak to include your measurement unit.

Clever idea using the fidgit spinner. Inexpensive bearings. As last year's hot toy, every kid probably has at least one, probably several.

BESS test media filament has been thoroughly tested. Your fishing line may be, too, however, you do not present any supporting documentation. Some reference to fishing line tests would give weight to your testing.

Securing your line needs to be 3.0, especially using your tester with multiple knives. The problem is not your design; it's the operators. Most do not have any more manual dexteritythan I do, and most have less patience. Stick with it; you need more prototypes to efficiently secure your line.

I wish you the best of luck with your project.

Ken

[Jan]

Mr. Blade Banter welcome to the forum.  

Thanks for posting the video with your sharpness tester. It uses the same principle as Mike’s instruments.

From physical point of view we have to measure the force necessary to cut the test medium.

I am wondering about the way how you use the Lyman trigger pull gauge. Your video shows that the pull is oriented rather horizontally and so only small part of this pull acts vertically and contributes to the cutting process.

I would recommend to orient the pull vertically, downwards. Than the reading of the pull weight can be used as a measure of edge sharpness.

Jan

[Blade Banter]

Welcome to bessex, Blade Banter.

This is actually my second reply. I had my first reply 95% complete during my quiet early morning coffee before my wife and grandchildren arise. I checked UPS tracking from an email and inadvertently lost my reply. No problem. It gave me a chance to mull over a new reply and watch your video a second time.

High marks for your video. Well organized and technically fine. (refreshing  

I was confused by your 14.2 reading. You don't mention your measurement units. It appears to be ounces. Correct? The BESS crowd work in grams, although we are not adverse to other measurement units. I suggest a short audio editing tweak to include your measurement unit.

Clever idea using the fidgit spinner. Inexpensive bearings. As last year's hot toy, every kid probably has at least one, probably several.

BESS test media filament has been thoroughly tested. Your fishing line may be, too, however, you do not present any supporting documentation. Some reference to fishing line tests would give weight to your testing.

Securing your line needs to be 3.0, especially using your tester with multiple knives. The problem is not your design; it's the operators. Most do not have any more manual dexteritythan I do, and most have less patience. Stick with it; you need more prototypes to efficiently secure your line.

I wish you the best of luck with your project.

Ken

 Ken,
     Very much appreciate the time taken to respond twice.  
    Yes the measurement was in lbs and ounces.  The pull gauge has a gram setting too which I'll probably utilize going forward.  If the calculation is correct that puts the knife at about 402 grams.  
    Initially I was going to have the line affixed on one side and gain tension with a 6 counce fishing weight.  Held by a screw in the middle of the fidget spinner.  In theory this seemed to be a good idea, but the center is a bearing too so it wasn't a fixed point to hold the tension.  
     I started with dental floss sticks and found that they were horribly inconsistent.  I may opt to buy a refill of BESS media to test with the set up.  
     I'm in no way trying to take away from the equipment used.   I haven't used the edge on up device and appreciate Mike for allowing me to get feedback on my hairbrained device.

David

[Blade Banter]

Mr. Blade Banter welcome to the forum.  

Thanks for posting the video with your sharpness tester. It uses the same principle as Mike’s instruments.

From physical point of view we have to measure the force necessary to cut the test medium.

I am wondering about the way how you use the Lyman trigger pull gauge. Your video shows that the pull is oriented rather horizontally and so only small part of this pull acts vertically and contributes to the cutting process.

I would recommend to orient the pull vertically, downwards. Than the reading of the pull weight can be used as a measure of edge sharpness.

Jan

   Great I'll give that a try as the way that I was doing the test seems like a good way initially as I'm trying to keep as many factors the same during the test.  I can see that you brought it up using the upper hole may act as a lever causing the force to be less as it adds leverage when rotating the spinner.  
     I'll give the vertical pull a try to see if there is a difference on the result.  Aslo Ken brought up a good point on measurement in grams other than ounces.

David

[EOU]

Hello Blade Banter and thank you for the video. We have several thoughts with regard to the mechanics of your edge tester and have expressed those thoughts via private emails with you. Our predominate thought, however, is this;  you can be nothing but commended for recognizing the need for quantifying edge sharpness levels and then taking steps to build a device that attempts to do so.  We have no idea where your efforts might eventually lead but that's not important to us. We simply applaud first, your recognition of the need and second, your genuine attempt to bring your ideas to fruition. We say kudos to Blade Banter!

[Mark Reich]

Yes Mr. Blade Banter, I applaud your ingenuity and your effort most sincerely!

I recognize the feedback as good suggestions too.

I don't have any of the pre-strung BESS test media holders, but I wonder if they could be incorporated.

[Blade Banter]

Yes Mr. Blade Banter, I applaud your ingenuity and your effort most sincerely!

I recognize the feedback as good suggestions too.

I don't have any of the pre-strung BESS test media holders, but I wonder if they could be incorporated.

    That would be an option as the tension should be preset, will just need to figure out how to mount it.  It looks like I might be able to run a bolt through it and attach it that way...  Will need to see one in hand.  I think they are $15 for 100

[Blade Banter]

Hello Blade Banter and thank you for the video. We have several thoughts with regard to the mechanics of your edge tester and have expressed those thoughts via private emails with you. Our predominate thought, however, is this;  you can be nothing but commended for recognizing the need for quantifying edge sharpness levels and then taking steps to build a device that attempts to do so.  We have no idea where your efforts might eventually lead but that's not important to us. We simply applaud first, your recognition of the need and second, your genuine attempt to bring your ideas to fruition. We say kudos to Blade Banter!

EOU it would be great to hear from you when you have a moment.

[KnifeGrinders]

The idea, the principle has been in the air since 2000, and since then I've seen dozens of similar makeshifts good for personal use only, and even so with many reservations.

What made that principle a method and those home-made devices an instrument was the EOU highly standardized test media, technical & firmware solution for reproducible results, and the internationally recognized BESS scale tied to a standard DE razor as a unit and backed by SEM data.
Mike's instruments are capable of telling edge radius in nm, and enable us exchange sharpness data over the globe.
Mike B. has spent best years of his life to have this giant task completed for us to enjoy.
Refusing fruits of his labor is beyond my comprehension.
ONLY Mike's instruments and the BESS scale have made possible the "edge stability" SET project to be carried out in collaboration between the USA, Australia and UK.