ERU sharpener review. Latest Feedback 2/14

Sigh i was trying not to get sucked in this thing....lol....i guess my post was an indirect at you above without knowing it was lol.......no disrespect all chuckles..... this was your quote "You say it doesn't cut, and I haven't seen a carbide sharpener that doesn't" a carbide sharpner will only cut if the angle isnt set for the blade it is passing through or if the blade is distorted. So in essence you don't know how to use a pull through sharpener....lol
 
Trying to get a better example of an edge done with the ERU. This blade is a forged 1084 that I made and carry every day. Its only seen the ERU for a year and a half. If done with good technique this carbide "V" sharpener will keep a great working edge on most all your knives. This is a 24 degree edge with a 28 degree micro bevel. The micro can be seen in the middle of the bottom pic.
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somerandomind said:
Sigh i was trying not to get sucked in this thing....lol....i guess my post was an indirect at you above without knowing it was lol.......no disrespect all chuckles..... this was your quote "You say it doesn't cut, and I haven't seen a carbide sharpener that doesn't" a carbide sharpner will only cut if the angle isnt set for the blade it is passing through or if the blade is distorted. So in essence you don't know how to use a pull through sharpener....lol
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Right. So you're going to tell a 20 year machinist that sharp carbide cutting edges won't cut steel. Got news for you: the normal pull through sharpeners have sharp edges and the angles presented to the blade have clearance behind the contact point. Every one I have ever seen will indeed cut, no matter the included angle. I'm sure others who have used pull-through sharpeners have seen shavings pulled, and seen the damage (tear-out mostly) to the edge as a result. When the angle is close, you just get much less cutting because the pressure at the cutting edge is distributed along more surface area and therefore small amounts of tiny shavings/swarf. When the angles don't match, the pressure is concentrated on a much smaller surface area and as a result, you get larger shavings/swarf. If it's not cutting, it's not doing anything other than "steeling" the bevel. Fred's on the other hand apparently doesn't have the clearance and sharp edge, so is using a different mechanism to do its work; abrasion rather than cutting.
 
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Fred.Rowe said:
Trying to get a better example of an edge done with the ERU. This blade is a forged 1084 that I made and carry every day. Its only seen the ERU for a year and a half. If done with good technique this carbide "V" sharpener will keep a great working edge on most all your knives. This is a 24 degree edge with a 28 degree micro bevel. The micro can be seen in the middle of the bottom pic.[]
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Fred, those are much better, thank you. It does appear that there are a few nicks, rolls or perhaps tears in the edge, are these just from using the knife? Mostly it looks quite good though.
 
eKretz said:
Fred, those are much better, thank you. It does appear that there are a few nicks, rolls or perhaps tears in the edge, are these just from using the knife? Mostly it looks quite good though.
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Its a user, boxes, tape cord and the like. Its been a couple of days since touch up. It's surprising to me, how well it does work. This is 1084 and if your familiar with it you know it does not give the best looking edge. I have a W2 blade that takes a cleaner edge. I'm looking at some other material, than the carbide strips.
We will probably offer different abrasives after we get production smoothed out. If your a machinist then you know whats entailed, bringing a product to production status. Making one is nothing like making a hundred or five hundred.
For the vast majority of field users, the carbide inserts will work perfectly well. They will not be looking at the edge with a jewelers loop but they will be thrilled if they can put a decent edge on there working knife easily.

Fred
 
Yes, I know where you're coming from on the prototype vs. production front. I haven't used much 1084, but I have made a few knives and tools from the tool steels and 1095, as well as 52100. I haven't had too many tear-out issues with those, but I normally stick to 30° edges on most knives other than my straight razor, (17° inclusive) which micro-chips easily if I'm not very gentle. It's a carbon steel, but Im not sure which. Obviously it's not a candidate for this tool though. I am looking forward to trying it on some field (skinning/cleaning) knives and a hatchet.

As far as the inserts, I was thinking more along the lines of longevity really. With time and some of the harder steels, I would expect the tungsten carbide to wear and develop smoothed areas. I'm guessing your inserts are textured to provide a facsimile of an abrasive surface, am I correct? If not, that might also be an avenue for future investigation. A light bead blast with diamond or CBN grit might be an easy way to refresh the surface also.
 
Fred, I'll get this out to B. Kenny by the end of next week, if you would please email me his address so I can get it out to him. My camera been acting up so I'm going to get some pics but so far it's be working very well, I've used it on a bunch of different knives, my review is still in process just gotta finish getting it on the computer.

This tool definitely has it's place and I do have a couple of suggestions FWIW, I'll put them in my review.
 
T. Erdelyi said:
Fred, I'll get this out to B. Kenny by the end of next week, if you would please email me his address so I can get it out to him. My camera been acting up so I'm going to get some pics but so far it's be working very well, I've used it on a bunch of different knives, my review is still in process just gotta finish getting it on the computer.

This tool definitely has it's place and I do have a couple of suggestions FWIW, I'll put them in my review.
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Address sent; hope you and your's have a great Thanksgiving. Fred
 
Fred, your post in KennyB's review of your ERU product. btw - I like F.Z. quote. I post this here to avoid polluting Kenny's thread.
Fred.Rowe said:
Kenn,

Thank you for taking the time to access this new tool. I had you pegged, for someone without preconception or bias and your post confirms this.
As an inventor and a knife maker I find I make better decisions and greater discovers, when my mind has not taken a firm set or bias. It is human nature to do so I know, but in order to move forward its necessary. Above my work table is one of my favorite quotes: "Without deviation from the norm progress is not possible". F.Z.

Regards, Fred
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Your assertion above seem a little bit unwarranted, especially toward many people seek answers & clarifications about your ERU product. After some time had passed and I still would like to know your take/answer to my question #1 below.

bluntcut said:
Fred - look like you've put a lot of thought into this product, an adjustable sharpening 'v' angle is brilliant.

1. Do the tungsten carbide faces rotate or allow shifting? I am asking because over time the WC faces will be worn down by VC, which will affect the knife apex and somewhat the bevel. Sure, it won't be a problem for knives without or a little VC.

2. From your estimate, how much abrading vs burnishing go into the pull/pinch sharpening stroke? Say a D2 at 60rc for example.

3. About what finishing grit range the result be? again D2 example with feather light pull stoke.

4. Lastly, what to do for a convex edge?

Sorry about asking too many questions but while back I was thinking about using a WC scrapper as a sharpening tool, luckily you get there first with something much better than my envision :D

Thanks
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I am no stranger to have 'deviation' or 'outside-the-box' ideas. Here http://www.bladeforums.com/forums/s...one?highlight=s90v+vanadium+carbide+sharpener
I use s90v as a sharpening stone, where VC serves as abrasive. This abrasive surface can be renew by flattening & re-haze the face.

Also I've been using WC scrapper blades as sharpening stone. I can use diamond plate to flatten & sharpen the scrapper blades as needed.

Both of these instances, I found high VC percentage blades will wear/dull WC face. 1st case, when WC is dulled (completely smooth surface & rounded corner/edge), the sharpener became a burnisher. 2nd case, when worn by VC, the surface & edge no longer true, will/might reflect the imperfection to the resulting bevel & apex.
 
bluntcut said:
Fred, your post in KennyB's review of your ERU product. btw - I like F.Z. quote. I post this here to avoid polluting Kenny's thread.


Your assertion above seem a little bit unwarranted, especially toward many people seek answers & clarifications about your ERU product. After some time had passed and I still would like to know your take/answer to my question #1 below.



I am no stranger to have 'deviation' or 'outside-the-box' ideas. Here http://www.bladeforums.com/forums/s...one?highlight=s90v+vanadium+carbide+sharpener
I use s90v as a sharpening stone, where VC serves as abrasive. This abrasive surface can be renew by flattening & re-haze the face.

Also I've been using WC scrapper blades as sharpening stone. I can use diamond plate to flatten & sharpen the scrapper blades as needed.

Both of these instances, I found high VC percentage blades will wear/dull WC face. 1st case, when WC is dulled (completely smooth surface & rounded corner/edge), the sharpener became a burnisher. 2nd case, when worn by VC, the surface & edge no longer true, will/might reflect the imperfection to the resulting bevel & apex.
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I don't understand your comment. How is it unwarranted to compliment someone for being unbiased? If said to me I would take it as a compliment. Its one thing to be assured in ones thinking and another to be biased. I find one preferable to the other.
Why anyone would be offended by the comment is beyond me.

The carbides in the current configuration are set and do not rotate.
The tungsten carbide shown here is only a step in the development of this sharpener. We are currently working on replaceable inserts that will be offered in a range of grits. Diamond is the material.
The reason the presentation did not focus on the abrading material and did focus on the design features is because of what is stated above.

Carbide "V" sharpeners are nothing new, what is new with the ERU is the adjust-ability over a wide range of angles, the accuracy and portability.

Sorry I did not respond to every question ask and I apologize if you were offended by this omission.

Regards, Fred


PM Sent.
 
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Thanks Fred! Your answer and future options for this ERU are exactly what I was looking for. I reckon my choice of words weren't best as intended, I merely seeking intellectual learning materials but came across poorly... My apology!

Your courteous & professional PM is well appreciated. It's a long way before I earn/graduate from my tinkering into the realm of innovation, until then...

Oh worry not, we MTE tinkerers will continue to probe for holes in any products & ideas.

With respects,

Blunt.
 
bluntcut I was also wondering how alloyed steels might come out, which is why I mentioned specifically in my reivew that I was using simple steels.

I would be interested in discovering the Vanadium content of the kitchen knife I was working on a little bit though. It is apparently kitchen cutlery from around the 60s or 70s with their own "stainless vanadium" alloy. I can't imagine that the V is very high, probably just to improve grain structure and so on. But it's worth noting that whatever percentage it did have, I couldn't see any noticeable wear on the carbide whatsoever.

I'm curious about it too though given the popularity of S30V but I think most users of high vanadium steels are already accustomed to needing specialized sharpening equipment especially for something like S60/90/110V. As far as other steels with minimal amounts ( 1095 CroVan or AUS-8 for example ) I think are low enough to be negligible, but that's just based on whatever that "stainless vanadium" in the kitchen knife I used was.
 
From what I gathered, you are right - early day low % vanadium stainless are mostly for grain refinement. And VC form also be sub-micron in size, so sparsely + tiny = low abrasion against a 50%+ carbide by volume ERU block/insert.

For that experiment used s90v as a sharpening stone (9% VC) against s30v blade (bm940) & cpm-m4 (GB). The carbide hazed stone surface became quite smooth/dull, afterward it greatly reduced its effectiveness against simple carbon knives. ERU employed both flat surface and edge of the WC inserts, however wouldn't able to guess what their effective abrade grit & burnish topographic/shape. IDK whether one can prepare the WC to some given/target grit (like carbide haze or micron-file).

I suspect the wear for ERU going to be concentrated around the apex 'v' area. This wear can take place by either hard abrasive (VC, diamond, vbn, bn, etc) or large abrasive (AlO, SiC, Natural grit). Eventually instead of a 'v', you get a slight convex cutting edge. Of course, just like any tool, ERU will deliver if use it properly. Fred was very upfront and mindful in named this product a 'edge renewal', very handy for field & quick usage, while require very little skills.

Your review is excellent & quite thorough - thanks very much. My previous post made was more about ERU capacity & situation coverage. My original question, eluded that maybe a rotatable+removable square/hex/octagon insert may greatly extend durability of this ERU :cool:

KennyB said:
bluntcut I was also wondering how alloyed steels might come out, which is why I mentioned specifically in my reivew that I was using simple steels.

I would be interested in discovering the Vanadium content of the kitchen knife I was working on a little bit though. It is apparently kitchen cutlery from around the 60s or 70s with their own "stainless vanadium" alloy. I can't imagine that the V is very high, probably just to improve grain structure and so on. But it's worth noting that whatever percentage it did have, I couldn't see any noticeable wear on the carbide whatsoever.

I'm curious about it too though given the popularity of S30V but I think most users of high vanadium steels are already accustomed to needing specialized sharpening equipment especially for something like S60/90/110V. As far as other steels with minimal amounts ( 1095 CroVan or AUS-8 for example ) I think are low enough to be negligible, but that's just based on whatever that "stainless vanadium" in the kitchen knife I used was.
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bluntcut said:
From what I gathered, you are right - early day low % vanadium stainless are mostly for grain refinement. And VC form also be sub-micron in size, so sparsely + tiny = low abrasion against a 50%+ carbide by volume ERU block/insert.

For that experiment used s90v as a sharpening stone (9% VC) against s30v blade (bm940) & cpm-m4 (GB). The carbide hazed stone surface became quite smooth/dull, afterward it greatly reduced its effectiveness against simple carbon knives. ERU employed both flat surface and edge of the WC inserts, however wouldn't able to guess what their effective abrade grit & burnish topographic/shape. IDK whether one can prepare the WC to some given/target grit (like carbide haze or micron-file).

I suspect the wear for ERU going to be concentrated around the apex 'v' area. This wear can take place by either hard abrasive (VC, diamond, vbn, bn, etc) or large abrasive (AlO, SiC, Natural grit). Eventually instead of a 'v', you get a slight convex cutting edge. Of course, just like any tool, ERU will deliver if use it properly. Fred was very upfront and mindful in named this product a 'edge renewal', very handy for field & quick usage, while require very little skills.

Your review is excellent & quite thorough - thanks very much. My previous post made was more about ERU capacity & situation coverage. My original question, eluded that maybe a rotatable+removable square/hex/octagon insert may greatly extend durability of this ERU :cool:
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Thanks I'm glad you enjoyed it and thought it was thorough. I think the points you're addressing are very intriguing and not wiithout merit, but the sign of a very analytical and detail-oriented mind.

I think I understand now what you were trying to hint at with the rotatable inserts, that this would possible reduce the wear that steels with high vanadium content may impart on the insert surface? I think that is an interesting idea, but I believe the flat surface does the best job of ditributing the forces across a greatest surface area, and plus I think it would redice the simplicity of the design. I suspect that with diamond, further abrasives inserts will be more resilient than with natural/stone alternatives.

One thing that may not be observable of the ERU from my review, is that the adjustment range for the angle is extremely fine. The marked graduations belie just how fine the angle adjustment can be made, and I believe that there's actually enough variance in every time the angle is set that the area of the insret that is being abraded is actually changed (extremely minutely mind you) each time you set it. So because of that and the really small area of the apex where the wear will be concentrated the most I think it would be distribiuted evenly enough that abrasion will be difficult to achieve over multiple uses, as the area the wear/abrasion is concentrated at will change every time.

In other words, imagine that you set the device to 40 degrees by the graduation. Well, just going by your eye alone you are not going to be able to set it exactly to 40 degrees, but within a few minutes ( or possibly seconds) of it--or whatever decimal equivalent that is. With such a minor varience, the bevel will easily conform to the new angle ( within a few passes ) and the location that the apex will be abrading the insert at will be different with each usage. Because of that, I don't think that the wear will ever be concentrated at one location long enough especially because as the apex slowly forms to the new angle, the rest of the bevel will also begin distributing the pressure along the rest of the bevel.

Anyway that is all speculation but given all that, I believe that while wear is possible with these high-alloy steels, it will probably be at such a hugely slow rate when the tool is used as intended that it would never wear to an unserviceable extent within one's lifetime. When it comes down to it, even DMT's diamond plates will wear out if you use too much pressure on them, but when used properly probably never would. Given all this and a slight familiarity with carbide cutting tool's lifespan in machining purposes, I really can't imagine wear of the carbide becoming an issue. If one were to put it in a vise, and take a high-percentage vanadium blade and try to reprofile as I did though... I'm not sure, I really don't have enough experience with such steels to comment, but I do think that such a task would be an error on the user's part, because obviously it goes beyond the tool's intended and expected requirements.

In addition to this, if/when Fred begins offereing interchangable inserts, I would guess that buying replacement carbide inserts would also be an option.
 
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Most likely the angle, if changed every time one used the sharpener, would be difficult to get much closer than 1/2° (30 seconds) by eye. This is a function of the degree spacing and the ability of the human eye to differentiate and align without magnification. If one used a magnifier to set it one could probably get closer if setting directly on a line. IIRC, the calibration lines are only every 2 degrees. The best way to set this sharpener would probably be to set the angle initially, then sharpie the knife and see where it hits. Adjust the sharpener if necessary so it applies a micro-bevel and sharpen it.


I do believe that if this sharpener is used as intended, for field touch-ups and micro-beveling only, the carbides will last for quite a long while. I would definitely not suggest using this to re-profile a knife, and neither, I believe, does the maker suggest doing so, though I'm sure it would be possible although take quite some time.
 
Hey Fred, (and all the fine people who have posted on this thread),
I do not make knives, nor do I have sophisticated equipment to put the "edge" on knives. I am one of the previously aforementioned hunters who has working knives and a large selection of hunting knives and EDC's. Believe it or not, there are some very educated hunters and outdoors type men who wish they had a device that could put a quality edge on their blades with a few quick strokes! I believe that I am your target market. As an avid hunter and due to the fact that my parents owned one of the best gun store/sporting goods store here in Augusta, GA, I have accumulated a large number of production fixed blades and folders as well as quite a collection of hand made knives. My uncle was a knife maker of some renown in this area of the country. I was taught how to put an edge on a blade, pretty much any blade, the old fashioned way........using stones and oil. At any given time you will find bald spots shaved on my left arm as I am right handed. I like 'em sharp. Thinking back, I probably changed every angle on every blade to the "tried and true" angle I achieved on the stone, and that was determined by gut....not too steep, not too flat, once on the right, once on the left. I am not a long time member of Blade Forums, however, I am a lifetime knife owner and I have read this entire thread with great interest. I do have something to say about your ERU. The ERU is EXACTLY the device I am looking for!! I would love a device that would not only put a quick edge on my blade, but also allow me to keep the same angle on the edge that the manufacturer originally matched to the knife. Maybe it's just me, but that makes one hell of a lot of sense! I am assuming that the maker of the knife put what they thought was the optimal edge angle on their blades. I would like to keep the same angles when I sharpen them. Obviously, it would be a great tool for use out in the field as I skin five or six deer that my family members took down. However, I also think I would find it useful at the house. I switch out EDC's depending on whether I am in a suit or if I am in casual clothes or even jeans. My knives get used, except some of my custom knives which have the original edge that was put on them years ago and don't get used. I don't plan on ever having to sharpen those! As you can all attest, it is amazing how often you use a blade if you have one in your pocket! I learned that if you don't let your knife lose its edge, it is much easier to "touch" it up and keep the blade nice and sharp. Most of the labor and time saving devices out there seem to be limited to 30 degree angles. I have learned from this thread that 30 degrees may not be the correct angle for optimum sharpness. In addition, as has already been pointed out, they eat up the steel in the process. I will admit that I don't know much about the technical aspects of a knife edge with bevels, micro bevels and such. I can't really tell if those magnified edges in the pictures will shave the hair on my arm, but pic number two seems to have a pretty nice edge to it. I know sharp by testing, and I can tell if the edge is "pretty" and consistent with my naked eye. With that being said, I applaud your ingenuity and would like to buy one of your devices. I will even re-post and let all the fine people on this thread know what a regular guy thinks about the ERU. After all, it's guys like me that buy the custom knives that some of you produce. In summary, Fred, I would like to buy one of your ERU's to use on my working knives. Let me know how I can go about getting my hands on one. I will share it with my friends and family and provide a respectful and honest review.
Regards,
Donnie
 
IME with 90 degree edges of carbide scrapper blades... thereby my speculation. Initially ERU is a cutter & burnisher. Burnishing remain after the insert edges are rounded. Since the area of contacts (bevel intersect with 2 insert faces), it will take much large force to burnish with this than in compare to a glass/steel rod.

Put a piece of tape on the 'v' bottom between you & the ERU to catch swarf. Use a knife with bevel stropped-clean and apply pull strokes for 10 minutes, then check the tape to see quantity of swarf accumulation. Ignore long & large chunks if any (i.e. debris from cutting). a lot of black sub-micron dust = abraded metal -> my speculation is baseless.

To be quite clear, to me, burnishing action is very useful for wide range of today low & high alloy blades. Understanding ERU interaction physics may increase its effectiveness in applications.

Kenny - your critical analytical + common sense perspectives are 99% applicable to users of this device. Knifenuts are the exception. btw, diamond surface won't last long against large tools (axe, chopper, etc..). For those tools, I would count on carbide cutter/scrapper.

Fred - Thanks for your PM replied. Your openness & ambition are well received. Best regards - Blunt.
 
I understand how this can produce a reasonable bevel. The pics show that. But the only thing that I'm interested in is the actual cutting apex. And I still don't understand how this creates a clean apex any differently than a carbide pull through sharpener (which does not).
 
Magnaminous_G said:
I understand how this can produce a reasonable bevel. The pics show that. But the only thing that I'm interested in is the actual cutting apex. And I still don't understand how this creates a clean apex any differently than a carbide pull through sharpener (which does not).
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Well, as I stated in my review I viewed the edges using a combination of different magnifications. 45x, 60x and 100x. Through all ranges of magnification I could see grisp lines running paralelle to the edge ( indicating they were created with the ERU ) and a good crisp and clean apex, with very little distinguishable from an edge done on a 600 grit DMT credit-card hone ( I belive you're familiar with those in your portable setup ) and really bare no resemblance to the ones that come out of a normal carbide pull-through device.

I really don't know enough to sepculate the how or why it does this, but as I've said I believe there's an action similar to steeling going on here in that the edge is being pushed in, straightened, re-aligned, etc. On the other hand, there are moments where by the nature of damaged or misaligned steel passing through the hard riged inserts, there is metal removal--and in fact there are cutouts beneath the carbide inserts to allow room for swarf. Initially I thought that this must be because the carbide is producing a cutting action--which to an extent it is--but only until the edge is formed to the apex of the carbide insert's angle.

Going back to the "ekco flint" kitchen knife I tried to restore the edge on. It had a lot of heavy chips and rolls and initially I could feel an obvious tactile sensation of cutting (and visualy observe a good deal of swarf, but as you put bluntcut they were rather large pieces), but after a few minutes it became quite a "smooth" feeling and it became obvious that there was no longer any real metal removal taking place. What this did was take all the rolls and chips, and ( I'm guessing ) compressed all the metal around them so that the edge is relatively straight and as thin as it can be, so still sharper.

bluntcut I think you would be able to shed a lot of light on the mechanical aspects of how the ERU works, and in fact I'd be very intersted to find out from a purely curious and academic standpoint. But speaking from an "empirical" observational standpoint, it's in my mind almost an entirely different beast than the normal carbide pull-through type of devices when looking at just the results themselves. I wish I had the proper tools to take highly magnified images.

I recall another thread here at one point in the distant past where a member here posted very high magnification images of an edge produced with a traidtional carbide scraper. Now the thing about it was that, it was clear to see that the edge had been mangled and that there were little series of chips where it had gouged metal out and basically tried to tear it away from the edge. It was quite interesting and when I first learned about the damage those things did, I'd like to see the same done for an edge done on the ERU and I think it would really demonstrate what I've been able to see for myself that it's radically different from what those carbide-scrapers do.
 
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