ERU sharpener review. Latest Feedback 2/14

This thread really has me wanting to buy a cheap carbide scraper and see what it does, especially with oil.
Also, and with all due respect, 100x is not much in terms of magnification for looking at the apex.

Speculatively, it must be removing steel every bit as much as it burnishing. There is a relatively modest limit to how much stock manipulation/removal one can expect from a burnishing action, and it sounds like the ERU is well beyond that. As for the usual carbide scrapper and the ERU, the raking angle the heads make their approach at will result in a huge difference in how the carbide scrapes/shears/burnishes, so sounds like a big improvement in that regard.
 
This thread really has me wanting to buy a cheap carbide scraper and see what it does, especially with oil.
Also, and with all due respect, 100x is not much in terms of magnification for looking at the apex.

Speculatively, it must be removing steel every bit as much as it burnishing. There is a relatively modest limit to how much stock manipulation/removal one can expect from a burnishing action, and it sounds like the ERU is well beyond that. As for the usual carbide scrapper and the ERU, the raking angle the heads make their approach at will result in a huge difference in how the carbide scrapes/shears/burnishes, so sounds like a big improvement in that regard.

Yeah, I wish I would have at least had a 300x usb scope or something but had to use what I had.

What kind of magnification do you have?
 
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.

I jump back and forth with the ERU if I'm sharpening an EDC that has been sharpened with this sharpener 4 or 5 times. I use a glass to set the indicator edge if I have one handy or get in direct sunlight. The accuracy is very very exact. You notice the angled [alum. colored] indicators thin [1/32"] where it contacts the inscribed degree markings. Good light and a glass and I think, 1/4 degree is possible. There's a double line @
12--24--36--degrees and they are radial to the indicator edge; the alignment here is very repeatable; for the IE runs parallel to the double incised line. The next time I run 4 or 5 "nicks" along the edge, up and down, Set the ERU at the previous angle use on the edge and watch it remove the marker in a few passes. I might then move the indicator edge a slight amount, putting a 1/2 degree micro bevel on the edge; or really just removing the very tip of the edge a micro measurement. Both the set and the pen in combination gives a lot of control of the edge cross section.

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

Thank you for your post; you are most welcome here and I enjoyed your perspective as a hunter and someone who harvest and processes meat. I don't hunt these days, the over used knees say so; but I hunted and took game for 35 years. Its helped me to understand what a cutting edge looks like and how it can come about.
I live in hunting country and most of the people around here hunt and trap. I tested the ERU in the field for a year before getting this far into it.
Again, thanks for taking the time to share. E-mail me if you want to purchase one of these. fred.rowe@bethelridgeforge.com[/ur]... the edge is stroked along its entirety. Fred
 
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If the edge is smooth enough to slice or push-cut phone book paper, or whittle hair, the fact that it 'looks' ragged at 300x magnification becomes irrelevant information.

If we use high enough magnification, even polished glass isn't 'smooth.' But it's still 'smooth enough' for its intended use.
I think the same needs to be applied to edges...


Stitchawl
 
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).

I would agree with this.

In another thread I offered to pay shipping both ways for one of these to come see me up in Canada in the passaround. Havent seen a reply yet.
 
Interestingly, I ran across this at a local store today. First adjustable angle pull-through I've seen besides the ERU. Angle adjusts from 14°-24° per side IIRC. Looked like carbide for roughing, ceramic for finishing.

image.jpg~original
 
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Interestingly, I ran across this at a local store today. First adjustable angle pull-through I've seen besides the ERU. Angle adjusts from 14°-24° per side IIRC. Looked like carbide for roughing, ceramic for finishing.

That's interesting, and it's only about $20-$30 from a quick search. Does the adjust change all three angles simultaneously?
 
That's interesting, and it's only about $20-$30 from a quick search. Does the adjust change all three angles simultaneously?

The middle one is fixed but the other two adjust. Though from a quick youtube search, the angles are preset to 6 different ones according to common angles used... Looks like they kind of "click" into place.

I have seen other similar adjustable ones though, and they all claim to be the first ones to do it. Did you get a look at the carbide teeth in there eKretz
 
Sadden,



I saw your post; just been crazy busy and had not had time to respond. Let me send you a PM about this. I'd thought it through.

Fred
 
I looked at this sharpener at Cabella's' I put the tip of my pocket knife up against the carbides in the locked position and watched them rattle around in their holders. The set angles are not close to whats indicated. I take a set of ground steel angle wedges around to the stores with me to check the accuracy of the indicated settings.
It is plastic so could be left out in the weather without worry. It can be had for any where from 21.95 to 39.95; whats it really worth? Ha Ha!

Possible Smith's would send one of these here for a passaround and it could be put through its paces and given and extensive review. :thumbup:

Surely this is not the ERU's competition :(, Fred
 
If the edge is smooth enough to slice or push-cut phone book paper, or whittle hair, the fact that it 'looks' ragged at 300x magnification becomes irrelevant information.

If we use high enough magnification, even polished glass isn't 'smooth.' But it's still 'smooth enough' for its intended use.
I think the same needs to be applied to edges...


Stitchawl

For the most part I agree. We have an edge that isn't fading fast and seems to be reasonably sharp (no one mentioned whittling hair). If we want to understand what's happening when we do certain operations, there has to be something more than "it cuts OK". If we just want an effect and aren't concerned with how to improve beyond a certain degree, or understand exactly how the steel is being worked, 3 finger sticky and shave arm hair - that's plenty sharp. I like to know what's going on under the surface as it were, especially if a process is being described to me.
 
Yeah, I wish I would have at least had a 300x usb scope or something but had to use what I had.

What kind of magnification do you have?

The microscope I have access to at work goes from 40x through 1600x, though in terms of maximum detail I stop at 1000x. I only bring this up because there is a lot that cannot be seen even at 400 or 640x. For that matter there's still a lot that cannot be seen at 1000x but is at least the upper limit for optical microscopes.
 
The middle one is fixed but the other two adjust. Though from a quick youtube search, the angles are preset to 6 different ones according to common angles used... Looks like they kind of "click" into place.

I have seen other similar adjustable ones though, and they all claim to be the first ones to do it. Did you get a look at the carbide teeth in there eKretz

You are correct; the coarse and fine change with the knob adjustment but the serrated station is fixed. Not sure why the photo is upside down, it's right side up on Photobucket.

I did indeed get a good look at the carbides; I made a point of it after discussing them here. They have close to neutral top rake but quite a bit of side rake (clearance) so they will definitely do some cutting rather than abrading. I didn't buy one so can't confirm or deny Fred's report that it's a flimsy P.O.S.
 
You are correct; the coarse and fine change with the knob adjustment but the serrated station is fixed. Not sure why the photo is upside down, it's right side up on Photobucket.

I did indeed get a good look at the carbides; I made a point of it after discussing them here. They have close to neutral top rake but quite a bit of side rake (clearance) so they will definitely do some cutting rather than abrading. I didn't buy one so can't confirm or deny Fred's report that it's a flimsy P.O.S.

The only independent review I saw on line stated that it was a fine way to turn a 200 dollar knife into a butter knife. There were lots of paid for reviews stating it
was the holy grail of knife sharpeners and I believe that because it was on the internet.

Why did you post this; are we supposed to compare the two? My invention is a precision tool the other is a what; a precision tool? Right!

I contacted you and told you there was an opening on the passaround list for the ERU, but you declined. I assume you had no interest in checking out a precision made tool. :)

Maybe next time, Fred
 
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You already know what it does & doesn't. I mostly use mine for scrapping & cutting annealed steels. In a pinch, I can use it to cuts new bevel for hardened blade, getting reasonable sharp (but not very clean nor durable) apex.
This thread really has me wanting to buy a cheap carbide scraper and see what it does, especially with oil...
 
Hi Fred,

I'm completely "new" to knives, although I seem to be comfortable with freehand stone sharpening (maybe from experience dealing with saw blades, chisels and drill bits) .... So forgive me if my question is too newbie-ish.

One question I have - there are scandi, flat, convex ... All sorts of blade geometries that are around. And I have NO idea what the bevel angle is on any of my knives... My mora, leatherman, SAK, or any of the kitchen knives. Ive no clue.

How would I know what angle to set on the ERU?

If I closed the ERU on the blade, would it effectively "auto-find" the current bevel angle? (maybe on a scandi blade, but what about something with a microbevel?)
 
Black Sharpie line on the edge and a light draw through the ERU will show you which way to adjust it, if your bevel are decent you can adjust by eye, a strong light from the other side of the sharpener will aid in seeing the angle enabling you to adjust till the light leak is minimal.

Convex grinds after not really possible, although I believe if you set it to the apex of the edge you can clean up/realign the very edge of a convex grind, the carbide bits being straight would eventually turn your convex grind to a flat grind, (it wood take some time though)
 
Hi Fred,

I'm completely "new" to knives, although I seem to be comfortable with freehand stone sharpening (maybe from experience dealing with saw blades, chisels and drill bits) .... So forgive me if my question is too newbie-ish.

One question I have - there are scandi, flat, convex ... All sorts of blade geometries that are around. And I have NO idea what the bevel angle is on any of my knives... My mora, leatherman, SAK, or any of the kitchen knives. Ive no clue.

How would I know what angle to set on the ERU?

If I closed the ERU on the blade, would it effectively "auto-find" the current bevel angle? (maybe on a scandi blade, but what about something with a microbevel?)

Not only all sorts of blade geometries but distorted geometries as well. I worked on a thin kitchen slicer, last evening that had two different edge bevels, side to side. That made it interesting.

With straight scandi ground blades it's, as you say, easy, just close the jaws and read the angle. With any other edge grind some investigation has to be done. The routine I use with a blade where I don't know what the edge angle is I go with a magic marker, red is my favorite :) I put nick marks at 1/2 or 3/4 inch intervals along the edge; set the indicator about half way along the scale, 24 or 26 degrees and make a half dozen passes through the "V". You will be able to see where the cutting edge is contacting the abrading surface by viewing the removal of the marker. If the marker is being removed high along the cutting edge, it indicates the inclusive angle is to narrow, open the "V" by a couple of degrees and make a half dozen more passes, take another look at the edge. The idea is to mate the entire edge surface, Bevel, with the carbide face. The adjustment is exact and once you have found the true angle of the cutting edge it is only a matter of recalling the previous set and adjusting the angle to match.
Trying to follow a convex ground edge is a little more challenging but it is quite doable. Again, once you have the edges of your knives at known angles, keeping them at a polished working edge is easy. I have a half dozen blades that I have kept working sharp for a year and a half and it is not only easy but pleasurable.
Saber grinds can be kept sharp by laying the back against one carbide surface and adjusting the ERU to match the single bevel.

Fred
 
Well my initial impressions after using the ERU for a couple of weeks are it is very well built,I would have no problem chunking it anywhere in a pack or tacklebox. It's design especially with the robust sheath makes it seem pretty indistructable. It would require no "special placement" or packing in your gear, just throw it in as is. That in itself makes it very desirable. Now as for the using of it as Fred states it is not the "end all" sharpener, it will not replace your sharpening stones. When I used it my biggest fear is that would work the same as the carbide steel sharpeners. The traditional carbide sharpeners seem to sharpen a blade by beating it into submission with the ripping off of the old edge, not Fred's though. The ERU feels as though you are smoothly refining your edge between two high quality sharpening steels. I would love to have this with me while skinning or fileting. Initially I had the same impression about the belt clip being unnecessary or that it should be removable. This opinion changed after a few uses for me. I liked that it naturally kept your fingers in a safe position. Although, it would be nice if it had the previously mentioned "cut outs" and a removable clip!!!

Jared

P1000275.jpg






ERU Review



1) Initial impressions – Well built from sturdy materials. Good looking sheath. Simple construction.

2) Instructions – Clear and easily understood.

3) Operation – It took a little while to get used to centering the knife, but a few minutes later the process was simple. The sharpie marks method of aligning the blade works very well. The knife I sharpened first had a much steeper bevel than I estimated, but about four adjustments later, I had a perfect match.



Opinions:

Positive – I liked the look and portability. I could easily see a hunter clipping this on his belt or tossing it in a camping pack.

I really liked the ability to match the tool to “my” edge angle…not the two or three some factory thinks I should be using.

Operation was just as described. It won’t shape a bad edge, but will bring a previous good edge back quickly. The edge produced is “rough” or “toothy” in the way that makes a good general use cutter. I had no problem slicing meat and tomatoes after touching up a dull kitchen knife. It won’t replace a good bench stone, but will touch up a blade for cutting chores quickly and efficiently.

Negative – The one thing that really is a concern is the need to place the fingers directly below the blade. Placing the ERU in a vise with padded jaws solved that problem, but unless you conveniently have a vise in your kitchen or backpack, I think most use will be hand held. If I used this a lot in a hand held position, I can easily see cutting my thumb eventually.



The top of the carbide plates is sharp. They catch and scratch if sticking up when in the sheath. When placed in the sheath, placing it in with the carbide downward is a good idea.



Stacy E. Apelt, FSA,Scot
 
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Well i saw this for the first time at the meet on Saturday and have to say i'm really impressed.

Tom had asked me bring along a blunt knife, the knife i took (Buck) had been abused and was blunter than any butter knife. The sharpener was easy (idiot proof) to use just set the angle and go...within 3 minutes the knife had a sharp usable edge. Hopefully you can make out the new bevel in the pic.




All in all a great piece of kit. Not one that's gonna replace your existing equipment IMO but something to keep in your bag for that time when your miles from home and just need to restore that edge and get cutting again...
IMG_3450_zpsbe8e0fe9.jpg

Thanks to Tom (tomj) for bringing it along
 
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