How to get good surface finish to blades and how they look?

[supersharp]

Really interesting, thanks for the plasma cutting attachment. 

I see a lot of factory sharpenings that look almost okay (which is a better surface finish than our rink produces) but the edges are off level, usually in a parallel manner. I don't think they spend any time trying to center the ROH on the blade; they are just putting a groove in it.

Ultima blades are generally closer to level than Wilson or MK in my experience. SkateScience doesn't bother to put a radius on the blade at all. I think they correctly assume that if you are buying their blades, you understand that you need to have new blades sharpened. It does take significantly longer to do the first sharpening when the blade is flat, so I have come to appreciate the grove that the other manufacturers provide, even if it is off level.

One of the pieces of information that is included when you look at blades for sale is often ROH.  I am mystified as to why the manufacturer claims the blade has an inherent ROH. I've had parents ask me if they should order a particular blade, it has a 7/16" ROH, is that okay for their skater?  I just tell them to ignore the ROH because I will give the skater what they are used to skating on or adjust to a more favorable ROH if needed. Generally this is only necessary if the new blade is a different width, which changes their edge angle at the same ROH. If they are skidding on the new blades and they weren't on the old blades, we need to address it.  Although from a skater's perspective, I think correcting the skidding with improved technique is often an opportunity that should be embraced to some extent.  I've had a few skaters that want their blades really sharp all the time because it masks their unbalanced technique better. I can sharpen them every 2 weeks if they want, but I always emphasize that the blade life is going to be short.  Of course they say it's fine...but then are in complete disbelief when I tell them that the blades are ready for replacement. 

I have one adult skater who finds it very challenging to adjust to a fresh blade with the original profile after letting her blades get old and flatter. She says "promise me you will make me get new blades earlier next time", so I do as requested.  A year later, she is still "almost ready" to get around to order new blades.  I keep reminding her that she is making it harder on her future self, but of course she says that she is being kind to her present self by keeping the blade the same.  "As soon as I get better at XXX we can change it" but then she never feels like she is enough better at XXX.  Maybe she would be better at XXX with a blade with a new profile, I suggest.  "Hahahaha" is the answer.   

My new Little Edger is supposed to ship today or Monday, so maybe I can at least restore some shape to the front of her blades when it arrives.  Fortunately I have dozens of old blades to practice with before I attempt to gently adjust a pair that is in actual use. Exciting and terrifying all at the same time.

[Query]

I guess I am less picky than some of you. I skated fairly happily on (old style) Ultima Matrix blades with factory sharpenings. I found their edges far better, more consistent, and sharper than what the majority of pro shops could provide, including what very high end skate techs provided. (Though in fairness, I didn't realize that Mike Cunningham had to be asked for an extra sharp edge - he believed most skaters were better off with relatively dull edges, so that they wouldn't have to change the way they skated before and after sharpening.) For the most part, only a careful hand-sharpening seemed to do as well or better, from my perspective.

I guess part of the problem with using rocker bars is that you want the profile to have a continuous direction at points where the rocker curvature changes - e.g., for the tangential direction of the main rocker curve at the point of change to be the same as the tangential direction of the spin rocker curve at that point. Am I correct that CNC (computer controlled) cutting or routing machines can easily do that? (But that unfortunately such machines are pretty expensive, for the individual skater?)

I have seen CNC routers and CNC cutters that seem to shape wood pretty accurately. Perhaps the wood piece could be used as a guide for a conventional grinding machine, just like a rocker bar? Ideally, the sharpening machine would have a fence along which the CNC cut bar would slide with the skate clamp, and it would push in the blade by just the right amount.

[Kaitsu]

Query, you need to remember that blade manufacturers has changed slightly their strategy from those times when Matrix runners were still replaceable. In the past blade manufacturers made quite deep hollows, at least based on their web pages. You could see on manufacturers technical data that ROH could be 3/8" or 7/16". Now-a-days most of the manufacturers makes ROH to be somewhere 9/16" - 5/8" and they don not even try to make sharp edges. There is two reason for this...I would say. Most important for them is cost saving. Another is that they believe that flat hollow extends blade lifetime. When the hollow is anyhow skater specific, hollow is made so flat that in theory skate tech should remove material just from the bottom of the hollow and not from the edges. Reality is anyhow that hardly ever the edges are even and typically edges are also dull or even rolled. Their nice idea to extend blade lifetime is ruined when they make edges to be uneven. I have to say that Ultima makes typically better quality on edges evenness than example Wilson.

Facts is that many things on figure skate´s sharpening is matter of opinions. Someone likes more flat hollows and some likes more deeper. Someone likes that hollow is deep, but blade is anyhow dull. Unfortunately skates techs does not have Chrystal ball which would tell what the skaters really wants to have. Often skates are just dropped with instruction that please sharpen them. Sometimes skaters might give some advice's, but still there is risk that you are talking about apple and skate tech believes you are talking about perry. Example I got call from one of my fried whom normally makes hockeys. Figure skate coach did bring him his skates and instruction was that deburring has to be made so that with the nail tests, blades should have same sharpness to both directions. ROH was not changed and in the deburring skate tech tried his best to make what was requested. When the Coach went into ice with sharpened blades, he said "These are way too sharp". I always say that good sharpening is result of co-operation of skater and skate tech.

Here is example from the Matrix Legacy at factory condition. https://www.dropbox.com/s/w989c2l9bhmoudv/Matrix%20grinding.pdf?dl=0
Its totally possible that someone likes this kind of blades. In that means skate techs may do wrong assumption by making sharpening in the way how she/he believes to be better for the skater.

Here is I possibly one example from such a skate tech assumption. Customer ordered new boot, blades and mounting for them but no sharpening. This is what they got. https://youtu.be/WUyeMs-Oyy4

I can guarantee that this is not factory sharpening. Its sad that this retailer seems either to try save some service time by making pre-sharpening for all blades on their stock or either they believe to make good customer service by sharpening blades without request. This same issue happens almost every time when people buy skates form this retailer. It happens even the customer specifically highlight that NO sharpening, meaning that do not touch my blades. It same as you would buy a brand new car and when you go to pick it, you will get car which paint surface is "polished" with sand paper and sales person saya that we only thought your best.

When I was ordering blades from different retailers, I made very clear that I will ship blades back to them if they are not in factory condition.

[Query]

I didn't realize factory sharpenings were using larger ROH than they used to. Interesting. As far as I can tell, MK, JW, Ultima and Paramount no longer list factory ROHs.

ROH is only one component of skate sharpness - and not always the most important one.

I think effective "Sharpness" is mostly determined by how abruptly the cross-blade direction changes at the edges, and by whether the tip of the edge extends straight down. E.g., if you round off the edge after sharpening by stoning it at an angle (to "deburr" it), as most skate techs do, it won't act very sharp even if you use small ROH. And if the edge is bent sideways, it acts even less sharp.

Those of us who like "foil edges" can get very sharp blades even on speed skates, with no hollow curve (i.e., ROH=infinity).

(But foil edges are fragile, and don't last as long as less sharp edges. In fact

  https://scienceofsharp.com/2015/01/13/what-is-a-burr-part-2/

which has beautiful micrographs of sharpened razor blades, treats foil edges as a defect to be removed. But I treat them on skates as the true edge that just need to be polished smooth, and bent to be vertical.)

Back to your original topic, I don't care much how blades look - but I think that smooth surface finishes, both below and on the sides, makes blades glide faster and longer. I don't know if there have been any scientific studies about that. But there have been many studies that show ships and boats with smooth finishes require much less energy to move. So military ship builders spend huge amounts of money to make ships smooth.

I'm not sure, but maybe smooth finishes glide more quietly on the ice too.

[Kaitsu]

It is true that the way how you deburr the blade after grinding affects how the skates feels. More aggressive hand oil hone vs example fine grit oil hone and the angle how you hold the hand hone all affects. If you want to get ridiculous sharp skates you make deburring with Sweet-Stick or similar stick sharpener. I have seen also such a cases.

I would like to buy high quality microscope but 1000$ is way out of my hobby budget 

[Query]

I would like to buy high quality microscope but 1000$ is way out of my hobby budget 

To match the "Science of Sharp" imagery, you would need a decent electron microscope - significantly over $1000. I suggested he create skate blade images, for blades sharpened in different ways. He said I would have to give him the blades, and pay a few hundred dollars. I'm not that curious.

The Science of Sharp guy didn't think optical microscopes could produce comparable imagery to an electron microscope - but it is possible something comparable could be done with a super-resolution optical microscope. The one my brother uses at Intel costs about $30,000,000. He also uses electron microscopes, which have comparable resolution (I guess they can see different details). Alas, I doubt Intel would be interested in examining skate blades - they are too busy trying to fill the demand for digital processors, and many people there already work 80 hours/week.

[tstop4me]

The Science of Sharp guy didn't think optical microscopes could produce comparable imagery to an electron microscope - but it is possible something comparable could be done with a super-resolution optical microscope. The one my brother uses at Intel costs about $30,000,000. He also uses electron microscopes, which have comparable resolution (I guess they can see different details).

Not sure I'm reading this right.  Are you saying that your brother uses an optical microscope that costs 30 million dollars?  If so, what is it?  [ETA:  I thought you might be talking about the new generation of confocal microscopes.  I checked those prices.  A high-end unit is on the order of $500K.  So I'm still curious as to what fetches $30M.]

[Query]

If you look at a Wikipedia article

  https://en.wikipedia.org/wiki/Super-resolution_microscopy

you see that merely confocal microscopes are not at the top end in resolution. You need to use other things to see the effects of an out of place atom on electron band states that can mess up some semiconductor devices.

I don't have the exact reference or manufacturer handy, though another of my relatives works (in sales) at the company that produces it.

A "super-resolution" microscope is one in which one obtains a preliminary 3D shape model, then iterates the image processing by modeling defraction effects. That is iterated until, in this case, you obtain about 1/10 wavelength resolution, probably in the far ultraviolet. To some extent that is achieved by taking advantage of fluorescence effects. (I don't know how that helps. Perhaps since fluorescent photons are emitted from the surface itself, so don't have to go through as much diffraction. Also, such effects would be great for detecting band state energy changes, which lie at the heart of what makes solid state ICs work.) In principle a single atom out of place or of the wrong type (or even the wrong isotope, though that is partly because decay energies are enough to switch the state of small semiconductor devices) could mess up a small gate size semiconductor device. I don't recall the exact resolution, but I think it was well under 100 nm - I think they can sort of seethe effect of out of place atoms on electron band states. As with MRIs a lot of the cost is for the superomputing chips and the software that do the processing, combining information from multiple shots - and because few people buy these devices.

By the way, their electron microscope do destructive testing. The beams of electrons dissect the chip, stripping off layer by layer. They can reverse engineer competitive products, by seeing their exact structure. Though, if I remember right, that only had about a 100 nm resolution - but the processing was much faster than the highest resolution optical microscope. I used to know a grad student at the University of Maryland, who used the prototypes,  developed by a professor there. I once saw an RFP for a $100,000,000 10 nm or better resolution microscope of the same type - possibly for use by people like the NSA. Don't know if it was ever filled, or what the current technology is. The NSA apparently has a significant amount of money to work with too. 

My brother works in quality control. It is an area critical to the semiconductor industry. In particular, doing it "right" has allowed Intel to have a higher yield (% of successful devices) than competitors, and has put the, AFAIK, at the top of the CPU market, with AMD as their only real competitor in top end CPUs. (It helps that a new production line at the smallest gate sizes that are commercially practical runs about 10 billion USD - a serious barrier to entry that killed most of their competitors.) But Intel works everyone very hard, with very long hours. My brother is the oldest person at his plant that isn't in management. And, if my brother tells it right, they are viciously competitive, even to the point of some people trying to steal or undercut other people's work. Just about everyone else there who isn't a manager is in their 20's, who mostly come straight out of grad school. After they burn out, they move on to other companies - but having Intel on the resumes sounds good. Intel also has great pay, great health insurance, and some other great bennies- but because the workforce is so young, and doesn't stay long, they don't bother with a pension plan!

Personally I sleep too much to have ever worked 80 hour work weeks, so I could never have worked there, nor would I have wanted to. I think there would have been no time to skate or hike or ski or kayak. Yuk. But a lot of grad students in physics and engineering dream of working there.

[Query]

This is way off-topic, BTW, but I think companies like Intel mostly don't push microscope technologies, in terms of resolution. (What does? See https://news.cornell.edu/stories/2021/05/cornell-researchers-see-atoms-record-resolution.) What they want are fast results, to keep very expensive production lines going with high yields. Also the $10 billion production plant figure I mentioned was a figure Intel has thrown about on public media in connection with next generation plants to reduce the ongoing chip shortage - and it is conceivable they hope to be subsidized by the U.S. government, and have padded that figure a bit to match that hope. I don't know if current generation plants are really that expensive.

I do not believe we need microscopes that cost millions of dollars to produce good ice skate sharpenings. I think we can mostly feel when we have edges that meet our needs. I'm also not sure if the extent to which skating is affected by surface finishes - either in the hollow, or on the sides - has been well established. I believe it is affected significantly, as I think does the o.p., but some people, including much better skaters than me, and including some professional skate techs, don't think surface finishes are all that important. Some skate techs don't even bother cleaning up the metal filings from their sharpening machines very often, and I think most don't use a lubricant or polish when they sharpen.

So my interest in looking at skate blade edges and finishes under a microscope is to some extent more a matter of curiosity than anything else. I was also trying to find an efficient way to teach beginning skate sharpeners. I thought being able to see the results of sharpening attempts, and matching them against good results, would help. I've so far only used an old rather low end CCD microscope, that I can only connect to an old computer. You can get that the modern equivalent type now for about $25. Much better ones exist, that would show much more, for as little as several times that. But I don't know how to actually translate what I would see under a microscope into how well the blade skates. E.g., is a somewhat ragged edge desirable to prevent skidding? I don't even know what optical resolution size is needed to see things that might affect skating, which makes it hard to decide what type of microscope would be needed.

[Kaitsu]

I was talking more about this kind of "home microscopes". https://www.dinolite.us/en/products/digital-microscopes/usb/edge-series-all/am4517mztl and Query dives directly to scanning electron microscope (SEM) type of microscopes which are used example to investigate metals micro structure, chemical structure and nano level of photographing. They are nice equipment's and it would be interesting to investigate why some blades are much harder that the others...even they are presenting same brand and model. But if we land back to reality, this video is presenting the microscopy level what I would like to reach https://www.youtube.com/watch?v=QJT5BVt7c5c
For example, see timeline 3:50 - 4:15

[Query]

I'm not certain, but I think you could get the level of photographic detail in that video with a $50 USB microscope, or possibly a $100 microscope.

I don't know why, but something is missing from the Dinolite product specifications: the real (not interpolated and/or digitally edge enhanced) source pixel size, and the optical resolution. Without those, you don't know how much detail you can see. I have been guessing that I want want both to be no larger than 1 micron, maybe .1 micron, for ice skates - but I'm really not sure. Unfortunately, a lot of microscope providers don't list these things - but the Dinolite product is expensive enough you would hope to know them.

Some people instead list "magnification". But magnification depends partly on the size of the display screen, not just the size of the source pixels, so you don't know how small the details are that you can see.

Also, that microscope only provides 1280x960 pixels. (I don't know if that is an interpolated size. And to add complexity, most CCD cameras have a "color mask" - e.g. some source pixels might be red, some green, some blue. Software then tries to guess how to interpolate and extrapolate that to red, green and blue values at every pixel, much like is done on low to moderate price consumer market cameras.) But assume you can adjust and focus it to have about 1000 true pixels across a .15 inch thickness ice skate blade, which you probably can't quite manage. That gives you a pixel size of about .00015 inches - or about 3.81 microns. Maybe, by the time you are done, about 5 micron optical resolution?? Not great.

But I don't know if it is good enough for skate blades...

Celestron makes a number of USB microscopes at an intermediate (non-professional) level, that many online reviews have rated well, though they are more expensive than what I suggested. Some can be bought used - though you have to be careful - some older USB microscopes or their software are designed to import images only to old (e.g. Windows XP) computers. I'm sure there are other reasonably good brands too.

The knife edges shown in that video might not be what you want on skate blades. You don't want to cut hair (a fairly hard substance at a microscopic level) with virtually no effort - you only want to sink into soft ice just enough to prevent skidding, but not so far that it slows the glide much. So you don't want the narrow edge angles on that knife - you want edge angles that are almost 90 degrees wide, perhaps augmented by a foil edge - see below.

As I said before, I do like relatively sharp skate blades. The burrs the person on the video want to remove, is what I want to keep, on my skates. I just want those burrs to be more uniform along the whole edge, and to be polished and straightened into a thin plane. That is a "foil edge". Those foil edges, I think, sink into the ice, about up to their length, preventing cross-blade skidding, but are too thin and short to slow the glide much. (Foil edges mostly aren't rugged enough to cut hair, metal, or to some extant, hardwood. They don't have to be, on skates.) Such foil edges stop skids even on fairly rough ice, because they cut through the poor ice on top, whereas an edge formed just by the intersection of a hollow arc with the side of the blade sometimes doesn't, especially if that intersection is "deburred", i.e., deliberately blunted.

[Kaitsu]

I do already have 30$ USB microscope and I am not happy for it. As Query already referred, still pictures they can take are often with very low pixels. I am a bit scared that Dinolite´s 1000$ microscope does not provide any better image quality.

There are two things what I would like to see more clearly than with normal digital camera.
1. When removing the burs, I have noted that I will turn burr easily to hollow side and not actually removing it. I would like to see the same what I can feel with my fingers.
2. I would like to see what happens for grinding traces and edges if I try to polish hollow with hand honing. So far my polishing trial has mainly made edges dull.

Here is example from the blade where I made hand polishing with PBHE 15 microns root radius hone. I got some steel dust in to the white table, but its almost impossible to see any difference between the power grind and hand honed blades. At least with my eyes. Blades in the picture are exactly same. One picture presents situation before polishing and another after polishing.
https://www.dropbox.com/s/qrmotqab2odbs5n/Which%20one%20is%20honed.jpg?dl=0

[supersharp]

It's almost impossible not to hit the edges a little bit with the radius-honing tool.  Maybe there is a way to mount it to the IE to use the guidance rails for a final plush of the radius?  It would need to be something that could clamp on in exact alignment with the grinding wheels, and then the blade would already be perfectly aligned with it. 

[Query]

I do already have 30$ USB microscope and I am not happy for it. As Query already referred, still pictures they can take are often with very low pixels. I am a bit scared that Dinolite´s 1000$ microscope does not provide any better image quality...

Your posts have pretty good image quality, though they aren't super-high detail. The camera built into my smartphone can't do nearly that well, partly because it doesn't focus very close.

What type of camera did you use for those pictures? Did you use a macro lens? Or were the pictures you posted made with your USB microscope?

To a very crude approximation, the size of detail you can see is inverse to the distance at which you can focus. You could order glasses that let you focus very close - e.g., the prescription where you add enough to get a spherical correction of +12.00, the highest correction that Zenni Optical, a discount glasses provider, will provide. For me that would focus at about 2". I thought about that when I ordered my last set of glasses. That won't help you take pictures, but you can see more than with normal distance glasses. I didn't do that - the closest I ordered was for 8" - which is certainly better than longer distance glasses, but not as short as I should have ordered for maximum detail.

One issue, with any microscope, is that you need a way to hold the microscope still relative to the blade, so you don't get motion blurring. And it should be at the optimal distance from the blade, so it is in perfect focus. You may also want to play with the lighting angle, and maybe even to play with polarization, to enhance contrast. I don't know whether a color filter would also affect image clarity much. But if you can increase depth of field - by using a smaller aperture (which needs a longer exposure), that might help you get a good clear image. But you sound pretty technical, so you probably know all that.

[Kaitsu]

What type of camera did you use for those pictures? Did you use a macro lens? Or were the pictures you posted made with your USB microscope?

Photos are taken with Samsung S7 and S20 without any additional macro lenses.

I really am not an expert on adjusting exposures etc. I know their principles, but I have been too lacy to play more with them. Manual focus is mainly what I use. As you said, photography is playing with lightning and view angles. Its interesting to see how much you can change the photo just by finding correct view angle and lightning. Sometimes it takes long time and several trials to get good photo. For this reason I have couple thousands photos just from the skate blades.

One issue, with any microscope, is that you need a way to hold the microscope still relative to the blade, so you don't get motion blurring.

You are absolutely right. More you magnify, more stable the camera has to stay as it magnifies all your tiniest movements. In my cell phone I use always timer to avoid shaking while it takes photo. Another issue on microscopes is that its much more difficult to change view angle and shiny steel does not make things any easier. Even you can adjust the USB microscopes lighting, its causes still lots of problems. Often they also magnify way too much.

Here are some example photos from the same damaged area on the blade:
https://www.dropbox.com/s/guyvn9uwlkycoin/1.jpg?dl=0
https://www.dropbox.com/s/19h5xuhp6qbctdb/2.jpg?dl=0
https://www.dropbox.com/s/19h5xuhp6qbctdb/2.jpg?dl=0

I probably have change to test Dinolite 5 Megapixel USB microscope at January (2022). I will post test pictures if I get that change.

[supersharp]

I find it very difficult to get good images of blades. I think lighting is a huge proble, particularly with the reflection off the steel. You need just the right angle to reveal chatter and texture.  At this point, I'm using old blades as test cases, writing the info on the diff with a sharpie, and saving them for comparison, because the photos aren't an adequate representation of the finish I'm getting. 

Maybe we should start a thread on photo tips for blades?

[Kaitsu]

Some new invention. I am a bit skeptic how well this really works. I believe it will not polish the edges which are actually used. Polishing the areas which does not even contact to ice does not make sense. If they are able to polish edges, they must have genius invention not to round the edges while polishing. My assumption is that this may work on hockey skates with very flat hollows.

I have sent them some questions, but they never replied to me. Perhaps I asked too difficult questions when I requested high quality pictures from the polished figure skate blades and explanation how they prevent rounding of the edges. I asked also price. Rumors says that this device costs several thousands $.

https://diamond-sharp.com/en/diamond-sharp-en/
https://youtu.be/o7ece2JuZV0

[supersharp]

"Thanks to better edge guidance, gliding on the ice is much more efficient and stronger than with a standard ice skate."

It looks like pretty standard "edge guidance" when you watch the video.  I would love to hear their explanation.

[Query]

I confess I don't understand Russian (if that is what it is), so I don't know what they are saying.

If they polish too much, they will create a significantly thinner blade. Presumably the blade is designed the way it is, with a specific thickness, in order to skate in a specific way. Perhaps some might not like the thinner blade. I wonder if they remove too much?

[supersharp]

I didn't see the second video the first time I looked at Kaitsu's post about the Diamond Sharp. 

The skate tech never checked to see where the wheel was hitting the blade, never checked for level...I am not favorably impressed.  I'm still curious about how they get that finish, but I definitely do not want that guy near any of my skates.

[tstop4me]

Some new invention. I am a bit skeptic how well this really works. I believe it will not polish the edges which are actually used. Polishing the areas which does not even contact to ice does not make sense. If they are able to polish edges, they must have genius invention not to round the edges while polishing. My assumption is that this may work on hockey skates with very flat hollows.

I have sent them some questions, but they never replied to me. Perhaps I asked too difficult questions when I requested high quality pictures from the polished figure skate blades and explanation how they prevent rounding of the edges. I asked also price. Rumors says that this device costs several thousands $.

https://diamond-sharp.com/en/diamond-sharp-en/
https://youtu.be/o7ece2JuZV0

* According to their website (https://diamond-sharp.com/en/diamond-sharp-en/): "With the patented Mirror Sharp polishing machine, we have started a revolution in grinding."  <<Emphasis added.>>  The principals in the company are listed as Carsten Brunet and Markus Lausberg.  Since the website proudly boasts, "Diamond Sharp - Mirror Sharp: The Revolution Made in Germany"  <<Emphasis added.>>, I searched the patent database of the European Patent Organization (EPO).  I searched under each principal's name separately and came up with this one relevant result: https://worldwide.espacenet.com/patent/search/family/073198196/publication/EP3819081A1?q=pn%3DEP3819081A1.  They have filed patent applications with the German Patent and Trademark Office and with the EPO.  Neither application has issued as a patent; they are both pending, according to the information on the EPO site as of this date.

* The applications are in German.  My German is really rusty, so I punted to the English machine translation provided by the EPO (machine translations to other European languages are provided as well).  This is purely a goodwill service for convenience of patent searchers, not an official translation.

* Here are the English machine translations of the first three claims from the EPO published application:

1.

Transportable device (1) for processing a surface (2), in particular the running surface, comprising a blade (3), in particular an ice skate blade an electric drive, arranged in a housing (4) designed in particular as a portable and/or rollable case, for rotating a surface treatment agent (5) mounted rotatably in the housing (4) and designed as a polishing wheel
and a control device (11) arranged in the housing (4) and having actuating means for controlling the drive of the surface treatment means (5),
characterized in that the surface treatment means (5) has a treatment zone (17) in the area of the circumference, which comprises a cross-sectional area with a slope and/or a taper (20) and/or a chamfer and/or a rounding (21).

2.

Device (1) according to Claim 1, characterized in that the surface treatment agent (5) comprises a textile fiber material such as felt, in particular containing wax and/or a diamond additive, such as diamond dust, or made of textile fiber material such as felt, in particular containing wax is formed.

3.

Device (1) according to Claim 1 or 2, characterized in that the processing zone (17) of the surface processing means (5) is slightly narrower than the width of the runner or than the distance between the runner edges (26), so that during the surface processing of the runner (3) the edges (26) of the runner (3) remain unprocessed.


* My summary of key points.  The independent claim 1 (broadest scope claim) does not place any limitation on whether or not the edges are polished.  The dependent claim 3 (narrower scope) specifies the thickness of the polishing wheel to be narrower than the distance between the inside and outside edges of the blade such that the edges are not polished.  The dependent claim 2 (narrower scope) specifies a polishing wheel made at least in part of textile fibers, such as felt.  The felt is treated with wax, diamond abrasive, or a combination of wax and diamond abrasive.

* When I have time, I'll read through the entire application to see whether they discuss polishing the edges themselves.  But I agree that polishing only surfaces that do not contact the surface of the ice is a waste of time.

ETA1:  I've read through the application.  They do not address polishing the edges.  On the contrary, they claim that it's preferable not to polish the edges such that they stay sharp.  English machine translation of Paragraph [0042] of the Description:

[0042]

A lateral view of the polishing wheel 5 resting on the skid 3 can be seen in Fig.

2C can be removed.

During the machining of the runner surface 2, the disk 5 rotates at at least 3,000 rpm, and the runner 3 is guided along the polishing disk 5 in a horizontal direction, preferably in the opposite direction, i. H. so that processing zone 17 and skid 3 have opposite directions of movement during processing.

A polishing paste 22 can be used between the runner 3 and the disk 5 .

A particularly good result in the surface treatment of the runner 3 is achieved when the polishing wheel 5 is a little narrower than the distance between the runner edges 26.

The effect of this is that the runner edges 26 are not processed during the finishing process, the edges 26 thereby remain "sharp" and the runner 3 becomes "more sharp-edged".  <<Emphasis added.  Not clear to me what "more sharp-edged" means.  That could be a machine translation issue.  I'll check the original when I have time.  ETA2:  Yep, the runner is sharper if you choose not to dull the edges by polishing them.  Imagine that!!!>>

This measure means that the runner 3 has better gliding properties with regard to cornering stability and/or changes in direction or load.

[tstop4me]

I confess I don't understand Russian (if that is what it is), so I don't know what they are saying.

If they polish too much, they will create a significantly thinner blade. Presumably the blade is designed the way it is, with a specific thickness, in order to skate in a specific way. Perhaps some might not like the thinner blade. I wonder if they remove too much?

?? The device polishes the surface of the hollow.  How does that affect the thickness of the blade?  Here, I'm using the common convention for "thickness" as the distance between the inside and outside edges.  Are you using "thickness" to refer to some other parameter?

[supersharp]

Excellent research, tstop4me!  Very interesting and quite puzzling as to why so much effort is made to have a mirror-smooth hollow. 

[tstop4me]

Excellent research, tstop4me!  Very interesting and quite puzzling as to why so much effort is made to have a mirror-smooth hollow.

Yeah, no reference to any supporting technical data (not required in a patent application).  Just this brief, unsubstantiated statement in Par. [003] of the Description:

"A highly polished running surface of the runner has a reflective shine and a correspondingly smooth (running) surface. The runner with finish processing has better running and gliding properties and thanks to the features of the device described herein, these improved surface properties of the runner compared to the prior art can also be reproduced at any time at the place of use of the runner."

Makes no sense to me.  And even if it did, I wonder what the price of their dedicated polisher is vs. the price of another sharpening station outfitted with a polishing wheel (assuming you don't want to swap grinding wheels and polishing wheels on a single station).

[supersharp]

I definitely would not want to be switching grinding wheels to polish unless I had a second setup.  And even with that, if the alignment of the second grinder was not identical, you would risk affecting the edges, and would have to go back to your primary grinder.  You would have to exactly measure the ROH in order to duplicate it on the second machine, and getting the blade lined up perfectly centered...sounds like a lot of room for disasters. 

I've been trying to come up with a system for aligning and controlling hand tools so I can use them as a final polishing step, but all my ideas so far don't quite work. I'm happy with the final product of the grinder, but of course I am always striving to make it even better.  At this point, doing a very slow, careful final pass on the grinder is producing the best overall product so the only hand-work I do is de-burring of the edges.  Hand polishing after machine grinding creates an even smoother final finish, but it can't be controlled adequately, so it reduces the perfect centering of the hollow...so the blade is smoother but has worse geometry.

I've skated on both versions (grind only vs grind and follow with hand tools) and the machine grind geometry gives a better skating experience than the smoother but less consistently shaped hand tool polishing.  And ultimately, that is the final test.