A way to center a sharpening machine on the blade

[Query]

A question arises as to how to get the edges even on powered sharpening machines, by centering the dressed shape of the sharpening wheel on the blade. Some people, like the person who tried to show me how to use such a machine (badly), iterate the process  - get it close, sharpen, get it closer, resharpen, etc. That wastes a lot of steel - and therefore enormously reduces the lifetime of the blade.

You can virtually eliminate such iteration by taking measurements. Let me suggest the opposite approach, and take many measurements. This will waste little or no metal, other than what is needed to make the blade sharp. Many people would say this is overkill, far more measurements and time than a well-practiced skate tech would need. But for a novice skate sharpener, the "magic of measurement" can compensate for a lack of experience.

1. Check that you really need to sharpen. 1/2 to 2/3 of the time, you can save metal by just straightening a bent over edge. You can feel a bent over edge by running your finger across the blade sides and over the bottom. (Do not run your finger along a blade edge or burr - it is easy to cut yourself that way.) Ideally you can straighten the edge with a "steel", such as is sometimes used on kitchen knives. I use a very fine grain (e.g. 5000 or greater grit number) flat sharpening stone. I run it gently along the sides. If you want to avoid roughing up the sides (a good idea), you can use tape almost up to the bottom (hollow) of the blades. You may wish to tilt the stone a tiny bit inwards, towards the hollow, especially if you apply tape, but keep the tilt consistent.
2. Dress the wheel to the desired ROH (Radius of Hollow).
3. If your sharpening machine's blade holder forces the blade straight while you sharpen, skip to step 6.
4. Place a straight edge across one side of the blade. The shortest dimension on the straight edge is usually the straightest, so place that against the blade. Do they touch perfectly, all the way, or is the blade warped? Now do it on the other side of the blade. In some cases, the blade sides aren't straight and parallel, so it will appear to be warped. In that case, in the best possible solution is the one that creates the same deviation from straightness on both sides.
5. If the blade is warped, straighten it. Many sharpening machines have a small tool (maybe on the side) that can push against the center of the flat part of the blade, to straighten it. If the machine doesn't have such a tool, use a vice. The vice won't quite make it straight - you may need to overcompensate a little, by putting a few thicknesses worth of paper against the side the blade is warped away from. Go back to step 4 and repeat, until the blade has no warp. Note: de=warping a very warped blade can break it. So one skate tech I have known returned new blades that had more than about 1 mm of warp. This probably annoyed the blade makers – he had to pay shipping costs, and they sent the returned blades to a less picky skate tech. But if it has significantly more than 1 mm, you very likely will break it, and you will have lost the costs of the blades.
6. Use a square to mark two straight pencil lines at approximately right angles to the bottom of the blade, one near the back, one near the front of the length to be sharpened. You will eventually take measurements along these lines to test centering.
7. For the next steps I assume there are two places to adjust the centering of the dressed wheel on the hollow surface of the blade, one near each end of the blade. Assuming the blade is mounted horizontally (turned on its side), this is done by raising and lowering the blade holder, or the table, at each end. If these is only one point of adjustment, the best you can do may be to  compromise between centering at the two ends, or perhaps to use the center of the length.
8. With the machine turned OFF: Mount the skates (or blade) on the machine's blade holder, centered as well as you can on the blade holder by eye. If there is no holder, but just a table on which to rest the blade, likewise adjust the table height to be as well centered as you can.
9. With the machine still off: lightly touch the wheel to the blade at one end on the outermost pencil line. Adjust a divider or Inside Calipers to the distance between one side of the blade and that side of the wheel, along that line. Check that the distance between the other side of the blade, and the other side of the wheel is the same. If not, adjust the height of the blade. Repeat until the centering is perfect. You could get an even more consistent match by using a depth gauge, such as is included here (though Harbor Freight tools are not always of high quality), or the depth probe present on many precision calipers.
10. Do the same thing at the other end of the blade. Repeat step 9 and 10 until both are perfect.
11. Things might still not be perfect, because some machines don't quite dress symmetrically on the wheel.  So, with the machine still off, use the wheel to scratch a very short mark across those pencil lines at each end, moving the blade (or blade holder) by hand to make the scratch.
12. Now repeat what you just did in step 9 and 10 with the sides of the wheel, but use the sides of the scratch. Repeat this step until both until the scratches at both ends are perfectly centered on the blade.
13. Use a broad magic marker to create a dark layer across the whole hollow of the blade. (Some people use pencil - but I'm not clear how to make a uniformly thick layer of graphite with a pencil.)
13. With a cloth, wipe a very thin layer of light machine oil on the sides of the blade and along the hollow, so the cut will be clean. Not everyone does this - some people say it gums up the wheel, which then needs to be cleaned of oil. But I believe clean edges glide longer and faster.
14. Turn the machine on. Very lightly draw the length of the blade across the rotating wheel. (If there is no eye guard, wear safety goggles! Also, tie back long hair, and do not wear baggy sleeves, that can get caught in the machine.) You want to remove just barely enough metal so that the magic marker mark disappears. If you aren’t adjusting the rocker curvature or sweet spot, try to take the same amount of metal off the whole length. Do NOT round off the back of the blade, and do NOT touch the toe pick.
15. Take the skate or blade out of the machine. Using a square across the blade, check that the inside and outside edges are level. If not:  the previous skate tech must have sharpened the blade very far off center; make another pair of pencil lines 1/4 - 1/3" inwards from the first ones, and go back to step 7. The repetition will waste metal. (It is actually a good idea to use pairs of straight edges, and line them up by eye. The two straight edges should be perfectly parallel. Some straight edges designed for the purpose are magnetized, so they stick to the blade)
15. At this point, depending on how coarse the wheel is, there may be a lip or burr, oriented outwards to the sides, along each edge. You can feel it by very gently running your finger across the blade sides, just like the bent over edges in step 1. (Again, do not run your finger along the blade edge or burr.) You can do one of two things: "Deburr" it by removing the burr, or straighten the burr, and polish it flat, to make an ultra-sharp foil edge. Most skate techs think they deburr it, but actually do something in between. True foil edges are very fragile – taking even one step off ice bends them over or breaks them. But they make the blade super-sharp even if the ROH is large, which I believe means they can be used to extend the lifetime of the blade. But people who don’t take good care of their edges should not use foil edges.
16. In either case, do the same thing with the steel or flat stone that I mentioned in step 1. If you tilt the stone slightly inwards, it tends to deburr rather than create a foil edge.

[Query]

Clarification:

I have very little experience with power tools. My only experience with a powered skate sharpening tool has been with an out of date machine and mostly out of date blades, and was done under the instruction of someone I did not consider a master, without the benefit of measuring tools. I have watched real masters sharpen without using most of these measurement tools.

I do not know whether the procedure will work sufficiently well, let alone with specific blades, blade holders, sharpening tools, or measuring devices.

Plus I did not include an explanatory video, in part because I don't have a powered sharpening machine.

And I should not perhaps have pictured the Harbor Freight/Pittsburgh Technical Measuring Set. While Harbor Freight tools are relatively cheap, and they provide a lifetime hand tool warranty, if you keep the receipt, my personal experience with measuring tools provided by either brand has been that they were not especially well made or especially consistent. A kit or tools from a higher end brand might have been better - I don't know what kits or brands might do better.

I would appreciate any comments on how well this would work with real equipment, and higher grade measuring tools.

Also: The blade holder I used was hard to adjust. You loosened bolts, then shifted the blade by hand. if a blade holder were adjusted instead by screws or button pushes, you could probably do what I specify faster by calibrating how far off the centering measurements were with how much to adjust the blade holder. An better design would be to build the measuring tools into the blade holder, or even better, to incorporate a self centering mechanism. I have seen blade holders that you could adjust better, though I haven't personally seen any with integral measuring tools or self centering mechanisms, unless you count the self-centering mechanism built into the Sparx machines, which I personally wouldn't want.

I have left out fine points, like Kaitsu's suggestion that you spin-balance the sharpening wheel, or various people's suggestions to polish the blade, or even how to apply tape or remove pencil marks.

(The no-longer-made hand skate sharpening tools I use, the Pro-Filer and especially the Berghman sharpeners, are more or less self-centering, but they sharpen more slowly than a professional skate tech would want, and have their limitations, as do all tools. E.g., Tstop4me says that Pro-Filers would not work with many modern blades, such as Jackson Ultima Matrix blades and Paramount blades, without modification. The Berghman tools included crumbly coarse abrasive cylinders, and only came in 1/2" ROH, and I haven't used them on modern blades either.)

[Kaitsu]

I would say that forget the idea that you use caliper to measure if blade is symmetrically in the middle of wheel. Why?

1. I can guarantee that radius in not dressed in to the middle of wheel. Why? => diamond is not most likely in the center of diamond quill + wheel thicknesses varies, errors in machines, etc.
2. Wheels side surfaces has some small amount of axial runout
3. Your caliper tip does not most likely contact exactly to the corner where chrome removal ends and hollow starts. Chrome removal angles vary a lot and they have not grind symmetrically compared to the chromed areas.

If hollow is already in the middle of blade when you start sharpening, all you need is precision square and marker pen. No matter how precise you try to make measurements before starting grinding, you need to do skate carriage height adjustments during the sharpening. At least I have never-ever managed to sharpen any skate without needing to adjust the height while sharpening.

If you have lots of money and want to try some more fancy measurement system, see…
https://blademaster.com/web/en/gauging-accessories/247-bhc2005.html
https://www.youtube.com/watch?v=i1dOFcz_LL8&t=7s

[Query]

BTW, I made an obvious mistake in my description. The pencil line should be across the hollow surface, not the sides.

Thanks!

While I have seen a Blademaster machine where the diamond tip seemed to be in the center of the wheel, it makes sense that there might be some variation in the things you mention.

So I wouldn't expect centering the wheel on the blade to give a perfect solution. But it might make a good starting point, before you may your first scratch.

If you add variation in wheel thickness, diamond point offsets, and axial runout, do you happen to know about how much total variation do you see, from reputable companies like Blademaster, on the $10,000-$30,000 machines? How about Wissota?

I have talked to skate techs who use the scratch centering technique, before they turn on the machine, who claim it is essentially perfectly, though of course it slows them down a bit. But I don't know the exact details of how they do it. I assume, but do not know, that the hard part would be lining up an edge of the scratch mark with the end of a caliper or divider point or depth gauge (or depth probe), by eye. I don't know how precisely one can do stuff like that by eye. I think it would be easier if you let it just barely touch, but am not certain.

I do wonder whether the wheel , if the blade is almost perfectly sharp with the same ROH, can make a scratch with clean edges. If the blade was already perfectly sharpened, the wheel would touch the entire hollow area, not just the bottom. Even if it were only close to perfect, perhaps that scratch would be too wide, to have a clean shape??

Many very good skate techs say they remove about .003" of metal/sharpening on figure skating blades. That doesn't leave room for many mistakes.

[AlbaNY]

I don’t know why I read all about sharpening, because I can feel it making my eyes glaze over, yet it’s somehow interesting.  I cannot imagine trying to sharpen blades myself.

It’s not useful information, but it may interest you to hear about how sharpening works where I am.  According to my coach there is no machine for holding and sharpening figure blades in the entire country, just hockey.  Coaches and high level skaters go to one hockey guy who has been sharpening since before the eastern bloc fell apart, and I’ve recently had my second sharpening done by him. 
I don’t know my radius of hollow, and he didn’t ask my preference either.  I think everyone just gets the same whatever it it?  In conversation he asked about how much I skate and who my coach is, but I’m not sure if that was chatter or meant to be useful information.
He makes no markings and uses no straight edges etc.  He just looks at the blade a bit, adjusts his wheel, then holds the skate and makes a bunch of passes very carefully while still chatting about skating stuff.  Eventually he holds up the skate and peers at the blade carefully and maybe does another pass or two before scuffing the edges to de-burr.    ETA: he holds the skate in just his hands and brushes the blade against a vertically mounted wheel unlike the horizontal way I’ve seen otherwise.

It’s impressive, but I wish I had remembered to trace my blade before the first time and since to compare like Bill does, because I think it would have been interesting.  Skating has been much nicer after the sharpenings, but I do wonder just a bit about changes to the sweet spot and such over the course of many.  I went an absurd amount of time before sharpening, accidentally, but I know my coach purposely goes more than forever between his.  I was at (I forget for sure, but something like 70 or 80 hours,) and my coach was like “Ah, that’s fine.  You could wait much longer.” 

[Bill_S]

It's amazing what a person with considerable experience can do.

But still...   

[supersharp]

Yikes!  Alba_NY: It would be interesting to trace your profile and compare it to the profile of a new blade of the same type.  What blade are you on?

As Bill says, impressive what experience can do, but eeeeeeeeeek!!!  Maybe look for a ProFiler or even a Bergmann hand sharpener?

[AlbaNY]

I know right?   

I realllly wish I had remembered to do the tracings.  I suppose I should now and compare when I get new blades if I send my boots to Harlick this summer, (as I hope to for new soles to add a tiny bit of toe width?)  If I have a mechanical pencil around I’ll see what I can do. 

They are Ultima Aspire XPs mounted in April, a month before leaving NY.

Skating has felt much better after both sharpenings with no weirdness at all… just nice feeling, but I haven’t been learning to spin yet which I assume would make any change more apparent?

[Query]

Some very good skate techs seem to do pretty well without taking any obvious measurements. E.g., they can judge edge evenness by sighting along the bottom of the blade, as it sounds like yours does. I have advocated taking measurements, partly because I think it speeds up the learning process. Most of the time, I don't measure either - just once in a while I recheck the profile.

There is a special blade holder that forces figure skating blades to not be warped, and there are also special holders for certain types of figure blades that won't fit in normal holders (including some figure skate blade holders), but for the most part, I think hockey sharpening machines - as long as they aren't automatic - can sharpen figure skates.

I would be horrified if they use a sharpening machine that automatically creates a "standard" hockey profile. For example, if it removes or trims toe picks or rounds off the back, or if it causes the blade to have relatively flat rocker (longwise curvature) in the center, but to have much more curvature at the ends.

If almost all the figure skaters in your country go to the same skate tech, maybe they have given that skate tech a fair amount of feedback, or if the skate tech is conscientious, they may have taken the time to learn about figure blades, so it is possible they might do pretty well.

And a lot of the same principles apply.

It is true that hockey skate techs usually remove more metal - but a conscientious hockey-trained tech who has also read up or studied or received feedback on figure skates might not do that on figure skates. I would guess that if you get about 30 or more sharpenings out of a blade pair (calculated by assuming each sharpening removes about .003", and the relationship to the toe pick remains fairly good for the first .1" or so of metal removed (people disagree on those exact numbers)), they are doing about right in terms of amount of metal removed.

When hockey trained techs try to restore or modify blade shapes, they typically seek a shape appropriate to hockey - typically one shape for offensive players, one for defensive players, and goalies need their own shapes - but, again, a conscientious well trained skate tech might know better than to do that on figure skates.

So I don't think we should casually assumed that the person does a bad job, just because they take no obvious measurements, and they don't have a machine specific to figure skates.

Also, I don't know whether either a Pro-Filer or a Berghman sharpener will work with your specific blades. tstop4me has pointed out that my casual assumption that you can make them work with all modern figure blades (mine are out of date) may not be true, for several reasons.

E.g., Pro-Filers are specific to one specific ROH (radius of hollow), and they were available for more than one blade width (e.g., hockey blades are thinner than figure blades) - and the hockey Pro-Filer kits had less stuff. I wasted a lot of time making a hockey Pro-Filer work on my figure blades. I widened the slot size, and reduce the depth of the slot, using a file, while keeping the slot centered on the stone. If you are a little afraid to use tools, that might seem scary. The Berghmans were only available for 1/2" hollow, the stones that came with them were of an older crumbly type, and were pretty coarse, and I don't know if they will work with all modern blades either - the slot width is adjustable, but the depth is not. (OTOH, the old used Berghmans are fairly cheap.)

(BTW I use " as an abbreviation for "inch", which is 2.54 cm in my country. E.g., 1/2"=1.27 cm. Do most people in your country know what inches are, and do they know about the " abbreviation?)

As a good starting point, you are right -  if you can scan in the shape of your blades (you may not need a mechanical pencil. If you are careful, and don't scratch the glass on your scanner, you can gently place a blades on the scanner , and just put white paper behind them, and get a good scan, without using a pencil - regardless, you should also place rulers on the same scan, so we can figure out the scaling, or put graph paper with a known spacing behind them), and someone else here happens to have the same blade style, you can check the shape. If the blade shapes are pretty close, that would be a good indicator that your skate tech might know what they are doing. Do it for both blades.

[marc]

bonjour,
Je suis en France (et papa d'une patineuse figure skate) et j'attends d'ici quelques jours ma blademaster 850 d'occasion.
on ne trouve rien en incredible edger ni wissota, alors on achete ce qu'on trouve avec des pieces détachees  facilement trouvable.
Peut on utiliser la piece jointe en photo (Grinding Stones and Carbide Sharpener with Dual-Component Handle ) au lieu de la pierre à affuter.
Je suis jardinier et je fais qu'avec cela pour affuter mes outils.
Pour centrer les patins, pourrait on imaginer avec une bonne regle de mesurer l'axe de l'arrondi taillé par le diamant et de calculer facilement l'axe du patin reporté par un comparateur quelconque?
Auriez vous des astuces pour mieux faire glisser le porte patin  (cire, w40, autre...).
Quelle meule? (la machine sera équipé de 8mxruby)  je pensais déjà acheter une meule 88R.
Comme certains l'ont dit ici, c'est pour éviter de courrir des centaines de kilometres que je fait cela....
J'espère au moins avoir la satisfaction d'y arriver.
Merci pour toutes les infos précieuses que j'ai trouvé ici et là dans votre forum
Hello,
I'm in France (and daddy of a figure skate skater) and I'm expecting my used 850 blademaster in a few days.
we can't find anything in incredible edger or wissota, so we buy what we find with easily findable spare parts.
You can use the attached picture (Grinding Stones and Carbide Sharpener with Dual-Component Handle) instead of the sharpening stone.
I am a gardener and I do that with it to sharpen my tools.
To center the pads, could one imagine, with a good rule, measuring the axis of the roundness cut by the diamond and easily calculating the axis of the pad reported by any comparator?
Do you have any tips to make the pad holder slide better (wax, w40, other ...).
What grinding wheel? (the machine will be equipped with 8mxruby) I was already thinking of buying an 88R wheel.
As some have said here, it's to avoid running hundreds of miles that I'm doing this ....
At least I hope I have the satisfaction of making it happen.
Thank you for all the valuable info that I found here and there in your forum

[Query]

What brand and model of blades you are sharpening? What ROH (radius of hollow) do your child's skates use?

I don't know enough about the hand tool you picture to say anything. The ideas behind most sharpening tools are relatively simple. But only a few have been made accurately enough to do a good job on ice skates. And sometimes the tool has to fit the the specific blades.

Some hand tools are designed to replace powered sharpening machines like your Blademaster. The good ones work with only one ROH.

Other hand tools, like flat stones, are designed to deburr (or polish and repoint the burr) after another sharpening tool has been used. They can be very simple.

Others - like "kitchen steels" are designed to straighten or slightly modify an edge that is already there.

I'm not smart enough to figure out from your picture all the things the tool is supposed to do.

AFAIK, gardening tools don't require high precision or accuracy. But if you are good with tools, you have a big advantage.

Blademaster is a very well known maker of skate sharpening machines. Many pro shops use their machines, including some very good shops. Of course I don't know whether your machine is in good condition.

Blademaster has made many different types of blade holder. Some of the old ones are very hard to adjust: you loosen bolts, move the blade by hand, with no guidance or scales, and re-tighten them. So sometimes you make the centering worse instead of better. That wastes a lot of metal on your blades. I hope you get a blade holder that makes it easy to tell how much you have adjusted it.

I did my best here to suggest a method of centering, that I thought would work. But some other people here have expressed doubts about at least some of my methods. I haven't used a powered sharpening machine enough to be sure.

There are a lot of videos on Youtube that show people how to use Blademaster machines. Many good ones are made by people who work for Blademaster. I think Blademaster's own videos are all in English. but do not know.

[marc]

J'aurais le porte patin sh2000 et la machine n'est pas très vieille et elle est très propre.
Il est moins bon je pense que le porte patin wissota mais je pense que c'est une bonne base.
J'aurais aussi le contrôleur de Care ( perpendiculaire).
Celui qui affûter avant faisait à l'oeil, donc je suis assez confiant, pour le centrage
I would have the sh2000 pad holder and the machine is not very old and it is very clean.
It is less good I think the wissota skate holder but I think it is a good base.
I would also have the Care controller (perpendicular).
The one who sharpened before did with the eye, so I am quite confident, for the centering

[marc]

excuse me for the previous bad translation
I would have the sh2000 pad holder and the machine is not very old and it is very clean.
It is less good I think the wissota skate holder but I think it is a good base.
I would also have the Care controller (perpendicular).
The one who sharpened before did with the eye, so I am quite confident, for the centering
I would have the sh2000 pad holder and the machine is not very old and it is very clean.
It is less good I think the wissota skate holder but I think it is a good base.
I would also have the Care controller (perpendicular).
The one who sharpened before did with the eye, so I am quite confident, for the centering
Modify message

[Kaitsu]

Hello Marc,

I would say that Bahco sharp-x is not good for skates. Its designed more to garden tools and probably there you have get used to this tool.

[tstop4me]

You can use the attached picture (Grinding Stones and Carbide Sharpener with Dual-Component Handle) instead of the sharpening stone.
I am a gardener and I do that with it to sharpen my tools.

Marc:  Please clarify.  I assume you are using this tool instead of a flat whetstone for finishing or repairing edges on the exterior sides of the skate blades.  You are not using it to create a hollow.  Is this correct?

I've never seen that tool before.  But, in general, sharpeners designed for garden tools tend to have coarse abrasives, too coarse for skate blades.

[marc]

yes i thought i would use this tool instead of a flat whetstone for finishing or repairing edges on the exterior sides of the skate blades.  You are not using it to create a hollow.
this tool is great for deburring but I think it won't be long enough,but i will try it anyway

[Kaitsu]

Marc

Remember that blade is curved. Long honing tool will not give you any benefits. It just creates problems for you. You really do not need any longer stone than what can be seen on attached picture. You need to follow chrome removal grinding and profile of the blade keeping honing tool constantly in same angle. I would say that its difficult with Bahco sharp-x. Traditional honing stones are quite soft and they will wear quite quickly when you remove nicks and therefore it needs to replaced relatively often. It comes also cheaper to replace just small piece of honing stone than large one. 

[marc]

Merci Kaitsu,

mais je ne connais pas du tout cette pierre à roder en France et j'ai beau chercher, j'en trouve pas.
Même si bacho sharp-x est plus fait pour aiguiser de l'acier, je vais essayer quand même d'ebavurer les patins en inox.

Le plus dur, dans tout ça, c'est de bien centrer la meule.
Et je suis convaincu qu'il y a une solution pas trop chère, mais faut la trouver.
Le blademaster bhc 2005 est bien trop cher.
Je suis décu que l'axe de la meule n'est pas l'axe du radius. Ca aurait été si simple.
On doit pouvoir mesurer par rapport à la table de glisse cet axe et ajouter la moitié de l'epaisseur de la lame de patin et le reporter sur un comparateur mecanique?

Thanks Kaitsu,

but I do not know at all this stone to be lapped in France and no matter how much I search, I cannot find any.
Even though bacho sharp-x is more suited to sharpening steel, I will still try to deburr the stainless steel runners.

The hardest part in all of this is to center the wheel properly.
And I am convinced that there is a solution that is not too expensive, but it must be found.
The bhc 2005 blademaster is way too expensive.
I am disappointed that the axis of the grinding wheel is not the axis of the radius. It would have been so easy.
Should we be able to measure this ax in relation to the sliding table and add half the thickness of the skate blade and transfer it to a mechanical comparator?

[marc]

Je connaissais pas l'equilibrage des meules, et j'ai découvert ça en m'interessant à l'affutage des patins.
y a t  il vraiement une grande defférence entre équilibré et non équilibré?
Ca n'agit pas sur le centrage mais plutôt sur des petites vagues tout le long du patin?c'est ça?

I did not know the balancing of the grindstones, and I discovered that while interested in the sharpening of the skates.
Is there really a big difference between balanced and unbalanced?
It does not act on the centering but rather on small waves all along the skate? Is that it?

[Bill_S]

A wheel that is out of balance vibrates. That reduces the quality of the surface finish of the sharpened blade. It is rougher.

Here's a photo showing a very rough sharpening on a pair of skates that I received for work. The blade is shown mounted in my holder right before sharpening.



How sensitive skaters are to this is a variable that probably depends on the skater and their skill. A slightly rougher finish might feel like a skating glide on warm, soft ice because of a little more friction. In my rink, a rough vs. smooth finish on a blade is not going to be as noticeable as how recently the ice was groomed, or if we have a warm spell causing softer ice.

That said, the wheel on my Wissota sharpening machine was adequately balanced from the factory. It's not perfect, but I get a better finish from my machine than most rink pro shops I've visited. It's certainly better than the rink sharpening shown in the photo above.

[Query]

With regards to using a coarse stone of any sort to deburr -

I personally have chosen to use an expensive 5000 grit (U.S. standard) flat stone, designed to help sharpen razors. I like the finish it creates, and feel it does less damage to the edge. If you use a coarse grit, it rounds off the edge a lot, which means your edge is effectively much less sharp. Even when I am not trying to create an ultra-sharp edge, I like this stone. But it may be finer and more expensive than it needs to be.

I tried coarser grit stones before, and did not like the results.

But a lot of people who sharpen skates make due with less expensive and somewhat coarser grit stones.

I would be curious what grit sizes the other people in this discussion use.

The type of edge you want for garden tools may be different from a figure skating or hockey blade. A garden tool sometimes hits rocks, so it should not be very sharp. On well maintained ice rinks, there are no rocks.

I think a little unevenness and variability doesn't matter much on garden tools, but can affect skating a lot. A flat stone is easier to control than a curved stone, so it is easier to produce a uniform edge.

[Kaitsu]

I believe Marc was referring to original topic, how to level the blade before starting grinding (to save some material / extend blade lifetime). I believe that if the blade does not contact exactly in the middle of wheel does not have so much to with chatter marks. Eccentricity would do that. Attached picture where you can see how much I do have currently offset on my machine. I could adjust it to be better, but I have been too lazy to do that. Randomly I may use some other wheels with different thickness.

Lots of skate techs uses method where they start machine and make witness marks to the blade and adjust the height based on the witness marks. I do not like this method as I feel that in long term blade would look like a bread knife (exaggerated). I use almost same method, but I do my best to avoid changing the blade to become bread knife. Like I mentioned earlier, in my opinion all you need is precision square and marker pen. Here is link to instruction how I do the leveling for every single blade before stating the machine. https://www.dropbox.com/s/pco8i1q090te7st/Simple%20instruction%20for%20levelling%20blade.pdf?dl=0


I know that the next question is that what about if the edges are not even?

That mistake (hopefully) has been made someone else than you and unfortunately repairing that consumes always some metal / liftime of blade. Typically before the edge which was lower has become sharp, you have found the levelness. At least very close. Levelness may still change a bit until both edges are sharp. If you wheel cuts very aggressively (typically means lots of sparks) you will remove material also very quickly. My recommendation is dress wheel so that it will not cut so aggressively until you have got edges to be even. You can even use wax on wheel to reduce the cut until you have found the levelness close enough.

So if the edges are not level when you start grinding, you need to adjust your skate holder so that you remove material from that side of the hollow where edge is higher. Witness marks on painted blade helps on this task. Estimating correct amount of error compensation requires some experience and good luck too. Sometimes you are luckier than in another time. That is the way how life goes.

Precision hair edge square is the only edge checker what I personally trust. Commonly used magnetic edge checkers are also good as their long "wings" increases accuracy. With the square measuring distance is much shorter. Magnetic versions are made from aluminum and they wear in use. Another more major issue is that blade side surfaces are not always flat. If you take a look my Youtube videos, you can see how badly blades side surfaces can be convex. Precision square tells me also that. When square shows me that the side surface is not flat, I can try to make sharpening so that cabs on both sides of convex shape are identical.

Its more matter of opinion which edge checker tool is best. The main message is anyhow that even eyes can be accurate, they will not beat good measuring tools. Even the wooden pencil is better that just eye balling the blade. See an example https://www.dropbox.com/s/89qufzkgp26yws5/Edge%20checking.pdf?dl=0

 

[marc]

kaitsu,
merci encore pour ces riches informations.
Quelle est ta chaine video toutube?
ou peut on trouver cette petite equerre 'Precision hair edge square'
Puisque tu es en europe ou peut on aussi trouver une equilibreuse de meule? (je trouve pas)
et je vois qu'il y en a un qui a ouvert un nouveau post

kaitsu,
thank you again for this rich information.
What is your toutube video channel?
where can we find this small square 'Precision hair edge square'
Since you are in Europe or can we also find a wheel balancer? (I do not find)
and I see that there is one that opened a new post

[Query]

The type of edge you want for garden tools may be different from a figure skating or hockey blade. A garden tool sometimes hits rocks, so it should not be very sharp. On well maintained ice rinks, there are no rocks.

I think a little unevenness and variability doesn't matter much on garden tools, but can affect skating a lot. A flat stone is easier to control than a curved stone, so it is easier to produce a uniform edge.

Actually, I want to completely unsay that.

A figure skate should sink deep enough to prevent sideways skidding, but should not go too deep.

I don't garden much. Some of th elittle I have done might have been easier if some of the tools were very sharp.

I suppose a garden sheers might be work best if ground very accurately, so the two blades slide cleanly and snugly against each other.

So - please disregard those comments.



Kaitsu: Your pictures and instructions in the link you mention are very clear. I love how clearly you have shown everything.

But I think you are assume that the blade is already fairly sharp, If it isn't, you won't get marks all the way across the blade in step 4. Many people don't sharpen very often, so the blade may not always be that sharp. So, instead, you will get a mark somewhere in the center. That is the assumption I made.


Also, some people don't want even edges. E.g., some hockey players skate mainly on their inside edges, so it is harder to push them over. So do some beginning figure skaters, though I'm not sure you should accommodate that, because they should learn to use outside edges soon. Some skating referees use their outside edges more than their inside edges, when they are dodging pucks and sticks. Neither I nor you addressed those issues here.


I also didn't talk about the deliberate "skids" (shortened outside edges) people add to parts of the blade. E.g., many hockey goalies often slide side-to-side, and want skids on the back outside edges. A very few skate techs add skids to the front outside edge on the jumping foot of figure skates, once figure skaters start doing skidded double jumps. But I think both of those skids are usually added after the blade is sharpened, or during the deburring step.


Some issues that have nothing to do with sharpening:

Your link also talks about blade warping and the reasons it occurs. Let me mention a few other things that can warp or twist a blade.

Many skate techs have told me  that MK and JW blades are often sent from the factory warped, even when new. Many skate techs feel that MK's and JW's quality control program (they are owned by the same company now, and I was told they are made at the same factory, possibly on the same production line) should reject warped blades more often.

BTW, Mike Cunningham, a (retired) skate tech who had once been a welder, told me he suspected that MK and JW blades are often warped because of the way the runner and base are welded together. Metal expands when it gets hot, and if you aren't very careful about the way the pieces have been heated, after the two pieces cool, one may contract more than the other, or they may contract unevenly, creating a warp. I suppose that if the base and runner are not made of the same steel alloy, and they don't have the same coefficient of thermal expansion, that could complicate matters too.

I am not sure, when you talk about a bent "blade holder" in step 5 of your link, whether you mean the way in which the runner is attached to the base on the skate, or the blade holder you use when sharpening. Certain hockey skate companies have bolted or riveted runners on the skates between pieces that are manufactured bent, in some skate sizes, and that forces the runner to bend with it. Even if the blade is straightened, it keeps warping. Is that what you meant? Or is the blade holder that you put the blade in to sharpen it sometimes bent too?

Another skate tech told me that hockey blades often become very warped because one skater runs into another skater's blades. I'm not sure if hockey sticks can also hit the blade hard enough to bend them.

Also, the way you mount a blade on the skate can easily eventually create a warp or twist. I think you shouldn't want the skate to put a twisting or bending force on the base, which will eventually in turn warp or twist the runner. That's one of the reasons people sometimes place shims between the blade mounting plate and the skate. Also, if you mount one end of the blade on the skate, tighten it, and mount the other end to create a specific alignment, and tighten it, that eventually warps the blade. Some people mount the blade using the temporary (sliding) screw slots, look how well the blade aligns with the skaters body when they skate, and whether their weight is centered on the front and back of the runner. Then they hammer one end or both ends of the blade sideways so as to cause the screw to slide to improve that alignment. Later they use the permanent (round) screw holes, maybe after a few days or weeks. That is a relatively fast technique, that initially can create a well aligned blade. But the procedure has probably created a twisting force on the blade, which will to some extent transfer a warp to the runner. I personally think one should instead mark where a proper alignment places the front and back of the blade, and only then use the permanent holes to create the same alignment, being sure to create no warping force on the blade. But that takes more time to do, and not everyone agrees.

[Query]

Another more major issue is that blade side surfaces are not always flat. If you take a look my Youtube videos, you can see how badly blades side surfaces can be convex. Precision square tells me also that. When square shows me that the side surface is not flat, I can try to make sharpening so that cabs on both sides of convex shape are identical.

I assume you know that blade side surfaces are often DELIBERATELY not flat. Blade companies usually charge more for blades with non-flat surfaces. E.g., with dovetail shapes, that are wider at the bottom - though that would be concave, not convex.

I'm not sure if there is a good reason for a blade to deliberately have convex sides. But perhaps there is a structural engineering reason to shape them that way - i.e., can you ever make a slightly lighter blade of a given strength or stiffness shaped that way? It wouldn't surprise me if ultralight blades whose runners are bound to non-metalic substances, such as carbon fiber, were often deilberately not flat on the sides.

I should have also clarified that on plated runner blades whose plating has been removed at the bottom working surfaces (e.g., that have a "chrome relief"), the hollow should be centered on that portion of the blade, not the plated portion.

I do not know if there are any runners that are plated with a softer metal at the bottom too. If so, that would create problems if the plating is not the same thickness on both sides. I can't think of a good way to solve that, since if your edges are initially level, they might not stay that way as the plating metal wears away.