Sharpening near the toe pick

[Bill_S]

Long post follows...

I made some measurements this morning in order to answer the question "how close to the toe pick to sharpen." Some sharpeners will grind far enough to remove some of the pick, others leave a long un-sharpened length to avoid contacting the toe pick. Even the most careful sharpener won't sharpen immediately behind the toe pick because of sharpening machine geometry.

I took two different blades that I had on hand, and marked the front of the blade in 1/4 inch increments. I set them on a flat piece of wood (flat, like the ice we skate on), and tipped the blades up so that the pick just contacted the surface. I could read off how much dead space there was behind the pick. I also made photos.

I realized that toe picks "dig in" the ice when actually skating and that might affect the dead-zone, so I drilled a shallow hole in the wood to simulate the pick engaging the ice lightly.

First up were my daily Coronation Aces, now 10 years old. The rocker is still very close to the original. I traced it when new for a reference. Also I have a lot of good metal left for sharpening. (I hand sharpen, and that's much gentler than a power grinder.)

Here is a side shot of the pick area when the pick just contacts the surface. The distance back from the pick where the blade contacts the ice surface is 7/8".



When the blade rocks forward and the pick is embedded in the ice a bit, it changes the distance. In my simple experiment, I could see that I need to have a sharp edge within 5/8" of the pick. That small distance surprised me a bit...



I have a pair of Jackson Synchro blades that I once intended to use. They are unused.

The first photo shows that an length of 1-1/8" is not engaging the ice when the blade is flat on the surface...



The photo of the pick embedded in the surface a bit produces an unused length just over 3/4"...



Through this experiment, I found that the Jackson blades have a longer bit of blade not engaging the ice. It might be that the rocker is positioned rearward too, but the result is that this would be an easier blade to sharpen.

One last photo - most power sharpening equipment uses a shaped grinding wheel along the length of the blade. Because of geometry, this prevents the operator from sharpening right up to the toe pick.

My case is a little different because I use a Pro Filer hand sharpener, and I can push the stone right up to the pick. However that part of the blade has not been pre-sharpened at the factory, and it would take forever to build a hollow right behind the toe pick. Still, every time I sharpen, I run the device up to the pick.  Slowly, I'm building a hollow there. Here is a shot showing my blade area behind the pick...



I'm creeping up on an edge right behind the pick, but from feel, there's about a 1/2" length that remains without a good edge. Thankfully, my measurements for Aces show that even with the pick engaged, I still have a good edge on the ice. That first 1/2" length of sharpened blade isn't needed.

One conclusion is that various blades have differences in the unused length. I would expect that with worn blades that sharpening would be required nearer to the pick. Check your own blades on a flat surface to see if your sharpener goes far enough.

[icedancer]

Being blade-obsessed at times I love your analysis and conclusions!

Also wondering about that Synchro Blade - what size is it?  Ever think of selling it?  (I would love to try a Synchro Blade as my Super Dance 99 are just WAY too short and sometimes unstable (10.25).

Thanks!

[Bill_S]

My Synchro is 10.5" (mounting plate tip to toe).

I hadn't considered selling it because I always thought that I'd mount it and try it out. I've skated only on Aces since I started, so I was curious about trying something different.

I think that I'll hang onto the Synchro blades a while longer just in case I get ambitious. Ask me in another year or two if I've mounted them! 

[icedancer]

That's okay!!

I think if I do ever get new skates they might be a little bigger so I might be able to use that 10.5! 

I can wait.

Those that know me know that I am always looking to pick up an extra pair of blades here and there - was so jealous when a friend who recently came back to skating after a 10-year hiatus found a brand new pair of MK Dance in the back of her closet.

And actually unless you are doing dance and tripping on the backs of your blades those Aces are great!

[tstop4me]

One conclusion is that various blades have differences in the unused length. I would expect that with worn blades that sharpening would be required nearer to the pick. Check your own blades on a flat surface to see if your sharpener goes far enough.

Yes, the unused length [referred to as the non-skateable zone by Sidney Broadbent] is a function of the spin rocker radius, which varies with different blade models.  Paramount has informative videos on "Blade Profiles" and "Lift Angles"  here:  https://www.paramountskates.com/videos .  From limited info that I've been able to gather, Ultima and Eclipse blades nominally patterned after MK and Wilson models have a flatter (larger radius) spin rocker than the MK and Wilson originals, resulting in a longer unused length, moving the sweet spot further back, and reducing the maximum lift angle.  Paramount claims that they follow the spin rockers of MK and Wilson closely.

Yes, the advantage of the hand-held Pro-Filer is that you can sharpen right up to the drag pick.  Standard commercial skate sharpeners typically use a 7" or 8" diam grinding wheel, which limits how close to the toepick you can sharpen.  The Incredible Edger uses a smaller (3" diam) grinding wheel and can sharpen closer to the toepick.  One skate tech I used to go to used an Incredible Edger, and I was not happy with the results, though. 

My current skate tech uses a Blackstone machine. After repeated sharpenings, if he needs to touch up the (usually) unsharpened area just in back of the toepick, he uses a cross grinder, available as an attachment to the main sharpener.  Over time, if you need to maintain the same maximum heel lift as a new blade, you also need to grind down the drag pick carefully.

Sidney Broadbent designed a blade with a removable toepick assembly so you could sharpen the entire length of the blade.  But it never caught on.

[Query]

I actually prefer a coarser stone than either of the Pro-Filer stones to make the initial cut on the previously unsharpened part - like is on the old Berghman sharpeners - because it is fast enough to create a full depth hollow in a more reasonable amount of time. The way I see it, if the hollow isn't ground deep enough to touch the sides of the blade, it doesn't actually create a sharper edge angle.

Unfortunately, the Berghman sharpeners were only made for 1/2" hollows, so the front part wouldn't be the same hollow, unless you finish it with your Pro-Filer. The oldest are available on eBay for as little as $5, though a more modern one, made in the 1950's, would have a less crumbly stone. The Berghmans too can be used right up to the toe pick - in fact I find it easier to control. However, because they are coarse, they can't create quite as sharp an edge, if you are into super-sharp edges. I prefer the Berghman handle to the Pro-Filer handle, but you can place the stone your Pro-Filer handle - use a hammer and a "pin punch" to remove the pin keeping the old stone in that handle; maybe you could use an appropriate size cheap disposable hex key instead. (I'm not sure if a rivet remover could also be used.) You can hammer the pin back in when the new stone is in place. (The Berghman tools use a wing-nut driven pressure fit instead, and stone replacement is much faster. As with the Pro-Filer, rotate the stones periodically to get uniform wear, and since the stones are crumbly, to get a more uniform radius hollow.)

You can also buy online appropriate diameter (2*ROH) cylindrical sharpening stones (search for "cylindrical stones", and if you can carefully use cardboard, "abrasive sleeves" and "spiral bands") from several sources, with various grits. I think a 60 - 80 grit stone will cut fairly fast. I think you can even use the cylindrical stones from a hockey tool, like http://www.thebladedoctor.com (though that page doesn't seem to work anymore).

As far as how close you should come to the toe pick: Try this experiment: Color the bottom of the blades with pencil. Skate. Do some 3-turns and jumps. I think you will find that the ice wears off the pencil all the way up to the back pick - and also takes off the hollow on most of the blade, which implies that even more of the blade (briefly?) touches than you think. I don't know how much that depends on technique or how hard you jump and land, as I have only tried it for me. I don't point my toes enough to use the other picks, but I'm told a better, more flexible skater would.

When I sharpen the area close to the toepick with Pro-Filer or similar hand tools, I put cloth tape (I use cloth first aid tape, but duct tape should work) on the pick itself, so I don't accidentally touch and dull it. I think that is a good idea.

You can also VERY carefully enhance the edge on the toe pick itself - but only if you ARE very careful not to dull the corners. I'd never try that with a standard machine sharpener. Whether or not you need that depends on how much sideways grab you want the picks to have. Clearly the majority of the figure skating population makes due with the factory grind on the toe picks, and the Jackson Ultima blades start out VERY sharp, including in the toe picks. For that matter, most figure skaters get by without sharpening the area close to the toe pick at all, and most don't believe it is needed. So unless and until you have to trim the back pick to match the wear on the rest of the blade, you might decide to leave the toe pick itself alone.

I guess you theoretically could sharpen very close to the toe pick using the cross-grinder on a standard powered sharpening machine, if it has one. You might want to turn the skate around mid-sharpening, to get the edge symmetric, because cross-grinders don't otherwise do that very well. I haven't enough experience to trust my blades at all to those powered sharpening machines. I feel they take off more metal, and it is too easy for me to make mistakes on them. So I haven't tried sharpening close to a toe pick on them.

[Slowpoke]

I have never heard of the Pro-Filer tool before.  Looking on their website, it looks like something I would like to try.  I skate every day, so my blades get a lot of use.  The only thing is, I use a 3/4" grind.  Only the Pro-Filer for hockey skates comes in 3/4".  What is the difference between the hockey tool and the one for figure skates?

I have Eclipse Aurora blades.

Slowpoke

[Query]

Slopoke:

I think the hockey tool has a thinner gap, which wouldn't fit a figure skate blade.

But last I knew, you could call the company, and ask for a custom gap size. It might also be worth a call, to see if they could produce a figure kit for 3/4", for you.

I think the hockey tool only includes a coarse stone, no fine stone, so you can't create quite as clean and fine an edge - and you will take off a little more metal, though perhaps not more metal than your typical pro shop skate tech.

There is a significant learning curve in learning to sharpen your own skates, no matter what tools you use. I've made a few mistakes! E.g., it is very important to trace and/or photocopy your current rocker profile at the start, so you can maintain it over time. And you probably want to maintain and/or accentuate your sweet spot (the point(s) where the rocker curvature changes up front).. You may also want to tape the sides of the tool (which requires a slightly larger gap width), so it doesn't scratch the sides of your blade, and reverse sharpening directions part way through, to keep the edges symmetric. In fact, you should check symmetry. And there are several ways to repoint the burr (to create a very sharp, thin "foil edge"), or to deburr. Etc.

If you can't spend the time to get everything right, you may consider using the Pro-filer to only do touch-up work, between professional sharpenings by a great skate tech, who can fix your mistakes.

But the Pro-Filer is a very pretty tool, that looks as professional as something small enough to put in your skate bag can look. Once you figure out what to do, it can be fairly easy to use, and you can easily recreate a nice edge in 5 - 10 minutes or so, which might be faster than you can travel to and from the pro shop. It is at the upper end in price of hand sharpening tools. Also, I think side honed blades (e.g., parabolic or tapered cut, rather than sides that are completely parallel, creating a uniform thickness blade), could be problematic.

FWIIW, I'll send you a link to my page.

[tstop4me]

I have never heard of the Pro-Filer tool before.  Looking on their website, it looks like something I would like to try.  I skate every day, so my blades get a lot of use.  The only thing is, I use a 3/4" grind.  Only the Pro-Filer for hockey skates comes in 3/4".  What is the difference between the hockey tool and the one for figure skates?

I have Eclipse Aurora blades.

Slowpoke

(1) Hockey unit comes with only one sharpener:  diamond-coated mandrel.  Figure unit comes with two sharpeners:  (a) diamond-coated mandrel, (b) abrasive finishing stone.

(2) Hockey unit has a heavy-duty handle, assembled with screws.  Figure unit has lighter-duty handles, assembled with roll pins.

(3) Hockey unit has slot configured for thin blades (~.10 inch).  Figure units have slots configured for thick blades (~.16 inch).  I have the Eclipse Aurora; the blade thickness is .150 inch.  Not sure if the standard hockey unit will have enough clearance (some vintages have slots with two different widths); check before you buy.

(4) Hockey unit cannot sharpen as close to the pick as the figure units, due to differences in handle configuration.  [I think they may be changing over to the hockey handle (with a different slot width) for the figure unit as well, once the current inventory is exhausted.  So if you want to get right up to the toepick, check carefully on what's being shipped.]

3/4" ROH is really shallow for the Aurora blade. More typical is 1/2" or 7/16".  I use 3/8".

If you really want 3/4" for Aurora, contact Brad Anderson (owner) and explain exactly what you want.  He does offer custom-modified units.  One word of caution, though.  A couple of forum members here have used Pro-Filer for a long time and swear by it.  Me and at least one other member have tried it and stopped using it.  Can be a bit finicky to setup and use. 

How often are you having the Auroras sharpened?  One big advantage I've found is that it holds an edge much longer than a Coronation Ace.


ETA [1]:  <<Query replied while I was writing, so I wasn't aware of his post.>>

ETA [2] (11/26/17):  The main reason I gave up was I couldn't get the small ROH I wanted.  I was originally aiming for a 7/16" ROH.  With the 7/16" kit (which actually is the same as the 3/8" kit),  I was getting an ROH in the 1/2" to 9/16" range.  But since you are interested in a relatively large ROH, you'll likely be OK.  I previously had problems with the unit on a Coronation Ace because the thickness variation of the blade (I think mainly due to variations in the thickness of the chrome plating) caused some binding of the sharpener.  But the Aurora is mirror-polished stainless steel, and I found the thickness to be highly uniform along the length of the blades (+/- 0.001 inch).  The Pro-Filer uses the sides of the blade as a guide, so you should check the thickness uniformity of your Auroras.

[Query]

We are really going off-topic here. I once bought a used hockey Pro-Filer. I had to modify it for my figure blades, using metal files. Many people wouldn't want to work that hard.

TStop4Me, what sharpening tool do you now prefer? Could it sharpen close to the toe pick?

[tstop4me]

We are really going off-topic here. I once bought a used hockey Pro-Filer. I had to modify it for my figure blades, using metal files. Many people wouldn't want to work that hard.

TStop4Me, what sharpening tool do you now prefer? Could it sharpen close to the toe pick?

For now, I've stopped hand sharpening.  I found a local skate tech who knows what he's doing.  With the Auroras, I do a weekly hand honing with a butcher's steel to maintain the edges between machine sharpenings.  I've found that I need a machine sharpening only ~ once every 3 months; that's ~ 90 hrs ice time for me.  Also, I'm changing over soon to Paramounts. The Pro-Filer doesn't work on those.  But I bought the Paramounts in 440C stainless steel, same grade as used in the Auroras.  If the Paramount processing is at least as good as the Eclipse processing, I should get ~ the same edge life.  Right now I'm hoping that the Paramounts will have even longer edge life. 

[Bill_S]

Bringing this back around to the original topic...

I looked over my experiments one more time, and it dawned on me that despite the significant differences in the two blades, there's one measurement in common. If the toe pick is lightly embedded in the ice, it moves the contact patch of the blade forward by 1/4"regardless of the blade measured.

I'll conclude with an easy test for average blades - not worn down, end of life blades. Place a ruler or other straightedge across the toe pick and touch the blade. If the sharpened area doesn't go at least 1/4" further toward the toe pick from where the ruler touches the blade, there's a possibility that you could slip on the forward edge. You should find a way to get that extra 1/4" sharpened if it isn't already.