How much of a difference in blade profiles do you think would be acceptable?

Started by Kaitsu, September 19, 2023, 10:56:17 AM

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Kaitsu

I know there is no clear answer to this, but I would hope that the blades advertised as the best blades in the world would not have such differences when they are brand new. My personal expectation is that the right and left blades would be more identical when they leave the factory. https://www.youtube.com/watch?v=z82VYcBl9f8

If even the right and left blade are not identical, do you think that there would not be similar differences in different pairs of blades? I can assure you that they also have it, and this is probably due to the fact that at John Wilson, the profiles are ground manually in few different process steps after the laser cutting. This can be seen in the videos what they have published in the Youtube.

Sometimes I really wonder about conversations related to the 8 and 9 foot rockers, when in the reality also their radii can differ greatly from what was promised.

Nate

Honestly, you would likely just acclimate to the differences and not notice them after a while. If they're the same type of blade, the disparity will not be large and frankly this has been common for a century due to how blades were made. The only difference is more people may be searching for this nowadays.

Kaitsu

True, even if you lose one of your legs, you get used to it too. Today, however, efforts are made to prevent accidents so that people can live a healthy life instead of saying "you'll get used to it". Attitudes and technologies has developed over the time.

As long as customers accept this "you get used to it" attitude, some manufacturers will make things in the same way as they have been made "for ever", even though manufacturing techniques have improved significantly over time. With today's technology, it is entirely possible to make more identical blades.

Query

When you layd the left blade on top of the right tracing, it isn't completely clear you lined things up quite right.

For starters, the toe pick positions and orientations don't match - though that is partly because the toe picks are assymmetric, left-to-right.

What two reference points on each blade did you try to place on top of each other? Or did you line things up another way?

For that matter, there are even discrepancies between the right blade and the right tracing. I think this is because the pencil has a certain width, and it is hard to hold them completely vertical, or whatever you tried to do. I've had trouble with this myself. I wonder whether it isn't better to use a technical felt tip pen, and hold it at an angle, so that all that touches the blade is writing surface.

It's one of the reasons why I sometimes prefer to use an optical scanner to capture shape - except that optical scanners can distort things too - as you may notice if you try to scan a piece of graph paper.

Nate

Quote from: Kaitsu on September 19, 2023, 12:42:08 PM
True, even if you lose one of your legs, you get used to it too. Today, however, efforts are made to prevent accidents so that people can live a healthy life instead of saying "you'll get used to it". Attitudes and technologies has developed over the time.

As long as customers accept this "you get used to it" attitude, some manufacturers will make things in the same way as they have been made "for ever", even though manufacturing techniques have improved significantly over time. With today's technology, it is entirely possible to make more identical blades.
/UberBoggle

Lol.  Weird response.

Every manufacturer has tolerances, so there is almost never a set of blades where two of them are identical.  As long as the blades are within tolerances, they are generally good and sold as a set.  People who want tighter tolerances can buy blades from a manufacturer who uses licensed profiles and manufactures to much tighter tolerances.  However, there are no blade manufacturers that will guarantee a perfect match, and it's almost impossible to deliver on such a promise.

This isn't about accepting a "get used to it" attitude.  It's about accepting that two blades don't have to be identical to 0.0000000005% tolerances for them to be identical in feel.  There is such a thing as a reasonable expectation.  Your expectation juxtaposed practicality and reality is what determines whether or not there is a problem there (for you - physiology differs between people).

Even if the blades were perfect matches, within a few months they likely would not be due to unequal wear between the two blades and sharpening removing metal - unless you expect the tech to go through every time to manually force the profiles to match whenever he sharpened them.

None of my blades match perfectly after some months of use for this very reason.

If the profiles do not match and the difference is relatively extreme, then return them for another pair before sharpening or mounting them.  They don't need any of that to be done for you to trace the profiles of the blades and see if something is outside of your comfort zone (for keeping the equipment).  98.6% chance they will be sold to someone else who will skate on them with no effect on their performance whatsoever.

I've returned more expensive equipment for less, so I'm certainly not trying to judge ;-)

Nate

@Query:  I noticed the Toe Picks don't line up and it's off too much for it to be attributed to the asymmetric cutting of the pick clusters.


The blade is also being moved & rocked back and forth as the video is panning along the length of it, so at different points it looks like as if the blade is at a different position relative to the tracing.


Going L->R, the blade looks almost on top of the tracing.  R->L the tracing looks like it's 1-1.5MM above the blade.  L->R the blade looks like it's jutting up above the tracing.  So, the blade is moving throughout the video, on top of the pick cluster not being lined up.  It's unusable for actually comparing the profiles.  This is probably due to the same person holding the blade recording the video - I am not saying it's being intentionally done.


Personally, I don't like JW/MK blades and I've been pretty up front that I would buy a Paramount Blade over theirs unless I got the JW/MK blade for like $150 less than a Paramount 420SS.  That's the only reason why I got JW P99s.  Without that discount, I would have bought from Paramount, because I dislike the wide tolerances that JW/MK uses when manufacturing their blades.


I will say that at the beginning of the video, I can clearly see the front rocker of the blade on the Right of the Frame is more flat than that of the blade on the Left of the frame, and this would be very noticeable when skating on the blades - for me.  I would return them for that reason alone.  Differences towards the back of the blade are something I highly doubt I would notice at all, frankly.  Even if I measured and saw anything back there (in isolation/barring any other issues), I would likely ignore it.  It's totally possible that observation is just a visual effect from the difference in angle and distance from the camera, though.

Query

Quote from: Nate on September 21, 2023, 04:05:25 PM
Differences towards the back of the blade are something I highly doubt I would notice at all, frankly.

I would notice if the back was significantly rounded off, like a hockey blade - something that some careless or ignorant skate techs have sometimes done. I don't know if JW / MK ever do that.

I agree with you that the differences shown in that video are probably within most athlete's ability to adapt, though the shifting positions make it hard to tell. And it would be pointless to expect HD Spots to meet high end machine shop standards - the next skate sharpening would ruin that. But Gold Seal Revolution blades sell for about $859/pair in the U.S. At that price, is it unreasonable to ask for near perfection?

The people I've seen who are most picky about matching rocker profiles are (short track) speed skaters. They use expensive gigs so they can sharpen both blades at the same time, side-by-side, with uniform rocker radius. Then again, racers in any sport sometimes worry about minor stuff that most others don't. They point to the small number of races won by a few thousandths of a second, and say EVERYTHING matters.

Nate

Quote from: Query on September 22, 2023, 01:18:51 PM
But Gold Seal Revolution blades sell for about $859/pair in the U.S. At that price, is it unreasonable to ask for near perfection?
I think that depends on how one views it.


I mean, is it worth it, and why does any specific person think they are?  That's more of a "food for thought" question than anything.


I find their QC to be lackluster as a result of the looser tolerances, where two blades can deviate in different avenues, yet still be within tolerance of the reference rocker profile (but more out of line with each other, as a result), leading to issues like this.  I don't disbelieve OP, even if the video makes it impossible to really verify, because I know their blades generally differ to greater degrees than many competing blades (and have seen it myself).


With JW/MK Blades, this is something I expect is a very real possibility.  Ordering their blades is like ordering a new monitor and spending the days while waiting for it to arrive praying to God there aren't any dead pixels in the panel (people call this the "Pixel Lottery," Lol).


I do think the Phoenix Blades are going to avoid this issue, as they are using more up-to-date manufacturing for those.  But they are $1,200 blades and out of range for most consumers.

Query

Some of the more competitive skaters have two complete pairs of skates set up. It gives them options if one becomes damaged, is lost in transit, or needs to be sent back to their skate tech for sharpening, etc.

I suppose someone whose feet sweated a lot might even do it so they could use  a different pair for short and long programs so the long program pair didn't start out too soaking wet. Or maybe they paint each pair differently so that the skates can match their short and long program costumes.

In many of those cases the skater needs to transition between the two pairs with a very short time delay between them. So they don't have much time to adapt. So the two pair should be as similar as possible.

You can say only a small fraction of skaters keeps two complete similarly set up pairs like that - but we are talking about a pretty expensive pair of blades here. Maybe there would be a fair amount of overlap? After all, the cost of skates and blades is much less than most serious competitive skaters spend on lessons, ice time, travel, off-ice training, etc.

Nate

Quote from: Query on September 25, 2023, 08:14:00 PM
Some of the more competitive skaters have two complete pairs of skates set up. It gives them options if one becomes damaged, is lost in transit, or needs to be sent back to their skate tech for sharpening, etc.

I suppose someone whose feet sweated a lot might even do it so they could use  a different pair for short and long programs so the long program pair didn't start out too soaking wet. Or maybe they paint each pair differently so that the skates can match their short and long program costumes.

In many of those cases the skater needs to transition between the two pairs with a very short time delay between them. So they don't have much time to adapt. So the two pair should be as similar as possible.

You can say only a small fraction of skaters keeps two complete similarly set up pairs like that - but we are talking about a pretty expensive pair of blades here. Maybe there would be a fair amount of overlap? After all, the cost of skates and blades is much less than most serious competitive skaters spend on lessons, ice time, travel, off-ice training, etc.
That's cool, but it doesn't matter with base JW/MK blades as they are not the highest-end Carbon Steel and dull/nick/rust easily.  You can get five pairs, but sharpening will still push them out of reference - to varying degrees - due to what needs to be done to keep the edges clean and level.  All blades - even two within a pair - have different patterns of wear-and-tear.  Reality is, most skaters are completely accustomed to skating on pairs of blades that deviate from each other and the reference rocker to varying degrees.  A pair of base JW/MK blades that are perfect out of the box will probably remain that way through 1-2 sharpenings max for an active skater, unless the Pro is spending inordinate amounts of time fixing or matching rocker profiles at each sharpening (for every pair of blades he or she sharpens...) - completely independent of whether or not the degree of deviation has any actual/material impact on skater performance.

Kaitsu

Nate, I agree most of the things you said. Loosing the leg was in purpose an extreme example of the tolerance. Somewhere it is "within tolerances" and you have to just adapt it without any compensation, when in some other more modern cultures such would totally unacceptable. It depends a lot how much people are willing to accept to be an tolerance. As long as customers accept products quality without complains, makers does not have so much motivation to do any improvements. That is how business world goes.

Same is valid for the sharpening s. Poor quality is generally accepted because situation has been same for century. People has used to keep it as an "general standard" because its so hard to get good sharpening s.

For me this example pair was far out of my expectations for the new blades, but they were not my blades. In the end owner always decides if they are taken in use or not. I was just interested to hear other peoples "tolerances".

There was some doubts about the video and specially second blade alignment to the  pencil tracing. Like Nate mentioned, one hand was holding the phone and another blade. Camera losses easily focus, so making clear video isn't so easy. However you possibly missed one important detail from the video. There was 5mm difference between the left and right foot blade touch point lengths. This was the indication why I even started to compare left and right foot profiles to each others.

Even it is true that blade profiles changes during the sharpening s, I have never managed to get 5mm difference to the left and right foot blades touch point lengths. Not even they have been sharpened many many times with poor machine. I would say that such a difference requires cross grinding.

AlbaNY

Quote from: Nate on September 22, 2023, 10:01:36 PM
I think that depends on how one views it.


I mean, is it worth it, and why does any specific person think they are?  That's more of a "food for thought" question than anything.


I find their QC to be lackluster as a result of the looser tolerances, where two blades can deviate in different avenues, yet still be within tolerance of the reference rocker profile (but more out of line with each other, as a result), leading to issues like this.  I don't disbelieve OP, even if the video makes it impossible to really verify, because I know their blades generally differ to greater degrees than many competing blades (and have seen it myself).


With JW/MK Blades, this is something I expect is a very real possibility.  Ordering their blades is like ordering a new monitor and spending the days while waiting for it to arrive praying to God there aren't any dead pixels in the panel (people call this the "Pixel Lottery," Lol).


I do think the Phoenix Blades are going to avoid this issue, as they are using more up-to-date manufacturing for those.  But they are $1,200 blades and out of range for most consumers.

I liked the look of the Phoenix blades, and they were gently recommended to me, but so often I've read that traditional styled blades are better for various reasons.  With some there are complaints about function and noise, and other times it is the lack of hand holds available.  I didn't even notice the difference in price point.  Ouch.  I thought 99s were bad! 
With Coronation Ace I especially saw a lot of advice against the non-traditional version.

I ended up buying another normal pair of Pattern 99s, but I'm intrigued by the Phoenix.  One, or a few, sharpenings can take away any advantage of consistency they have though.