Blademaster 88R or 8mx ruby

[marc]

Hello everyone,
Well, after 2 years of closure of the ice rink (Castres 81100 FRANCE), it will finally reopen in a few days.
In the meantime, I became an official sharpener according to the law...
skating forum is a gold mine of information and I always read with great interest.
My question of the day and since I need to order grinding wheels, I wanted to know which is the best grinding wheel between 88r and 8 mxruby.
I already have both but I don't understand the difference and I can't figure out which one is better.
I already do a lot of coronation ace blades for girls in competition with 8 mxruby and the result is very good with a ROH 5/16.
For beginners, I use an 88R grinding wheel with a ROH 7/16 or 1/2.
There are YouTube videos but I don't understand either.
Also which diamond: tsm 687 or 688.
thank you in advance for your answers

[Kaitsu]

Marc, congratulations on the new ice rink and official sharpener status!

I do not have experience about either of these wheels. Blademaster´s Ruby wheels I use are super hard. You can notice clear difference already by ear when you dress the wheel. White aluminum oxide wheels are so easy to dress, when they are so soft. With my experience ruby wheel has been harder than any of other types I have tested. However the wheels I use are 3", when yours are 8".

Blademaster specifications says that pink 88r has uniform grit and closed structure. Its not clear to me if grit size is then 88 or something else. Closed structure may not be the best for the stainless steel blades. In my opinion closed structure clogs easier and you might need to dress it more often than open structure wheel. You can read more about the wheel structures and their impacts / benefits example from here => https://www.linkedin.com/pulse/grinding-wheels-od-processes-walter-graf

Ruby wheel specification says that it is suited for heavy press grinding. This is interesting information. Another interesting thing is that they claim wheels to been precision balanced.

At least in my machine surface finish quality varies from blade to blade. Even I have two pairs of Coronation Aces I may get better surface finish to one pair than the other even I grind them at same day. Wheel wear will also affect. Circumferential length reduces when wheel gets smaller, but I believe wheels are also not so uniform. There might be variations in the different diameters. I would try also other brands wheels if you can get them from France or even from the Europe.

Unfortunately my reply was not providing you clear answer which wheel you should use. I believe no-one is able to say to you, which wheel works best for you. There are so many variables which affects to the end result. Try different wheel types and trust to your eyes, ears and how the hollow feels with your finger nail when you scratch perpendicularly to the grinding traces. Smoother the surface finish feels to your finger nail, better glide you will get.

By the way... 5/16" (8mm) is quite deep hollow. I do not ever do so deep hollow, except if skater is specially asking it.

[Query]

To further explain why Kaitsu think 5/16" is unusual - it takes more effort for the skater to skate fast, or to glide for a long distance. The higher the ROH, the faster the blade moves, and the longer the glide. Unless you take it too extreme in the other direction (e.g., over 1"??), so the pushing foot has trouble pushing hard.

But if the skater has trouble producing clean edges, or has trouble turning, or is very light or is skating on very cold hard ice, or is simply used to 5/16", maybe it makes sense. You should probably give the skaters what they ask for on their own blades.

AFAIK, 7/16" is most common for figure skaters, though MK Dance blades, because they are ground fairly thin at the bottom, are often ground with 3/8" (= 6/16"). School figures skaters, or possibly those trying to do certain "Moves in the Field" - now called "Skating Skills" in the U.S. - also tend to go larger - sometimes 3/4", or even 1", so they can glide longer, but it is possible most stay with what they use for other skating.

Hockey skaters need a lot of speed, so on average they tend to go with a bigger ROH - e.g., 1/2", though that varies too. And once again, skater weight and the temperature/hardness of the ice matters.

I think most ice rinks sharpen all rental skates to 1/2" or maybe slightly more, because larger radii edges are more sturdy if the skaters aren't gentle with the blades - e.g., if they walk off-ice onto the rubber mats (which I hope you have) without covering the blades with blade covers, as they mostly do. If you do that with 5/16" ROH, perhaps the edges would get bent over more easily, which effectively makes them very dull.

But there is actually a lot of variety among what skaters want. Many skate techs just try to match what the blades had before - you can maybe use a "radius gauge" to measure that.

[marc]

Query and kaitsu

my question was not really about the roh but rather about the millstones but since you talk about it well I will talk about it:
It's been a long time since I understood low roh and high roh.
my daughter, as well as her friends in competition, are used to skating in 5/16. And it's true that I could stay at 5/16 for the small and thin ones and I could go to 6/16 for the larger and more robust ones.
then for less experienced beginners, I do 1/2 but I never do less than 1/2.
For my daughter (thin and small) who skates (edea with coronation ace) at the highest French level, I don't dare go to 6/16 because she skates a lot on the edge but she could gain speed between figures. I suggested she go to 6/16 but she doesn't want to. One day, I will try in secret but... when there is not an important competition right after!

I may also sharpen some hockey skates because a little boy gave me his skates and he has never had such well sharpened skates (with my 1/2" sharpening) whereas before he had a bigger one. roh and poorly sharpened! But if I continue to sharpen for hockey, I will have to do it according to each person.

Query,
yes we had and we will have rubber mats. But everyone I sharpen wears blade guards and takes care with their sharpening.

Query
What do you use as a grindstone?

Kaitsu
I now understand that you can't help me and that I couldn't find any information on my question!
so I'm going to stay on these 2 wheels and I'll follow my instinct, look at the noise.
What is certain is that almost from the beginning (thanks to you and you here) I have been able to make edges that are smooth to the touch.

In any case thank you in the meantime to you 2

[AlbaNY]

Marc, that's great your rink is reopening, and congrats on becoming an official sharpener.
That's mostly what I am commenting to say, but...

I only sharpened on a Blackstone machine with their pink wheel.  It did a fine job although the skate tech I used had a higher quality wheel on his machines.  (He did use our Blackstone sometimes when I asked him for a sharpening at my rink instead of travelling to his place.)
I don't know what the Blackstone wheel specs are, but again, it was alright and I expect any wheel is okay if used skilfully.
ETA: I'm happy with an otherwise even sharpening as long as the metal is smoothly removed without that fish scale looking chatter mark or burning from someone making the passes too slowly.

Talking about RoH... as a figure skater I like 7/16ths best.  I did have 1/2" at first and then the infamous bench grinder hand held sharpenings for a while in Romania before switching to Pattern 99.   
I sharpened rentals at 1/2" and most hockey players wanted 1/2" also.  A few skaters requested 3/8, but only a few. 
In Germany the rinks only ask hockey or figure and not RoH preference.  I haven't trusted any techs or Zamboni guys here and do my own blades with a Profiler 3/8".  (Two of the rinks I go to use a Sparx machine.  Sorry, no way my blades are going in there!  A couple have machines I'd be comfortable with but am unsure about the guys.)  I miss doing sharpenings. 

[Query]

What do you use as a grindstone?

The figure skating Pro-Filer kit. No longer available new.
See https://www.afterness.com/skating/profiler.html

Had 2 abrasive cylinders ("stones"), whose radius was the ROH. The coarse grain cylinder had diamond grit. The fine grain cylinder had something else.

It was available for 5/16", 3/8" and 7/16" and 1/2" - but the 7/16" was actually 3/8"
(where " = US standard inch = 2.54 cm)

Each cylinder fit into a handle, with a gap to fit the blade at right angles. I added scotch tape to each side to make it snug, and stop scratching, & folded the tape over the top, so the sides wouldn't scratch.

There was a flat stone, which could be used to shape or remove the sharpening burr. Mine was missing, so I used a 5000 grit flat stone.

Kaitsu 3D printed something similar.

The hockey version contained 1 cylinder and one handle. It was coarse grained; the gap was too small for figure blades. Some are for sale on eBay. I once carefully widened the gap so it could fit my figure skating blades.

Another good but very old hand tool was the Berghman skate sharpener, available used on eBay. I love the design, but the stone was a natural stone (??) - very coarse grained and crumbly. Probably should be replaced by a better finer grain diamond grit cylindrical stone. ROH=1/2"

I have tried some other hand skate sharpening tools, but none of those I tried were good enough quality to give consistent results. But I think they may be some good ones for hockey skates.

As with any sharpener sharpener, the tricky part is keeping the edges even (I reverse the blade every few strokes), making a smooth grind (I lubricate with water; some use oil), maintaining the profile (good idea to trace or photocopy the blade at the start), and eventually you may want to trim the drag pick (the pick nearest the main part of the blade), when too much metal has been sharpened away, and if you aren't careful you will smooth out the difference between the spin rocker and the main rocker, too much, or round off the back. (Some JW blades have two spin rocker zones.) And many skaters want the transition between the main rocker and spin rocker moved to be under the ball of their foot, or 1 or so mm ahead of it.

[Qsior]

Marc, I use a 8mx ruby wheels for all skates, hockey, figure and rental, it is the most universal. I think that 88r is softer and should be pressed more gently during sharpening. It extends the time but gives a better surface.
Of course, the quality of the diamond is very important. I use tsm688, it has more carats, which means the diamond is bigger, it should last longer. I replace it after two seasons at most.
Remembering to turn it often so that the surface of the wheel is perfect

[marc]

Qsior,

yes, I think you're right: it seems to me that you need to press more gently with the 88r.
On the other hand, I can't see if the surface is better with the 88r, and do you think it's better with the 88r than the 8mx? (I'm looking for the best possible finish for competitors...)

very interesting your feedback on the diamond and I therefore think that I will listen to you by taking the tsm 688 and it is true that I do not turn the diamond often enough, what do you often call: every 10 pairs? 40 pairs?

are you a professional sharpener in Poland? or employed in an ice rink?
and thank you for your feedback

[Qsior]

Marc,

this is very important, I turn the diamond every 4, 5 pairs, you can feel it when the dressing of the wheel is not so smooth. sometimes I have to find the right position of the diamond by turning it a few times.

I have been sharpening skates on an indoor ice rink for 5 years now. mainly recreational skates but also professional and hockey skates. am I a professional? I try, I learn all the time, I have learned a lot here on this forum. Big thanks Kaitsu, AlbaNY, Query and others.

[marc]

Qsior
Encore merci pour ton retour d'expérience et je ferai plus attention à mon diamant.

Oui, ici on apprend énormément, c'est toujours rempli de petits détails ( comme toi tu m'en a dit un).
Comme je vois qu'il y a pas longtemps que tu dois être ici, je te conseille de remonter les sujets de conversation et de lire et relire quelques posts...

Oui kaitsu est très précis dans l'affûtage et les explications, et tout ce que tu as cité aussi entre autre nous aident beaucoup.
Sans oublier la chaîne youtube 'Annick's'...