Blackstone Flat-Bottom V Thread

[jcp2 2]

I think that the bite angle would be the same, but the depth of the fangs would be deeper on a wider blade such as a goalie blade, because the width of the flat part is fixed from the geometry of how the spinner shapes the grinding wheel. Maybe shallower fangs allow a quicker release and slide when there is a lot of pressure on the edge?

[Law Goalie 147]

That's what I don't get. With the blade-width as a constant (.110), widening the flat-bottom sharpens bite-angle; deepening the flat-bottom sharpens bite-angle; hence 100/75 feels 'sharper' than 100/50, and 90/75, and 90/50, and so on. Widening the blade itself, while keeping the same flat-bottom width and depth as constants (100/75 for argument's sake), would appear to significantly DECREASE the bite-angle. Understanding that I could be way, way off-base here, it seems that keeping the same FBV shape on a wider blade has exactly the opposite effect of keeping the same ROH on a wider blade.

My head hurts. I'm going back to Aristophanes, where everything makes sense...

edit: I think I may have misunderstood you, jcp. By 'deeper', you meant that the fangs would have a longer hypotenuse (ie. inside of the edge) on a wider blade with the same shape. This is certainly true. That being said, the actual depth and width would remain constants; the angle itself would appear to be shallower, but with a longer surface on the inside of the blade on which to work, as you observe.

I'm just not sure how this will work in practise.

Edited November 3, 2009 by Law Goalie

[ktang 34]

What does a 40/80 profile mean? (on Gonchar's 1" hollow)

[Law Goalie 147]

I believe that's a CAG profile.

I have the same profile as Brent Johnson on my player skates (65/130), which is funny because it was total trial-and-error on my part. The shop called CAG because they didn't know what hell to do with somebody who wanted a goalie profile on player skate, and the response was utterly unhelpful. The Pens' EQM must have figured it out for him.

Edited November 3, 2009 by Law Goalie

[jcp2 2]

That's what I don't get. With the blade-width as a constant (.110), widening the flat-bottom sharpens bite-angle; deepening the flat-bottom sharpens bite-angle; hence 100/75 feels 'sharper' than 100/50, and 90/75, and 90/50, and so on. Widening the blade itself, while keeping the same flat-bottom width and depth as constants (100/75 for argument's sake), would appear to significantly DECREASE the bite-angle.

Are you talking about using the same spinner that is rated at 100/50 or whatever for a player blade? I think that the 100/50 or whatever rating works only with the player blade width. The spinner has the cross section of a trapezoid so as to dress the wheel in the appropriate FBV profile. When applied to the player blade, the flat part of the sharpening as well as the bite angle of the fangs is defined by the spinner. The depth of the fangs is defined by the width of the blade. As player blades are more or less pretty close to each other brand to brand, Blackstone can give a fixed rating for each spinner.

Think of the reverse situation, where Blackstone puts out a spinner with a really wide flat spot, designed specifically for wider goalie blades. When applied to a narrower player blade, it might be the case that all that happens is a speed skate sharpening, with no hollow and no fangs at all.

The other end of the spectrum would be a super-V profile, with no flat spot at all. The bite angle would always be the same regardless of blade width, but the depth of the fangs would be vary depending on the width of the blade.

[Law Goalie 147]

I'm pretty sure JR said that he had put shapes into goalie blades with the same spinners. Guys have discussed it in the goalie forum, too, and their shops don't seem to have a different set of spinners.

I mean, either way, the spinner is a trapzoid that's going to cut a flat-bottom 100- or 90-thousandths wide and however deep, no matter the width of the blade.

Your two extreme cases make perfect sense, but the V-profile is a little misleading, since it would effectively be a 0/75 FBV, throwing out one of the two variables. That's why it would create the same angle on blades of whatever width, I think. If you cut a V into the middle of a rectangle, no matter the size, the angles remain constant.

Ah, but I think I see what you're saying, now.

If you cut a trapezoid into a rectangle wider than it was made for, you end up with this:

_

|_/ \_| ----- as opposed to this, on the normal width:

_

|/ \|

There would be two small flat spots on either side of the flat-bottom V, instead of two fangs to dig into the ice.

Yet I don't think that's what is going on, in practise, or no goalie would be able to skate on FBV currently. If you start with the edges of the blades as your reference points (rather than the middle of the blade, where the imaginary V would come together), and cut from those edges a trapezoid with a flat-top of X width and Y-depth in the middle, you end up with two the FBV fangs, but a shallower angle relative to the edges of the blades.

Edited November 3, 2009 by Law Goalie

[Hockeyman11385 1]

I think what he is saying is that the flat spot will be deeper with a wider blade, not that you would have two flat "fangs". With this the fangs will be deeper resulting in more bite.

\______/ = Wheel Shape

.\_____/

..\____/

...\___/

\_______/ = Goalie Steel

.\_/.....\_/

..\/.......\/

..\_____/ = Player Steel

...\/.....\/

A wider blade will go deeper into the wheel resulting in longer fangs, which leads to more bite.

(I apologize for all of the periods and underscores, it was the only way I could get everything to line up.)

Edited November 3, 2009 by Hockeyman11385

[jcp2 2]

That's what I'm saying, with the assumption that the spinner and dressed wheel profile is significantly wider than the player blade and goalie blade width.

[Jarick 5]

Wow, I thought NHL'ers typically used shallow hollows...

Is there a big difference between 90/75 and 100/50? I'm thinking about trying something with a bit more bite.

[jcp2 2]

I used to skate on 5/8ths. I tried 90/75 and 100/50 and liked 100/50 better, even though I don't like 1/2.

[Law Goalie 147]

I guess where I'm getting confused is that I *had* thought that (somehow) the width AND depth of the flat were being controlled independently - which of course makes no sense given the physics of the spinner.

Thanks to the diagrams and repeated explanation, I think I get it now. The spinner is a trapezoid in profile with a flat of X width (90, 100, etc.) at its peak, and sides sloping at angle Theta. The sharpener can 'push' this flat and those angled sides a certain distance into the blade (75, 50, etc.), creating Y depth. However, these depths are calculated based on a constant blade-width of ~.110"; thus, on a wider blade, the sharpener effectively has to push that flat of X width deeper into the blade in order to make the sides slope all the way to the edge of the wider blade. So, in the end, FBV does have the same effect as ROH on a wider blade: the flat and bite-angle remain constant, but the depth increases as the shape (whether trapezoid or circle) is pushed further into the blade, creating taller edges.

So, in other words, goalies should generally stick to X/50 shapes, since their sides are going to be deeper anyway, unless they really want to be on the rails.

Cheers guys - I think I've got a handle on this: 100/50 for me, and a possible hold-out for 110/50 or whatever the new shape turns out to be. This also tracks nicely with the estimations that 100/50 bites like 1/2-5/8", given the traditional 1/8" increase for the same hollow on goalie skates. All is right and well in the universe.

Edited November 3, 2009 by Law Goalie

[Jordan 13]

What does a 40/80 profile mean? (on Gonchar's 1" hollow)

That is a CAG profile, as law goalie pointed out.

The numbers work as follows:

The second number (in this case "80") is the total length in millimeters on the blade that contact the ice when gliding or standing...or the mid-section of the blade.

The first number (in this case "40") is the number of millimeters of that working area are in front of the mid-point of the blade.

[freestyla 0]

I'm sorry I'm sure this has been asked but roughly what would 3/8 and 7/16 translate to? I'm newer to this, tried to read as much as I could on Blackstone site and this thread.

Edited November 3, 2009 by freestyla

[jcp2 2]

I guess where I'm getting confused is that I *had* thought that (somehow) the width AND depth of the flat were being controlled independently - which of course makes no sense given the physics of the spinner.

Thanks to the diagrams and repeated explanation, I think I get it now. The spinner is a trapezoid in profile with a flat of X width (90, 100, etc.) at its peak, and sides sloping at angle Theta. The sharpener can 'push' this flat and those angled sides a certain distance into the blade (75, 50, etc.), creating Y depth. However, these depths are calculated based on a constant blade-width of ~.110"; thus, on a wider blade, the sharpener effectively has to push that flat of X width deeper into the blade in order to make the sides slope all the way to the edge of the wider blade. So, in the end, FBV does have the same effect as ROH on a wider blade: the flat and bite-angle remain constant, but the depth increases as the shape (whether trapezoid or circle) is pushed further into the blade, creating taller edges.

So, in other words, goalies should generally stick to X/50 shapes, since their sides are going to be deeper anyway, unless they really want to be on the rails.

Cheers guys - I think I've got a handle on this: 100/50 for me, and a possible hold-out for 110/50 or whatever the new shape turns out to be. This also tracks nicely with the estimations that 100/50 bites like 1/2-5/8", given the traditional 1/8" increase for the same hollow on goalie skates. All is right and well in the universe.

Glad that we were able to use Euclid to balance Aristophanes.

[Law Goalie 147]

Yeah... I was getting close to Pythagorean numerology there for a minute... senex mathematicus.

Edited November 3, 2009 by Law Goalie

[jcp2 2]

"Goalie - the thinking man's position"

[K9 Unit 1]

I'm sorry I'm sure this has been asked but roughly what would 3/8 and 7/16 translate to? I'm newer to this, tried to read as much as I could on Blackstone site and this thread.

100/75 fbv = 3/8" roh

100/50 fbv = 1/2" roh

90/75 fbv = 5/8" roh

90/50 fbv = 3/4" roh

i think thats the only choices so far retail wise, i believe pro's can get custom spinners done

Edited November 3, 2009 by K9 Unit

[Law Goalie 147]

"Goalie - the thinking man's position"

If it weren't for the concussions, I'd be able to agree with you. :(

There are times I can't tell my ass from my elbow; so I spend all day, like Rodin's Thinker, sitting on my elbow until I figure it out.

[sarmalidu 1]

Keep in mind that the amount of bite you get relates in part to how much you weigh. So, heavier fellows will tend to run with a larger radius (less bite) than small guys. Being that most NHL players tend to be, say 190+ lbs with excellent edge control, it's not too surprising that their hollows would trend towards 1/2+.

[vek 0]

I just had a terrible skate tonight on a fresh 90/75. The outside edges of my blades were completely washing out unless my full weight was put on them. Unfortunately jammed my knee pretty badly falling into the boards as a result.

Its strange, because I've had decent success on that cut before... perhaps this bad performance was due to the harder ice. I've tried 100/75, and it was far too deep a hollow.

I don't believe my LHS has a 100/50, so I'm going back to a 1/2 roh.

[JR Boucicaut 3759]

Or a bad sharpening?

[vek 0]

I suppose its possible, but the reason I got the fresh sharpening is because I felt the same washout/"floatiness" on my last game, (but nothing as bad as this), and was losing confidence in the edges being there when i needed them in low speed/low bite angle movements.

It'll be a good experiment to try the old 1/2 roh, and see if I can feel a major difference in stability (and reduced glide)

[JR Boucicaut 3759]

But why would it get worse from a fresh sharpening? It shouldn't.

I hear ya on the rest.

[vek 0]

Yeah, ; I was attributing it to the ice getting progressively harder over the last few weeks. The rink was an icebox tonight. Although I'm suprised that it (the ice temp) could have such a dramatic difference; perhaps there's other factors, as you mention.

[VakarLajos 5]

the fact that the "washout" was only on one edge makes me think it was a bad sharpening. could be wrong though.