Blackstone Flat-Bottom V Thread

[jagged 0]

For what it's worth, I have access to an atom-scale profilometer and got profiles for 1/2" and 100/50 cuts made with mini-spinners on an X-01. I thought I had a 90/75 spinner but can't find it. Can try to compare to other hollows.

ARGH, I'm reposting the image due to some conversion errors between angstroms, microns, inches and mils. I ended up doing it the old fashioned way with pencil, ruler, and calculator. The dimensions are more surprising overall than it was the first time around.

http://s20.postimage.org/pwus1ifnx/hollows.jpg

The FBV 100/50 is actually only about 0.082" across the flat. A stylus tip radius of 9 mils would account for this, however the stylus radius is only 1mil. The flat also isn't very flat. It's not as deep as circular hollow which is the intent. The depth for a 0.114" skate blade would be 0.93mil, which is a bit more than the 0.50. If I had to put a number on the spinner, and accounting for a finite stylus radius, I'd guess my 100/50 is more like an 85/85, and as always the second number will change with a thinner/wider skate blade.

The 1/2" spinner has a hollow depth of 2.6mil. If my calculations are right, a 1/2" r.o.h. should be 3.3 mils deep. The 2.6mil depth, assuming it's circular is more like a 5/8" r.o.h. That's surprising, I would have guessed the spinner would have a smaller hollow. If the spinner started with a 1/2" hollow, and diamond dust was added to it, that should make the radius slightly smaller. Maybe that's accounted for a little bit (or too much).

The Wissota 1/2" hollow is almost identical in shape however overall it's bit smoother. Surprisingly the hollow depth is only 2.3 mil, which (again if my calculations are right), is more like a 0.7" r.o.h. Maybe the sticker wasn't placed on the diamond dresser exactly where it needed to be.

Edited February 5, 2013 by jagged
Convert your PDF to .jpg and host it on a photo hosting site.

[AfftonDad 88]

For what it's worth, I have access to an atom-scale profilometer and got profiles for 1/2" and 100/50 cuts made with mini-spinners on an X-01. I thought I had a 90/75 spinner but can't find it. Can try to compare to other hollows.

thanks for the conversion JR, here's a direct link to the image http://s20.postimage.org/74607x0i5/profiles_1.jpg

It does show pretty much what you'd expect, but actual results are always interesting to see. The depth of cut assuming a 0.114" thick skate blade really is close to 50/10000 and the width of the flat bottom is close to 100mils. The stylus of the profilometer does have some width to it (1-2 mils), so maybe the flat is 94 mils instead of 100 mils, but it's close. I'm surprised the flat is as rough as it is, but the cross sectional area is smaller than for the 1/2" which is the intended purpose.

Wow! What a great tool to have around. I want one of those! Have you put it on a wheel and a sharpened blade to see what they look like? I'd also be curious to see how a mini-spinner compares to a full size spinner.

Another thing you should do is get the profile of the spinner when it is new and check every N number of sharpens so you (we) can get an idea of how these things degrade over time.

As far as the roughness, I would expect it to be rough as you pick up the individual diamond particles (just looking at the spinners you can see texture). I'm am surprised it's not flatter. Is this a brand new spinner?

Edited January 31, 2013 by AfftonDad

[AfftonDad 88]

I'd also be curious to see what multiple cross sections of the spinner averaged together would look like. And more importantly, what individual and averaged cross sections of a spinner sharpened blade look like.

[Law Goalie 147]

Speaking of my earlier issues, I recently had a *terrific* set of FBV sharpenings (100/50) at the National Sports at 1770 Dundas East in Mississauga, at the hands of Paul D. and the recommendation of our own pmurphy17 -- with ZERO guff about FBV and goalie skates. If you're looking for a good FBV sharpening near Toronto at a very reasonable rate, check them out.

[jagged 0]

I had to repost the image above due to some calculation errors.

http://s20.postimage.org/pwus1ifnx/hollows.jpg

To answer your questions AftonDad, I essentially looked at a skate blade, although it wasn't a skate blade. Basically, I dressed the wheel, touched a block of stainless steel that's wider than a skate blade, up to the wheel. Then profiled the hollow in the ss. The profilometer doesn't like large drop-offs, plus I wouldn't be able to get a skate blade vertically under the stylus.

There wouldn't be much point in profiling the wheel itself because that's way too rough and only looking at one small cross section isn't what happens. The resulting finish is due to the entire wheel passing over the blade, so it's a cumulation or summation of the entire grinding wheel surface.

I did look at a couple different sections ground with the same dressing, and they all looked pretty much the same.

The 100/50 spinner was used to dress a wheel maybe 10 times.

On the 1/2 spinner, it's dressed many more, probably 40 times.

I can look at just about any profile like this, I just don't have access to just about any profile.

Edited February 5, 2013 by jagged

[oldtrainerguy28 478]

Speaking of my earlier issues, I recently had a *terrific* set of FBV sharpenings (100/50) at the National Sports at 1770 Dundas East in Mississauga, at the hands of Paul D. and the recommendation of our own pmurphy17 -- with ZERO guff about FBV and goalie skates. If you're looking for a good FBV sharpening near Toronto at a very reasonable rate, check them out.

wonder where he got that idea from?

[AfftonDad 88]

There wouldn't be much point in profiling the wheel itself because that's way too rough and only looking at one small cross section isn't what happens. The resulting finish is due to the entire wheel passing over the blade, so it's a cumulation or summation of the entire grinding wheel surface.

I did look at a couple different sections ground with the same dressing, and they all looked pretty much the same.

OK... I thought what you were profiling was the spinner itself. I was hoping that the large drop off in the flat part of the FBV was a localized "pit" in the spinner that would be "averaged out" as the spinner spun on the wheel and then subsequently as the wheel spun on the blade and as the passes are made. I was hopping that the result on the blade "on average" was much flatter than the profile you showed. It sounds like you already looked into that and found that the "pit" actually is a "groove" that runs the entire length of the blade.

It makes sense that a traditional diamond dresser would be smoother because it is the exact same single point that passes through every spot on the wheel as opposed to a textured surface applying it's texture to the wheel.

Edited February 6, 2013 by AfftonDad

[Monty22 832]

Looks great. If my 8 month old shows ANY interest in skating that will be all the justification I need to pick one up.

So I put this off for as long as possible, and with my son and I both skating a ton between mites, our backyard rink and my men's team I bit the bullet and picked up a very lightly used X01. I saw mention of using mineral spirts to clean the spinners when needed- will this have any adverse effect on the bearing in the spinner? Also, is there a template or materials list for putting together the PVC vaccum attachment?

[JR Boucicaut 3797]

Just oil the bearing after you're done.

[Monty22 832]

Mobil 1 synthetic ok, or is there a specific oil I should be using?

[JR Boucicaut 3797]

Any light oil will do. You have guns, the oil you use should be suitable.

[Monty22 832]

Mobil 1 it is then. Thanks JR.

[IPv6Freely 2092]

JR, what was the name of the Blackstone guy at WF?

[Chadd 916]

Mark

[IPv6Freely 2092]

Thanks!

[Mikej411 2]

A couple questions...

I've read that since this is fairly new, you need to find someone who knows what they're doing. Is this true and does anyone know of a place in Pittsburgh PA that does FBV and does it right?

Out of the people who converted, do the majority stay with the FBV or go back to ROH?

Is it true that it's easier to lose an edge and when it happens, you lose most of it?

I skate on 7/16 to 1/2, so would 100/50 be best for me?

Edited February 19, 2013 by Mikej411

[Chadd 916]

I believe Total Hockey is doing FBV at the store in Robinson, Very few of my guys liked 100/50, most prefer 95/75

A couple questions...

I've read that since this is fairly new, you need to find someone who knows what they're doing. Is this true and does anyone know of a place in Pittsburgh PA that does FBV and does it right?

Out of the people who converted, do the majority stay with the FBV or go back to ROH?

Is it true that it's easier to lose an edge and when it happens, you lose most of it?

I skate on 7/16 to 1/2, so would 100/50 be best for me?

[Vulcan7905 88]

A couple questions...

I've read that since this is fairly new, you need to find someone who knows what they're doing. Is this true and does anyone know of a place in Pittsburgh PA that does FBV and does it right?

Out of the people who converted, do the majority stay with the FBV or go back to ROH?

Is it true that it's easier to lose an edge and when it happens, you lose most of it?

I skate on 7/16 to 1/2, so would 100/50 be best for me?

I converted and I will never go back to ROH. I have maybe lost an edge a couple of times and I would blame that mostly on my self for poor control.

[Mikej411 2]

I believe Total Hockey is doing FBV at the store in Robinson, Very few of my guys liked 100/50, most prefer 95/75

I just got 100/50 on mine last night. Why did they not like 100/50, and what is 95/75? The chart doesn't list 95/75

http://www.blackstonesport.com/technology.cfm

[mnpucker 33]

Converted and will never go back. Obviously owning a X02 makes it easy for me. Curious about why people did not like 100/50 as well. It happens to be preferred for everyone I know.

[AfftonDad 88]

I just got 100/50 on mine last night. Why did they not like 100/50, and what is 95/75? The chart doesn't list 95/75

http://www.blackstonesport.com/technology.cfm

This chart does...

http://www.blackstonesport.com/FBV_Comparison_Chart.pdf

They started with just the four. Then they added more. I'm pretty sure the shops around here just offer the original four. I have 95-75 at home though and that is what most of the people I sharpen for prefer (admittedly though, if they don't know what they should use, that is the one I start them on).

[wrangler 157]

I started with 100/75, then went to 100/50. I might try the next step, just to see, but right now I'm doing fine with what I've got.

[Mikej411 2]

This chart does...

http://www.blackstonesport.com/FBV_Comparison_Chart.pdf

They started with just the four. Then they added more. I'm pretty sure the shops around here just offer the original four. I have 95-75 at home though and that is what most of the people I sharpen for prefer (admittedly though, if they don't know what they should use, that is the one I start them on).

So according to that chart., the difference between 100/50 and 95/75 can be determined. 100/50 is not only faster, but it has more grip. The only thing 95/75 has over 100/50 is that it has more edge height.

[AfftonDad 88]

I think that you just have to try them and see which one you like best. Because there is interplay between the variables, I actually prefer to think of the 50 edge depth ones and the 75 edge depth ones as two distinct scales. For example, I think if they made them and they were free, I would like to have spinners of...

88-50, 90-50, 92-50, 94-50, 96-50, 98-50, 100-50

and

88-75, 90-75, 92-75, 94-75, 96-75, 98-75, 100-75

I would then tell a person to pick an edge depth (50 or 75) and then tweak within that scale. Since they aren't free though, that would of course be cost prohibitive.

[Chadd 916]

I just got 100/50 on mine last night. Why did they not like 100/50, and what is 95/75? The chart doesn't list 95/75

http://www.blackstonesport.com/technology.cfm

The feedback I got was that 95/75 had more bite and that was what they preferred about it.