Blackstone Flat-Bottom V Thread

[GunRunner 28]

Quick question regarding new steel. I thought I read somewhere that for new steel, just sharpen them twice and that is good. I have an X-01 and I'm not getting them profiled so I will sharpen them for the first time on my machine. Is there anything special I should do? I have searched high and low for the answer and I can't seem to find it. Thanks

[Davetronz 109]

No different than previously sharpened steel. You will have to do more passes to get rid of any unevenness or rounding from the factory when they cut the steel. Aside from that, nothing unique. Some cheaper steel may have a "coating" or protectant from the factory which may feel a bit different the first few passes - but that's typically on fairly low quality skates.

[GunRunner 28]

No different than previously sharpened steel. You will have to do more passes to get rid of any unevenness or rounding from the factory when they cut the steel. Aside from that, nothing unique. Some cheaper steel may have a "coating" or protectant from the factory which may feel a bit different the first few passes - but that's typically on fairly low quality skates.

Thank you very much, that's what I was thinking but wanted to make sure. This is LS2 steel so at least I won't have to deal with inferior steel. Thanks again.

[x-track 8]

hi ...can somebody please tell me the exact size of the shaft thread where the grinding wheel sits on ?? thx

[Davetronz 109]

For which machine? Personal? Professional?

[x-track 8]

sorry , I opened a seperate thread with x-02 in the header , but apparently it was merged into this one !!

[notquitedeadyet 13]

1/2" -20 UNF

Left hand thread.

Edited April 3, 2015 by notquitedeadyet

[x-track 8]

thank you!

.....none of the specialized hardware stores in our country had this in stock nor could get it,...

getting a handmade locknut was out of question as I needed it today ....luckily I remembered that the gas installation of my RV uses some left hand thread inch size....and I could cut off a matching nut from a gas installation hose .

[AfftonDad 88]

Anyone have any experience replacing the motor on an X-01 and can comment on how hard it is? After 5 or 6 years of much harder use than it was spec'd at, my X-01 motor is finally giving up the ghost.

Edited May 15, 2015 by AfftonDad

[AfftonDad 88]

Anyone have any experience replacing the motor on an X-01 and can comment on how hard it is? After 5 or 6 years of much harder use than it was spec'd at, my X-01 motor is finally giving up the ghost.

Update: I just replace my X-01 motor. Wasn't bad at all. Hardest part was getting the hex head screws broken free.

[x-track 8]

to those of you owning a x-01 or x 02 ...if you grab the grinding wheel and move it up and down and left and right ....do you feel a little play in the shaft ??

also , if you install the grinding wheel on the shaft ...does it sit tight or does it have freeplay as well ???

mine ( x 02) has so much freeplay that when I tighten the nut it comes out of center and vibrates ...this sucks as you will never get a perfect finish , no matter how good a sharpener you are .....thx

affton dad ...i sent you a pm !!

[Davetronz 109]

That doesn't sound right at all x-track... I'd email blackstone and see what they have to say.

[x-track 8]

that's what I already did ...but they questioned my ability to judge and measure " out of round " and requested photos and videos ..which i sent ...but no reaction .

all of the 6 grinding wheels I have got so much clearance on the shaft that I can stick a feeler gauge in there

[Chadd 916]

I had one bad wheel and it was dangerously off balance. The funny thing was that it was at Winterfest and someone from Blackstone was there to see it first hand.

[Davetronz 109]

I had one bad wheel and it was dangerously off balance. The funny thing was that it was at Winterfest and someone from Blackstone was there to see it first hand.

Never had an off-balance Blackstone wheel, but had a bunch from another company. Watch them wobble! They wouldn't even sit flat on a machined surface. I guess quality control is a thing of the past for some companies.

Have had really good luck with my authentic Blackstone wheels.

Does anyone have any reviews of the Black Walnut 8" wheel for the pro-series? Someone was talking them up to me.

[GunRunner 28]

On my X-01, I've used both the orange wheel that came with the machine and now I'm using the ruby wheel. All of the wheels have runout on them and when turned my hand, you can see it wobble. Obviously once the machine spins the wheel up to its max RPM, you can't see the wobble. I'm pretty anal and feel from a machining standpoint, the wheels should be as close to true as possible and the runout that the machine has, bothers me. With that being said, the machine yields a nice grind and I am able to get even edges so I guess I have to just get over some things.

[fbvnyc 12]

I've also noticed movement on the arbor. It's actually quite large as I used a digital caliper on it.

Same boat as GunRunner in that it still does yeild a nice grind and consistent edges. I guess given the rpm and wheel diameter the wobble is negligible at full speed.

[All Flash 49]

Agreed ... I have the same issue as Gun and fbvnyc on my X02. The top bearing is hard to get on and then it is loose once it is all the way up. Taper isn't the word I would choose but after about and inch or so of sliding it on, which is tough, it moves freely after that until I have it in place. I also get the wobble which always worries me. But alas just as NYC stated some things must be let to slide.

[Mimizk 114]

I've been understanding as that wider bottom width is better for glide though, is the sentence of this page about Base Width correct?

This page says that narrow bottom width decrease drag with the ice so able to get better glide. If my memory is correct, it has been said as that wider bottom width allow us better glide.

[AfftonDad 88]

I've been understanding as that wider bottom width is better for glide though, is the sentence of this page about Base Width correct?

This page says that narrow bottom width decrease drag with the ice so able to get better glide. If my memory is correct, it has been said as that wider bottom width allow us better glide.

This has always been a source of confusion with Flat Bottom V. There are 3 things that are all intertwined. Flat Bottom Width, Edge Depth and Edge Angle. Edge Angle is determined by Flat Bottom Width and Edge Depth. Edge Depth is determined by Flat Bottom Width and Edge Angle. Edge Angle is determined by Flat Bottom Width and Edge Depth. Each one of those three things therefore has a "glide factor" and a "bite factor". For example as you make the flat bottom bigger (for the sake of this discussion, while keeping edge depth constant), you would get better glide due to the fact that there is a bigger flat (more surface area) for you to glide on. However, the increase in width also causes the edge angle to become more steep (sharper) which causes it to more easily cut into the ice. This decreases the glide factor and increase the bite factor. Because of the intertwining of the components, it is difficult to make "generalized" statements about which FBV has more glide than another. You should do yourself a favor and hold one of the things constant (I generally hold my edge depth constant at 75) and then tweak the other number until you find one you like. If you can't find one you like at that edge depth then try holding constant at one of the other edge depths and start tweaking. Because of this interdepdence, there is overlap in the FBV settings and you can get somewhat similar results in different FBV settings. For people who are familiar with bicycle gearing, it is analogous to how there is overlap in the gears and you can get very similar gear-inches in several different combinations of front and rear derailleur positions.

[jimmy 194]

Because of the "overlap" it is nearly impossible to tell the difference between many of the settings. In addition, us mere mortals cannot tell any difference in speed between any of the settings, it's so small it's indistinguishable.

[Mimizk 114]

This has always been a source of confusion with Flat Bottom V. There are 3 things that are all intertwined. Flat Bottom Width, Edge Depth and Edge Angle. Edge Angle is determined by Flat Bottom Width and Edge Depth. Edge Depth is determined by Flat Bottom Width and Edge Angle. Edge Angle is determined by Flat Bottom Width and Edge Depth. Each one of those three things therefore has a "glide factor" and a "bite factor". For example as you make the flat bottom bigger (for the sake of this discussion, while keeping edge depth constant), you would get better glide due to the fact that there is a bigger flat (more surface area) for you to glide on. However, the increase in width also causes the edge angle to become more steep (sharper) which causes it to more easily cut into the ice. This decreases the glide factor and increase the bite factor. Because of the intertwining of the components, it is difficult to make "generalized" statements about which FBV has more glide than another. You should do yourself a favor and hold one of the things constant (I generally hold my edge depth constant at 75) and then tweak the other number until you find one you like. If you can't find one you like at that edge depth then try holding constant at one of the other edge depths and start tweaking. Because of this interdepdence, there is overlap in the FBV settings and you can get somewhat similar results in different FBV settings. For people who are familiar with bicycle gearing, it is analogous to how there is overlap in the gears and you can get very similar gear-inches in several different combinations of front and rear derailleur positions.

Afftondad, also I've read all of your past post on this thread and it was very useful and helpful sentences. I've been understood your logic.

Because so, I wanted to say on my former post that this page says different thing from we often discussing. This page explain as narrow bottom width=touching smaller flat area with the ice would create less friction so we can get more glide. This explanation is not came from just "confused" as Afftondad said. Its saying is different radically from we are thinking.

[Mimizk 114]

I'm considering the way to get smooth surface with FBV.

A few months ago I talked with a president of a sharpening equipment company. He said he doesn't like spinner type dresser because surface of grinding stone would be roughened. So he doesn't like FBV and BFD either because flat bottom sharpening don't have the way to dress without spinner.

Today I went to local shop and got sharpening with FBV 90/50 spinner. Long time I had used BFD X7 for my skates but I felt a need to change because ice condition have also changed to soft by summer arrival.

I checked edges after sharpening. Definitely it was roughened. Compare both spinner of FBV and BFD, FBV spinner is smaller and rougher than BFD's. Also I used oil pass finish for this time sharpening though, I felt some roughen from finished edge surface.

[jimmy 194]

I'm considering the way to get smooth surface with FBV.

A few months ago I talked with a president of a sharpening equipment company. He said he doesn't like spinner type dresser because surface of grinding stone would be roughened. So he doesn't like FBV and BFD either because flat bottom sharpening don't have the way to dress without spinner.

Today I went to local shop and got sharpening with FBV 90/50 spinner. Long time I had used BFD X7 for my skates but I felt a need to change because ice condition have also changed to soft by summer arrival.

I checked edges after sharpening. Definitely it was roughened. Compare both spinner of FBV and BFD, FBV spinner is smaller and rougher than BFD's. Also I used oil pass finish for this time sharpening though, I felt some roughen from finished edge surface.

Spinners produce a beautiful smooth finish. If it's not smooth, it's the sharpener, not the spinner.

[AfftonDad 88]

Afftondad, also I've read all of your past post on this thread and it was very useful and helpful sentences. I've been understood your logic.

Because so, I wanted to say on my former post that this page says different thing from we often discussing. This page explain as narrow bottom width=touching smaller flat area with the ice would create less friction so we can get more glide. This explanation is not came from just "confused" as Afftondad said. Its saying is different radically from we are thinking.

I would agree with you that the following statement they made on their page...

BASE WIDTHS: Shorter widths allow less steel on the ice for increased glide; longer widths allow more for better traction.

doesn't include 100% of the details of what is going on and therefore can sound a little non-intuitive.

If you have ever talked to the guys at Blackstone, they will sometimes admit to you that they have to "dumb things down" for marketing purposes. They have to keep things as simple as possible so that the majority of people can have a fair understanding of the LARGEST contributors to the way FBV feels. They are faced with trying to respond to a very broad group of people, many of whom demand a SIMPLE answer to which FBV is "sharper" than which other FBVs AND how each one compares to various ROH settings. I think if you look at that page in context, the message they are tyring to convey becomes clearer.

The first thing they say (I'm paraphrasing) is FBV is specified with two numbers... Flat Bottom Width and Edge Depth. They then try to explain what those two numbers mean within the context of the FBV "setting number." They explain 1) The narrower the flat width number the more glide and 2) the higher the edge depth the more bite.

Now the statement 1 above is the one you have problems with and I understand why and I agree with you to some extent. Perhaps a way to make the statement closer to 100% correct would be to say the following (this would of course be too confusing for a marketing piece though):

If you assume edge depth to remain constant and blade width to remain constant then you can assume the following:

1. Narrowing the flat bottom width DECREASES glide (in the area of the flat bottom, due to having less surface area to glide on)
2. Narrowing the flat bottom width INCREASES glide (across the ENTIRE cross section of the blade, due to lessening the edge angle and making the ENTIRE cross section of the blade more flat, therefore increasing glide across the ENTIRE cross section of the blade)
3. The amount of glide gained by 2 above is much greater than the amount of glide lost by 1 above.

There is a "duality" in each one of the THREE factors (Edge Depth, Edge Angle, and Flat Width). All three of these things have bite/glide interdependencies and because of the fixed width of the blade, interdependencies between each other. That is why the only real way to arrive at what you like is to go to someone who knows how to correctly sharpen (and can therefore REPEATABLY give you a real representation of the FBV you are asking for) and then through trial and error find what you like. Having said that, you should be able to reduce the number of trials if you hold one of the numbers constant. Since there are a lot more widths than depths, I would recommend holding the depth constant during the trials.

Murray Wilson of Blackstone once told me that they originally didn't even want to provide those FBV to ROH comparison charts OR the ORIGINAL FBV chart that went

90/50 90/75 100/50 100/75

<-Less Bite More Bite->

but the shops and customers pretty much demanded them. In my opinion the best the charts can do is to give you a rough idea of where to start. I would have rather they introduced FBV at a SINGLE depth (perhaps 75) and then the FBVs available could have been identified as 85, 87, 88, 100, 102, 104, 106, etc. That would have then been very easily understood. The higher the number, the more bite. Then down the road perhaps, some other depths could have been introduced if people were really clamoring for it.

EDIT: Actually, after all that I just re-read blackstones statement and I do think it is wrong... It seems backwards... it should probably either say:

BASE WIDTHS: Shorter widths allow less MORE steel on the ice for increased glide; longer widths allow more LESS for better traction.

OR

BASE WIDTHS: Shorter widths allow less steel on IN the ice for increased glide; longer widths allow more for better traction.

Edited August 7, 2015 by AfftonDad