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Wissota powered skate sharpener review

Started by Bill_S, November 04, 2019, 06:55:19 PM

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tstop4me

Here's what Wissota claims about their wheels (https://wissota.com/product/blue-wheel/):

"All Wissota grinding wheels are hand balanced and side finished to remove any wobble.  You can find wheels with different grinding properties than ours, but you will not find a better running wheel!"

Question:  Unless there are gross nonuniformities in either the flatness, thickness, or density of the wheel [which should be subject to good manufacturing control], wouldn't the dressing operation itself balance the wheel (i.e., make it axially symmetric about the rotational shaft)?

Bill_S

I suspect that the balance variability is just a factor of just how tight manufacturers can hold tolerances in a composite material like a grinding wheel.

To address your question about dressing, I'm certain that dressing will improve a wheel's balance if it is out-of-round, or doesn't fit perfectly on the shaft, but won't completely balance it. As a thought exercise, take the following illustration showing a perfectly static-balanced grinding wheel (blue) mounted onto a shaft (gray) with purposely exaggerated wheel I.D. vs. shaft O.D tolerances. The dashed red line shows the wheel periphery after dressing, and it makes the wheel O.D. concentric with the shaft.



Before dressing, the large amount of material at the periphery that is outside of the dressed wheel line (dashed red) contributes heavily to an unbalanced system. Dressing removes this lopsided distribution of material, but there is still the little bit of air space at the shaft on one side, and wheel material at the other side where it touches the shaft. This is much less important than any un-concentric wheel O.D. errors because the radius is much smaller, the mass mismatch is smaller, but at rapid rotations could still would contribute to a slightly unbalanced system.

It's beneficial to have a tight fit between shaft and grinding wheel to reduce this secondary imbalance. I noticed that the I.D. of the Wissota grinding wheels have a circular bushing to reduce slop in the fit with the shaft. See the photo below... [Click to enlarge]





Bill Schneider

Kaitsu

Quote from: Bill_S on December 19, 2021, 12:23:34 PM
I started the machine and watched the needle on the dial indicator for any cyclic displacement. It indicated no motion and the needle was dead steady.

I believe that I benefit from the large and heavy section cast iron table/motor clamp plus the hefty 1/2" diameter shaft. The dressing diamond and supporting structure is also motor-mounted which would be an advantage for not "dressing-in" any vibration-caused runout.

I fully agree that heavy mass and cast iron are good features to absorb vibrations. These are definitely good features even thought many hockey teams gives more value for more light portable machines.

What I disagree is that dial gauge would be good device to demonstrate vibrations. I tried that also in practice and needle was dead steady, just like in your video even there was clear vibrations on my machine.

Post modified as I did forget to add some disclaimers which are needed in certain countries.

Query

Quote from: Kaitsu on December 23, 2021, 09:54:20 AM
I prefer more old classic test where you put glass of water on top of the machine.

I'm sure that someone as careful as you would test for visible vibration first! :) Spilled water can destroy a sharpening machine. I know of a case where a leaky roof caused that.

The electrician I knew installed and maintained hundreds of sub pumps, and other pumps, powered by electric motors, on a University campus with a high enough water table to flood basements if pumps failed. While linking the pump and motor, he checked very carefully for seen, heard or felt vibration. He said poor mounting often destroyed bearings in a month. But 30 years after he figured out how to do it right, all the pumps he installed were still working. (Another issue he claimed could mess up bearings, if the coupling has an adjustable travel, each bearing should be in the center of its travel. He also said it was extremely important that the motor, if it doesn't have a sealed bearing, is lubricated correctly. He claimed too much grease can do just as much damage as too little. Also, if there is a Xerc fitting, make sure you know how to grease it properly. It isn't sufficient to pour grease on top of it. He claimed you should open the fitting for a minute and let the running motor squeeze the excess grease out, but a mechanic trainer told me that isn't optimal - each bearing is designed to be greased at the well calibrated  pressure the appropriate grease gun delivers.)

supersharp

Quote from: Bill_S on December 19, 2021, 03:18:22 PM
I suspect that the balance variability is just a factor of just how tight manufacturers can hold tolerances in a composite material like a grinding wheel.

To address your question about dressing, I'm certain that dressing will improve a wheel's balance if it is out-of-round, or doesn't fit perfectly on the shaft, but won't completely balance it. As a thought exercise, take the following illustration showing a perfectly static-balanced grinding wheel (blue) mounted onto a shaft (gray) with purposely exaggerated wheel I.D. vs. shaft O.D tolerances. The dashed red line shows the wheel periphery after dressing, and it makes the wheel O.D. concentric with the shaft.



Good image of the wheels, Bill, thanks!  And I agree, dressing an out-of-round wheel will change its balance, since you will be removing more material from some areas than others. 

Differences in what is most important probably vary with machine type.  I use the Incredible Edger, and here is what is working for me right now:


  • The wheel should be dressed first, then balanced.  I think the biggest source of imbalance is inconsistency in the abrasive material mix that is used to form the wheels, so the imbalance is more related to areas with different densities within the wheel.  There is no way to predict where they will be and they will be different on every wheel.  As the wheel wears down and loses diameter, you will eventually need to rebalance it.

    Regarding shaft fit on the wheel, that definitely needs to be addressed.  Adding a shim (DIY bushing, I suppose) to get as close of a fit to the spindle shaft as possible is recommended.  After installing the shim/bushing and doing an initial dressing of the wheel, you are ready to balance it.  I have found that it makes quite a big difference in surface finish to balance the wheels. 

    Since it is almost impossible to get a wheel onto the spindle that does not have at least some small amount of extra space in it, I have been marking my spindle with a Sharpie and lining it up with the "light side" mark on the wheel when I dress it (some wheels come pre-marked with a balance line that indicates the lighter side...or you can just mark the wheel anywhere and use it as a lineup point).  When I replace the balanced wheel, I line it up at the same place just in case there are tiny variations in the spindle that could affect vibration.  Probably not important, but it all adds up, and consistency in as many areas as possible has been helpful in revealing a difference (or not) when testing different techniques for improving the finish.

    I also hand-rotate the untightened wheel with the dressing diamond at the center of the wheel to try to re-align the wheel at the same center as before balancing, since having a big change in the center of the wheel is likely to affect the overall balance. 
This probably sounds like a lot of effort, but I have been very pleased with the improvements in surface finish that I am getting from balancing the wheels.  It is also much nicer when the machine hums along nicely with absolutely minimal vibration.  Once you balance the wheel and install it, you get quite a bit of use out of it before having to rebalance or replace the wheel, so it is effort well spent.

I have had balancing weights fly off the wheel on the Little Edger (cross grinder) while using it.  There is an immediate increase in noise and vibration.  If I hadn't been convinced before, I would be after experiencing this.   

Bill_S

It sounds like you have thought through the pitfalls with your procedure.

I took a look around the web for accelerometers today. There are some very inexpensive sensors available today. My circuit design chops have decayed enough that I probably won't do anything with that idea though.
Bill Schneider

supersharp

I got a lot of assistance from Kaitsu on getting the IE tuned up.  At this point, I have disassembled and reassembled almost every part of the machine. I replaced a spindle cartridge with worn out bearings, looking forward to dissecting it to see how bad the bearings look.  It would be good to get it rebuilt for use as a spare.

SkaterNomad

Machine arrived, got it set up.

Build Log:
-----------
Total: ~$2500 (upto $2800 if counting items already had)

Wisotta 911 Sharpener: ~ $2k
- 911 Skate Sharpener Package
    - 911 Machine
    - 3-D Three Dial Skate (Hockey) Holder
    - 1 80 Grit Pink Wheel
    - 1 Diamond Dresser
- Elite 3-D Universal Figure Skate Holder
- 911 FIGURE Skate Sharpener 100-Grit Blue Grinding Wheel Stone
- Wissota "Elite" Even Edge Checker

Sharpening Accessories:
- Radius Gauges: ebay/McMaster-Carr (7/16", 5/8", etc): Set 1, Set 2 (like Set 2 a little better)
- Toe Pick protector: Empire 3/4 in. Brass Stair Gauges (2-Pack) - Home Depot
- Steel ruler (1/10" or finer) - Home Depot
- Caliper, Digital - Home Depot

Workbench: ±$500
- Bench: Whalen Industrial Rack (Costco) - 77"W/24" D/72" H
- Plywood topper: 4x8 sheet - Home Depot
- C-Clamps Qty:4 - Home Depot
- Power strip with individual power switch - Amazon
- Light Bar - Costco
- Eye Goggles - Home Depot
- Dust Mask(s)
- Mini broom/sweep brush - Home Depot
- Dedicated Shop Vac - Home Depot
  - +Bungee Cords, 36" - Home Depot
- Bench stool, 21"-29" seat height - Costco
- Temperature gauge - Walmart (roughly floating F50-55)

=====

Observations:
- Wheel is bigger than expected (was thinking hockey puck, its closer to medium sized pizza)
- No unique label between skate holder types: Easy fix, printed label
- Edge checker is low fanfare (plastic bag), custom cardboard packaging might be +1
- Manual is loose leaf/stapled: a nice booklet/folder with laminated holders would be +1

Question: Can't seem to find 7/16" on diamond dresser, manually carve/mark? Caliper then mark? Idea for thin line marking/scribe tool?

Status:
Haven't used yet, turned on once or twice. Mostly set up space. Will be long time (source old blades) before have anything of hands on experience.

Images:
======
Prep:






Arrival:




Unpacked:




"Final"-ish setup:



Bill_S

Very nice. Glad that you have it all set up.

QuoteQuestion: Can't seem to find 7/16" on diamond dresser, manually carve/mark? Caliper then mark? Idea for thin line marking/scribe tool?

I just sight halfway between the 1/2 and 3/8" lines on the dresser. It's going to get as close as you can measure or feel while skating.

The diamond dresser shaft is hard enough that I couldn't scratch it with a typical workshop awl this morning. If you still want a mark, I'd just put a fine Sharpie mark on it using a small square for straightness. If you get it wrong, some rubbing alcohol will remove it so that you can try again. It won't be as fine as their engraved and paint-filled lines though, but it will serve. Still, just sighting halfway between existing marks is easy and accurate enough in practice.

Let us know how it goes when you get some practice blades. If you can get them already mounted to old boots, that would be ideal.  If not, you can still practice with blades-only, but that's not the typical case when sharpening. I actually prefer to guide the holder by the boots instead using the skate holder's plastic handles.

Be sure to use LIGHT pressure. Don't bear down on the wheel with a blade, and be sure to keep it moving without pauses when sharpening.
Bill Schneider

supersharp

Very exciting to get your equipment! 

I also use the Sharpie mark system for 7/16".  Since most of the people I sharpen for are trapped here in my isolated community, I think they benefit most from getting blades with a consistent radius rather than whether it is exactly 7/16". The Sharpie slowly fades so I renew it as needed. I also have a mark for 9/16".

Good advice from Bill on looking for practice skates that are a boot and blade combo. The first sharpening I did was on unmounted blades (discarded patch blades). It was a little disconcerting to make the switch to blades mounted to boots when I did the first pair that were "real" skates.  It's probably best to get some practice on both mounted and unmounted blades before you start working on anyone elses's blades.   

Consistent light pressure and and a slow, even speed...I haven't used the tabletop type of sharpener before, and I'm sure the feel is different, but I find that I get the most consistent speed on my machine when I have a little pressure between my hands, basically pressing my hands toward each other a little so both hands are connected and moving at the same speed.

Have fun and get ready to learn a whole bunch of fascinating things about blades and grinding.  It gives you a whole new appreciation for how skating works.



Query

Quote from: supersharp on December 25, 2021, 05:20:25 PM
Good advice from Bill on looking for practice skates that are a boot and blade combo. The first sharpening I did was on unmounted blades (discarded patch blades). It was a little disconcerting to make the switch to blades mounted to boots when I did the first pair that were "real" skates.  It's probably best to get some practice on both mounted and unmounted blades before you start working on anyone elses's blades.   

If you want practice skates, many skating rinks throw away rental skates (usually with blades on them) when the boots wear out. If you catch them at the right time, they may give them away, or sell them cheap. Barring that, Salvation Army and other thrift stores sometimes sell used skates cheap. (AFAIK, Salvation Army doesn't bargain on price, but thrift stores and pawn shops often do.) Rental skate blades have softer steel than most high end blades do (though a few high end hockey blades use soft steel, on the theory that it can temporally take a sharper edge - I don't understand why), and different shapes. But it's still a cheap way to learn from your mistakes.

I think it's great that Skatingforums is allowing sharpening machine discussions. I looked for a discussion board that serviced skate techs, and couldn't find one. Too bad I'm getting left behind here because I can't afford the semi-professional level powered skate sharpeners you folks are buying. (I'm also not a good enough skater to test out some of the things I would like to test out, or to fully understand what high level figure skaters require.)

Sid Broadbent (http://www.iceskateology.com) once got a USFSA grant to study skate sharpening. I don't know if he was much of an expert on the subtler aspects of figure skating. Perhaps one of you folks could get one too, to study that subject more, and come out with a detailed guide on sharpening for figure skaters.

When I asked, the https://scienceofsharp.com guy offered to take electron microscope micrographs of sharpened skates, I think for a few hundred U.S. dollars. He makes gorgeous pictures! Maybe when you guys master things, you can use him and post the results, and show just how beautiful your edges look at the submicron level. :)

supersharp

Hahaha, more likely I would be completely deflated by how my seemingly mirror-smooth finish turned out to look like the Rocky Mountains under an electron microscope! 

Sid Broadbent was a fairly skilled skater in his younger years, so he would understand what figure skaters of the time needed in terms of edge quality, edge angles, and consistency.  Technique has changed quite a bit over time, as well as the advent of various new types of blades such as the Matrix, Paramount, and Revolution.  I would guess that for the most part, though, things won't have changed much in terms of what can be considered a good sharpening: level edges, a smooth finish, no burrs, and a preserved profile...

Feel free to add whatever features I missed.

Query

Quote from: supersharp on December 27, 2021, 04:54:26 PM
...things won't have changed much in terms of what can be considered a good sharpening: level edges, a smooth finish, no burrs, and a preserved profile...

Feel free to add whatever features I missed.

The best techs I've known don't just preserve profile (as well as ROH and other sharpness parameters) - they customize them to the needs of the skater. But they try not to create unintentional changes.

To me, the most important thing is probably consistency, both within each sharpening (e.g., consistent degree of sharpness along both edges and the whole length), and sharpening-to-sharpening, as I often find it hard to adapt to changes.

Level edges aren't good enough. You could theoretically vary the centering of the wheel or stone along the blade, but level the height of the two edges out afterwards. That would create an inconsistent shape and feel to the edges.

Also, I don't like bent-over edges. I at least want the vertical.

"No Burrs": maybe. Except that some skaters prefer to have the burrs re-directed and polished into foil edges, because they are effectively much sharper than deburred edges. It's especially useful on rough ice. Contrariwise, some skaters want the initial edges dulled a bit, because they are uncomfortable on ultra-sharp edges.

I also think that most figure skaters don't want the ice picks modified except when necessary. But maybe you consider that part of the "profile".

Some sharpeners manage to overheat the blade, and modify the degree of hardness in undesired ways.

Preserve as much metal as you can.

Hockey skaters usually want the nicks gone, even if that wastes metal. Some pairs and dance skaters must occasionally create nicks too, by colliding into each other.

Most skaters get upset when the skate tech delivers something different from what was asked for.

I'm sure you can think of more...

supersharp

Good point, I definitely should have said "level edges with a centered radius of hollow".  I have seen blades with multiple parallel ROHs that generally make the edge angles inconsistent from one side too the other.   Preserve metal, yes!  That's an important goal.

Personal preference is part of it as well. Query likes the extreme foil edges. I like my blades to be de-burred after sharpening to make them less grabby.  I mostly do dance (plus spins and a few single jumps) I prefer maneuverability over a strong bite.  It also makes the overall feel more consistent rather than having to adjust to them being super sharp at first and then having that change over time.

I have only ground down parts of the toe pick when trying to help skaters maintain a usable profile towards the end of the blade life.  It does allow the blade to rock forward more and keep the spin contact area closer to the intended zone under the front of the foot, but the modest size of most drag picks doesn't give you much to work with. I'm comfortable using this as a way to get a beginner skater to be able to get some life out of skates that are too worn for a skilled skater (beginner will be fine with the smaller drag pick, as long as the blade has a functional profile that allows them to learn to rock forward for turns and spins) or to buy a little time for a more advanced skater to finish out a season.  Overall, though, I've just come to accept that blades have a limited life.  The skate tech's role is to optimize the blade condition through that lifetime, rather than to attempt heroic measures to have blades last forever. 

And also, part of this role is to let the skater know when the blade is moving toward being a hindrance rather than a help.  The kids get it when I ask: Do we try to use a wooden pencil down to the last cm?  Not usually, because it makes writing awkward.  It's better than no pencil at all, but if you need to write much and you want to write well, get a new pencil.  Blades are kind of like pencils, you sharpen them and use them and eventually, there isn't enough left to work right.


Query

I've sometimes trimmed my toepick too to get a little extra life. School figure skaters often do it too, for other reasons.

For that matter, some people don't want level edges.

But I think you are right - the basic ideas behind good sharpening probably haven't changed all that much since the late 19th century. Skating books from that era already mention debates over rocker, hollow, side honing, and sometimes toe picks.

This 1877 or earlier machine might be an ancestor to machines like the Wissota

  https://www.flickr.com/photos/amber-tree/49062875948/

It is discussed at https://blackstonesport.com/technology/history-of-skate-sharpening


Kaitsu

Quote from: tstop4me on December 19, 2021, 02:14:08 PM
Here's what Wissota claims about their wheels (https://wissota.com/product/blue-wheel/):

"All Wissota grinding wheels are hand balanced and side finished to remove any wobble.  You can find wheels with different grinding properties than ours, but you will not find a better running wheel!"

And here you can see one example how Wissota´s balanced wheel can be in unbalance. Pay attention to skate holder when machine is started.
https://www.youtube.com/watch?v=fnfvOj8s9to

SkaterNomad

Any boot holders available retail?

e.g. https://skatesus.com/product/mounting-stand/ (seems to not be available)

Precision Blade PBHE Adjustable Skate Anvil is option, won't fit current stand without larger C-clamp size.

Bill_S

Good luck finding a suitable retail unit. The Precision Blade unit looks good, but if the c-clamp doesn't work as-is, you might be able to adapt something to work with it.

I just made my own from wood and use it with a vice.  The vice allows easy fore-aft positioning for locking level in that direction. See this thread... http://skatingforums.com/index.php?topic=8486

I use it with my drill press to drill blade mounting holes.
Bill Schneider

Kaitsu

Probably there is some other retailer whom sales EDEAs Mounting stand? At least in my country these stands are available only on customer request / order.
https://www.youtube.com/watch?v=7eRApwFNxfc

EDEAs stand is pretty simple design and easy to make by your selves if you just have some contacts to metal workers. This stand is very useful. Helps a lot in blade mounting.

Bill_S

Quote from: SkaterNomad on January 28, 2022, 03:57:43 PM
...
Precision Blade PBHE Adjustable Skate Anvil  is option, won't fit current stand without larger C-clamp size.


Just brainstorming here, but you could possibly clamp a thinner board to your stand, and overhanging it by a few inches. This would provide a thinner substrate for the Precision Blade unit to clamp onto. Because you would clamp it to overhang your stand, it would give you extra head-room when drilling mounting holes.
Bill Schneider

SkaterNomad

Didn't realize such a limited retail availability of boot holder(s).

Thinking maybe cobbler/shoe repair industry would have options, but mostly see antiques/vintage.

Maybe will try contacting Edea distributor to see what options they have. May also order Precision Blade PBHE Adjustable Skate Anvil and rig as suggested, would likely work.

I could attempt mimic of Bill's wood variant, but liked concept of the metal ones. No metal worker contacts, but maybe reasonably doable via parts from home depot. More project than perhaps wanted for just boot holder.

If anyone finds retail option(s), please share.

Query

I take it you wouldn't feel comfortable wrapping a thick towel around the boots and putting that in a vice?