The Sparx user manual is online:
https://cdn.shopify.com/s/files/1/0932/7770/files/11058D_Users_Manual_Text_bleed.pdf?16234843337139765932I’ve owned a Sparx for 7 months and its brilliant. $1000 including figure skate adapter, but it doesn’t work with all figure skate blades. I have hockey skates, and do one pass before skating, four passes is a full sharpen. You need to buy a grinding wheel for each hollow.
Have you measured how much metal it takes off in one pass, with the grinding ring height set to 1 to take off the least metal? (E.g., find a reference point on which you can repeatedly position a micrometer or high precision calipers, and measure the before/after distance to the bottom of the blade...)
I didn't realize it had a figure blade holder. Potentially, that sounds like a very big plus for the people on this forum.
https://www.sparxhockey.com/pages/faq says
We offer a figure skate adapter for $99. With the figure skate adapter in place, Sparx can sharpen most traditional, flat-sided blades. Sparx is not compatible with the multiple-piece blades often used in competitive skating.
https://www.sparxhockey.com/collections/accessories/products/sparx-figure-skate-adapter, including the very informative video there, provides additional info, and provides a contact point.
But the video left me with some obvious questions, which I just sent to Sparx:
I watched the video at https://www.sparxhockey.com/pages/installing-the-figure-skate-adapters
1. Do I understand correctly that you are expecting the Sparx sharpener to remove 1-2 mm of steel during the sharpening process?
2. The blade in the video has been slightly rounded off at the tail - i.e., the rocker radius is less there. Does the Sparx sharpener tend to do that on figure blades?
3. You say it doesn't work on multi-piece blades, I assume you specifically mean Ultima Matrix and Paramount blades? Have you tested it on MK and Wilson "Revolution" blades?
4. Am I correct that each sharpening will introduce a slight forwards to backwards tilt, shifting the skater's balance slightly backwards?
I'm pretty happy myself with using hand tools - at this point it only takes me a few minutes, though there is a learning curve and initially I made mistakes. But I bet the Sparx could do an ROH change pretty fast, without wearing out an expensive hand tool.
I'm guessing the Sparx isn't fancy enough to let you create or restore a custom rocker profile. I could be wrong, and have often been wrong before. If I'm right, Bill, since you love to play with tools, it might not do everything you would like to be able to do. Maybe if you are going to invest in a power tool, you should go all the way to something that gives you more control?
If my guesses are right about the Sparx tool, based on the video, you COULD choose to remove less metal than the 1-2 mm they appear to imply should be removed on their video with each sharpening - once the tail has been rounded off what might be their way.
Even 1 mm is more than an order of magnitude more metal than the .003 inch (.0762 mm) (two different expert pro sharpeners have told me they try to remove. At that rate, a figure blade would have a substantially different shape, and be judged almost unusable by many picky figure skaters, after 3 or 4 sharpenings - rather expensive given the high cost of the best figure skating blades.
And just to be clear - many figure skaters don't want the tail to be rounded off at all.
I do like that it appears that the Sparx lets you sharpen almost right up to the toe pick.
My guess that the figure skate sharpening process Sparx endorses in the video does introduce a slight forwards/backwards tilt - because you adjust the tail mount to sharpen the tail, but keep the toe piece mount height the same, so as to miss the back pick, is a potential problem with any skate sharpening device. Some pro sharpeners do that too, on any machine. But most of the most expert pro sharpeners do eventually trim the back toe pick a little. I suppose you might be able to do that with the Sparx too, by adjusting the height of the toe pick mount.
(Because of the shape of the toe pick, it isn't really possible to maintain the same relationship between the the toe pick and the rest of the blade without trimming it or adjusting the tilt, as you gradually remove metal during skating and successive sharpenings. That's probably the biggest reason most figure skaters consider an old, many-times sharpened blade to no longer be adequate.)