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Someone should re-start making the Berghman sharpening tools!

Started by Query, June 23, 2019, 11:39:03 PM

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Query

I keep trying to convince people to start making a modern version of the old Berghman hand-held skate sharpening tools

  https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1311.R1.TR1.TRC0.A0.H0.Xberghman+skate.TRS0&_nkw=berghman+skate+sharpener&_sacat=0

The old Berghman's are still available on eBay used - and you can replace the stones with modern composition ones, of various grit sizes. It would be hard for a new tool to compete in price with the used ones. But the old tool could only hold 1/2" ROH (radius of hollow) stones. If someone made these now, they could make ones for other ROH.

These tools used to be very common from about 1929 to the early 1950's - I think they were one of the most common ways to sharpen skates before purpose-built powered machine bench tools were made that allows pro shops to sharpen more blades/hour. In short, they were professional grade purpose-built skate sharpening tools. Except for speed, which isn't as important to the individual skater, I consider them superior to the modern powered machine tools, because you have better control, and they are small enough to fit easily in your skate bag. I have played with them, and like them very well.

The original tools had fairly coarse grit stones - which worked quickly, but could not produce a super-sharp fine quality edge. Also, I think they may have been made from natural grind stones - they are fairly crumbly, and some of the old ones aren't in very good shape.) Modern cylindrical sharpening stones, made of abrasive powders (e.g, diamond dust, aluminum oxide...) embedded in a plastic resin, are better. They are sold under many names, such as

    abrasive round stone
    cylindrical sharpening stone
    abrasive cylinder

Ideally, there should be at least 3 grit levels available. A very coarse grit, appropriate to changing ROH or rocker profile - maybe 40-50 grit. A medium grit, perhaps 80. (About what the Pro-Filer diamond-dust coarse grit stone uses?) And a fine grit, about 200 - 250, for creating the final edge. As with Pro-Filer, if you sharpen often enough, you would only use the the fine grit stone.

While you are at it, you could use stainless steel; some of the old ones have rusted.

Except for the stones, and the rust issue, they were a much better design than the Pro-Filer, the closest modern equivalent:

1. You can adjust the gap size with the wingnut, so there was less play, in both the gap and the holding of the stone. This let you center the tool on the blade better.

2. Also, you can open up the gap to add tape, to avoid scratching the sides - and I guess you could use foam tape on the sides of the gap to slide snugly along side-honed blades (e.g., parabolic, tapered, dove-tail cut...).

3. When working near the toe pick, tail or sweet spot, you can see what you are doing better, because you can mount the stone right next to the edge of the tool. On the Pro-Filer, there are pins in the way, so you can't quite see what you are doing.

4. The 2" long stones followed any warp in the blades marginally better than the 3" long stones in Pro-Filers.

5. It was easier to change stones.

(OTOH, the Pro-Filer is beautiful, and has elegant simplicity. The Berghmans were serviceable but ugly)

The tool consists of two steel plates, that are curved to fit around a cylindrical sharpening stone of the correct radius. On one side of the stone, two bolts, with nuts, hold the tool together - and work against springs. On the other side, driven together by the springs, there is a gap through which you slide the blade. The gap size is adjusted by a wingnut.

It looks like you could make them using a saw (to cut them sheet metal to size) (or a CNC cutter), very strong sheet metal bending tools (someone on this forum told me you could probably do it with a stamp press, whatever that is), and a drill.

AFAIK, the original manufacturer is out of business, and the patents must have expired.

So - anyone with manufacturing skills want to try making them?