He he, good luck! You can see how (un)successful I've been at "getting a life" as demonstrated by publishing extensive notes on sharpening skate blades.
Since you work in this field, here's the ultimate blade measuring machine, circa 20 years back...
All very interesting thanks indeed. Spent a happy hour or so balancing blades, ball bearings and micrometer, what fun! The ball bearing has a tendency to leave . I got 0.7 in for a hollow that looks very like the planned 0.5 it's supposed to be, but then looking at the maths carefully I wonder how much use this method is in the real world. Arriving at depth of hollow (single figure thousandths of an inch) by subtraction of two measurements of approx 1 inch (blade depth), one of them involving a ball bearing in the loop... hmm, well I don't think that is all repeatable to better than 1 thou accuracy? Clearly better than 1/10 thou for depth of hollow is essential to get anything meaningful out here. Errors make a *huge* difference to the result given that 8x hollow depth is used as a divisor in the final calculation.
Also reading the later comments, I think maybe I too need to get a life ...
Must try the dial gauge on this problem next, I suspect that would give a more accurate hollow depth????
Thanks again for the input
Steve
(apologies to all, wrong email got posted in error in original, this one is correct)
william.schneider@ohio.edu wrote:>
sjw2005@cix.compulink.co.uk wrote:> I'd like to get the>> hollow really accurate, and have tried sighting against a light using>the>> little round gauge disks supplied - it has to be said that is not a>truly>> precise method, slight variations in hollow are not easy to detect.>> Anybody got a better way to do this>
If you have a micrometer (or even some accurate calipers) you can use a>small ball bearing or smooth BB to guage the radius of hollow. I have a>web page at>
Hmm yes, I think once could be quite enough. Vaseline - don't think I can face adding that into the loop. Messy. I'm going to put that blade on the milling table and wipe it across the dial gauge next. Would this be an economic business model for a future grinding service I wonder. Grinds at 50GBP to you Sir, but the hollow is utterly *guaranteed* to 1 thou radius ... unless of course you choose to go skate on the blades.
Steve
"William Schneider" <william.schneider@ohio.edu> wrote:>>>Spent a happy hour or so balancing blades,>ball bearings and micrometer, what fun!>
He, he - things get a bit fiddly, don't they? That's why I did it only once.>
Bill>
p.s. a little dab of Vaseline helps keep the bearing in place for measuring, >but it's still like herding cats. >
It's not that critical for each grind, but it would be good to have regular checks of machine setup I think, the calibration of the diamond wheel dresser "out of the box" was very poor. The wheel was being ground off centre and the hollow was nothing like what it was supposed to be. The Skate Mate thing looks interesting, a better set of hollow test gauges would probably do the job for me, I have a very limited selection of discs at present, and can't really get a feel for which is "best fit".
Steve
"Dave Curtis" <dave@davecurtis.net> wrote:>Yes, is it really that critical? I just use a little SkateMate thing>and that seems fine for me. I just feel with my finger to see if it>seems like there's an edge on either side.>
It's not that critical for each grind, but it would be good to have regular checks of machine setup I think, the calibration of the diamond wheel dresser "out of the box" was very poor. The wheel was being ground off centre and the hollow was nothing like what it was supposed to be. The Skate Mate thing looks interesting, a better set of hollow test gauges would probably do the job for me, I have a very limited selection of discs at present, and can't really get a feel for which is "best fit".
Steve
"Dave Curtis" <dave@davecurtis.net> wrote:>Yes, is it really that critical? I just use a little SkateMate thing>and that seems fine for me. I just feel with my finger to see if it>seems like there's an edge on either side.>
It's not that critical for each grind, but it would be good to have regular checks of machine setup I think, the calibration of the diamond wheel dresser "out of the box" was very poor. The wheel was being ground off centre and the hollow was nothing like what it was supposed to be. The Skate Mate thing looks interesting, a better set of hollow test gauges would probably do the job for me, I have a very limited selection of discs at present, and can't really get a feel for which is "best fit".
Steve
"Dave Curtis" <dave@davecurtis.net> wrote:>Yes, is it really that critical? I just use a little SkateMate thing>and that seems fine for me. I just feel with my finger to see if it>seems like there's an edge on either side.>
William Schneider 5 April 2005 01:52:40 [ permanent link ]
jet engine "dental work." Couldn't quite make out the probe types.>>Renishaw, maybe?
It's been too long ago, and that cmm was a small part of a much larger project. Much gray matter has gone missing since - caused by impacts with the ice maybe?
Here's a crop of the probe area scanned from my 4x5 inch negative. Perhaps you can tell from that.
Bill Schneider ...who's getting depressed that the rink will close soon for the season. Time to get the boots rebuilt.
Bev & Jack Rienks 14 April 2005 06:05:26 [ permanent link ]
I started out the same as you but now I maintain about 100 pairs of blades for skaters in this part of Florida. I made a set of disks to measure hollow and find that to be adequate. I dress my stone to the hollow the customer wants or I measure the old hollow at he heel of the blade and dress the wheel to the same as what I read with the disks and let it go at that. Sometimes I have to interpolate a little if none of my disks fit the old hollow exactly. I have never checked to see how accurately the wheel is dressed in relation to the setting on the dressing bar. If a customer complains of the hollow after a sharpening I adjust it and make a note of it in my records so I can reproduce it next time. I guarantee my work so I don't recharge when the skater wants the hollow changed after he/she tries them. Hope this helps.
Interesting to hear about someone else who does this, sounds like it's made a nice business for you! I think my main problem was that though discs were supplied with the machine, there were not enough, I'm sure discs would be fine if I had bothered to make some more as you did. As it was the gauges I bought cost about 5GBP each, so I took the lazy option. It is actually quite a rewarding exercise sharpening blades, and I wouldn't rule out doing it commercially I suppose, I'm sure it's a nice business to be in.
Steve
Bev & Jack Rienks <skating.rienks@verizon.net> wrote:>I started out the same as you but now I maintain about 100 pairs of >blades for skaters in this part of Florida. I made a set of disks to
