Can a Prosharp sharpening alter the Profile?

[hockeydad3 51]

Can it be that a Prosharp machine alters the profile of a runner due to repeated grinding?  After about 7 sharpenings through my LHS with a Prosharp AS 2001 my runners with a Quad XS Profile began to have a tendency to catch an edge. I compared them with a second set of runners with a fresh profile on them. The fresh profile has less steel in the front and rear than the older one. The difference is not big but you can definitely feel it with your fingers. I made a direct comparison between the two sets of runners on the ice, the fresh ones are way more agile than the older ones and no more tendency to catch an edge.

How can this happen even though the prosharp shouldn't change the profile?

[hockeydad3 51]

Maybe I didn't express myself clearly enough. I was only using one pair of runners for about 7 sharpenings with about 12h on the ice between them. The catching an edge is new for those runners, it started with the penultimate sharpening, got better after a few hours and was unbearable after the last sharpening (went from 7/8" to 3/4" due to a weight loss). The difference of the profiles begins after maybe 20% in the center of the blade towards the toe and the heel area. The whole profile is flatter, it looks like I would expect it for something like a Quad I. And the skating experience feels like I would expect it for a comparison between a Quad XS with maybe a Quad I.

Can this be caused by an operating error, an incorrect setting or a defect in the grinding machine? Or is it typical for a Prosharp that it takes away more steel in the middle of the blade? The height of the runners is quite low due to some profiling experiments, can this be a reason for the alteration and should I remove them from the holder for grinding?

Edited April 15, 2022 by hockeydad3

[puckpilot 314]

All it takes is one user error to create a bad sharpening and ruin a profile. So anything is possible. I always inspect my steel before I hand it over and after. I line up the steel on top of one another to compare the height to make sure they're even, from toe to heel. I've had it in the past where the difference in height was very noticeable. I didn't return to that shop.

One thing kind of stuck out in your description. From my experience, fresh steel tends to have more on the toe and heel, and a overly aggressive, poor sharpening tends to grind too much off the toe and heel. Which is kind of opposite of what you've described. Though, I do vaguely remember someone describing how a shop basically ground their blades flat 

[hockeydad3 51]

2 hours ago, puckpilot said:

All it takes is one user error to create a bad sharpening and ruin a profile. So anything is possible. I always inspect my steel before I hand it over and after. I line up the steel on top of one another to compare the height to make sure they're even, from toe to heel. I've had it in the past where the difference in height was very noticeable. I didn't return to that shop.

One thing kind of stuck out in your description. From my experience, fresh steel tends to have more on the toe and heel, and a overly aggressive, poor sharpening tends to grind too much off the toe and heel. Which is kind of opposite of what you've described. Though, I do vaguely remember someone describing how a shop basically ground their blades flat 

I know, but a Prosharp gives you an automated grind which, contrary to a free hand grind, should retain the profile.

Edited April 15, 2022 by hockeydad3

[flip12 735]

Could it be misalignment of the pivot point?

[Vet88 674]

16 hours ago, hockeydad3 said:

Can this be caused by an operating error, an incorrect setting or a defect in the grinding machine? Or is it typical for a Prosharp that it takes away more steel in the middle of the blade? The height of the runners is quite low due to some profiling experiments, can this be a reason for the alteration and should I remove them from the holder for grinding?

Ask @PBH, he has as AS2001 (mine is on its way but taking a while due to current supply chain issues). If your steel is really low and the sharpening is flattening the middle I'd suspect the contact point / grinding wheel height setting and they aren't adjusting it when they put your skate into the machine?

[hockeydad3 51]

7 hours ago, Vet88 said:

If your steel is really low and the sharpening is flattening the middle I'd suspect the contact point / grinding wheel height setting and they aren't adjusting it when they put your skate into the machine?

This could be. My LHS guy is very friendly but not 100% familiar with his machine.

[VegasHockey 1284]

On 4/15/2022 at 1:45 AM, hockeydad3 said:

Maybe I didn't express myself clearly enough. I was only using one pair of runners for about 7 sharpenings with about 12h on the ice between them. The catching an edge is new for those runners, it started with the penultimate sharpening, got better after a few hours and was unbearable after the last sharpening (went from 7/8" to 3/4" due to a weight loss). The difference of the profiles begins after maybe 20% in the center of the blade towards the toe and the heel area. The whole profile is flatter, it looks like I would expect it for something like a Quad I. And the skating experience feels like I would expect it for a comparison between a Quad XS with maybe a Quad I.

Can this be caused by an operating error, an incorrect setting or a defect in the grinding machine? Or is it typical for a Prosharp that it takes away more steel in the middle of the blade? The height of the runners is quite low due to some profiling experiments, can this be a reason for the alteration and should I remove them from the holder for grinding?

You mention "profiling experiments," which leads me to believe that we don't have all of the information to decide your situation. If you have profiled the steel multiple times, you are removing material every time. If they are not adjusting for the pivot point, they are moving the pivot point each time they apply a new profile, resulting in an excessive loss of steel. 

[hockeydad3 51]

1 hour ago, PBH said:

You mention "profiling experiments," which leads me to believe that we don't have all of the information to decide your situation. If you have profiled the steel multiple times, you are removing material every time. If they are not adjusting for the pivot point, they are moving the pivot point each time they apply a new profile, resulting in an excessive loss of steel. 

He did adjust. And the profile had the same properties like my newer higher steel, I did compare them on the ice. The lower steel just felt more stable for me so I went with the lower one until I noticed the catching of an edge. 

[Leif 161]

On 4/15/2022 at 11:13 AM, puckpilot said:

Though, I do vaguely remember someone describing how a shop basically ground their blades flat 

Several years ago I changed out my blades for some new ones, and when I compared the profiles I discovered that the old blades were almost flat. That was before I had skating lessons, so my skating was poor anyway. These were Step blades, which take a lot of sharpens before replacement is needed, and manually sharpened. That LHS is one of the few locally that can get even edges, and yet they can’t maintain the stock profile. No doubt this was due to uneven pressure. I mentioned this here, so maybe you remember my post. That is one reason I now own a Sparx. This does not explain the ProSharp issue above, I assume that machine uses a spring to apply even pressure. 

[VegasHockey 1284]

39 minutes ago, Leif said:

Several years ago I changed out my blades for some new ones, and when I compared the profiles I discovered that the old blades were almost flat. That was before I had skating lessons, so my skating was poor anyway. These were Step blades, which take a lot of sharpens before replacement is needed, and manually sharpened. That LHS is one of the few locally that can get even edges, and yet they can’t maintain the stock profile. No doubt this was due to uneven pressure. I mentioned this here, so maybe you remember my post. That is one reason I now own a Sparx. This does not explain the ProSharp issue above, I assume that machine uses a spring to apply even pressure. 

ProSharp machine uses a weight, #5 in the diagram below, which keeps even pressure on the blade as you are sharpening. 

I think Sparx are nice machines, I just wish they had a better finish. 

[218hockey 50]

On 4/20/2022 at 3:59 AM, PBH said:

 

I think Sparx are nice machines, I just wish they had a better finish. 

Finish?

[VegasHockey 1284]

12 hours ago, 218hockey said:

Finish?

The end product of Sparx is not nearly as nice when compared to sharpening on a Wissota, Blackstone, Blademaster, or other machine that uses ceramic wheels. 

[218hockey 50]

Right. That's what I thought but wasn't sure.

I have thoughts but can take them to the Sparx thread.