How to measure Base Bevel Angle

[Tony S]

Thanks for the replies!

I tried putting a light source behind the gauge. The way it is positioned there should be no light under it, right?

View attachment 184587

As I don`t have a true bar, the closest thing I have is a caliper gauge. I decided to check if the base surface is flat, well it`s not It is concave, not what I expected from a brand new ski Should I do something with that surface? Make it flat somehow?


View attachment 184588

Further investigation showed, that the gauge itself is not precisely machined, considering its price. I expected to be with straight edges. Seeing that, I am starting to question the quality of the cut angles

View attachment 184590

You're picking it up fast. If these issues weren't ubiquitous we wouldn't spend so many cycles on them.

 

[Dwight]

Thanks for the replies!

I tried putting a light source behind the gauge. The way it is positioned there should be no light under it, right?

View attachment 184587

As I don`t have a true bar, the closest thing I have is a caliper gauge. I decided to check if the base surface is flat, well it`s not It is concave, not what I expected from a brand new ski Should I do something with that surface? Make it flat somehow?


View attachment 184588

Further investigation showed, that the gauge itself is not precisely machined, considering its price. I expected to be with straight edges. Seeing that, I am starting to question the quality of the cut angles

View attachment 184590

Nordicas?

 

[ScottB]

The gauge should be like a true bar, flat and straight. If its not, it will introduce error into the measurement. Ski bases are supposed to be flat, rarely they are from the factory. That's why base grinding machines were invented. So yes, you need a base grind to make your ski perform its best. You also need a true bar to compare the gauge to, so you can tell if its truly flat as well. If its not, well I hope you didn't pay very much for it.

 

[draco]

Nordicas?

No, Augment

The gauge should be like a true bar, flat and straight. If its not, it will introduce error into the measurement. Ski bases are supposed to be flat, rarely they are from the factory. That's why base grinding machines were invented. So yes, you need a base grind to make your ski perform its best. You also need a true bar to compare the gauge to, so you can tell if its truly flat as well. If its not, well I hope you didn't pay very much for it.

Well, it was 50 euro. You would expect better quality when you buy 6 plates with angles. I am almost sure, that the caliper gauge is flat

You're picking it up fast. If these issues weren't ubiquitous we wouldn't spend so many cycles on them.

yeah, just started to dive into the tuning and sharpening universe....I have a feeling that it won`t turn out well

 

[draco]

The edge seems straight, but there are a few bulges on it. I can even feel them with my fingers.
I wonder how are these made, maybe laser cut?

 

[Swiss Toni]

The gauge is made in Germany by LG-Sport GmbH and is sold under the FK SKS Kunzmann brand. From the photo on their website it looks like the measuring surfaces on the side edge side at least are ground http://www.kunzmann-skitools.de/3157.html I think the gauges will most likely be stamped from sheet metal and then have their angles ground to size. You could try emailing them.

 

[Atomicman]

The gauge should be like a true bar, flat and straight. If its not, it will introduce error into the measurement. Ski bases are supposed to be flat, rarely they are from the factory. That's why base grinding machines were invented. So yes, you need a base grind to make your ski perform its best. You also need a true bar to compare the gauge to, so you can tell if its truly flat as well. If its not, well I hope you didn't pay very much for it.

The base only needs to be about flat 10MM in from each edge. If that is the case, they will ski fine. If concavity goes closer to the edges then that, they need to be ground. I always ski on the first to determine how the skis perform before just grinding. If it ain't broke why fix it.

 

[draco]

The base only needs to be about flat 10MM in from each edge. If that is the case, they will ski fine. If concavity goes closer to the edges then that, they need to be ground. I always ski on the first to determine how the skis perform before just grinding. If it ain't broke why fix it.

Well, in my case it`s 3-4mm max.
What should be the behavior of the ski if the base surface is concave? More difficult edge release?

 

[Atomicman]

Well, in my case it`s 3-4mm max.
What should be the behavior of the ski if the base surface is concave? More difficult edge release?

Yes, Very unpredictable, similar to a railed ski or a hanging burr. . Won't roll on or off edge smoothly & predictably since the edges are closer to the snow than the base.

 

[draco]

Yes, Very unpredictable, similar to a railed ski or a hanging burr. . Won't roll on or off edge smoothly & predictably since the edges are closer to the snow than the base.

Damn, so I would better grind the base before I go to some resort, where I don`t know the quality of the ski service shops.

 

[Atomicman]

Damn, so I would better grind the base before I go to some resort, where I don`t know the quality of the ski service shops.

Depends on where you going. I got a stellar tune on my FIS 188 30M GS ski last year at Jans Rennstall Tech Center at the Base of Deer Valley . .7/3 They skied like a dream.

 

[Viking9]

Interesting Aman I had my Rossi 84s done there and they also skied great.

 

[draco]

Thanks for the replies!

I tried putting a light source behind the gauge. The way it is positioned there should be no light under it, right?

View attachment 184587

As I don`t have a true bar, the closest thing I have is a caliper gauge. I decided to check if the base surface is flat, well it`s not It is concave, not what I expected from a brand new ski Should I do something with that surface? Make it flat somehow?


View attachment 184588

Further investigation showed, that the gauge itself is not precisely machined, considering its price. I expected to be with straight edges. Seeing that, I am starting to question the quality of the cut angles

View attachment 184590

I bought a true bar and feeler gauge to measure what exactly is going on
I can insert 0.02mm plate under the true bar in the middle of the base, and less near the edges( I can`t measure that exactly)

I also tried measuring the base angle with the method @ScottB described, but I couldn`t achieve so distinct light leaks as his images. Either my edge is thinner or rounder(is it possible?), or I need to buy magnifying glass ) The closest I could get was 0.5 degrees, which is what it is supposed to be

 

[Magikarp]

Is it a big deal if I'm using diamond stones to sharpen at the wrong angle? Since I don't sharpen my base edge with a file to reset the angle, I don't always know what the base angle is. I'm also not very good at measuring it...

 

[KingGrump]

Is it a big deal if I'm using diamond stones to sharpen at the wrong angle? Since I don't sharpen my base edge with a file to reset the angle, I don't always know what the base angle is. I'm also not very good at measuring it...

You don't really "sharpen" the base bevel. Unless you want to increase the base bevel angle, there is not much you can do with the base bevel once it is correctly set. The usual operation performed by the home tuner is to take out the "outies" from rock strikes. Not really a major task. Could be performed free handed without a guide. That also depends on how good is your hand.

 

[Magikarp]

You don't really "sharpen" the base bevel. Unless you want to increase the base bevel angle, there is not much you can do with the base bevel once it is correctly set. The usual operation performed by the home tuner is to take out the "outies" from rock strikes. Not really a major task. Could be performed free handed without a guide. That also depends on how good is your hand.

Oh alright, I was worried if I diamond stone with the wrong angle guide long enough, it will mess up the edge angle. I'll just try not to think to hard

 

[KingGrump]

I'll just try not to think to hard

I usually used a 400 grit diamond stone with a little water free hand to take out the outies. I can match the bevel angle very easily. Soft hands. You can hear the stone on the burrs. When the sound changes, the burrs are gone. Not much to it.