All skew'd up...or...bevel this

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YoYoSpin

YoYoSpin

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If you've seen any of my tutorial videos, you've probably noticed that I use a skew a lot, as it cuts a really smooth finish. However, the angle of the skew's bevel has got to be right for best performance. Here's a little drawing that I should have published long ago that shows how I think things work...skew-bevel-wise :)

SkewShapes.jpg
 
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Man, those last too.. Are they 1" suqare stock??!! That's one thick skew! [;)]

I recently re-shaped my 3/4" skew as I noticed the shape getting a bit long from too many hand touch ups. Big diffrence!
 
I think one of the biggest sharpening tips I took away from Alan Lacer's The Skew video (the first one) was not to get TOO hung up on the shape. He had some ratio, and now I can't remember what it is off the top of my head, between the thickness of the tool and the length of the bevel. I think his was somewhere around 80-90%, which would be consistent with Ed's drawings. I've found that there's some margin for the ratio to wander, but as Ed alludes to, there are limits to how far you can stray from the "magic" number. Ed's comments about sharpening versus vibration are very interesting, and I'm going to have to keep them in mind - I don't always check the ratio for my skew as I sharpen it, but next time I think I'm sharpening too much or getting too much vibration, hopefully that will remind me to check the sharpening angle.
 
Thanks Ed, I have mine similar to the first one. I do get some vibration. I'll have to give the middle bevel look a try. It looks to be around 55 degree's.[?]
 
I am very bad then...mine is even worse than the first pic! [:0]

BUT...I don't have any problems with it and works for me [;)]

I will try the middle angle on my other skew though and see how it works.

Thanks!
 
Originally posted by JimGo
<br />.....Alan Lacer's The Skew video.....He had some ratio, and now I can't remember what it is off the top of my head, between the thickness of the tool and the length of the bevel. I think his was somewhere around 80-90%, which would be consistent with Ed's drawings.....
Click to expand...

Jim has been sniffing a lot of CA recently so I am not surprised that his memory is shot. He even has to hide his real name in his screen name so he won't forget who he is!!![:D][}:)][:D]

Anyway, I tried to extract some actual measurements from Ed's posted pictures. I don't know if they are really to scale or not so the following may or may not be accurate.

The angle of the first drawing is 45°± and the ratio is 75%±. The angle of the middle drawing is 78°± and the ratio is 125%±. And the angle of the third drawing is 100°± and the ratio is 150%±. We will have to wait for Ed to get back on and throw some more light on the subject.
 
Randy,

I think the ratio Jim is talking about is

bevel length : thickness of tool

Basically the inverse of what you showed.

Of course I could be wrong.
 
Dario: Jim said the ratio is thickness to bevel which is what I calculated. You are suggesting it should be bevel to thickness. Having never seen the Lacer video, I have no idea which is correct. But doing the inverse calculation, based on your definition of the ratio, the numbers would be 133%, 80%, and 67%, respectively. To be honest, your definition makes more sense, since ratios are usually set up to where the fixed parameter(in this case, thickness) is the second element in the ratio. Guess we have to find out which definition of the ratio is correct??
 
Ed,

Because of the difference in monitor sizes, it might be helpful if you could label the appropriate degree measurements. Perhaps that is what has been said, but I don't instantly equate ratios to degrees of angle.[:)][:)]
FWIW
 
As with many other pencrafting issues, it appears that no single answer will apply to all situations.

I did a little research on the Internet and found seemingly credible web sites that recommended sharpening angles ranging from 25° to 65°. One thing came up that has not been explored in this thread concerns whether you use shearing cuts or scraping cuts or both. It seems that shearing cuts require an angle in the 25-45° range while scraping cuts are better accomplished with angles in the range of 45-65° range.

And finally, don't ask me to explain the different cuts. I'm not sure I fully understand what the difference is??
 
Ed I just began watching you video on closed end pens. I have to say we all have different ways of shaping our tools. What works for one does not work for all. Much of it depends on if your cutting or scraping. The best thing here is you gave your advice and opened a good exchange of ideas. You do some great pens so I won't argue against your methods.
 
Some may have missed the small print caption at the bottom-right of the skew bevel drawing..."Just my opinion". That's one of the great things about this hobby of ours. In the end, we're all right, as whatever works for us...works.

The real key IMHO is to get enough practice under your belt to find what does and does not work for you. Finding your own "voice" in terms of technique and design will reward both yourself and those who view your work for many years to come.
 
My two cents worth is that the angle is also a function of what you are turning. We have two venerable references discussed above -- one turns cast media predominatly and the other turns wood predominatly. The Lacer ratio per his recent article in American Woodworker is bevel length to thickness of 1.5; which works out to a 3/8 bevel length for a 1/4 inch thick chisel. The Lacer article is about sharpening a curved skew.

Ed's ratio appears to be more closly approximated at 1:1 - bevel length about the same as the thickness. The more acute angle at the intersection of the bevels and a straight grind works well on EPR and the like. For me, the sharper angle or thicker cross section results in fewer "buzzes" and minor chipping.

My conclusion is that both are "right on" depending on what you are turning and your skill level. What is in common is that both are master of skews!!

Nice to have a few masters around to learn from -- but you have to work out what works for you with what you are doing at the time.
 
When I teach the first thing I tell students is that with the exception of safety there is no right way or wrong way to do anything. The grinds on my personal tools do not match the grind on the tools that are in the classroom. At least one observative student notices this each class. I always tell them my grind is mine, it has evolved, and that while I am accustomed to it I wouldn't necessarily encourage others to use the same grinds. I always suggest a very middle of the road grind and tell people they can modify the grind after they are competent with that grind. I then usually get asked how it is that I can use either my tools or the tools at the shop and make cuts that appear to be of equal quality. I tell them technique is far more important than grind.

One of the biggest problems I have while teaching is I can't remember how I normally hold a tool, I spend soo much time turning left handed in class, so that students can see what the tool is doing, that I can't remember how I normally hold a tool when asked. Thankfully, when I turn for myself I don't have to think about it, so muscle memory takes over.

Drew
 
I just got Alan Lacer's video this past weekend and watched it. In it he says that the angle from long point to short point should be 70 degress and the length of the bevel (the length of the ground face) should be 1-1/2 times the thickness of the metal. I haven't tried to duplicate it as of yet and I am far, far from being knowledgable on the skew.
 
Thanks Jerry, I have to give that a shot. I'm at 7/16ths now at 30 degrees on my skew. There is some vibration with that bevel angle. I should shorten the face by 1/16th of an inch to meet the equation specks.
 
Originally posted by Jerryconn
<br />I just got Alan Lacer's video this past weekend and watched it. In it he says that the angle from long point to short point should be 70 degress and the length of the bevel (the length of the ground face) should be 1-1/2 times the thickness of the metal. I haven't tried to duplicate it as of yet and I am far, far from being knowledgable on the skew.
Click to expand...

That ratio is fine for visualization; but probably doesn't have much practical value to most folks. For people who have Wolverine sharpening systems or something similar, where you can actually dial up an angle, the ratio that Lacer mentions translates to an included angle of 40°.
 
Originally posted by YoYoSpin
<br />Some may have missed the small print caption at the bottom-right of the skew bevel drawing..."Just my opinion". That's one of the great things about this hobby of ours. In the end, we're all right, as whatever works for us...works.

The real key IMHO is to get enough practice under your belt to find what does and does not work for you. Finding your own "voice" in terms of technique and design will reward both yourself and those who view your work for many years to come.
Click to expand...

This is so true!
 
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