Almost everyone when they set the vari grind they put 2 inches out of the holder...I have notice they also sell the 13/4 and 21/2 guage blocks also...can someone tell me the difference....
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Almost everyone when they set the vari grind they put 2 inches out of the holder...I have notice they also sell the 13/4 and 21/2 guage blocks also...can someone tell me the difference....
Different extension gives you a different side profile. I just mounted a block on my grinder base 2" from the front of the base. Who needs to buy gauge blocks?
The whole point of using a jig for sharpening is to standardize your process so it returns the same results every time you sharpen. The stickout can be anything (within reason) that gets the bevel angle where you want it. I believe that the stickout (combined with the distance of the pocket from the wheel) has the most effect on the nose angle. The leg on the varigrind, the pocket distance, and the stickout all combine to put the appropriate angle on the nose and wings.
Why buy a block? I drilled a hole into a square piece of wood to the desired depth, put a small eyehook in the block and attached it to my sharpening station with a piece of construction string.
That said, as stated, it helps set the angle to the same angle every time you use the Vari-grind.
You can incrementally change the parameters of any grind by changing one of the adjustments.
1. Nose angle, by moving the arm in and out
2. Wing angle, by changing the jig angle adjustment
3. Wing length, by changing the amount of protrusion.
Adjustments should be one at a time as each one slightly effects the other two, especially in the transition area between the nose and wing.
2" is the default but an 1/8" or a 1/4" in dither direction will give you different results to better suit your turning style.
Politely, I would beg to differ if the suggestion is that the resulting shape of the tool will always be the same. The mount of time each part of the cutting edge spends on the grinding wheel will affect the resulting shapel. Spend more time on the nose and it will be more rounded. Spend more time on the middle of the wings and they become concave. The grinding angle may be constant, but the user needs to pay attention to the shape and how much time is spend on each part of the cutting edge.
I have a Wolverine setup on a slow speed grinder and a tormek with all the bells and whistles. And as much as I tried to like the jigs for turning tools, I go to the platform and sharpen by hand for exactly the reasons you mention. Not only can you focus on the edge accordingly but (for me) the tool is easier to use as the cutting angle is the same all the way around. I find the jigs change this consistency and also remove my focus as I depend on the jig to do it for me.
Quote:
Originally Posted by Don Stephan
Good point – All a jig can do is provide consistent angles; the user decides how much time to spend on any given area of the grind. That's why any two turners using the same jig settings can come out with different grinds. Knowing what to avoid - like concave wings - and how the nose shape contributes is where experience and the advice of a good mentor can really help.Quote:
Originally Posted by Don Stephan
I used to free-hand all my gouges and got pretty good at it. I kept reading about Vari-grinds et al and bought a Oneway. I now prefer using the Vari-grind and I think it is easier to get repeatable shapes and probably removing less material. But, as was said, a jig certainly does not totally determine the result.
Jigs like the Oneway don't ny themselves determine the final result but they eliminate many of the variables. Having to focus on time and pressure only and not orientation angle and rotation at the same time, yields much more consistant results. The more consistent the grind the more consistent the cut.
See Doug Thompson's video on using the Vari-Grind jig starting at... https://www.youtube.com/watch?v=ttYyulsM7wg&t=541Quote:
Originally Posted by jeff oldham
Like Doug, I also use 1-3/4" protrusion out of the Vari-Grind and Tru-Grind jigs. I prefer 2" on another jig that has a slightly different geometry.
Glenn Lucas also sells charts for setting up the various BG jigs...
https://www.glennlucaswoodturning.co...gnature-tools/
Keep in mind that Glenn's signature BGs have parabolic flutes (which Thompson and D-way BGs don't have).
Try both 1-3/4" and 2" protrusion and see which one you prefer.
I have used BG jigs for the last twenty years and before that I platform sharpened for thirty years or so. There is a bit of peeing on posts when it comes to platform sharpening and I guess when I was only doing it that way I could do it along with the best of them, but I prefer and use jigs now wherever I can. I find it just as quick for me to use a jig.
And, yes, how you grind with a jig is equally important, but that also assumes that you understand the flute profile on the gouge you are sharpening and what edge profile you are after for the way you use it. In my experience there is limited understanding of these dynamics.
If you find (or are given) a grind that works for you then stick with it and master its use. Just don't assume that everyone else turns the way you do and it will work equally as well for them...:rolleyes:
Also keep in mind, we are all standing, or attempting to stand, on the shoulders of those who have pioneered the way before us. It wasn't that long ago (1982) that Jerry Glaser was experimenting with the first bowl gouge jigs. I think the leg on this prototype pivoted off the floor(?)..
FWIW, a great turner who taught turning and sharpening at the club I was in said, "Everybody over-thinks sharpening".
Sounds like a smart guyQuote:
Originally Posted by Bill Howatt