mythbuster, anyone ?

monk · Mar 16, 2014

i shaped 2 identical 90's using hss blanks. i cut a groove in one face both gravers were used to cut copper, brass, and cold rolled steel. both gravers produced very similar curls. the groove in the 1 graver had no effect at all on what the curl did. i did this out of curiosity. the foto was taken with an elcheapo digital microscope.

phil · Mar 16, 2014

Were you hand pushing or power assisted Monk? In Europe I have seen a few people use the graver with the groove in. I am under the impression that it reduces surface area friction of the metal curl pushing into the face as you cut. Obviously it is more noticeable with hand pushing.
PS. Did you sort your 0.5 out.

mitch · Mar 16, 2014

having watched several super-slo-mo micrograph/videos in the last couple years, i'd say the groove is too far from the point to make any difference. by the time the chip is separated that far all that's gonna happen has already happened. in these videos it shows the metal actually parting ahead of the cutting edge. in other words, for the most part the metal is being wedged apart before any actual direct contact with the cutting edge of the tool. imho, the groove would need to be almost right down to the point, much like a V-groove veiner for woodcarving.

monk · Mar 16, 2014

phil: both ways, air and push. the curl curves far forward of the face, not coming even close to the notch. there were 15 degree heels/45 face, finished at 1000 grit diamond. not sure if the curl would have been the same without heels. i think the curl curvature would change a bit, but not enough to get any effect from the groove. i truly think this would just require a little less time in re doing a dulled or broken tip. i didn't test this on an onglette, but i don't see any real difference that would have made. yes i got a.5. it's on the way.
mitch: i recall that video. when i did the test cuts, i paid no attention to a cut line. i simply watched the curl & what it did. by the time a curl would already be touching the tiniest portion of the face , it also started up in the air, far forward of the possible groove "effect"

Tira · Mar 17, 2014

Interesting.... The only application of the groove that I've ever seen was in Alexandre Sidorov's stone setting class. He had us make the face with a similar groove for the purpose of sharpening. It was easier to hand sharpen under the scope with the groove. It cut down on the "bulk" of what had to be taken away and also it helped align the plane of the face (mind you, these were very small graver faces being sharpened by hand under the scope). I never have heard of the groove as useful to move the chip in a certain way. The only thing I've heard about directing the chip came from Ron Smith who told me to make a small stub on the end of the point to make the chip go straight up and not ride the face.

BLW · Mar 17, 2014

Tira it was Alexandre Sidorov's sharpening video which started this quest so hopefully you've explained the mystery behind the grove

Thanks

mrthe · Mar 17, 2014

Yes the qiestion was mine in an another thread thank you Tira to explain that is just for a re-sharpening purpose

Gemsetterchris · Mar 17, 2014

He`s got 15 other gravers each with it`s own mark.. A.L.E.X.....R.O. & that one is the V

monk · Mar 17, 2014

maybe it's how i hold my hand, my curls start coming straight up a very short distance, then they usually wonder off to the side a bit. maybe a function of the point geometry ? i cant imagine sharpening under the scope ! if you recall my pic, the groove was way off center. just did this with no glass in front of my eyes, just a pair of polycarb safety specs.

Aurifex · Apr 25, 2014

Vitalij Kricuk a stone setter in Germany does this also. He is on YouTube and also sells DVDs on his techniques. I now tend to use this method but for stone setting mostly. Vitalij tends to cut tge groove to the edge of the graver. The gravers are highly polished and sharp.

mythbuster, anyone ?

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