Geometry for "strong" tips on carbide gravers

Texasgerd · Sep 8, 2015

I've always had others say use a strong geometry for carbide gravers. Just wanted to ask what is considered (generally) a strong geometry?

Higher face angle, wide/narrow face, less heal angle, wider heal?

Personally, I've done a lot of grinding and have what I think works to minimize fracture, but wanted to tap a more experienced audience.

Dan

atexascowboy2011 · Sep 8, 2015

Whichever geometry you use, make sure to dub the point as a last facet.

Texasgerd · Sep 8, 2015

Already doing that, and increased my face angle too.
I don't necessarily like a steep face (for general feel) but it does work. I didn't know if there was something else others were doing.

Dan

monk · Sep 8, 2015

Texasgerd said:
Already doing that, and increased my face angle too.
I don't necessarily like a steep face (for general feel) but it does work. I didn't know if there was something else others were doing.

Dan

i'm growing weary telling people this"""" stick gravers in a fresh potato overnight. the results can vary, but it's worth a try.

SamW · Sep 9, 2015

But the hash browns taste so funny the next day!

Crazy Horse · Sep 9, 2015

And they're hard as hell to mash.

Beathard · Sep 9, 2015

I've always been told to engrave softer metals...

monk · Sep 9, 2015

SamW said:
But the hash browns taste so funny the next day!

hot sauce can make anything palatable. even possum innards.

monk · Sep 9, 2015

Beathard said:
I've always been told to engrave softer metals...

i made the mistake, early on, to accept 2 s & w's in stainless. i was half way thru one. having fits ! i called lynton mckenzie for advice. he told me to avoid doing them. period !
after finishing the pair, i agree with you--- soft stuff for me. it does teach one how to sharpen a graver.

Dani Girl · Sep 12, 2015

Tex tell us... I would like to try what you are doing in the titanium I am engraving.

TallGary · Sep 12, 2015

Texasgerd said:
I've always had others say use a strong geometry for carbide gravers. Just wanted to ask what is considered (generally) a strong geometry?

Higher face angle, wide/narrow face, less heal angle, wider heal?

Personally, I've done a lot of grinding and have what I think works to minimize fracture, but wanted to tap a more experienced audience.

Dan

Dan,

I personally don't use a different geometry for my carbide gravers than the tool steel gravers that I use. I do polish the face of the graver (diamond spray on a ceramic lap) to remove any "micro-cracks" that could propagate and cause a tip fracture in heavy use. I also use the ceramic lap to put the heels on the graver, and put a micro radius on the point of the graver to reduce the stress at the tip. As with any technique, your mileage may vary but I find that I need to sharpen less often than if I don't take the time to polish a carbide graver.

Regards,

atexascowboy2011 · Sep 12, 2015

Dani,
Sharpen your graver as you normally would.
Then, holding the graver face at an 80-85Â° angle to the face of a CLEAN!, hard ruby stone, make three SHORT (2&1/2") pulls towards your body.

This creates an 80 to 85Â° cutting face, which is VERY strong !
Experiment with the amount of downward pressure needed to get a good facet for YOU.

Recently Barry Hands or Pilkington? was talking about the hard materials that Steve Lindsay cuts requiring sharpening every other cut.
I doubt that Steve takes the time to chuck up his graver in one of his templates every 5 seconds or so, but PROBABLY uses the method that I just described to you.
Frank Hendricks, the Godfather of MANY an American engraver taught this technique which was probably garnered from the heavy cutting Germans, such as Eric Boessler who taught Terry Theiss this very same technique.
Today's American generation, having gone to the power hone often skips this procedure because they think the power hone is the ultimate sharpening technique and once the P.H. is finished that is it.

Since my phone will not allow me to post pictures, IF you need pics OR a drawing of this facet, send me your email and I will oblige.

Above all, DO NOT OVER ENGINEER this procedure ! :beatup:

LVVP · Sep 13, 2015

Will be very nice to see the pictures, please

dlilazteca · Sep 13, 2015

I just wrap mine in a tortilla overnight, has to be flour torrilla or it will not work

Saludos,
Carlos

atexascowboy2011 · Sep 13, 2015

Vlad,
As stated ,I am unable to post pictures on this forum.
Therefore you will need to PM me with your email address for me to send you pics.:beatup:

atexascowboy2011 · Sep 13, 2015

And here I thought y'all did it Barbacoa style by burying it all night.

Tira · Sep 13, 2015

I sharpen my carbides with a 55 degree face and a 110 degree V angle. If I am using it in something hard - like titanium - I also dub the front. To do this, which is similar to what has already been explained, I hold the tip of the graver straight up and down (90 degree style) and trace an X and O very lightly on the ceramic lap charged with the diamond spray. This combination has worked on Ti very well for me (even the 6AL4V). This also works for a 90 degree tool, but this tool isn't quite as tough as the 110.

Crazy Horse · Sep 13, 2015

There are many types and grades of carbide:

Toughness, abrasion resistance, wear resistance are but a few of the carbide properties. Another important factor of carbide is the carbide grain size and the type of binder. Unfortunately in the engraving world the merchants who sell us those little .093 pieces of carbide don't tell us exactly what properties the carbide graver is designed for.

There's such a thing as "negative rake" in the machinist's world, and dubbing the tip of a graver makes the tool behave in a similar fashion, in that it no longer "cuts" but rather pushes the metal away.

The fact is if the carbide is of the proper type it will cut very well. If the carbide is not designed for a particular property it will fail and you'll be sharpening far too often. The merchants should be telling us exactly what grade of carbide we are purchasing. The fact is we should be asking what grade of carbide tools they are selling. Just having a a "carbide" label doesn't make it suitable for our purposes.

atexascowboy2011 · Sep 13, 2015

For years,I have wondered WHY some of us are trained to put various degreed faces on our gravers only to finish them off with an 80 -90Â° cutting face when cutting on steel, stainless, etc.
Why not skip a step and go straight to the 80-90Â° face ?
I think this can best be answered by the H&C folk.

Sam · Sep 13, 2015

Crazy Horse said:
Just having a a "carbide" label doesn't make it suitable for our purposes.

I'm glad to hear somebody say this. Many people think all carbide is the same and it's absolutely not the case.

Geometry for "strong" tips on carbide gravers

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