Question on tool setup

[thekoabenchgoldsmith]

I have received the Ron Smith practice plates from GRS. Since I don't hardly ever cut steel I decided to cut borders around the plates to get a feel of the material. Just long straight cuts at first. Then a series of graduated circles...that sort of thing.

I pretty much set the 120 degree gravers up as rec ommended elsewhere: 45 degree face and very short 15 degree full-width parallel polished belly.

I found that the tool wanted to dive deeper and deeper into the metal. I lowered the angle to make the cut more shallow. But when the cuts became long enough for the handpieces (I am using a Magnum and a Monarch with the fine spring) to override the metal they bumped the edge of the plate. I lifted the handpiece up to clear the plate then the graver dove deeper into the material.

Should I increase the belly angle to allow a steeper cutting angle that produces a shallow cut? Or develop a cutting style that allows a shallow cut even with an angle steep enough to allow the handpiece to clear the plate?

Or is there another solution?

In the jewelry engraving I have done in the past the cutting was very deep, but it was never on a broad flat surface so handpiece clearance was never an issue.

Thank-you for any suggestions.

I will be getting my m'scope in a day or two and will begin to include images of the situations I post about after that.

Aloha,
Robert Booth
The Koa Bench Goldsmith

 

[Swede]

Robert, it sounds like your heel is not functioning as it was designed to do. A sustained cut should in theory, if you are using a 15 degree heel, place the tool at 15 degrees relative to the plate, more or less. Your sharpening fixture may be off a few degrees. It's possible rather than 15 degrees, you have 11 or 12 and the tool handle is colliding with the plate.

Suggestion: Try a 20 degree heel. If your current heel is just a miniscule pair of "bands" or facets, as it probably should be, it's really easy to fix. The surest way is to hone the face down at the original angle of 45 degrees until the current heel facets simply vanish. At this point you have no heel at all, so set the fixture up and hone in a pair of 20 degree heels.

Further suggestion: Make these heels a bit larger than you did at first. This will ensure that any issues you are having aren't due to not having enough heel ground into your graver. Try a straight line and see how it goes. Excess heel (I refer to too large a facet, not to any particular angle) will give grief in tight turns but shouldn't affect a straight line. If 20 degrees helps and seems to cut fine, then you can always carefully hone the face down to remove any excess heel faceting.

I hope this makes sense. It's often hard to describe graver geometry with just text.

 

[Andrew Biggs]

By the sounds of it you need to raise your heel. (I could be wrong here)

Try going from 15 to 17.5 degrees. There is no absolute rule on heel angle as it varies from each individual. Too steep a heel and you get wrist/hand fatigue and to shallow a heel you bump into things.

Take the time to play with the heel and find the "sweet spot" that fits your hand and technique.

You will find that as you go from flat to curved surfaces you will need to raise and lower your heel for different occasions.

Heel width is also somthing to keep an eye on. It's easy if your heel is very small to start cutting deeper than your heel which generally is not a good idea. Generally my main cut gravers have a bigger heel as I want to go deeper. My shading gravers tend to have a smaller heel as I don't cut nearly as deep. Start at about 1/4mm as a starting reference.

These are things that you need to experiment with over time and find the level that suits you best. There isn't any universal "one size fits all" formula.

Another thing I would suggest is at the very beginning use a standard 90 or 120 grind. The heels on those graver grinds are really easy to play with and can be adjusted in seconds. Later when you are a bit more familiar with what fits you then you can move onto the lindsay grind (if you want to) which is a bit trickier to set up depending on your sharpening system.

Hope this helps

Cheers
Andrew

 

[sam]

When my students experience a problem such as yours, I have them double the heels size. A very short heel is desirable, but only if you can control it. In the beginning it's sometimes best to have a larger heel until you develop your control. Try that, and I think you'll see a big difference in your ability to cut without diving-in. Report back with your progress! Cheers / ~Sam

 

[monk]

don't be a dope like me . when i first began engraving, i was creating heels that sometimes were a bit in excess of 1/8" in length! they were nice to look at but fortunately early on, i wasn't doing too much small scroll.

 

[thekoabenchgoldsmith]

Thank you very much for commenting. I was busy since posting my question with some boat issues. Worked most of the afternoon, though and I think I have the problems solved. Mostly, it was a matter of getting a better look at what I was doing by (1) Improving the lighting around my bench, (2) setting up the microscope.

But the suggestions about double checking the angle and using a slightly larger heel until I have better control were all helpful.

It is truly amazing how much the microscope helps by showing so much detail. It is almost too much detail.

Thank you all again.

Aloha,
reb