Heels

Hey could someone please explain heel geometry and size as it pertains to it's effects on gravers?
It would be much apreciated and would make things a little clearer in my mind.
Rick

Hi Rick

The heel is there to prevent the graver digging into your work. As you dig the graver in initially, which is your angle of attack, it allows you to level out the graver and have some control.

Heels should be small. About .25mm as a rule of thumb. Larger heels are good for straight lines as the length of the heel acts as a rudder and helps keep the graver in a straight line without wobblying all over the place.

Smaller heels are good for very small, tight curves like scrolls etc. If the heel is too long on a small radiused curve the back of the heel will gouge out the metal behind it.

Heel size can also influence the depth of the cut. Larger heels allow you to dig deep, smaller heels keep the work shallower.

Heel angle also has a bearing on how high you raise the back of your graver handle (clearance) so you can grip your burin/airtool and keep your fingers from catching on the work. Most people, as a rule of thumb have their heels set at about 15 to 18 degrees. Depends on how chubby your fingers are!!!

Heel angles also need to be altered to cater for the surface of the work. For instance a concave surface you may need to alter the heel andle to 25 degrees to get the clearance you need.

Keep your heel size in relation to..............

1. The size of the work like curves etc. The smaller the work, the smaller the heel. The smaller the heel the more difficult to control.

2. How deep you want to go with the graver. The smaller the heel, the shallower the cut.

3. Angle of heel gives your fingers clearance to the surface being engraved

There is no one heel that suits everyone or everything all of the time. Have a play with different configurations till you are comfortable with the relashionship that suits you best.

Cheers
Andrew

Sam has an excellent tutorial that goes into the "ins and outs" of the various gravers and angles. You can see it here http://www.igraver.com/sharpening.shtml

Thanks again Andrew that helps my mind get a better picture of whats going on.
Rick

if you have several tool blanks conduct an experiment. make an xtra long heel- say 1/16 inch long at what ever degree. then do 1 much shorter say at 15 degrees. do one at say 17 degrees, maybe one at 20 . try another with a proper heel just about the with of a hair. try different cuts on a practice plate. you'll see a difference in how each tool cuts and how it feels. you will soon come to find one that you like the way it cuts as well as the way it feels. this feel thing is important. if a cut doesn't feel right, it isn't being cut properly !