engraving letters

[DG]

Hi guys, I am engraving small letters on a stamp. I'm using A2 steel and the letters are .01 high and .007 across the flat surface. Am I better to make a three sided carbide 5-7 degree cutter with a .01 tip or a standard single edge engraving cutter? The walls seemed to come o0ut pretty ragged on my first try with the three sided cutter. My boss wants to start making steel stamps on our Mikron three axis mill. I suggested we cut graphite but he wants to eliminate that extra burn cycle if I can get good results. Thanks for any imput.

[thtalim]

I used to use straight single lips with radius .002 . but very difficult to make.

[DG]

I should have added that I need to have draft of 5-7 so stamps don't stick in material.

[Steve Zirtzman]

DG,

Were you cutting the letters with only one pass?

[DG]

Steve, I was, I didn't have room to use mult pass. I used a four cornered 7 deg handmade and had some better results. I was wondering what they use on a panograh. The single edge wouldn't hold up. the tip kept braking down..

[camgeneration]

DG, you couldn't make multiple depth passes?

The 4 sided cutter your describing is what i use in tool steel for plastic injection molds, but i usually only take .0005" passes

[crazy^millman]

Well could you use one for roughing and one for finishing. As the finish one gets dull just make it a rougher and keep going that route. I have some information at the shop for a inserted engraving tool that I will look for tomorrow.

[edmBosto]

I think your boss will someday change his mind and just machine the graphite. It's easier, more consistant, and in the long run faster in my opinion.

You ever make pointed carbide engraving cutters by just grinding angles and having them come to a sharp point so the cutting angle is about 15 degrees. Works great when machining very small letters on graphite with flats as small as .003. Great finish and the the cutters can be resharpened in minutes. Then we burn the letters about .005 to .007 deep for the mold stamps.

The Mikron could mill a parargragh of letters in 15 minutes I'll bet.

[Piglet Trespassers William]

I use pyramide cutters for 10 years ,at least ,on every material including hardened steel on stamps ,molds and general engraving when taper angle is less than 30 degrees with huge success .

You can make it 3,4,or 6 edges .

I used to grind them myself from broken end mills .

~~~~~~~~~~~~

You ever make pointed carbide engraving cutters by just grinding angles and having them come to a sharp point so the cutting angle is about 15 degrees

~~~~~~~~~~~

I prefer to take off small relief angle on the sharp point against one of angles to turn sharp point to small cuttting diameter .

The cutter becomes stronger

I usually measure it on microscope to get correct results

[Thee Rickster ™]

I use edmBosto's and piglets

method with graphite for engraving

all the time. I take a piece of 1/8 carbide shank

and grind 3 or 4 flats at about 10-15 deg

to a point. (sometimes 5 deg)

Put a tiny flat on the end .005 t .015"

 

I have used this method on aluminum and

some steels too.

 

Works well.

[88Matt]

Do you have a license for the engraving toolpath?

If not, and you will be making very many I would highly recommend getting it.