aluminum die making

[BarryB]

Hello, I'm about to cut my first piece of aluminum, and thought I'd ask some questions for you veterans.  The piece I'm going to cut is for a die stamp that will be used to emboss into leather, or heated and to wood burn a logo into metal.

The metal I'm using is 6061 aluminum, and would like to know a few things if you guys know it.  First off, what is the usual depth of this kind of die.  Then what kind of taper is used.  What angle taper, and also if you start from a prestine logo, (lets pretend it's the letter O), is the regular full size of the O, at the outside edge?  Or are we tapering to a thinner O on the outside of the die?  By outside, I mean the part that touches the leather fiirst when it's stamped in.  I hope that makes sense.

Lastly what kind of depth and feed rates do you recommend?  I've got a 2 HP machine, air cooled.  Is there a table for feed rates on metal?  I found them for wood, but haven't found them for metal.  Btw, my mill is running flawlessly so far, I freakng love it!

Barry

[edvaness]

10 days and no replies. You probably have it done already.

Depth , anywhere from .030 - .060.   surface speed, FPM , for aluminum ,about 500. for steel, 85.
This is Feet per Minute, not rpm. You must figure your tool diameter x 3,   1/4" end mill would be approx .750 per revolution,
500 divide by .750=666 x 12"=8000 rpm. Feed , about .002 -.005 per flute for a 2 flute high speed end mill.

Taper , anything over 3 degrees, but not important. Hope this helps.
Please post some pics.

Ed

[BarryB]

Actually no, haven't started beyond modeling it.  I made the taper 3 degrees.  I'm gong to try an inner and outer taper to see what gives a better result.  I've only got one shop computer, and it's tied up right now lighting a scene;(

Barry

[kf2qd]

First off - I don't have a whole lot of experience with your particular application ...

If you are making a die for leather you probably don't need any taper because you are embossing the surface, and you may need to look at a radius on the edges of you pattern ubnless you want to cut the leater as you emboss it. A 90 degree edge will tend to cut the leather, where a radius edge will press into the leather without cutting. Are you going to embossing wet leather with a heated die - that does give a more durable image as the wet leather is more formable and the heat would drive out the water leaving a very pronounced durable image. Lightly oiling the area would then protect the image and the leather.

If you are trying to use this as a punch you would probably be better off using steel as the alluminum would probably erode rather quickly from all the rubbing on the leather as it punches through.

For a wood burning die you want enough clearence that any material (smoke, finish...) doesnt fill up the die to quickly and ruin any definition the you are expecting from you pattern. Narrow angles and small details can be a problem.

A better aluminum that would have better wear characteristic would be 7075. It is much harder and can be a real pain if you are trying to put small threaded hols, but it wears real wlell in die type applications.