"Reverse" Engraving

[HCProf]

Not sure if it has a technical name, but I want to engrave a pocket around a logo. So instead of cutting out the logo, cutting out everything else leaving the logo proud in a pocket.

I have done this before with a normal pocket toolpath, but it was a huge name plate. I was able to use a 3/8" end mill for roughing and re-machined with a 1/4" end mill to finish.

But this project is tiny, they are 1.5"Ø challenge coins for a military charity thing; I picked up some 0.010" and 0.020" tapered ball-nose endmills for it. So before I start, I wanted to see if there is a specific toolpath for something like this, or if anyone had any suggestions on what toolpath would be best suited.

I am using 2023 mastercam, and I dont want any vertical walls on the proud parts. Not sure if thats easier done in the geometry or if its possible to define in a toolpath paramter.

 

TIA!

[Leon82]

there is an engraving path that should work.

you could also use surface horizontal and pick the floor as drive and top of the letters as check 

but i would try a pocket set to zigzag with a tapered wall angle in depth cuts 

[SuperHoneyBadger]

Logo will be embossed, that's your key term.

If you run a 2D contour with a tapered tool as your finish pass, the walls will be at an angle dictated by the tool. For shallow geometry, don't worry about modelling the wall at a draft angle. You can run the whole thing off wireframes, really. or a model with vertical walls, and the tapered mill will just leave a bit of material at the bottom of the walls.

+1 to zigzag pocket ruff, will give you the quickest solution in 2D, without going into dynamic (which would be best overall)

[HCProf]

It WORKED!

Challenger Coin Engraving

Thanks ya'll!

I did the engraving tool path - first rough then finish, selected "clean corners" for my roughing, smooth corners, cut geo: at depth, with a 20 degree entry ramp, and a 10% stepover on a 0.040" diameter tapered ball mill.

 

These are still test pieces so I will keep working. My first attempt I did a re-machine with a 0.020" tapered ball mill and it just left a rough finish on the proud features.

 

I cant remember if I mentioned this or not, but this is for a program Im teaching called "Operation Next". Its a semester of online training, 7 weekends of shop time, and 4 NIMS certification test. It was started to help exiting military have a skilled job lined up after they get out; help transition into civilian life. Its just an Machine Operator certification, so loading parts and tools, and pushing buttons. But at least its a foot in the door at a machine shop and it counts towards credits if they want to come back and get their associates in machining later.

Regardless, I know the importance of challenge coins in the military. So, near the end of the semester, they will each submit an image and it will have the college on one side and their custom image on the other. They will be award these with their certificate of completion.

 

So, again cant thank yall enough for the help!

[Thad]

Nice work, @HCProf!

I got a challenge coin from my unit in Germany. SPEARHEAD!