Engraving Tips in CAM (Fusion360)

[Davie]

There have been a few times when working on an engraving piece where I wanted to add some shading that wasn’t in the original art. On a recent project at home I figured a few things out and want to share with you what I learned. For this purpose I am using the Tormach logo:

Before I go too far, I would like to shout out to NYC CNC for their video on engraving that got me started several years ago. Engraving Tools: Speeds, Feeds, and Tips! | WW237

For this engraving I used the Lakeshore Carbide 0.02 ball engraver.

CAM Notes
Note that I am using Fusion360 but I expect a similar workflow to work on your CAM platform of choice.

Now as you can tell in the original artwork there are is no shading or hashed lines, which is something I wanted to add in order to make this engraving pop.

• The first step in this process was to use the Trace tool path to follow the lines in the sketch. The only thing special that I did here is set the “Axial Stock to Leave” to -0.005"
  
  
• Next I wanted to fill in the sections of the T with diagonal lines. In order to accomplish this I used the Parallel tool path with a few key factors.
  • Stepover = 0.045" - Naturally CAM complained that the step over was wider than the tool but I just ignored that. Set this value to whatever makes sense for your project.
  • Pass Direction = 45 degrees. This was an artistic choice to make the lines diagonal.
  • For Machining Boundary I selected the sections of the T that I wanted to engrave.
    • Under Tool Containment select “Tool Center on Boundary” then add an additional -0.003" offset. This last part will keep the outside shape of the T in good working order.
      
• For the outside border I didn’t like the way that the 45 degree lines looked so I changed the pass direction to 18 degrees.
  
  

Here is the final engraving: (I scuffed it up a little trying to polish it for you all)

The original project that provoked me figuring this out is this engraving.

[Henry_Feldman]

Thanks for the tip, that’s so cool, I wonder if we could make that pattern in the original image using Illustrator (or other vector tool of choice) since cross-hatching is a feature, and then export that as a SVG into Fusion? how many passes of the end mill does it take? I have a similar project coming up so this is perfect timing. Do you do a single pass of the engrave and then another to deburr the narrow slots? I’ve only ever used the Tormach drag engraver thingy (that sort of drag knife for metal), which works “OK” on soft stuff like AL or brass, but seemed to mostly scratch stainless or harder metals, and can only work like a drag on a path (so no dots), but an actual engraving mill sounds better.

[Davie]

As far as making the cross hatching in an image editing process, that would work fine. I liked the flexibility of making these lines in CAM because I could adjust it on the fly based on how it looked on the part.
I did one 0.005" deep pass for this. I cleaned up the engraving by re-running the facing op except keeping the face mill 0.001" off the surface.

If you would like to see this run, we just did a video comparing some of our machines using this project. Tormach PCNC 440, 1100MX and 1500MX Engraving Competition

[Dan_Suskin]

I use a similar technique to put texture into a foot pedal I make - flat knurling

[Davie]

Wowza. That looks pretty cool