Lessens learned by a noob (2 sides engraving / pocketing)

I posted my project over here: 2 sided engraved penguin sign
but had some questions about it so I thought I post what I learned here instead of cluttering up the project post with individual answers.

I’m an AutoCAD user, so most of what I describe below will use AutoCAD terms/commands, but I’m sure most of them are used in other CAD software as well.

I’m sure if you’re experienced with CNC/milling crating G code, some of this stuff will come naturally to you, but I’ve only used AutoCAD to design buildings, never anything this detailed before, so it was a learning process for me.

  1. To start off I downloaded a reference image & imported it into AutoCAD. I traced all of the major outlines with a Pline (Polyline), as you can see on the right side. I then faded the image with transparency and started to fill in the interior areas (left side). As you can see I had to deviate from the original image to create the arrow & scale down the logo. My role of thumb was everything that’s black would be engraved/pocketed, with the exception of the logo.

  1. I offset each Pline 3/16" so the bit would overlap a little bit. Here was my first big lesson learned. I didn’t connect all the Plines. So the Maslow would engrave 1 path/Pline, lift the bit, go back to the other end, drop the bit, over & over again… It took over 4 hr. to engraving the first side of 1 sign.

  1. I then learned to connect all of the small single Plines into 1 long Pline.

  1. Then changed the width of my Pline to 1/4" (the size of the bit) to see what areas are being missed by the bit. This worked pretty good, but because of the way Plines work with sharp corners, it looked like it was cutting areas it really wasn’t. So if I made the width a little smaller, I could see the areas I needed to fine tune.

5, Lastly, getting the 2 sides to register & match up. This actually worked out better then I expected. I posted earlier on how to do this: Engraving on both sides of plywood
There were a lot of good ideas, like using 2 pins to register the part, but I went the simple & easy direction. In AutoCAD I laid out 1 side of the sheet & then mirrored it left/right. Remember to un-mirror your text/logos, so they’re readable. Since Maslow is a 4’x8’ sheet I could just use the edges of it to line up my 4’x8’ MDF sheet. The important part is where the router starts it’s home point. On side 1, I had it drill a hole all the way through. This hole was at the center of the sheet horizontally, so 4’ in from either side & then it did all the engraving for side one. I then flip the sheet left/right to side 2. I then use the Maslow controls to set my home point of the router over the hole that was drilled on side 1 & then start engraving from there. For the most part everything lined up perfectly. I did have a chain skip on one side & that made things around 1/4" off, but it was still good enough… :wink:

  1. Painting tip. Using this engraving method to “color inside the lines” is helpful, but it also had a down side. As you have to also make sure to paint the edge of the lip of the pocket or else you have exposed MDF between your 2 colors, so it can be a little tedious. I painted all the colors first & over painted the edges/lips & then filled in the black & cleaned the edges last.

I think that’s it for now. Let me know if you have nay other questions.


Interesting. So you essentially did half your CAM manually?

Sorry, I’m not sure what you mean by that… Noob remember :wink:

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Mea culpa.

It looks like you drew the paths you wanted the bit to follow. I am not sure what CAM program you used, but it sounds like you had it follow the lines you drew. (maybe I am way off here)

Usually the CAM program takes in the image as drawn and then the user defines things like pockets or outlines. For instance, instead of filling the penguin’s flipper with plines to define cutting paths, you would select the outline of the flipper in the CAM program and tell it to perform a pocketing operation within that outline and the CAM program would figure out the path to follow based on the bit size and step over requirements that you put into the CAM program.

Does that make any more sense?

Oh yes, I guess you’re referring to Fusion 360 or something similar. I don’t have access to it or know how to use it, but I’ve used AutoCAD for 20 years, so I’m comfortable with it. So I’d say I actually did all of my CAM manually, not half. :wink:

I exported to .DXF, then imported into InkScape, exported to .SVG, then opened in http://www.makercam.com
Some of the paths I set to “follow path operation” (center bit on Pline) and some of the other paths, like the logo, I used “profile operation”, sometimes inside, sometimes outside…

But I now see makercam.com has a “pocket operation”, so maybe that would have been a better option for me.
Another lesson learned. :wink:


fusion360 is free for hobby use, onshape is free if your designs are open for
others to use, take a look at them, they will be fairly familiar if you have an
autocad background

There are a number of people who do their CAM pretty manually (draw their shape,
then define offsets, etc), but there are a lot of tools out there to do a lot of
that work for you

In your case I am referring to Makercam.

but it seems you have already figured it out :slight_smile:

Amazon job especially since you did the CAM manually.