Inlay Work (Woodworking)

I would suggest starting with Carbide Create, which I started to cover above — the problem is, it lacks an offset path functionality, so one would need to do this by hand, and it would require that one do the mathematics to determine where objects go and what size they are.

EDIT: it will also be necessary to manually add rounded corners, a technique for this is shown in: — you really should start on some simple tutorials first. I believe if one only does paths with such suitably rounded corners no additional math will be needed.

The best free drawing program is Inkscape (if you have a Mac you may want to consider Cenon) — both of these are vector drawing programs and want one to understand Bezier curves and their on- and off-curve control points. If you have access to a copy of Macromedia Flash, it’s a nice alternative.

Answered that in my post above:

Thanks again for your patience I did manage to download inkscape onto my MacBook
I will try your method later on this evening as I have to head off to work right now but thanks again for responding so far it’s helpful
This is a new learning experience

To resume where we left off — we’ve opened the SVG image in Carbide Create and discovered that it needs to be fixed up to some degree:

Since we can’t asymmetrically scale a selection, we need to draw a new rectangle:

Then set the origin to the bottom left corner, and the X and Y to 0 and 0:

Then set the X and Y to the correct dimensions:

Repeat this for the opposite panel — duplicate the left panel, select the background rectangle, set the origin to be the bottom right, note the coordinates, select the duplicate and apply the coordinates to its bottom right corner:

If we were working with a laser with an essentially zero width kerf, we would be done — as it turns out, for a square ended round endmill, say a 1/8" diameter — we now have a file which we can’t cut out twice over and have the inner and outer elements match.

The problem of course, is the corners and other sharp points of inflection. We need to round the corners by a bit more than the radius of the endmill, and we need to offset the path for the maple leaf so as to ensure that it can be reasonably cut.

The rounded corners are (hopefully) adequately explained in: and that technique can be used here once everything else in the file is ready to cut.

Unfortunately, Carbide Create has no facility for offsetting paths as paths (it can do that for toolpath geometry, but we need a bit more control), so we must return to the Inkscape file.

Refer to Apollo’s post if you don’t understand why this is necessary: Inlay Work (Woodworking)

Return to Inkscape, open the file and break things apart until one has discrete paths and set the view to outline mode:

Make a duplicate of the path in place so as to have something to refer to.

Next we need to puzzle out about how much to shrink the path before off-setting it so as to preserve roughly the original size / proportion and appearance — 96% should be about right (you can do math to determine this, estimate it by trial and error, or inset a copy by half the bit diameter, measure it, and then do the math to determine how it relates to the original):

There are a number of ways to arrive at the desired geometry, depending on the drawing program. The most expedient in Inkscape seems to be to assign a stroke which is the same thickness as the endmill which will be used, in this case 0.125" or 3.175mm — the stroke should also have rounded joins, and if applicable ends:

One then does Path | Stroke to Path to arrive at:

The outermost path should be one which can be cut inside and outside by the cylindrical endmill which we wish to use — to verify this:

  • delete the other copy
  • break apart the paths — Path | Break Apart
  • delete the inner path
  • duplicate the maple leaf path
  • set the duplicate to a 0.125" stroke
  • do Path | stroke to path to arrive at an inner and outer path
  • break apart the paths

Unfortunately, Inkscape gets a bit confused at some points, but we can at least use this for a preview:

Fortunately, the paths are not needed for actual cutting, but merely for a preview. We assign a contrasting stroke to each of the 0.125" thickness which matches the endmill which we will be using and check for gaps in-between:

As we can see, there are several points at which the paths will need to be adjusted so as to allow the inlay to fit properly. The paths could be re-drawn, or we can try again with a narrower endmill — 0.0625"

Re-working the paths results in:

which previews just fine:

One then saves the SVG, imports it into Carbide Create and assigns suitable paths to the central path:

  • Toolpath | Contour | Pocket to cut out the pocket for the inlay
  • Toolpath | Contour | Outside Right to cut out the inlay piece

The SVG and a C2D file ready for importing or toolpaths are attached.

canada_flag.c2d (227.4 KB)


Hi Will, at the start of this topic you mentioned plug-in for Adobe Illustrator. I found it, looks great but pricey.
If I go for it I need to know what Post Processor I need for Normad 883 so the software creators will make sure they add new Post Processor for my CNC.
All I know is that Post Processor is the last stage for a CAD software to create G-Code file for a particular CNC.
Please tell me where to find/learn about Post Processor and which one is required for Nomad 883 Pro?

You need to have one which works with generic G-code / Mach3 / Grbl / specific machine type (in increasing order of desirability) — the post-processor is that small bit of software which describes to a CAM app the specific capabilities, features and idiosyncracies of the machine.

We do have some notes on the wiki:

In the meantime I received a message from the software company that they did some research and found that the Nomad requires XCarve post processor.
Is this correct?

It would be fine (they both use the same firmware, Grbl) — ask them what would be involved in adding support for a tool changer if the app would benefit from it — Carbide Motion with a Nomad will simulate an automatic tool changer and will re-measure the changed tool.

Sure, my response will go directly to your support address email for consideration.

Okay, we’ll work up a response and send that back to you as quickly as we can manage.