I’ve had my home built CNC router machine for a couple of years now, but one thing I’ve not really done with it is to create a sign. It seems like an obvious thing, but I’ve always been more interested in making mechanical parts.

I was down at the flying field the other day and noticed that our sign was looking pretty shabby.

Old Sign


First thing that popped into my head was “I can fix that!”. I went home and immediately started drawing up the new sign. It’s a bit simplified because I’m not much of an artists, but I think it came out okay.

You can watch the video or read the rest of the blog post, or both!

I drew the sign in Adobe Illustrator and Photoshop and then exported the combined file as a .DXF file.  I imported the DXF into CamBam to generate the tooling paths.

Original Art CAD


After setting up the tooling paths, I exported the .nc file which contains the G-code and set up the router and started the job. Unfortunately I didn’t realize that I had typo’d on the word ‘Spectators’ until after I had machined the sign.  I used 3/4″ high quality plywood for the sign.




In order to correct the misspelling I decided to cut down deeper into the plywood and then cut the proper text onto the sign.

The Fix CAD Drawing




As this was machining I was doing some web browsing on sign painting.  It turns out that I should have primed and painted the sign’s background first, then put a vinyl mask over the sign and cut.  It would then be very easy to paint the letters without getting paint on the background, etc.  I’ll try that out next time, it should save hours of work!


I laid down a laid down several layers of primer, sanding in between coats, before applying the final layer of exterior latex white paint to the sign.


Sign-With-PrimerI forgot to take photos of when I added the center background to the sign, the blue area and also when I started filling in the lines, but you can see the progression in these photos.  The paint is a spray paint, it would have been better as a acrylic latex like the base paint, but I had to use what I had.  The colors in the letters are acrylic hobby paints, I hope they do alright. There’s quite a few coats.

Detail-Painting-in-ProgressAnd here’s the final photo of the CNC’ed sign.



It turned out pretty good. Due to the combination of paint types and the heavy amounts of paint in the lines I am going to let the paint dry for 2-3 weeks before I do a final clear coat on the sign. I would hate to have moisture come up from the paint and bubble the clear, so I will have patience instead.  It’s probably going to be at least that long before the club field is used heavily.

I learned a few things in this process:

1. Having  a v-bit cutting software like V-Carve Pro would be really nice, but isn’t required to do basic signs.

2. I should have done the text with a V-bit instead of straight router bits. It would make the letters easier to paint.

3. Prime and then paint the base color on your sign blank first, then put a masking film over before you machine it. Once you machine it, the masking will stay in place while you paint your letters and protect the base colors.

I’m sure I’ll try more signs in the future, despite the troubles I had, knowing those few things above will make things a lot easier the next time around.  I showed the sign to the club members on our monthly meeting and they seemed to like it!


Tags: , , ,