Second Project, Goat Signage

The second project is a logo that was originally created a while back and it seemed like it could lend itself pretty easily to being CNCd.

 

The Cutting

The goat did lend itself to being reproduced by CNCing, but detail had to be eliminated before beginning production — the original amount of detail was way too much and had to be worked down and the extraneous and non-reproduceable information eliminated from the original artwork…keeping in mind that we were working with an 1/8″ straight cut bit.

Since starting with CNC, we have also come to find out that a lot of sign makers use V-bits for the majority of their work. We were wondering how a maker would get fine detail (when just using a straight cut bit?) and this seems to be the way to do it. This logo was done completely with a mill end straight cut bit with a 1/8″ cutting diameter with two flutes, 1/4″ shank, and a 3/8″ cutting depth. Experimentation with the V-bits is still to come for us though. If you want to see a nice, basic explanation of how V-bits work, visit the video by Dave the Woodworker.

Also, we were having some major issues with the depth of the cuts…starting out way too shallow and ending deeper than the proper depth (considerably deeper at some points). Overall it was cutting too deep when approaching the proper depth. After searching online for some modifications to address this situation, we found this at the Maslow forums: Cheap fixes for z-axis slop on the Ridgid R22002. Thank you geeklimit for the excellent information. This worked out pretty well. We would have liked to use a mechanical connection between the bushing and the tab, but weren’t able to tap and thread it. You can get the full details by clicking the link above.

This modification basically involved attaching a bronze bushing to eliminate the majority of the perpendicular play in the router body tab controlling the z-axis height and the placement of a small washer at the bottom end of the “worm” screw to eliminate the remainder of the major play in the mechanism. This took the amount of play from approximately 5mm to about 0.5mm…we were still experiencing some play here, so we intend on also placing the “bungee” method as well to keep the router body down consistently on the working surface.

Back to the logo…this took a huge amount of time to cut as an entire unit when we first started it, so we decided to break it down into separate sections for the CNCing. We still aren’t sure why the simulation time was so far off from the actual time that it took to cut the art/logo. We definitely didn’t want to be sitting in front of the machine for 15 hours keeping an eye on things. One of the drawbacks of the Maslow is it is a slower cutting machine. We set the entire logo up in the first file (in Easel), then duplicated it a number of times. Then for each duplication, we deleted everything except for one of the related sections for each file. We ran the files in succession and ended up with the completed logo/signage when all the files had been run/cut.

 

Gallery: The Overall Process

The gallery above chronicles the process up the point that it is now.

Here are the cutting issues in a nutshell:

  • Depth of cut: slop in the “out-of-the-box” setup for the router was definitely a problem (still addressing)
  • Type of material for the sign: this really should have been wood as opposed to a composite or plywood. This was a sanded birch, 1/2″ thick and an “MDF” type of material was used for some of the underlying layers. This had a tendency to create a “furry” surface if not cut all the way through
    • Also, there were some voids that opened up when cut into
    • Also, smaller/finer detail tended to blowout (most likely due to the layering of the materials and the type of bit?)
  • Type of bit: this was done with a “straight cut” bit and could have probably been done with a V-bit instead and turned out much better

 

The Finishing

This was the fun part, but probably could have been streamlined.

These are the colors:

  • Yellow/Orange for the main text
  • Red for the diamonds
  • Dark brown oval highlight ring
  • White for the recessed area of the goat
  • Blue gray for the second most outer ring
  • Black for the lines around and in between the horizontal green lines (not completed yet)
  • Dark green gradating to a yellow green for the horizonal lines
  • A medium stain (cherry) going into the oval area and on the raised areas around the goat (to hopefully bring out the white a bit in the goat – not completed yet)
  • A darker stain in the horns (not completed yet)

All painting was done by hand with no masking. Any mistakes were hand-sanded to remove. All the areas outside of the horizontal lines were masked off and the green/yellow green lines were airbrushed with a standard Paasche double-action airbrush. Black is still to be painted.

The final coat will be a clear polyurethane to help seal the sign.


Sign specs:

Sign is:

  • Purpose: created as a test/sample
  • Dimensions: 17″ x 12″
  • Material: 1/2″ sanded birch plywood
  • Eight color: yellow/orange, red, dark brown, white, blue gray, black (not completed yet), green, and yellow green
  • Two stains: a lighter cherry stain for interior areas around main text and the goat and what is called “Provincial” – a darker stain for the horns of the goat
  • Final finish: will be a clear, semi-gloss exterior polyurethane, three coats