…code, cg, electronics, 3d printing…

I bought & assembled my X-Carve cnc during Christmas, 2015.  Ever since then, I thought it would be perfect to do topo maps.  I had great success with Denali & Lake Tahoe, but always wanted to do something bigger.  In fact, a year before the X-Carve’s arrival, I’d 3d printed the (lower half) of the San Franisco Bay Area, which I felt turned out well.

Some friends and I took a trip to Firewood Farms in Half Moon Bay, where I picked up a couple slabs of redwood, without really knowing what I was going to do with them at the time.  Then the stars aligned, and I realized one was the perfect shape to do a cnc topo map of the whole bay area.  “The Bay” is the result:

More pics below.

Info on it:

• The piece measures 17×30″, and about 1.75″ deep.
• Rough cut was 3h, 10min.  Finish pass was 6h, 20min.   Total was 9.5h (my whole Saturday…).
• Used a 3-flute .25″ ballnose for both passes, DeWalt router on speed 1.
• Roughcut feed for X/Y was at 150″/min, finish pass was at 210″/min.
• Roughcut feed for Z was 20″/min, finish pass was 40″/min : I had to modify my firmware to get these speeds.  I tried a faster z-feed, but the machine couldn’t raise the spindle that fast, and chaos ensued.
• Very little sanding was needed, based on the 10% stepover during the finish pass.
• Used terrain2stl to get the topo data.
• Used Autodesk Maya for all the mesh modification, and text creation.
• Used MeshCAM for the toolpath generation.
• Used Universal GcodeSender to send the cam to the machine.
• Applied a ‘natural’ Minwax stain, and “Blue Lagoon” satin paint.

Issues:

• I think the poor Arduino Uno couldn’t handle the fast feedrate during the rough terrain parts:  The whole thing would start & stop over and over (giving me an anxiety attack at first), while the buffer caught up with the operations.  Maybe it’s time to get some new electronics?  That really slowed down the finish pass.  Didn’t have any trouble during the rough.
• I think I could speed up the rough-cut even more by not using MeshCAM’s ‘Use 3D Roughing’ option : while it makes a nice looking roughcut, who cares, it’s all getting cut out anyway.  The result was a lot of small up/down z-travels, that really slowed it down overall.

Here’s a series of photos showing the process:

A shot in Maya, while I got the text arranged:

1.15 million triangles:

The very first cuts:

Roughcut complete:

The final piece, before stain and paint:

In conclusion, I found this to be really satisfying project, and it looks great hanging on my living-room wall.

I’ve been teaching myself the MASH toolkit in Autodesk Maya.  It’s been a lot of fun to learn.  As a challenge, I decided to design a hexagonal-based structure, which I then cut into some reclaimed redwood with my X-Carve CNC:

I applied a ‘natural’ stain to the inside section, and a darker ‘walnut’ stain to the outside.  The rough cut was with a 1/8″ 1-flute upcut endmill, and I did a pencil-cleanup pass with a 1/16″ 2-flute upcut endmill.  Whole cut took maybe 45 minutes.  The piece measures 8″ square, and the cut is around 1″ deep at the lowest point.  I used MeshCAM to generate the toolpaths from the stl file exported from Maya.