Posts Tagged ‘ topographic map

CNC The Bay

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:

uberbay_final_web

uberbay_persp_web

uberbay_closeup_web

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:

uberbay_maya_web

1.15 million triangles:

uberbay_maya_polydensity_web

The very first cuts:

uberbay_initialcut_web

Roughcut complete:

uberbay_roughcut_web

The final piece, before stain and paint:

uberbay_unpainted_web

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

 

New Commission: Denali

denali02_webWas recently commissioned to make another Denali cut on my X-Carve.  This time I swapped out the 1/4″ ballnose used for the rough cut for a 1/8″ ballnose on the finish cut:  Really helped the mountain detail pop.

I had split the rough and finish cuts into two files:  Only downside was that using Chilipeppr, it started to choke on the 4.8meg finish pass file. It would cut for 8 seconds, then pause for 4, etc, repeat… making it take waaay longer than it should (3.5 hour finish pass). Talking on the GoogleGroup, I guess this is a known problem, and the SPJS grbl code needs a port from tinyG. Next time I’m going to give UGS a shot…

I’ll give another shoutout to Terrain2STL, the great app I used to generate the terrain data.