1st attempt at a topographic carving. Project is 11” x 7.25” and was carved from Sapele. The finish pass took about 7 hours, but my step over was 4% diameter of a 1/8” tapered ballnose. Finish is Odies Oil.
I am wanting to do the entire state of Montana, but am hesitant to run my spindle (Hiteco 4hp) for upwards of 24 hours non-stop. Any thoughts, concerns?
Nice work, Will. The full state project will be awesome.
The spindle will handle a 24h job, but the problem is the risk of fire. Assuming you’re not planning to sit with the CNC for the whole time, the risk is that something goes wrong and you’re not there to hit the ES. There cases where the travel has stopped, but the spindle kept spinning with the end mill in wood and it started burning. With no one there to intervene, the embers started a destructive fire.
You can pause the job while you’re not there, leaving the CNC powered. The drives hold position and with the spindle off, ready to resume.
Mike
Thanks Mike! I have servos with drive fault detection that auto kills everything which is a plus but I do plan on being around it and not leaving for any extended period. I like the feed hold idea. Thanks.
I recently did a similar piece with size 12w x 16h of the Colorado front range. Stock was ~1.75” high with the lowest portion around .3 inches, so ~1.4 inches from peak to floor.
Using Fusion 360, I did a 3D Adaptive clearing pass that took around 1.5 hours, then a morphed spiral pass that took about 4 hours. That used a 1/4” ball nose running at 90 IPM (18k) with roughly a 5% stepover.
These were mostly defaults for my tool setup and I could have no doubt ran the morphed spiral path much faster. The 1/4” roundover provided plenty of detail and no sanding was required. The piece turned out great (was made out of cherry). I don’t have a picture of it, but here is the fusion 360 screenshot to give you an idea of the topo:
Short answer is I suspect you could increase your feeds, speeds, and bit diameter and still get the results you desire.
Just ran a sim in Vcarve pro. Model is 34" x 19". With the 1/8" tapered ballnose, its gonna take about 12 hours at feed of 120 in/min. Will never reach this speed because it will be limited by Z
axis max speed. I may try a 1/4" ballnose and compare.
How big was your Colorado model?
Nice work!!! What DEM did you use? Also, how large an area and what part of Montana is that?
I use 5 percent, 10 percent and 15 percent offset depending on the terrain and have been happy with the larger offset. Try experimenting, it might save you some time plus try using a 1/4 ball nose.
Here is California using, I believe a 1/4 inch ball nose bit and 15 percent sideslip to give you an idea of results. Carved in 1 by 12 pine so will not be as smooth as in a hardwood. Used a 1/4 inch end mill for the clearing pass. Entire job was maybe 2 or 3 hours. DEM was GOTOPO30.
I usually run the ball nose at 200 or 250 inches per minute. Hope this information helps when you tackle the entire state of Montana. I will probably be doing Montana in the next few months, just need to decide how big a piece of wood to use, might do it in pine first, then a hardwood.
Nice! Got the topo from USGS as a DEM, modified it in QGIS and exported as STL and toolpaths in Vcarve Pro. The area covers Paradise Valley with Bozeman in the upper left, Livingston in the upper right, and Gardiner (Entrance to Yellowstone NP) at lower middle. The Z is exaggerated a bit (maybe 2x). I will probably stick with 5% step over. I do not want to have to sand the mountains.
Here’s a rendering of the entire state I plan on carving …
