I like to bring a variety of woodworking tools into my projects. I recently finished a Logs-to-Gnomes project and offer my work-in-progress summary along with some photos of same. This project used: chainsaw, angle grinder, bandsaw, jointer, CNC machine.
My yard backs up to a wooded area. Had a wild fruit tree branch come down in a storm along the tree line in back of my yard about five years ago. I cut it into 2-foot-long sections of diameter ranging from six inches to up to eight inches, coated the log ends with sealant, and put the log pieces in my basement for long-term drying. Opted to get them out a week ago and work them into manageable wood billets for carving on my CNC machine.
Prepping the logs for CNC machine:
Grind the bark off with an angle grinder out on the driveway … big mess and lots of fine particles came off the grinding wheel. Took about three hours to do six log sections. Temperature on driveway was 45* with brisk wind … was happy to get that finished and back inside the house. See Photo.
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Cut the two-foot-long sections into eight-inch long sections on my bandsaw with help from a jig for safely holding the pieces for the bandsaw cuts.
Resaw the eight-inch-long pieces in half using the bandsaw with another jig to safely hold the round log sections for resaw. See Photo
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Get good 90* ends top/bottom by carefully cross-cutting again on the bandsaw.
Run the flat side of the half-log sections over my jointer to get a nice flat surface upon which to place on my CNC machine table.
Machining on CNC machine:
The CNC relief design to be carved is 0.9 inches deep and 4.25 inches wide at widest point. Since the half log sections are round, needed to recess the top of the carving design 0.75 inches below top of log so widest part of carving is within round perimeter of the half-log billet. The half-log radius is 3 inches which leaves a base under the carved design of 3 - 0.75 - 0.9 = 1.35 inches.
With the half-log billet flat side down on top of CNC machine table top, I opted to machine the top of the round ‘top’ face down to a flat face … now 0.9 inches down from from outermost top side of round log surpace. This becomes the top of the 0.9 inch thick carving design billet. I left a one-inch section at the bottom of the log section at this height for the Gnome to 'stand' on. See Photo
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Next was to run the CNC machine to carve the Gnome and hope that the widest section of the relief carving would fit in the rounded log profile based on preliminary measurements. Of course, Murphy prevailed, and it didn’t. Had to go back and lower the CNC carving design top a little more to get the full depth of the model into the half-log billet at the widest section of the carving model. See Photos of 1) roughout machining
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and 2) finished machining.
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I'm pleased with the outcome. The log prep with traditional woodworking tools was most of the work and the fallen fruit tree limb machined well and has a nice look to it. I bought the ready-made CNC .stl 3D design file online. I crafted the CNC relief carving toolpaths to compliment the .stl 3D file with Vectric software. Combining the toolpaths on a round log and recessing the design into the half-log billet was new to me, but seems to have worked out ok.
Still have some spot sanding to do to clean up some tooling witness marks then will put a coat of Tung Oil on the pieces.
Hope this is of some interest to the SMC woodworking community.
Regards,
Tom
