Our CNC Router and Laser on Love Yurts

If you've never heard of a yurt, you are probably not alone. A yurt is a round habitable space that can contain many of the conveniences of a typical home. The roof of a yurt is conical in shape to conform to the round floor space. The wall of a yurt is an expandable lattice structure placed along the perimeter of the round floor structure. Yurts are low cost, very versatile structures and can be constructed in a wide variety of locations and terrains. Nathan and Jennifer make a living building these structures in Hawaii, Nathan chiefly focusing on the yurt structure and the furniture construction and Jennifer focusing on the fabric of the yurt (the "skin" of the yurt that keeps the rain out and can control the wind to a certain extent). She also finishes much of the yurt's exposed areas like the floor, ceiling and walls, and she also finishes the furniture with a bunch of cool techniques. Nathan, a customer of ours since 2012, asked us to set up a large 5'x10' greenBull CNC Router/Laser machine to help with the furniture projects he would be adding to the interior of the yurts, so we gladly obliged. We sent the greenBull 6'x12' CNC router/laser kit to Hawaii and Juan and I flew over there to assemble the kit. Once we settled in, we started building the CNC Router and Laser. Juan focused on the table structure and overall electronics to operate the machine and I focused on the gantry structure, Z and Y axes assemblies. It took us approximately 5 relatively short days to complete the CNC Router building process. The CNC router was not going to be placed in the most ideal environment. Nathan put together his own workshop using shipping containers and the fabric they use on yurts. The shipping containers form the main walls of the workshop with convenient storage areas of their own. Between these containers, they formed a concrete floor. The yurt fabric is used to provide shelter from the rain and intense sun. The openings at the ends of the fabric roof provided a nice breeze, especially when the main gate of the shop was open. However, this environment isn't the best for a CNC Router. Traditionally, CNC routers are made primarily of steel parts that can rust in these conditions. Our machine is primarily made of MDO (Medium Density Overlay), a heat pressed plywood product, which is very stable under humidity and temperature ranges. There are only a few components that are made of steel (the bearings, spindle, and fasteners). The danger of this environment will most likely affect the electronic equipment. So far, the CNC router has been in use for more than a year, so we will see if it stands the test of time in this environment. When the CNC Router was nearing completion, Nathan and Jennifer noted that during production of Love Yurts, things need to happen fast! Nathan wanted us to try to match this hustle by giving us 10 minutes to complete a specific task. The task he gave us was to form a deep inlay to tie two sides of a crack and maintain the structure of an expensive piece of exotic Hawaiian wood that will serve as a table top. Typically, wood workers will add a wood plug that resembles a "bow tie" to serve tis purpose, but Nathan didn't want the bow tie. Instead, Jennifer suggested we use a peace sign as tis was Earth Day. To create an inlay, a negative is formed in the master piece of wood, and a positive is formed from another piece of wood. To create contrast, the table top wood is a light shade of wood, and the peace sign to be inlayed into this table top is a darker (with a reddish hue) selection. We placed the heavy dense table top wood onto the machine's bed, positioned the spindle's end mill so the carved out negative portion of the peace sign would be positioned evenly across the crack to be tied together. Wood, having a grain structure, sometimes produces weak portions that can have unintended results, like a portion of the wood that is not supposed to be broken off while cutting out the negative portion of the peace sign. Fortunately, this loose piece of wood was able to be saved and glued in later. We then cut out the actual positive peace sign to be inlayed into the table top and glued the peace sign into the negative portions of the table top. If I remember correctly, the difference in tolerance for the positive peace sign to fit the negative space was 0.01". The fit was perfect. Both Juan and I were nervous as we just completed the assembly of the machine and had not done and practice cuts. I think an inlay would be the most difficult CNC Router task and with a newly assembled machine is a nerve racking experience. If there were any mechanical issues and electrical issues, it would make for a very embarrassing moment. Moreover, we were running out of time and were on our last days in Hawaii. With a little bit of time left, we decided to make a couple of signs. One sign showing our logo and another sign showing Ohana Yurts with its logo, Nathan and Jenny's yurt company. Nathan also wanted to see how well the CNC Router would be able to cut out a compression ring (yurt structual element). During this process, Nathan commented, "We are cutting out our compression ring for our 20 foot and 30 foot yurts. Essentially, its a big donut with a 6 inch thickness that is sandwiched together separated by a 4"x4" block. Once the compression ring is complete, we can start assembling our roof rafters and get them in place." Nathan and Jennifer were able to work with the CNC router for a while and asked us to come by to take a look at the CNC router, perform some maintenance and show them how to make some of the needed design elements for the yurts. Juan went back to Hawaii to do this.