At this point, I did another round of sanding - any faces with which I wasn't happy and chamfering all exposed edges. The top points of my risers protruded past the ring, so I just trimmed them off with the razor blade. I used some contractor paper to keep the glued surfaces apart while I worked my way around the nest - if they accidentally touch, they'll stick and that's frustrating. The third phase was more difficult because visibility became an issue. The large, top ring was my next target and went as smooth as the first phase. Glue up started with the small ring since it goes on the inside and I didn't want to have to try to squeeze it in place. Once you connect the three sets of opposing marks, you have six equal divisions. This was done by putting all the rings back together, setting the beam compass to the outside radius, picking a starting point on the outside edge, and marking arcs around the circumference. I also chamfered the edges of the smallest ring with the dremel (prior to assembly - when it's easy).īefore getting into the glue, I needed to mark my riser locations. For the inside edges, notches, and other hard to access facets, I used a dremel with a sanding drum. The oscillating belt sander was used for the outside edges of the rings, as well as some faces of the risers. This creates left and right pairs and makes it possible to hide the textured side in the glue seam Prior to assembly, I cleaned up the edges of the disc and riser laminations. Since I wanted the risers to be two mat thicknesses, I cut out a total of 12 - 6 from one side of the pattern, flip the pattern, and then 6 more. I cut out my sketched part, made a poster board pattern, traced them onto foam, and cut them out. Because the rings are concentric, the widths are set, so it's mostly a matter of vertical spacing - then drawing an arch and marking for notches. For the riser parts, I drew out a 2" grid on some paper and sketched until I was happy with a shape. Two small rings - glued into a 3 ply lamination. Two medium rings and one solid disc equal in diameter - glued into a 3 ply lamination with the disc on the bottom. This will leave you with: Three large rings - glued into a 3 ply lamination. Cut out the medium and small rings from the remaining two mats. Cut out all three large rings - the outside and inside edges. Sharpen your blade, steady your hand, and cut out some rings - but not all of the rings. Measuring in 2" and resetting my compass to 9" radius, gave me the middle sized ring. I marked the center of three mats, set my beam compass an 11" radius, and drew the circles. The largest ring I could get out of a mat was 22" in diameter. The second EVA foam component was the crows nest, which started with concentric rings. Note: Use the 3/4" copper pipe to keep the center holes aligned as you add layers The fully assembled blocks were then shaped using the oscillating belt sander I thin it with Barge thinner for easier/more consistent application and apply two coats - first coat, let dry, second coat, let dry, join the parts. Assembly is just a matter of gluing parts up and stacking them like sandwiches. I used the oscillating belt sander to put a chamfer on one end of the pipe, which is sharp enough to cut/punch through the foam mat with the aid of a rubber mallet. A center hole was punched in each disc and side using a section of 3/4" copper pipe. Note: Do not sand the side and end parts at this time. Once shaped, I used my shop made marking gauge to mark the center of each disc. Just sanded to the line in order to knock down any angular edges. Once all of the parts were cut out, I trued up/shaped just the discs, using the oscillating belt sander. Note: Mark the center point of each side before cutting them out - it's way easier. I highly recommend this Kershaw sharpener. It goes quickly - just keep your blade sharp. Single pulley: 2 sides, 2 ends, 1 disc Double pulley: 3 sides, 4 ends, 2 disc Triple pulley: 4 sides, 6 ends, 3 disc Since I needed two of each type, it was a fair amount of tracing onto EVA foam floor mats and cutting with a razor knife. They all use the same parts, just a different quantity. I needed three different block and tackle configurations - single pulley, double pulley, and triple pulley. In addition to this "side pattern," I needed truncated "end patterns," as well as a disc, for which I just traced around a 3" PVC cap. I sketched out a desirable size and shape on paper and transferred it to poster board to be used as a pattern. Fabrication started with the block and tackle, since I figured it would be the most tedious aspect.
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