Although my computer is down, I can still get online and do some posting. My research has come to a screeching halt, temporarily, but I can get a little bit of work done on the yurt.
We ordered 15 boards of 1" x 4" x 10' from a local millworks, which turned out to be cheaper and of higher quality than buying it from any of the chain home improvement stores. It only took about three days for it to arrive, and the 10 footers fit easily inside my grand caravan.
On Monday, Avelyn came by and we ripped all the boards into 3/4" x 3/4" strips for her rafters. Only a couple of them "reacted
" and twisted into a funny shape. We finished this by lunchtime, so we took a break, got some sandwiches, and then made plans to drill the tono.
We made a jig using a block of wood cut into a 30-60-90 triangle, and started drilling the tono. Shortly afterward, we discovered that our block was growing just a little bit with each hole drilled, and the angle was changing. Rather than continue to drill bad angles, we announced an all-stop to the project and called it a day.
After thinking about it for a few hours and talking with Kelly, we decided that we needed a bushing to prevent the hole from growing with every cut, and I thought a metal tube of some kind might work. The next day, Kelly suggested that instead of finding a tube, why not just stack a bunch of washers and glue them into the hole? Well, heck yeah!
Rummaging through our collection of washers, I found some that would fit the bill! 5/8" washer with a 1/4" hole. There were quite a number of them, so I knew that it would be plenty for what I was doing. The only thing I was worried about was whether or not I'd have a long enough drill bit to go through the jig and the tono.
I took a new 30-60-90 block and drilled a 7/32" hole with the drill press (slightly bigger than the 3/16" pencil rod). This the same size hole that would go into the tono. To make sure it was the right height, I took a piece of pencil rod and ran it through one of the previously-drilled "good" holes and the block. The 30-60-90 block was taller than I needed (intentionally so), which allowed me to trim the jig block to length. Off to the chop saw, one quick cut (OK, two...) and the block was the right size.
Back to the drill press, I then replaced the 7/32" bit with a big, fat 5/8" bit, the same size as the washers. I drilled the 5/8" hole about 3/4 the way through the block--NOT all the way through.
I stacked about 6 or 7 washers into the hole, until the top washer was level with the shallow end of the hole. I then took some Gorilla Glue and put a drop onto the hollow on the deeper end of the hole. Gorilla Glue swells as it cures, so I put a small 1" x 1" block of wood into the hole and clamped it down for a couple hours while we took a dinner-and-karate break.
Fast forward a couple hours, the glue is dry, and I pull the block out of the clamp and carefully run the drill through it to make sure there was no glue in the channel. I then lined it up with a previously-drilled hole to make sure it lined up the way I wanted--measure twice, cut once! Looks good, and it still lines up with my pencil marks the way I want.
Time to go for it. Lined up the next hole, gripped the jig firmly, placing my fingers carefully so they weren't in the way of the emerging bit on the hand drill (sliced a finger a few weeks ago with that kind of carelessness), and drilled. The bit didn't emerge, but after a quick adjustment, lengthening the bit, I gave it another go, and...success! I made quick work of the rest of holes and they look good and consistent. I'm very pleased with this result!
I still have to cut the rafters to length, then I have all the parts ready to set it up! Due to some poorly drilled holes, a few of them may have to be filled and re-drilled, but I will have to consult with my woodworking guru to see if it's necessary, especially after the test-run of the set up.