Big Yard Snake part 2

The next step in the construction of my snake is to round out the tapers I rather wildly cut on my bandsaw. Manipulating an 8-foot log while trying to take slices off the ends that weren’t clearly marked to begin with left me with some ugly and rather uneven cuts, but I’m not looking for perfection in this thing, and the ends aren’t that bad. So, I began by using a large bench chisel and a wooden mallet to round them out.chiseling wood

I worked my way “downhill,”chipping away until I finally had the ends mostly rounded and the tapers looking acceptable.end of logThis took a few hours and left me with a nice pile of chips which got collected for the woodstove. They are great fire starters.

 This still left the surface rougher than I wanted, even for a prototype, so I grabbed a small block plane and worked on smoothing the ends a bit more  until I had something a bit smoother and a surface that could be marked up more easily. block plane on endI had originally intended to use a sander to smooth it even further, but I was pleased well enough with how it looked after just planing.

 Remember the big crack that runs the length of the log? I decided that as long as I oriented my joints so that the split came on a “meaty” part of each segment, it would likely not be a big structural problem, and since, by nature of the joint, that means either the top or the bottom, if I make the split the belly of the snake it will be mostly out of sight.

 The individual segments are simple wedge shapes that will be produced by cutting down and towards the front from the top, and up and towards the front from the bottom, meeting at the center. So I need to mark a center-line along the length of this tapered log, apx 90 degrees from the crack. I did this with a crude scratch marker I made from some scraps with a nail as the marker.

marking gauge

 It did a rough but sufficient job, so I followed along with a red Sharpie to make the marks easier to see, and then stepped off 1 1/2” segments from the head to within about 6 inches of the tail. tic marks To mark the wedges, I used a drafting triangle to mark a series of 90 degree lines at each tic mark. marking the wedges

After numbering the segments so I could keep them in order, I cut along the lines to divide the log into more manageable pieces.log segments It was a pain in the butt trying to guide that 8 foot log through my bandsaw, trying to make two angled cuts intersect when I was often several feet from the blade, but I did manage to do it without breaking my blade, hurting myself, or doing any irreparable damage to the log. Still, I’d have to say this pretty much marks the size limit for that sort of approach.

 After dividing the log into smaller sections, it was not too tough to start cutting individual segments, though it could get tricky with the log segment wanting to roll on the flat bandsaw table. individual wedgesA 4” diameter is about as big around as I’d want to try without making some sort of sled or other device to keep it from rolling.

Keeping the segments lined up on my bench in order, the next step was to drill 5/16” holes for the 1/4” rope spinal cord that’s going to hold this all together. I don’t want the rope to have too much play, but I want it to be able to move a bit, and I also want to be able to string it easily. I made a quick and dirty “V” block to hold the segments while I drill the holes from back to front.drilling the hole Most of the time, the hole comes out pretty close to the center of the point, but since each wedge and the “V” block itself are all a little sloppy, and don’t always fit closely, I occasionally have to widen the hole a bit to make sure I can get the hole to exit through the point.

 After the segments are cut and drilled, they also need some additional shaping. If left as cut, they have a small amount of motion up and down because of the material removed by the saw blade, but virtually none side to side unless the joint pivots on the outside edge, and since my joint will be fixed at the center by a rope, that cannot happen. For the joint to pivot side to side about the center, I need to grind back the pointed edge, sloping it away from the center point (the rope hole), but keeping the tapered wedge shape. I do this on a 12” sanding disc with 120 grit paper on it. I judge the angles by eye, not bothering to mark them, but checking each segment against its counterpart to see if they can move some.checking the fit So the progression becomes: grab a log section, make all the angled cuts on one side, holding the log with the center-line facing straight up; cutting the wedgesflip it ’round, and one by one cut off the wedges by making the angled cuts on the other side, keeping the center-line up. When the wedges are all cut, drill all the holes, one segment at a time, taking care to see that the exit hole on the point of one segment matches with the entrance hole in its mate. Next, shape each segment slightly so that the edge tapers away from the center hole and also away from the top and bottom center-lines. Stack each section next to the previous one, keeping everything in order, and move on to the next section of log.

segments in order

After doing a couple dozen segments with many more to go, I figured I should string it together and see if the basic concept actually worked before I wasted any more hours on this. test sectiontest segmentSo far so good! I could probably stand to go back and tweak some of the segments, perhaps grind the edges back a smidge more to give me more range of motion, but for now it’ll do.

So that’s where I leave you today. Still much work to do, but I’m feeling better about the joints now that I’ve made a few of them and done at least a preliminary test of how they work. I also have a clear if somewhat tedious path ahead, that I think is going to get me pretty close to what I want. Time will tell.

See you next time.

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  • Paperkingdoms

    very cool!