hrj

Again, image-heavy so it's behind a cut. In this segment, I implement all the features I've designed so far and do a proof-of-concept cooking project.

So the first thing to do is drill bolt holes in the uprights at 1.5" intervals, starting at the lowest possible setting for a total of 8 holes. That takes the top-most hole high enough that all it might be used for is warming.

Note that the silver-colored upright will eventually be painted with stove-blacking like the other one. (In fact, I'll spray a bit in all the newly drilled holes just to cut down on the obvious rust opportunities.) Witness here my high-tech clamping system for drilling holes in steel. The bare feet are not actually recommended for an operation that has a by-product of little twisty bits of steel fragments.

I also decided to go ahead and drill holes in the uprights to match the bolt that pins in the leg in place. This makes them much more stable. No wobbling at all. Yes, this does mean that I need to commit to whether I'm installing the uprights or not when I assemble the legs during set-up. On the other hand, I envision adding a cross-bar at the top of the uprights that utensils and whatnot can be hung off, so all in all it's probably more useful than not.

The other thing I went ahead and did was color-code the legs (and uprights) into matching sets. The bolt-holes for the legs weren't identical to begin with. The original design used hex-bolts with friction against the leg rather than an actual hole through the leg. I much prefer something I can set up without special tools. (I don't normally carry a wrench set with my camping gear.) So I swapped in eye-bolts instead of the hex-bolts, but I didn't want to rely on being able to hand-tighten them sufficiently to avoid slipping, so I also drilled a matching hole in the leg. Not a threaded hole, just one slightly larger than the eye-bolt so it goes inside and then tightens against the opposite wall of the leg. I could generally eye-ball which leg went with which socket, but color-coding the sets will make life easier now that I have to match the uprights as well.

And here's the spit suspension mechanism all fastened together as intended. To attach the angle-braces to the uprights, I use an eye-bolt and wingnut. Again, this is so that I can use finger power to tighten them. (Another advantage to eye-bolts is that you can hang tools from them.) The vertical eyebolts/hooks that actually hold the spit have a double set of ordinary hex-nuts, since they only need to be placed, not tightened.

And, of course, there's no point in doing all this engineering without a test. After all, the proof is in the pudding ... or rather, the game hen. Game hens are actually fairly difficult to balance precisely, since there's only one place you can put the spit. But with a certain amount of care in placing the prongs (or whatever you call them), I got this precisely balanced enough that a spin would result in three or four rotations before friction stopped it. (I took a short movie on my iPhone but I haven't quite figured how to post it here yet.)

So the next thing to do is start some coals.

When I have a good pile going, split it to both sides of where the spit will lie.

Lay down a drip pan, and let 'er rip. And since this is proof-of-concept of the spit, not of the yet-to-be-designed turning mechanism, I cobbled together a way to use my electric grill spit-turner. The bird has been turning for about an hour and a half now, basted occasionally with pomegranate glaze. After the last of the glaze was settled in (about an hour into the process) I removed the pan and moved the coals a little closer (still leaving a gap directly under the bird) to see if I could speed up the finishing. I think, given that I made a fairly small fire, the spit really wanted to be about 4" lower, but I needed the additional clearance to fit the spit-turner in there.

Next project will be to add the top cross-bar and start playing with drive mechanisms. One thing that will help is that most of the spits have threads at the "head" end. (Some have a handle threaded on, some are missing the handle.) So I can embed a nut in some other object to serve as a drive wheel. One idea I had would be to put a fairly large fly-wheel on the top cross-bar, attached to a very small cog that connects via drive-chain to a larger cog on the spit. With a large enough gear differential, a good spin to the fly-wheel would turn the spit at a stately speed, and if it were well enough balanced I might get some decent duration on it. On with the experiments!