Okay I think that's everything. The heads are the most labor intensive part. After you make a couple you'll understand why they cost so much.
Let's start with preparing the rings. We wrap the rings to allow the rope to slide more easily and to allow the skin some protection from rust staining and also to aid in stretching. That's what the teflon tape or bamboo leaves are for.
Once the rings are wrapped, lets get those skins going. Soak the hide so that it's pliable [from 3-10 hours]. The dried raw hide will soften from something akin to fiberglass panels into something resembling maleable vinyl. At this point you can cut to size. I make sure that I have at least an extra 3" all the way around the outer dimension of the ring [i.e. a 20" piece of rawhide for a 14" ring].
So now you have a disc of soft rawhide and a wrapped ring. Mark a line 1/2" to 3/4" from the edge of the hide all the way around, then mark off intervals on that line. I find that odd number intervals work well. I use a multiple of 7. Then using the small leather punch (1/8"-1/4"), put holes at each marked interval. Now the confusing part. Based on your multiple, start lacing the hide over the ring by going to every 7th hole [so if you hade four sets of seven intervals, you would stitch holes 1,14, 21, then go to holes 2, 8, 22, etc.]
I also use a little lubricant on the skin when I do this. I mix up some knox gelatin and water to a runny consistancy to keep the hide from sticking to the ring. I've been thinking that KY jelly might work okay too. I'm sure you already know this, but try to avoid putting petroleum products on your hides, as it's not good for them.Lace it up and then start pulling it tighter. This will take some time, and you might want to wear gloves or use a dowel to assist you. Keep a wet towel around so the hide doesn't dry out too fast. When the hide gets pretty tight turn it and bounce on it. If you've got the body of the shime cut, and the edges rounded then you can set the head on the body and bounce on it. Then tighten the lacings and repeat. To get a head that sounds good and stays tight longer, you really need to stretch it tight. You can tell by the color of the hide how stretched it is - the skin turns whiter the tighter it gets. Once the head is as tight as you can get it, then fun really starts.
Now you need to layout the large holes and the stitching pattern. I think most shime use 10 holes though I have seen some with eight. The stitching pattern that I use has two rows just inside the rope holes about 3/8" apart and in about 3/8" intervals. It might help to make template. Now start stitching. It usually takes me about an hour to stitch up one head. I use one continuous piece of the synthetic sinew about 6'-9' or so. When you're finished stitching, then your head is done. You may need to trim the excess hide after you finish the stitching. Try to trim the hide to the size of the body, so the heads will stay pretty much centered on the body when you tension them. Now stretch and stich the other head.
Cut your 10" diameter water pipe to an 8" height or so. I found that for the 14" ring, the 8" body looks pretty good. Round the edges of the rim using a file or router. You can leave the body as it is, or paint it (best to use an epoxy based paint for durability.) If you paint the body, tape off the rims about 1/2", otherwise the paint may stain the heads. If you are using turnbuckles to fasten the heads to the body, measure them, then cut the body to length. We have found that the body height is a critical measurement to take in to consideration.
Please note that the heads will deflect as tension is increased on the heads. Depending on how tightly the skins are stretched determines how much deflection there will be. Some of our heads deflect about 1" to 1 1/4". [This will deflection will increase as the heads break in, and will become permanent in the head.]
Do this while the hide is still pliable. This should give you a little more tension on the heads. If you use turnbuckles this step is pretty simple. Place the hardware around the body hooking onto the steel rings at the large holes in the rawhide. Tension them evenly, then as if you're tightening lug nuts work in a star pattern to tighten until it sounds like you want it to High and slightly tinny. The plastic body gives it that tinny quality. A wooden body has a richer tone.
If you're a purist, or some sort of masochist, you'll probably want to go this route. It is the more attractive of the two methods. I'm not really sure about the lacing pattern here, I've just been experimenting. First slide your rope through the large holes in the hide alternating from head to head. Make sure that you place the rope through the holes in a consistant manner. Meaning if you go from the bottom of the head through the hole then over the ring, that is the way you do every hole. Otherwise you'll have problems tightening.
Once the heads are tied together on the body tighten the rope as much as you can then tie the ends off. You should have one short end and one really long end. Take the really long end and at the closest hole start looping around the other ropes alternating from head to head. Now tighten until you can't tighten any more this is the stage that really works up a sweat and can be a little dangerous. To tighten I use a 24" long oak dowel that's 1 1/8" in diameter I slide it between the ropes and twist it the length of the dowel gives me pretty good leverage oh and to hold down the drum while you do this lock it between your legs or if you want to build a frame to clamp it in. I find that since you must constantly move around the drum, holding it with your legs is the most flexible.
Copyright 1997 by Arn Shimizu. Used by permission.