At this stage I had a frame that I could wear on my hand with some empty deck track mounted on it. Time to mount some keyswitches. This design still has each keyswitch on a piece of coat-hanger-type wire, but instead of these wires all being mounted on a single kingpin, each one is individually attached to the deck track via it's own bolt and U-shaped piece of unbent paperclip wire. The advantage of this is that it makes each switch's position individually adjustable without impacting the other switches' positions. It also means keyswitches can be added or removed at either end of the track without touching the other switches.

The only microswitches I could get locally that were not too big for this purpose (Jaycar catalog number SM1036) have holes that are too small for any of the coat-hanger wire available to me, so I took one of the switches with me to my local Bunnings Warehouse (hardware chain) and went to the fencing wire section. It turns out that 2mm wire fits perfectly in these switches. I had to buy rather a lot more than I needed (a 40m roll or something), but it's pretty cheap, so I didn't mind much. I suspect that this has ended up working in my favour because this slightly thinner wire is probably easier to bend into the tight hooks that I wanted.

I have previously reported that I got part way through building a kingpin based chordite before starting on this version. I re-used the switch-and-wire assemblies that I already had. In hindsight this probably wasn't the best idea, at least not for all the assemblies because it has left some of my switches at slightly awkward angles (but not so awkward that I'm willing to go through the hassle of pulling the keyboard apart, making new assemblies and putting it back together again). Each "switchwire" is still attached to a bolt as in the kingpin based design, only now each switchwire has it's own little bolt, and each of those little bolts is attached to the deck tracks via a paperclip 'U' and a couple more little bolts.

The complete assembly showing the mounted switchwires.

Close-up view.

I used the same 12mm long 1/8 inch bolts throughout, with the deck track bolts cut short as described on the previous page. The paperclips I used are Tudor brand "33mm Large Elliptical Clips" (product code 47737), but any average-sized paperclips should do. They just need to be rigid enough not to bend under the weight of the switchwires (and your fingers), but bendable enough to shape into the 'U's. First I unbent eight paperclips (but seven will do if you're only going to have one pinky finger switch) to get eight straight pieces of wire, then I bent each one in the middle around a spare bolt until the two legs were parallel, forming the required U-shape.

Now I needed a way of attaching the bolt for the switchwire to the open end of the 'U', so I just made a loop at the end of each leg of the 'U'. Well, OK, it's not quite as simple as that. The two loops have to line up nicely and be the right size for the bolt. Just wrapping the paperclip wire around a bolt doesn't work because the wire sits in the groove making the loop too tight around the bolt. A small pair of needlenose pliers or two comes in mighty handy here, along with a fair dose of patience. Once you've done the first couple of 'U's you soon get the hang of it.

Looking straight down on an almost-finished 'U'
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A side-on view of the same 'U', more clearly showing that one end has not yet been trimmed.

As you might guess from the first pair of pictures, I ended up with much longer/taller 'U's than I really needed, so making your loops a bit closer to the curve in the 'U' is probably a good idea, and would also give you more wire to play with. Snip the spare ends off, then "flatten" out the loops. The left hand picture above clearly shows how the wire goes off to one side (so it can go past the main leg). This is what needs to be re-aligned so that the newly-cut end of the wire is directly above the leg part. You can probaly get away with not straightening these, but it will make attaching the bolt and switchwire unnecessarily difficult because the wonky ends tend to push the washers on the bolt into the space where you want the switchwire to go.

The bolt that will hold the switchwire goes in next. First put a spring washer on the bolt, then you have to decide which way around you want the bolt. Personally, I arranged mine so that the heads all face out from the centre, but you may think another way is better. To allow the 'U's to be very close together on the tracks, the first 'U's bolt-loops stick up above the deck tracks, then the next one's hang down, the next one's go up again, then down again, and so-on.

None of my photo's manages to show the alternating up-down loops all that well. This one probaly shows it best, particularly for the two pinky switches. I think only one of the other down-facing bolts is even visible here (the middle finger one). If you look closely (perhaps using the enlarged version), you can see that I used the up loops for the distal (outboard) switches, and the down loops for the proximal switches. In hindsight I think you might get better angles for your switches (at least the distal ones, which need the steeper angle) if you did it the other way around (down loops for distal switches, up loops for proximal switches).

You will need to keep this up-down business in mind when figuring out which way to feed the bolt through the loops: if you're holding the 'U' with the loops facing up and you insert the bolt facing the way you want it, but you then mount the 'U' with down-facing loops, you'll end up with the bolt the wrong way around.

Once you have worked out which way the bolt (with the spring washer still on it) needs to go, stick the tip of it through the first loop, and put on a pair of flat washers (between the two loops), then feed the bolt through the second loop and put a nut loosely on the end. The finished 'U'-with-bolt should look something like this (except that it appears that I didn't flatten the nut-side loop on this one).

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The next thing is to get the 'U' on the tracks. Take a couple of short bolts and stick a spring washer and then a flat washer on each bolt. Now put each bolt in turn through the 'U' and add a second flat washer and a nut. Only do the nuts up far enough so that they won't fall off. The fiddly bit comes next. There are probably many different ways to do this, but here's how I did it. Put a short bolt at each end of the 'U' so that you can play with one without the other getting in the way. Take the one at the curved end (as opposed to the bolt/loops end) and line it up with the deck track on the same side of the block as your braces. You want to slip just the nut into the inside of the track with a flat side of the nut against each side of the track. You will probably find that the nut tends to want to turn itself on an angle, which is what makes this a bit fiddly. Needlenose pliers come in handy once again, but I did manage to do some with just my fingers.

Once you have the first nut loaded up, you obviously need to get the second one into the other track. If you keep the second short bolt up near the loops end, and the 'U' on an angle across the tracks, then you shouldn't have too much trouble keeping the first nut in it's track while you get the second one in (unless you've made very short 'U's). If you do have trouble with the first nut popping out, you might try tightening it up a little so it doesn't slide back and forth in the track so easily.

When assembling my keyboard, I put one 'U' on, attached it's switchwire, put the frame on my hand, and adjusted the switch position before moving on to the next 'U'. The advantage of doing it that way is that you've got fewer other switchwires to get in the way of your adjustments in the beginning. To get the maximum benefit out of this approach, you would need to start with the middle-most switchwires and work your way out to the index and pinky fingers. The reason for this is that the middlemost switchwires are the ones most obstructed by other switchwires. This is the reason why my U-loop-bolts all have their heads facing out from the centre (although in actual fact I did not assemble my keyboard in this order -- aren't I a dummy?).

Well that's about it as far as the differences between this design and the kingpin based design. The next page has some pic's of my electronics with a few comments, and there may be another page yet to come if something else I want to try pans out (and maybe even if it doesn't, just in case someone else can work out what I did wrong or whatever). Here are a three more pic's of the hardware assembly that I didn't use elsewhere in the write-up. As usual, click them for bigger/better images.