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Friday, August 28, 2009

Rearranged Rear Turn Signals, Moved 3rd Battery

While I was at lunch at work, I moved the rear turn signals down to the same place as the rest of the rear lighting cluster, simply because where they were on the back of the seat, they'd be blocked by any cargo I put on that rear rack that's wider than a foot or so.

I needed to take home a stack of empty boxes, and they were going to cover the whole width of the bike, plus some. I could just use the LED turn signals, of course, but the automotive ones are brighter and more noticeable due to their larger surface area (and will be brighter still for daylight once I have the LEDs in them instead, with less power consumption. At night they will automatically be dimmer if I can make the ALS work correctly, so they won't blind people close to me, especially those in a direct line behind me).

So now rather than being screwed down into the steel tube of the seat back support, they're screwed into the aluminum bracket for the taillight bars, and then ziptied (for now) to keep them from wiggling.

Previously the wiggling was stopped by the back square of the signal housing resting on the top of the tubing, but now that's out in the air.

All these pics in this post of the lights simply show different lighting conditions, with the brake light engaged and the left turn signal blinking.

Most of the time I think I caught that signal somewhere around 2/3 brightness or less; it's hard to be sure.

If I'd been clever I'd've temporarily just hooked power directly to the light, bypassing the signal flasher, but I didn't think of that until just now. So the light amount varies from image to image--but it's so bright at this range that it's hard to tell.

The pics start out with a 15W CFL in an overhead light fixture on, plus the camera flash. I turned off the flash, then the overhead light, so that you can see the lights in different conditions. They light up the room pretty well, perhaps a third of the light given off by the overhead, including my CCFL headlights.

Another big change I made was to move the third battery from the top of that rack down to the middle triangle formed by the two bikes' intersections, above the motor.

This radically changes the balance of the bike, and it's handling improves enormously. Now, along with the forward shift of weight from having the batteries on the trays in front of the pods instead of *in* the pods, not having the lighting batteries on there (they were in the pods, too, recently), this change gives better steering at speed, and makes a more relaxing turn possible, with less white-knuckling when taking turns faster.

Used to be that the front wheel *could* skid during the turn, causing me to make a larger radius turn than I should have to, because all the weight at the back kept me from getting enough traction in front, unless I slightly squeezed the brake during turns to force the front end down some. Hitting bumps during turns sometimes made for unpredictable behavior.

Now, it doesn't do any of that. It might still do it if I have heavy cargo in back, especially on top of the pods, but for now it's fine.

You can also see the chain clearance to the battery is pretty narrow, but it's enough. The battery is not clamped down or anything yet, but it's in there prett tight. Took some doing, figuring, and putzing around with it to get it in there at all. :-) Now I need to find more of my big hose clamps to secure it and the other two batteries in place. Since the one I had holding this to the rack isn't quite (by about 1/4") big enough to work on the front battery, I put it on the leftside underseat battery, clamping both holder rack and battery to the cargo pod frame.

After I added the lighting to the leftside battery, it does run down a little bit quicker than the others, so I am making it my new starting point for the Sorenson, with the other pair on the wheelchair charger, then swapping them when they get closer to charging.

As soon as I have some money (yeah, right), I'm going to order some of the VoltBlocher PCBs so I can build a set of three for this pack. They basically only affect the charging when a battery goes over the limit you set in the VB. Then they shunt that extra thru large power resistors as heat, so that it does not overcharge and destroy a battery that's already charged more than the others in a string.

Then I can leave them all always hooked up, and just plug the battery main plug into the Sorenson's test input, which I would just set to a high enough voltage to charge them all. Or a better supply than even that once I can make or find one.

The next step in the cargo-hauling improvements is going to be to move both cargo pods up about an inch or two, so their tops are just above the top of the tire, meaning anything laid across them will automatically clear the tire. Then the rack will be levelled out and made flush with the tops of the pods, to just clear the tire.

Then I can flip that rear seat support so that it makes a top bar for the entire seat. It's only hose-clamped on, so it's easy enough to move around. But with it up there, I can then attach a headrest to it and relax a little more on the rides, at least when I'm testing the motor stuff out and not pedalling.


  1. I found out the led side lights that go on trucks work pretty good for turn signals and brake lights on mine. I did have to add one real bulb in each side though before I could get the little blinker can to work. I put the bulb type on each side of the trike. So they can see them blinking from the front side and back now.

  2. Back when I had money to spend on this project, I considered buying some of those instead of making my own, but I didn't like the styles, nor were they really bright enough for what I wanted, of the ones I had found.

    What I looked for but didn't find in any affordable format were the large and very bright many-LED units they use on large vehicles.

    So that's why I'm still wiring up my own, but it's tedious and time consuming, without a PCB (just unclad perfboard to physically hold them in place). There have to be four of them made, then I have to build the automatic brightness control and switching electronics, and then finally physically replace the bulbs and holders with these boards.

    The bulbs are one way to fix the flasher problem, but there are also electronic flasher units out there that don't require a current draw to make them work. If you don't mind buying them new, they are available from places that sell electric scooter parts, since those usually use much smaller bulbs than automotive ones and thus wouldn't trigger under the low currents pulled thru them.

    Probably even automotive stores sell them. Can't cost much; I'd expect less than $10 (which is still pretty expensive to me, but not to most folks).

    You can also just build one using a 555 and a couple of resistors and a capacitor, plus a transistor or two to do the actual switching of current for all your LEDs.

    On mine the power transistors are in the actual turn signal LED strings, so that the high current doesn't have to flow as far (wasting less power). It does make the wiring more complex by one wire, since I have to send the flash signal, ground, and power, instead of just the ground and flash power.

    The wire I used already had multiple conductors, so there would have been no weight savings anyway. In the back end it's an AT-style keyboard extension cable, chosen because I had them in coily-style, useful for extensions to run to the trailer, when I mounted my rear bike light cluster on that instead, during trips I used the trailer for. In the front it's all inside the CCFL enclosure on the bars, including the flasher, so not long enough wire to matter one way or the other.


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