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Friday, November 30, 2007

I can't believe it actually WORKED!

A new version of this kludged together electric bike actually WORKED today! Of course, an important part of it came apart less than a mile into the ride, but it WORKED! And of course I could still pedal the rest of the way, after tying the broken bits out of the way. :)

And I had started over again from scratch, too, so it was something I did and thought of in less than a day. Probably about six hours of work, maybe seven. I guess it's not bad for what would essentially still be an alpha-test version of it, certainly not ready for extended use. I guess this one is version 1.2.0. :-)

Remember that non-working electric scooter which had a burned out controller and a bad-smelling motor that read as a direct short circuit? I'd presumed the motor had gotten too hot, melted the enamel on the windings, and shorted out, blowing the controller in the process. Actually, the only part that melted was the power leads just inside the motor, because the Chinese factory that made it used regular low-temp thin-insulation wiring, which they very tightly zip-tied together just inside the opening, so when the motor got hot for whatever reason (too heavy a load? I'll never know, it happened before I got it), the wires' insulation melted together (red and black make a wierd color when mixed), and of course that let the power leads inside the motor touch, which makes a dead short. That's what blew the controller out.

It took only a bit of work with some tubing and some teflon shims (courtesy of the leftover ends of my old Slime Tire Liners) between the wires at the entrance, and a little silicone around them and all the seams of the motor casing before putting it together again, and now I have a "250 Watt" water-resistant motor that actually works. It's fairly quiet, though definitely wasting energy via noise/friction (probably in the brushes). I don't really get how they rate it as 250 Watt, given that it is also marked as 24 Volts DC @ 14 Amps (168 Watts), but it might mean that it *could* dissipate up to 250 under it's heaviest load. I haven't actually tested it's no-load current or it's full-load current.

The actual part that broke was of course the hastily-JBWelded-on sprocket for the motor chain. I'd had no other choice with the materials available to me, because the hole in the sprocket for mounting is actually larger in diameter than the entire rear axle, including spoke mounting ring! So I carefully centered it on the rear wheel's left side after applying as much JBWeld as I could get to stay on it there (obviously not enough), to hold it to the spokes themselves and the very rim of the spoke mounting ring, which is all that would reach the sprocket--there's about a 2mm gap between the ring and the inside edge of the mounting hole for the sprocket.

I'd wanted to use the actual mounting ring and coasting ratchet from the scooter's rear wheel, but there's no way for me to get it off of there without damaging it, since I don't have the special tools it requires to take it off--it's different from any of the bike versions of the same thing, and doesn't go on the same way. If I could, I'd just drill out the bearings in the middle of it that the scooter wheel axle would rest on, since I don't need them for my purpose, but I have no drill press, and that's what it would take to do it and still leave the ratchet intact. actually sells the mounting ring with ratchet separately, but I am trying not to spend any money that I don't have to, partly because I don't *have* enough even for rent/bills past the holidays, and partly because I simply want to make this bike project a continuing symbol of recycling usable bits of otherwise broken things no one else wants (especially things others threw away!).

Tonite it was pouring rain on my way home from work, including a second trip out to go to the store for essentials, so I'm drying out now, and warming up, and will probably try working out a way to get that ring off the scooter wheel later tonite or tomorrow. If I can't, it's time for lots more JBWeld. ;-)

Wednesday, November 14, 2007

Blowout from hell

Today, I thought it was time I trued the rims on the bike, since they've been fairly wobbly, with too much space having to be left for the brake pads to not scrape on the rims when not braking, etc. That took a while, since I've never done it before, and I dont' have a truing stand, so had to settle for the on-bike method, which is not as good. Now they're straight, with less than a millimeter of rim side-to-side wobble.

I can't fix the radial wobble yet, since a large part of it appears to be the tire itself, even without the tube in it. Perhaps up to 3 or 4 millimeters radial wobble, which is likely being damped by the pneumatic action of the tube/tire in actual use, but is taking energy out of my forward motion that I'd like to keep.

I wouldn't have messed with the wheels at all, if it weren't for having to replace the tube in the rear wheel, though. During my last overnight shift Monday night/Tuesday morning (till after 4am), the bike was "safe" in the warehouse of the locked building that all of us were inside, 3 regular workers including the store manager, plus maybe a dozen or so outside workers brought in to help with the stock reset. It was fine until sometime after midnight or maybe 1am, which was the last time I actually was at the bike, getting some snacks out of it's cargo container for a break. When it came time to go home, I wheeled the bike up to the front and noticed it dragged, and that the rear wheel was flat. Didn't think much of it, because often thorn flats would leak fast until the slime plugs them up, which can take a few air-ups, but usually last long enough to get me home.

The situation with people I didn't know waiting out front was a little wierd, so I deicded to ride a bit away first, to a well-lit area in clear view of a BofA's cameras, and an intersection with at least some traffic (it was after 4am, so it was starting to pickup a bit). I took out the pump to air it up, and discovered it didnt' have a stem--it had been completely cut off! Looks like a box knife cut. Can't have been the rim cutting it during my ride, because I have silicone around the valve stem partly to hold it in place, and partly to prevent nicks and such--I checked the silicone today, and it's intact. Even if it wasn't, I filed the rim edge smooth and round around the stem hole long ago, since it needed deburring when I got it. Someone didn't want me to get home that night, and I am pretty sure it was one of the outside workers, and I think I know which one it might be--a creepy guy that was asking where I lived (which I didn't answer with anything useful).

Except that I had to ride all the way home on a flat tire, with slime making the rim slide around on the tire's bead so I had no traction, nothing happened; it just took me a bit longer to get home, and I was worried the whole way that either the rim might break (it was undamaged, thankfully), or someone might see my trouble and help themselves to me as a victim--something I never want to go thru again, having been mugged once back in 2003 was quite enough.

That, however, wasn't the blowout. *That* happened tonite, about 20 minutes ago. I'd replaced the tire and tube with new ones, slimed the tube, and aired up the new tube hours ago, and left the bike in it's usual spot in the front room near my door. then 20 minutes ago, I heard what sounded like frying eggs, then a whistle, which all freaked the dog out. I got up, then as soon as I got to the door I could tell it was coming from the bike--turned on the light and saw it was almost flat on the rear!

Closer look shows the tube blew inside (can't tell where yet, gotta take it off the bike and wash slime off of it). But I am flabbergasted that a brand new tube blew at 60PSI without any load or ride, with a new tire around it that I had checked for sharpies or defects. The rim itself I have coated with silicone inside, to help stop air leaks around the spokes and such, as well as protect against sharp edges, plus the spoke belt normally there. So there ought to be nothing to cause something like this even during a ride, much less just sitting there! Heck, the air temperature in the room is probably 10 or 15 degrees lower than when I aired up the tire, so the PSI would actually have been *less* than 60, and the tire is rated for 65PSI. The tube does not list a rating, but being a thickwall anti-thorn tube, constrained by the tire, I would not have expected any kind of problem at these pressures with no load.

I guess I'll just have to air up all my spare tubes to see if they're gonna do the same thing, *before* I have to ride them. What sucks is that I don't have time to do this before leaving town for a few days, and I will probably have to work the very next day once I'm back in town (won't know till next week, because their schedule isn't made yet, so far never till Friday and sometimes not till Saturday or even Sunday the week of!). So I will probably lose much sleep time when I get back to testing and fixing the tube problem, so the bike will be rideable for work the next day.

I have been looking at airless tires for a while now, and I tell you that if I had the money, I'd buy a set just to keep from dealing with this problem at the last minute all the time for workdays--I've had three tubes from different makers and different stores, in two different rims, which blew around the stem itself, either at the base of the stem where it joins the tube, or at the top where the brass stem and valve are joined to the rubber stem. I've had over a dozen tubes blow along seams leaving holes too large to be patched. Probably 8 or 9 that were repeatedly patched for thorns until they blew somewhere else or tore from too many holes in one area.

Another one was destroyed by a roofing nail that went right thru the Slime-brand teflon strip that's supposed to be nail-proof. Yeah, right. I guess their slime sealant works well enough as a temporary seal, but those strips are useless. Maybe they could stop thorns, but certainly not a nail, despite their pictorial advertising that it will do so (they show screws, nails, thorns, glass shards, etc, all stopped by the thing--the nail went right thru the strip, leaving a bigger hole in *it* than in the tire!). "Slime Tube Protectors" product page.

I just wish companies didn't make such junk, and instead made well-designed, well-manufactured products designed to last. Instead, it's all made in China, by slaves that don't care (and I don't blame them), and there's no consistency in any of what's manufactured. Certainly msot things don't meet advertised claims, and are very very far from ever meeting customer expectations.

I don't expect miracles, but I'd like to at the very least have tubes that don't blow by themselves with no load, at nominal pressures (way less than max), when the bike is just sitting in my living room.

Update: see my new Slime post up above this one. This is actually one *good* company that holds to their guarantees! So while I still hold many companies in contempt, Slime isn't one of them. I'll freely continue to spread the good word on their products. I'm not removing what I posted in this entry, because it was still true for me at the time I wrote it.

Thursday, November 8, 2007

Minerva sprang from the head of Jove...thus 1.1.0 is born

While on the phone talking with Steven about other things, while marking out the metal pieces to make the mounting brackets I spoke of before, I had one of those "Minerva" ideas, the kind your brain has worked out in a fair amount of detail, then springs it upon you fully formed.

I was already going to use a part of the Murray's rear frame on the *front* wheel to hold the motor, gears, shifters, etc, but wasn't doing that on the back because it wouldn't really fit the way I wanted it to, and wouldn't mount right. I'd also found that that particular frame part was too bent up at the wheel mounts to work properly with a full wheel on it anyway (wobbled too much, and the metal was soft from the wheel bolt U cutout to the rear derailer mount).

However, I have a stack of old bikes/frames now, and at that moment I was looking at the wrecked Schwinn Ranger, which is a 24" bike, not a 26", but could be modified to work, and is a sturdy frame on the mostly-undamaged back half. It's derailer mount is bent a bit, but the U-cutout for the wheel bolt is not. I wanted to think about it for a bit, so I waited until I went with Steven to Bike Den, where I got one tool I needed (freewheel remover) and though they were out of the crank removal tools for sale, they had the one they use in their shop, and removed the cranks for me, from that Schwinn frame.

After I got home, it was a bit late for power tools, so out comes the hacksaw, and I got everything from the seatpost down to the crank/pedal bearings on back off the frame in one section (just like I did off the Murray before). Now, the way I want to mount it is to the wheel bolt itself, the same way the wheel is already mounted to the bike itself, but in reverse--the seatpost will be *behind* the tire instead of in front of it.

However, to do that, the wheel end of the frame piece I'm adding has to be expanded to fit *outside* the actual bike frame at the same point (because they're the same width, naturally, before modification).

I've got a 2-ton hydraulic pump jack from when I had to fix my mom's car a fair bit, so I dug it out and wedged it between the wheel mount points on the frame piece I'm adding, and jacked it apart about 1/2", just enough to slip snugly over the existing frame. This still leaves me enough wheel bolt to tighten the nuts down on securely, which holds both frames together as well. The seatpost top has a welded-on clamp for the seat itself to slide down into the tube and be clamped by, and I took the bolt out of it and am making a ring that will go thru that and around the tubing my rear cargo rack is made of, to secure the frame section from moving up or down.

Now the motor will be mounted along the right side of the frame section, just between the back of my normal rear derailer and the crank mount of the frame section. The 15/16" socket I needed I could never find in the right kind that would not be too loose, and the 7/8" sockets are all too small, and I couldn't find anywhere that had the size between them in 12-point star (only in hex). So I ended up filing the gear teeth in a couple of places just a teeny bit (less than a millimeter) on the motor's gearbox output gear, and now it fits very snugly in my original 7/8" socket, but comes out if I need it to. I bolted the socket into the crank mount on the right side, using the same bolt that held the crank on, and it tightens in the direction it has to turn to drive the wheel, so it should never come loose in operation even without loctite and such.

I *would* like to find a 7/8" socket that has a larger drive square hole in it; I think the one I have is 3/8"; if I could use something a hair bigger than a 1/2" drive (which they don't make) it would fit onto the square crank mount and guarantee not to spin in place as the motor torques against it (in "lab" tests so far, it hasn't been a problem, but no road tests have been done yet since the bike's not finished enough). I'd just need to get some washers to stack onto the crank mount to hold the socket against the bolt's underside to keep it tensioned against the motor's drive gear (otherwise it would end up sliding down the crank mount away from the motor and no longer engage the gear, as the crank mount's shaft is about as long as the socket's depth).

The 3 crank-chainrings are mounted on the left side, to line up with the sprocket that's been mounted on the left side of the rear wheel. It's still little-to-big, but closer to a 1:1.2 ratio instead of 1:3. I have a modification to fix that and add the absolutely necessary freewheeler to the left side, but I have some other work to do before I can build that. It will require cutting the axle-shaft (not the bolt, just the wheel portion) of two identical rear wheels, and taking the freewheel half including the spokes and such (not the rim) from one, and replacing the left (non-freewheel) half of the other wheel with it. I'd *like* to re-weld the two halves of the axle-shaft back together, but that's not something I have equipment for yet, so the best I can do is a small ring of pipe (or something) JBWelded across the two pieces to keep all torque forces as equal as possible from one side to the other. Once that's done, I *also* have to modify the freewheeler on the left side so that it works in reverse (which may require machining a new ratchet ring), otherwise it won't do me any good (since it will freewheel in the forward direction, not the reverse, as it must do).

There is no place the wheel's derailer can be mounted on for the right side currently, because of the size of the wheel's sprocket/chainring, so for the current tests the chain has been shortened to exactly fit the distance between the wheel's chainring and the motor's chainring (since without the wheel's derailer, there's also no tensioner). I'll re-add the chain back into it once I have a freewheeler in there, since it will then be small enough for the derailer to work normally. Derailer must be mounted "upside down" relative to the way they normally would, so it works in the right direction of chain path to perform it's job properly. For that reason, I may only use a wheel derailer, and leave the motor derailer off entirely (since I would need to weld on a few inches of post *below* the crank mounts in order to have a place to mount it). There are other "little issues" I have to work out, too, mostly clearance of parts to each other.

One more thing this frame section gives me is posts for a second set of rear brakes, which I will likely need to add due to the extra mass from all the motor/battery/frame/etc so I can have the same stopping power I did before. But those will wait until I need them, since they add even more complexity to the system (more cabling, figuring out where to put the Y-cable splice to the rear brakes, etc). Normally, I'd want better front brakes, but since almost all the weight is added at the rear wheel itself, or behind it, it will force the balance to shift less to the front during braking, especially on level surfaces (where I usually ride). So more rear braking is ok in this case, though I will eventually probably improve the front braking as well, in some other way.

So, at the moment, it's mostly bolted together, with some various mounts in the process of marking and making, again hoping by this Saturday I have a testable v1.1.0.

Sunday, November 4, 2007

Brake lights and horn

The Electricle™ has a brake light now. And a horn.

The light itself used to be a Microtek 35MM film adapter/backlight for a scanner--I just put a red stagelight gel on it, and a bit of silicone to seal it against splashes. Bolted it in place of the clip for the light I've been using on my helmet (which acts more or less like the 3rd light on cars/trucks, making me just a bit more visible, which is always good).

The light already runs on 12vdc, so I just hooked it up to the switch I've now got on the rear brake lever, and (via diodes to make an "or" gate) to the headlight switch, so when I turn on the headlight I get the very bright solid taillight, or when I don't have the headlight on, I get a brake light when I even lightly pull the brake lever, before the brake actually engages, so I can indicate my stop before I actually begin braking.

I was going to put a few more diodes into the taillight circuit so it would be dimmer than the brake, but I knocked over my bin of parts and didn't have time to sort them out yet tonite, before makin' some food and getting to bed (and posting here while I eat first).

Horn's not real loud, but it'll getcher attention if I need it to, most times. I don't need one often, but I have *really* needed it those few times--for some reason my yelling voice isn't enough, but a horn people are sort of conditioned to respond to by paying more attention for at least a moment, looking around them. Maybe it will save me from a scrape someday. It only weighs a couple dozen grams, if that, so not much effort to carry around.

LTL on THEMAnime pointed out that I:

  • "might try and find an LED trailer light. They make smaller rectangle lights that are already set up for dim and bright, and because they are LED they don't take up much power."

I've checked out those kinds of trailer lights, and they're kind of pricey for somebody that still doesn't have a fulltime job (not for lack of trying), but does still have fulltime bills. :-) I don't quite have enough super-bright red LEDs to build one yet, though the circuit is really easy (you just light up more LED's for the brakes when using the taillight, or all of them if the taillight isn't already on).

The scanner light was two bucks (along with some other junk at the same time, some of which I've already used), and the diodes and other parts all came out of the same old laser printer I got another motor and controller circuits from (still in the design stage), which cost nothing because it was given to me.

One more thing about the scanner light is that it appears as a single non-directional flat red "plate" of light. All other lights I have seen "pre-made" are fairly directional to the rear, especially if made from LED's. So for cars not right behind me, I'm not nearly as visible on an otherwise badly lit road, especially if their headlights are not pointed at me or my reflective stuff. With the "plate" of light, if they are anywhere up to about 85 degrees from straight behind me (to either side or above!) they can still clearly see my taillight/brakelight (though they might not be paying attention, they *could* see it if they were!).

That's the single overriding reason I built this one this way.

As a bonus, there's plenty of room in the plastic casing to hold rows of amber LED's on each side above the red bar, to make turn signals in, and on the ends facing left and right to put marker lights in (probably red LED's with diffusers). The whole thing is still pretty small, fitting down under my cargo bucket, just about even with the top of the wheel.

Saturday, November 3, 2007

Alpha Test Partial Success

Well, it works, sort of. The problem is that in my haste to get *something* working so I could at least test the theory, I forgot the sprocket-tooth ratio bit, and essentially have them reversed from what I need to get any speed out of the motor (though I could get plenty of torque this way), with the largest sprocket (from the old Murry Biotech's pedal sprocket assembly) on the left side of the rear wheel, and the smallest (from the Biotech's old rear wheel entire sprocket/axle/etc assembly) at the motor end.

Thus, I get a speed at which I could probably crawl faster than it could move the bike. Ah, well, I basically still need to get tools to take apart the rear-wheel sprocket assembly, so I can take out the very smallest sprocket from one of the many I have, and attach that to the rear wheel's axle instead of the very large sprocket I have now, and use that very large sprocket along with two or three more of stepped smaller sizes in a new sprocket assembly on the motor axle.

I made a "clever, yet simple" fix for it temporarily, by simply bolting a larger sprocket to the largest of the motor-axle sprockets, since I haven't got the mechanics setup for shifting anyway; this will at least give me a usable speed for testing (though I know I could easily ride faster than it will go).

I am still making semi-permanent mounts for all the motor and axle stuff, so all this will be tested in v1.0.1 sometime after Monday (last day of work next week, only get two 3/4-days this time).

Friday, November 2, 2007

Bicycle Bonanza

Tonight I was working more on the Electricle™, and found the chain was a few links too long to possibly work around. Easy to fix, with a simple ten-buck chain tool, which I didn't have. So I took a short ride to a bike shop that I hadn't been to before, mostly because they would still be open when I got there, unlike any others in easy range.

Got the tool, and while talking to the shopowner about getting certain parts (which he doesn't carry), I mentioned that I sometimes get what I need off scrapped bikes or ones from thrift stores, garage sales, etc. He just happened to have gotten a pile of them dropped off that he hadn't looked thru yet, so we went out back and he decided only one of them was worth doing anything with, and said I could do what I wanted with the others.

I called a friend with a pickup truck, and we took the lot home. A couple were pretty bad, one having been in a horrible wreck at some point (when I got a good look at it's front fork, I got the shivers, because whoever was riding it can't have gotten away unscathed--it looks like it was hit by a car, at the very least). Three are actually almost intact and probably could be ridden after a bit of oiling and tightening up of things. Three more are almost just a frame with some bits left on, but useful bits. Another wrecked one has a slightly bent frame, but not so bad on the rest of it (though no wheels/rims).

There's two of them with the same SRAM Gripshifters I use on my bike, and another that uses a different make of Gripshifter I can still use. Two of the working derailers are indexed and can be used with my bike; a third is also indexed but is badly damaged (off the first wrecked bike). All the brake levers are good, and most are metal, instead of plastic. Most tires are junk, some dryrotted, but some rims are nice enough to use. I dont' like any of the seats, even the ones that aren't sunrotted. They're all hard and/or narrow.

The best part about all the frame-only bikes is that they are small ones, pretty much exactly what I was wishing for today to use as a mount for my motor and gearing, under the cargo rack. Too late today to actually do the cutting and stuff, because of the noise, but tomorrow morning I'll be continuing the work, and hopefully will have a testable setup by Saturday.

Then comes alpha testing, where I get to completely redesign everything based on whatever horrible things happen to it when I ride. :-)