Let's Build It Already!

Upon pondering some transmission thoughts, I think that at least for now I will setup a system to switch the motors from series to parallel depending on A) speed and B) steering. It is far easier to do this than to mechanically deal with huge reductions and shiftable drivetrains (other than an internally geared hub).

So series wired for startups and slower speeds. Once past a certain speed, will switch automatically to parallel, and not drop back to series until a couple MPH slower than that setpoint. The hysteresis will prevent the switching system from chattering and blowing stuff up. :)

I will need to learn to drop the throttle when the shift occurs, so I don't end up with sudden bursts of speed. I will probably put a light and maybe a beeper on there to alert me to an imminent shift, maybe 1/2 second before it happens, which should be enough to react to until I get a feel for it.

Since the main reason I wanted series motors was so that I could get an electronic differential for turns, it means that turning would need to be done at slower speeds in order to get that differential. For gradual curves it may not matter; have to test that. For sharper turns, such as from a N-S road onto an E-W one, I will probably need that differential.



Hmm....maybe a much better idea would be to build up the second 2QD and tweak them both to run identically when matched with their own motors, then use separate controllers with one throttle, compensated for an electronic differential by having a steering sensor that changes the proportions of left vs right motor throttle. It'd be more electrically complex, but also simpler in a number of other ways. It also leaves me with redundant controllers as well as motors and drivetrains, which is a nice feature.

I think I already have all the parts for a second one, including another metal enclosure (from an old external harddisk) similar to the Jensen inverter case I am installing the first one into.

This also means I can leave the Curtis on the CrazyBike2's motor, to which it is more suited (given that motor's short-term power capability).



I could not sleep last night (again, it's a common problem) so in between dozing just long enough to know I dozed as my head hit the keyboard, I looked up tilt-steering (leaning) trikes, all over the web.

I found a little information here on ES, which eventually got me links to links to links to a place called Jetrike, an open-source recumbent bike / trike project. The creator of it has plans and construction notes for a bike and a couple of tested trikes there, and some of the stuff looks very interesting. The most interesting part is that he has run simulations for the designs to see what would "really happen" before actually building anything. And has data tables and stuff for a few critical types of dimensions and how to work them out for a particular design. The trikes are deltas, but he started on a tadpole according to his pages there. I'd be super-interested in seeing what he comes up with.

However, the link to that project is broken, and there are no updates to the site that I could find since late-ish 2007. There is also a discussion link, but skimming thru it's archives I don't see any indication that he has proceeded with that project at all, which is very disappointing, as he did good work on the previous versions, and has hard data on why some things should or shouldn't be done, and how they might be improved to fix problems reported with various ways of building trikes (including fixes for rear-steering trikes, which are notoriously unstable and potentially very dangerous, due to flaws in layout of the tested versions, apparently).

Anyhow, I have many more ideas on a tilting trike, but I am still not confident at all that I could design something around that concept and make it work safely and reliably. Not with the stuff I just happen to have laying around, anyway.

There are others around as well, and many images and a few clear videos of some in action. I may be able to learn enough to actually design one of my own, though first I need to learn enough about the math involved to grasp the solutions in my head so I can come up with stuff without having to actually sit down and do all that math (at which I really suck).


I think I need to just build the thing first and get experience with a trike, then start working out version two that will have more features on it, probably including tilting.

I might even go ahead and build a pedal-only trike first, just so I can get that part working, and get a feel for ergonomics of the design based around my riding, and THEN work out a replacement for the front wheels/forks that lets me use the motors on there. I've been putting off this trike thing for so long because I didn't have this or that or a way to figure such and such out, etc., and I am really wanting to just get it STARTED!

More Trike Thoughts

spinningmagnets on ES is looking out for internally-geared hubs, which would greatly simplify the switching-gears on the front wheels, and ought to be able to take the nominally 300-350W per wheel I would be putting thru them, as long as I set it up to cut power during shifting.

So I will probably build the front setups simply using regular rear hubs on both front wheels, and any multi-gear drivetrain I come up with for temporary use will be easily removable. I still need a ratio change of around 1:5 to get the 20MPH top speed, from the gearbox output that's intended to directly drive wheels half the size of the ones I'm using for 8MPH.

I have been pondering a way to swap the gears in the gearboxes so that they output closer to what I want to start with. I cannot remember exactly what ratios they are inside for which parts, but basically the main reduction is from the motor shaft's helical gear to the first right-angle gear in the box. Then that has another gear on the same shaft that meshes with the output gear, which is on a lever-type clutch to disengage the gearbox for manually pushing the wheelchairs these came from. I'm pretty sure that the last two gears are different sizes, with the larger of the two on the output shaft.

If the shaft diameters are the same between the output shaft and the first shaft, I can swap the gears so the larger one is on the first shaft, which will give me some amount of anti-reduction (gain?) within the gearbox itself. If they're not the same ID but I have or can make a collar adapter for the difference, I can still use the gears swapped; just have to lathe out the smaller one to fit.

Then I have just that much less anti-reduction to do from the gearbox to the wheels. If the gears are the same OD/teeth or the larger is already on the first shaft, I'll have to do all the work outside the gearbox.


I've also considered taking the motors off the gearboxes and affixing a timing-type pulley directly to the motor shaft but this would require creating a drive-end plate for the motor that supported the shaft, as right now that bearing is part of the gearbox. This is not that trivial a matter to do, for me.

I would then need a much larger pulley on the wheel itself. I can't recall offhand the motor RPM, but somewhere in the 3000 range, I think. That would be a ratio of about 9:1. The smallest belt pulley I have around here is for a V-groove, and it's around 1.5". So I'd need a 13.5" diameter pulley on the wheel!

I can't recall the way to figure minimum number of teeth I'd need engaged for a timing pulley, but I suspect it'd be at least an inch or two in diameter.

Can't really use chain; at 3000RPM at the motor end that would be a helluva noise.


Basically, at 9:1 reduction, compared to 1:5 anti-reduction, I'm better off sticking with the gearboxes and using bike chain/sprockets for output shaft to wheel transmission. It's not as "efficient" as less stages of changing ratios around would be, and it's heavier, but it is a lot easier to do, with less stuff I have to build from scratch to make it work.



Now, one problem I have is that for the right side wheel, to get power from the motor to the wheel, I need the motor on the right side of the wheel, just like it will be on the left side wheel. But that would be problematic for reasons of safety, clearance, and keeping the motor itself safe from damage. So the motor must go on the left side of the right side wheel.

That leaves the issue of how to get power to it. To use a regular bike hub for it isn't that big a deal, as I can just bolt a sprocket (or weld it) to the left side of the hub. But I will want to use the internally-geared hubs for this later, and those will need the sprocket on the right side of the hub. Meaning I have to get power around the wheel somehow.

Thus, I will probably end up using an extra hub at the rear of the fork, to act as a jackshaft and pass motor power thru to the other side of the wheel. I can simply use a front hub since I don't need to put any freewheels on there, or spoke a wheel to it, and just bolt the sprockets on thru drilled-out spoke holes if they line up right. An adapter plate if they don't. Or weld them on, one on each end.

I just weld on some little dropout tabs to the fork near the U end of it, just clear of the wheel.



For the fork itself, I'm going to need to take some 24" or 26" U-forks, and cut them in half at the stem end. Then weld a tube across there to space them far enough apart for a rear hub to fit in the dropouts up front. But since the internally-geared hubs need dropouts that are slotted to fit them, and I will need enough dropout length to use to adjust chain tension (no derailers), I'll need to remove the original dropouts and put on some from scratch or from BMX bike frames.

Alternately, I can just build the forks from scratch, which would simplify making them significantly, and give me control over every part of their design, as well as make them the same for each side, mirrored. (well, mostly)


Another thing I've been pondering, and that is which way to make the forks--vertical or horizontal.

Horizontal will keep more weight down low, which is very good for a trike. But it means the motor mounted on there will have to have it's weight swung back and forth on the pivot every time I turn, which will act as a pendulum weight and make steering a tad more difficult--it will tend to resist starting to change the wheels direction, and resist stopping that change, too.

Vertical will essentially fix the latter, but will place at least a little more weight up higher. I can still mount the motor itself so that it is centered about the axle, and that will keep most of it's weight low, but the fork will still be higher up and that weight will be above the centerline, giving the trike just that much more susceptibility to tipping in turns, especially if I use the kingpins/pivots up at the top end of the forks.

If I mount the motor vertically on a horizontal fork, it will end up as the best compromise, but it will interfere with the steering pivots and kingpins, unless I move it farther forward, and then the pendulum problem reappears.

Probably I will go with the horizontal fork, and change it if it doesn't work out right.


I've been going back to my old trike research and rereading info I found then but didn't apparently fully comprehend at the time. Now I have seen enough stuff in action and worked with various things in steering, and I understand them better. I think if I had built a trike before, unless I had simply copied someone else's design, I would have ended up with an unsafe or unrideable trike. :( Now I think I know enough to make a passable first shot at it. ;)


I am certain that I got lucky with CrazyBike2, in that it's configuration ended up working fantastically well for something so randomly chosen at each point in the process. I'm fairly good at the by-guess-and-by-gosh process, but it doesn't always work. :roll: The trike needs more thought put into it, and more choices of parts based on design rather than just whatever I have laying around. That said, I think I have a handle on it, and might be able to start building it in a month or so. Less if I'm lucky enough to figure the rest of the design out sooner.

ARTOO Concept Sketchups

So now for some concept images, created in Google Sketchup mostly using existing bike parts from things found in their 3D warehouse.

The wheels are 20", for visual scale. The main tube is 2.5" O.D.

The side view looks a little long. I am not sure if it will need to be this long or not yet.

There's no detail to anything yet as I am still working out positions, angles, etc.

The top view makes it easier to see the camber of the wheels, which is 7.2 degrees in the drawing but I don't yet know what it has to be in reality. It just "looked right".

The wheel supports angle back because that is the direction of pressure in a turn and it is also the direction I would want it to angle to during shock absorption if I ever get that far.

Front view shows camber clearly. The green bits are the Razor scooter headstocks.

I intend to have the line thru the headstock it pivots around point directly at the tire contact patch. If I understand how steering should work, that should give no scrubbing of the wheel during a turn, for better traction. I am not *certain*, but I do not think trail matters much in the case of a tadpole trike, based on the way I see it working in my head. Thus, there is no trail on this steering setup.

An iso view.

The steering pivots are behind the wheel pointing forward and outward at the contact patch. It is possible I will have to make it point forward of the patch instead.

Amberwolf's Recumbent Tadpole Ought-One (ARTOO)

Now that it has a smart-ass moniker better than the last bike, lets see about getting the design together. :) Sorry there are not a lot of pics yet, still working out the design ideas in my head.

It's based partly on Lee's most recent trike from The Packrat Workshop, after some conversations with him about what might be best adaptable to the parts I have on hand. So it likely won't have suspension, at least in front, for this version.

It'll be a single-tube main frame, probably made from a 2.5" fencepost I have.

That galvanized post with the mangled right end, within the L of square tubing, is the one.

One possible way it could be configured, but probably won't be:


Depending on length of things I might use this instead:

with the load-wheel tubing cut off, at the far right, and most of the mast up top cut off.



That will go back to a bottom bracket pivot point for any rear suspension. I will probably not have a spring/shock for it by the time I need to ride it, so it will end up with just a solid tube bolted in place of whatever shock I would have used. I still want to build the pivot into it now, though, so it can be much more easily suspended later. :)

The rear triangle will be a modified one off of a 24 bike, probably off the old Roadmaster frame I originally started to use for CrazyBike2's rear end, but swapped out for the much lighter and slightly longer Schwinn frame instead. The main modification will be to make it vertically shorter, by cutting the seat tube down and bending the seatstays to meet it at the much shorter location. Rather like the back end of CB2 already is. This is mainly so that the entire triangle will be "below the deck" of the cargo pods that will run alongside it. Probably a 24" wheel, too, since the best slick tire I have is for that size.


Those pods will be the pods off CB2, mounted on a frame very like the one CB2 has, except that it will all be hanging from the back of the main tube, not connected to the rear triangle. Thus all the cargo pods will be suspended with the rest of the bike frame.

The seat will need to be built from scratch, and will be a lot like the one on CB2, but more form-fitting, if i can bend the tubing this time. I'll be again using tubing off an old bedside potty chair, same as on CB2, since it is small-diameter and extremely strong. The webbing will probably be the same green stuff I used on CB2's seat, simply because I have more of it and it's lasted just fine for more than half a year so far. It'll be tensioned using the same parachute cord lacing I used for CB2.

Like Lee's trike, I'll use tank-style steering, as it's mechanically simple and easy to build. It also doesn't take much space for it's movements, and won't get in the way of getting up and out of it like handlebars would, nor will it get in the way of my leg strokes for pedalling while turning, as can occasionally happen with CB2's bars at extreme turns with my kneecaps. :(

Pedals will be over the main tube and out beyond the front wheel axle, though probably not beyond the whole front wheel. Not completely sure until I finish the 3D sketches of it how the alignment works out.

The front end is where things get different. Because I am going to be forced onto sidewalks sometimes by either traffic or ignorant law-enforcement personnel, I can't make it wider than the sidewalk. Since a number of bike paths have protection poles across them to prevent cars from driving onto them, and those are generally spaced wide enough for wheelchairs, the front end will be no wider than a wheelchair.

Some of the parts I am considering for it:



Each front wheel will have it's own non-hub motor, most likely a wheelchair motor with it's reduction gearbox, with a V-pulley on the output shaft and another V-pulley on the wheel hub. The gearboxes have a tubular indentation in the top of the mounting plate, which happens to be the same as the steering tubes on a couple of the 26" forks I have.

So one idea is to clamp the motor to the steering tube, and setup the pulley on the hub and shaft so that they'll line up just outside the tire's sidewall.

The motor would then stick out to the rear of the wheel, parallel to the ground.

It is just one mounting idea, but one that happens to involve the least modification to the fork to do it. There are some serious disadvantages to it, too.



Then another steering tube is welded to the inside-leg of the fork down nearer to the dropout on the side opposite the pulley, at an angle that gives me whatever camber/caster turns out best for this thing (I still have to work out enough of it to then be able to figure out how to calculate that out).

That steering tube will then go into the headstock off a Razor kick scooter. Those things are meant to fold, so a few inches away from the headtube is a pivot point in the square tubing. That headstock is then bolted thru it's original folding pivot point to the end of a square tube welded at a forward/sideways angle out from the main tube, like a very wide Y. Another pivot point is welded to the headtube above that, which will go at first just to another tube welded to a vertical mast on the main tube.





Later, part of that horizontal tube will probably be replaced with a suspension of some sort, which is why I want the pivot point there now. If I don't end up putting suspension there, I would like to still end up making some sort of four-bar-linkage so I can make this a tilting trike, to improve stability in tighter turns at speed.

As heavy as each wheel will be, that means that the front end should be fairly stable in turns anyway.

To add to that stability, the SLA batteries (probably 4x 12V 17Ah) will be slung underneath the front end and the seat. That should help keep the weight to 1/3 on each wheel of the trike, but I will need to actually measure everything once I get it mostly designed, to make proper placements for things.

There will be cargo pods up front, too; I don't know what their shape is yet as I am not certain what spacing I will have up there.

Behind the seat on it's rear brace will be a vertical post sticking up to windshield level on the average car. A box will be mounted atop that with front, rear, and side lighting appropriate to the direction it faces. There will also be separate lights at the outermost corners of the cargo pods in the rear and the forks up front, for markers, signals, and emergency flashers. I don't yet have a set of lights to put on here, so I will probably be custom-building them. The lenses will likely be made from various bike reflectors glued together, with LED (for any flashing lights) and CFL (for any steady lights) lighting behind them.

Brakes will probably be disk brakes, donated by the very generous AussieJester. I have to fabricate adapters for them, and thus will probably be using some 48-spoke rear hubs I have on some 48-spoke 20-inch rims. The rear hubs are freewheel threaded on the right, but I will flip them over to put that on the left side, and make disc adapters out of something already threaded to that. I might be able to use the bottom bracket tube from an old cottered-crank frame I have, if the threads are the same pitch and the correct handedness. Then weld the tube to plates, face them on the lathe, and drill boltholes to match the disks. Basically they would do the same thing as these.


If I can come up with the cash, I'd rather order a couple of these from Choppers US, as they'd also make mounting the pulleys much easier, too, since they're made for dual-disk, one on each side.

It would also mean I could have both discs on the inside or both on the outside of the wheels, rather than both on the left side, which results in the left wheel's brake on the outside and the right wheel's on the inside. I don't imagine it would make a difference in performance to be the latter way, but it might make fabricating the forks a little harder since they won't be identical nor mirror images.

The catch is those dual-disk hubs are 36-hole, and I really want to use the 48-spoke wheels to help more with the side-loads and weight on this thing.

That's it for the moment, until I can get some pics of parts I have and some 3D sketches done up. Or at least some pencil versions scanned in.

Now, hopefully [i]this[/i] little guy won't get shot in the head when I do the trench run. :roll:

2QD Repairs, Modifications, Thoughts

The repair of the controller has turned into a modification session, too. So it is taking considerably longer than I originally expected or intended.

I'm upping it to 48V capability, changing out a few transistors and whatnot, as well as installing the whole thing into a better case that will provide heatsinking over it's whole surface. The case used to be for a Jensen 300W car AC inverter that doesn't output anything, which I gave up on fixing for now (I can always rehouse it later).

The extruded aluminum case is not very large but is big enough to hold the 2QD board with the power end cut off, 3 very tall low-ESR caps (75V 1500uF each) off that giant UPS board instead of the dinky one I could fit on the 2QD PCB, so much better power filtering, and plenty of surface area to bolt multiple MOSFETs to. Plus I can seal it up for watertightness and still vent all the heat outward, unlike the plastic PacTec project box I had it in before, with the tiny heatsink out the end of it.

I'm still waffling back and forth on whether to just use the TO220 style FDP038AN06 FETs I already use, or the higher-power-handling but higher RDSon TO264 style NTY100N10 FETs I used so well for so long on the original rebuilt ScootNGo controller.

Either way, I have to hand-wire the FETs to the control PCB, as there is no way to fit the whole PCB in there in a way that lets me bolt the FETs directly to the casing, without removing the FETs from the PCB. So I cut the entire end of it off from the gate resistors on, and will just run wires to each FET and then bolt them to the inside of the case, using insulating pads to keep them electrically isolated between the upper and lower halves of the halfbridge.

The case also has a spot for an automotive blade fuse. I am not using it now, but I may wire it in later, once I have an easy way to set a limit for the current on the 2QD. Right now the 2QD limits current via a voltage drop measured across the MOSFETs, so it depends on their RDSon. Since the RDSon of the MOSFETs I am using now is so low, around 3.5mOhms (actually half that since I've got parallel pairs), the current limit is apparently very high. Beyond 153 Amps, at least.

There is a current limit fine adjust resistor, and it's coarse adjust next to it, so I just have to figure out the circuit so I can work out what potentiometer I can install there to give me a good range of limitation I can use, for as low as 5A to as high as 50A (more if I have MOSFETs installed that can handle that). Then I can also use this to test for various different limitations, such as batteries that can't supply as much current, like my Li-Ion and a pair of well-used NiMH packs someone on ES is sending me (which might put out 7A on a good day).

Also so I can test for how well it performs at the actual legal max of 750W. ;)

I've also been charging all the SLAs I have around here for the last week or more. Some of the UPS ones simply won't charge well, but I am still letting them trickle charge in hopes they might recover at least a bit. I think that with the two newer ones that came in that most recent powerchair case, I will have 7 good ones in the 17Ah range, and 2 not very good ones, and one dead one. Plus the three 31Ah U1s I'd started with but changed out due to weight when I got the 17Ah UPS batteries. One U1 seems a little weaker than the other two.

I haven't done a full discharge test on any of them yet, but will do that using the Turnigy meter to get an idea of how many Ah I can realistically expect out of each one, including the three already on the bike.

Adding Rear Suspension to CrazyBike2

I've got several options for doing this, and this is just the first attempt, doing it the "easy way", that lets me revert back to the original at any point, without cutting into the original rear triangle. There are certainly better ways of doing it, but because of the cargo pods, they all require severe modification of the whole rear end that would preclude going back if it doesn't work out.

*This* method allows me to even undo it when I'm on the road, if something breaks unfixably on a longer test trip, though that would be pretty annoying and take at least an hour to do.

It starts with the 24" rear triangle originally slated for the unfinished ReCycle, and bolts it's crankshaft/BB to the dropouts of the CrazyBike2's rear triangle, in place of the wheel. The wheel now goes into the new triangle.

Then a shock with coil-over spring, origin unknown but possibly motorcross bike, bolts to the top of the new rear triangle, pointing forward to align with the top of the original rear triangle/toptube to keep all the pushing forces along a strong line. Below is a simple example of how it might work, bearing in mind that CB2's rear triangle is much less tall than the bike frame on the right.

This adds about a foot to the length of the bike, and about 15 pounds (so much for making it lighter) but it appears to be the easiest first try.

First up is finding a way to compress the spring enough to get a large plate on the shock to hold it in. Neither of these thrift store finds had that plate; it was probably part of the vehicle they came from.

I didn't have a large enough washer or other plate just laying around, but I did have a strong steel tile-cutting blade, too worn to cut anymore but still strong, so that has become the first temporary spring-retention plate. It's not very thick, so I suspect it won't survive all that long in real use, but it will allow me to perform some tests without manufacturing something for a shock I might not even end up using.

So I zip-tied the spring on each side and carefully compressed it just enough to be able to assemble the shock, always keeping everything parallel to my body so nothing could hit me if the zip ties broke. I also made sure none of the dogs could get into the room I was in, so they wouldn't be in danger--they tend to show up at the worst possible time if something is going wrong (before I even start cursing ;-) )

Once compressed suitably, it was easy to screw it all together, then tighten the jam nut against the pivot ring's nut so it can't work it's way loose later.

Next up was a simple way to mount it to the rear triangle for a test:

...a couple of pieces of 1/4" plate steel from a big old desk chair, from the L bracket that holds the seat back to the base, spot welded to the rear triangle at it's strongest point where the stays meet the seat tube. I can easily cut them off and move them elsewhere should the need arise (and it turns out it does, later in the post).

First bolted to the shock to keep them lined up, then clamped in place to the tube.

Then spot welded at each corner.

That's the basic alignment, and approximate position under load, at a guess.

It sticks up a lot more than I would like, so even with the wheel out of the way, it'll be too far up to lay cargo across the pods. :-(

It would be perfect if it were like this:

But that's only prior to loading, with the handy-dandy adjustable-ride-height mechanism.
The front mounting point for the shock is adjustable, to give me about two inches of adjust range, for altering rear end height when loaded if it is necessary. I did this by cutting a strong hard steel plate off the bottom of that same desk chair as above to weld to the square-tubing that supports the cargo pods and seat, as that is the strongest point on this section of the bike.

The silver part is the steering tube from a discarded Razor kick scooter, along with it's "fork". I bored a hole in the plate large enough for the tube to fit thru, with the "fork" end pointing rearwards. I threaded the top nut for the tube on it's "rear" end, behind the plate, and the locknut on the "front" end in front of the plate. Those are what let me adjust it's length, and secure it to the bike. It will not be easily adjustable on the road, as it is under the seat; it is only there so I can change the ride height if I anticipate needing to do so before a particular trip.


The preloading will be done by a tub-balancing-support cable off an old washing machine which will restrict how far the bike can pop back up after I get off of it, which will normally be sagging loose during the ride, so it will only ever have a load on it when it's not being ridden. It's main purpose is to keep the chain from ever having to rub on the frame, and so I can see what the bike is like when I am not on it, plus not having to climb up so high onto the seat. :) The shock itself doesn't have a preload method built in.


This is what the whole bike looks like now, without the preload yet, so it's a lot higher off the ground that it will be.

The spring compresses about 2/3 of it's length with me on it, leaving a bit for bumps and whatnot. If I have much cargo in the pods, it will compress most of the rest of the way, unfortunately, requiring a different leverage method for the spring to use it properly. I'm mostly doing it this way now so I can easily undo it, and because this method is easy to build and test.

This is the rear view, again no preload yet.


A closer view partly from the top/rear, where you can see the extra derailer used only for it's tensioner, at the original dropouts. It's there solely to take up the slack as the triangle moves back down, and provide enough extra chain that I don't need to worry about the actual rear derailer jamming due to chain overtension when I'm on big ring front plus big ring rear on the occasions that must happen.


Now, chainlines I'm still working out, so stuff may change as I do this. In theory with the spring preloaded by cable, the chain should pass normally thru both triangles to the rear wheel. That might not work perfectly thru the gear range at the back, so I might need to add a guide wheel to get around the stays. Hope not, but....

A close up shot of the ride height adjuster.


In first testing, I already had a problem (of course). The steel plate the whole thing goes thru under the seat is great when pushing against it, but apparently not in pulling.

I didn't take a pic of it, but when I sat on the seat and started bouncing up and down to see what would happen (before I put this thing on the road), at full compression the angle of the shock is just above and down onto the front pivot point. That forced the pivot to pull on the plate rather than push against it, and the whole assembly sort of folded down into the empty original rear triangle. Easy enough to bend back up once I got enough leverage, but it certainly suprised me (and shouldn't have).

So I'll need to do some rethinking on this. I have a 1/4" steel bar that I put under the pivot point across the square tubing for the cargo rails, and this prevented it from happening again, but I don't want to add essentially another pound just for that--plus eventually that might bend, too. A thicker plate for the pivot to bolt into would help, too, but again, it's just more weight. There should be a better solution.

I could move the rear pivot point downward closer to the BB, so it is always pushing upward against that plate, or even better against a pivot point that is part of the cargo pod rails. That would actually counter the weight of cargo in the pods pushing down on them, and if the pivot point joins the rails horizontally it will also stiffen that part of the frame.

Chainline currently does not come out right, so having to rework this is actually helpful. I might wind up putting a large sprocket (to reduce noise) on a jackshaft in front of the rear wheel, between the cargo pods, to keep the top of the chainline clear of both sets of stays even during pivoting.


Another idea DrunkSkunk from the Endless Sphere forums had is to use a seatpost in the seat tube, and attach the rear pivot point to *that* instead of my contraption from the Razor/chair up front. Then I could move the seat post up and down for ride height adjustment, and if I use a quick-release seatpost clamp, that'd be very easy to adjust.

The same problem I have with the first arrangement comes in here, though, where the shock is in the way of laying cargo across the pods--something I would like to be able to do, and could not do with the tire there.

If I move the front pivot point to somewhere within the dropout area of the original rear triangle, then I can have both the new adjustment method and be able to use the top of the pods for cargo, too. I just have to put the bottom connection point on in a way that won't interfere with putting the bike back together the way it was, if none of this works out.

It'd look something like this, I think:

where purple is the original frame, brown is the load-bearing cargo rails, orange is the new triangle, gray is the seatpost, and red/black is the shock and spring.

More Broken Spokes, Need Rear Suspension

I'm pretty sure at this point that if I had rear suspension I wouldn't be having nearly the problems with the rear wheel that I do, so that is my next priority on this crazy bike.

Tonight I heard a rear spoke break TWANG as I hit a small 1" deep pothole around the diameter of my handspan, that I thought I avoided but didn't quite manage. As I stopped to see the damage, I could feel the tire rubbing against the frame in two spots, making it likely that there was at least one other broken spoke. There were four! All I could do at the time, about two miles from home, was to loosen some of the opposing spokes and tighten some of the ones around the broken ones on the same side, to eliminate the rubbing, and try not to abuse the wheel any more than necessary to get me home.

I'll have to take the wheel off and fix the spokes tonite, so I can head off to work tomorrow "worry free", as it were, but the worry that more spokes will break from the unsprung rear weight is not going to just go away.


I've had lots of ideas for rear suspension, most of which could be implemented reasonably easily if it weren't for the cargo pods needing to bolt the bottom rail to the rear triangle just above the dropouts. So I'll be creating a small piece of framework for the rear of the square tubing portion of the cargo pod rails, which are self-supporting, to "hang" the rest of the cargo pods structure from and keep them pushed outward at the bottom. I am not sure if this will work well until I try it out, but it is the only way short of a stiff tubing framework that will put the cargo pods fully outside the volume I need for the rear swingarm to move within.

Making a rear swingarm is technically not that hard, but may end up more difficult than I expect. The most compact option will simply remove the existing rear triangle and add a short extension to the front frame just under the seat that will hold the pivot point. The pivot point would be a BB and crank axle from a one-piece-crank type bike, of which I have several already disassembled for previous experiments. I'd leave the BB bearings partly exposed so I can get grease in there as needed, and then with no grease in it I'd weld the swingarm front end to the crank axle ends.

Alternately, I would cut a one-piece crank in half at it's center, then reweld it together as a U-shape instead of the S-shape it comes as. Then I can use the pedal holes in the cranks to bolt the swingarm to a little rearward of it's front end, and clamp it's front end to the cranks with some U-bolts, so that later on I can change things without cutting and rewelding, if necessary.

Either of those methods then requires a fairly compact spring, as there is not much room between the top of the ex-seatpost under the seat, and the front of the swingarm (perhaps 4 to 6"). I have a short and quite stout spring from a desk chair that is meant to preload it for tilting, which might help absorb a little bit of shock, but I would have to use something in addition to it to take up the preload of the bike weight plus myself, or there will be no compression left.

The other good springs I have are too long, and are meant to go outside a shock absorber from a motorcross bike (which I also have). These are about a foot long I also have the rear swingarm shock and spring from the Honda scooter, but it is also too long at around 10", and it is also probably not strong enough for this bike, as the Honda had a weight limit of only about 130 or 140 pounds, I think.

If I don't mind adding at least a foot to the length of the bike, I can bolt the front end of the swingarm *into the dropouts* of the existing rear triangle. This is easiest if I simply use the 24" rear triangle originally destined for the ReCycle that I never finished, as it uses square-taper cranks that I can easily just bolt to the dropouts.

This also makes it easy to use any of the shocks and springs I have; I could easily use the pair of motorcross shocks/springs, one on each side, and probably get a pretty good ride out of it.

Adding the new triangle plus the shocks would add at least 20 pounds to the bike, though. :-(

However, it is the best option, as it would also give me a place to put one more of those 17Ah batteries, for a 48V system and another 200Wh of power, which would give me about 18.6 miles of range at 80% DOD, with no recharge along the way, assuming 35Wh/mile. Right now, it's around 14 miles with three 17Ah batteries, by calculations. Realistically, I would get closer to 20-25 miles out of it, as I don't usually ride faster than 15-16MPH unless I'm in a hurry to get somewhere, and then it's 17-18MPH or maybe 19-20 for short trips--either of those eats up power too fast, though.

All told the battery plus the frame changes and shock and new triangle will add at least 35 pounds. So much for making it lighter. ;-)

But at least the weight will be sprung, so the rear wheel won't get destroyed by all the little holes and bigger potholes, plus the inch-or-more-high edges of driveways and such I must go over to get into parking lots and whatnot.

There aren't any pics for this post, as I need to get to fixing the problems now that I'm done with dinner, but there will be some of the spokes, and of some design ideas and parts, as soon as I can next post something. Also some pics of a couple of old 10-speed-type bikes I got for $5 at a yard sale a couple of days ago, one of which (a Schwinn 12-speed) has square-taper cranks (yay!), and both of which have lots of nice chromoly tubing, being very "tall" men's frames. I think that those bikes along with some other bits around here, including the old wooden seat from CrazyBike2, are going to become a Tour Easy clone, similar to that shown on the http://recycledrecumbents.com site. It'll be interesting to have a lightweight pedal-only recumbent not meant for cargo, but rather just for commuting.

CFL Taillight

I looked for my light meter as long as I could today, but never found it. I wanted to do before/after comparison testing in lumens with the lens and without, and with whatever new reflector I come up with. I guess I'll try it when I do run across the thing.


I did find a few of my higher voltage inverters, for laptops. A few Apple Powerbook 24V adapters, which are isolated but won't start on even 40V. Neither would two of the 19V generic adapters (one Targus and one no-name), but the lightest and smallest, an Averatec, did, and kept running down to at least 30V, where I stopped worrying. :) At least *something* from Averatec is actually useful. :P

The 24V Apples are lighter than the typical 19V laptop adapters I have, although the Averatec is lighter than all but one of the Apples. All the 19V will do around 3A, while the 24V will only do 1.25A; this doesnt' matter for this application unless I need to run more than 6 or 7 of these. ;) I think two ought to do it--one rear and one front. I might go for two on each end for redundancy, though.

I also found a little plastic box that will be perfect for the rear end. I don't know what it used to be, but it's ABS and about 3/16" thick walls. Black plastic, so will enclose light very well. I can just take white plastic drink cups and cut them up for the inside diffuser/reflectors, to line the box with to make most of the light go out. Then secure red bike reflectors (minus their backings) to the open areas to the rear. Cut some holes on the ends, and put more red reflectors there, for side markers. One light in the center ought to be plenty, but one on each end would be even better.

Still pondering for the front canister.

I made a temporary taillight out of the old Honda scooter's taillight casing, which is cracking from age and abuse. It'll last long enough to give me time to build the other one above.

Had to remove the incandescent mounting fixture and reflector (you'll see where I painted it white inside instead of black to help reflect more light out of it with the incandescent, during early tests with CrazyBike2's lighting, until I gave up on it due to too much power wasted on the incandescent).


Then I had to drill out the hole large enough for the base of the CFL to fit thru. So out comes MEGA DRILL, a very old B&D drill (still has a ground plug!) with a completely metal case (rescued by a friend from a trashcan especially for me), with a reduction-gearing hand-gripped drill extension to allow me to use the much larger-shafted Unibit for panel holes.


And a test-fit:




Then I setup a test rig to determine which of those AC adapters would work, using three identical batteries to what is on m bike, with about 3/4 charge on them. A back plate off the UPS they came from, holding all the AC outlets, is held between the third battery and the other two, and one outlet pair is wired across the pack, so I can just plug in adapters and meter their outputs.

Then I wired up the Averatec 19V adapter (which is isolated) so it's plugged into the pack for it's voltage input, with it's negative output wired to pack positive, and it's positive output wired to the screw base of the CFL. The tip of the CFL base is wired to the negative of the pack, with the Fluke measuring across pack plus Averatec, at 53.8/9VDC.

The pic above is with the camera flash on by accident. Below is no flash, with room lighting of 2x 40W 4-foot fluorescent tubes overhead at cieling height.

Then a pic of it with lights off, camera in auto mode no flash (ISO320)

and a pic of the wall facing it, about 5 or 6 feet away.(ISO320)

Then some manual-setting pics, first at ISO1000 (exp 1/5 sec) then at ISO80 (exp 1/60 sec):




then with the room lights back on



Then some other lighting comparisons, such as a CFL on battery at 56VDC compared to an identical CFL on 115VAC. Room lights off, ISO1000, F/7.1, 1/2000sec:

Same camera settings, both taillight and the battery CFL in parallel on pack/Averatec:


Then a 12V 43W halogen I found when looking for edison-base screw in sockets for testing:


It sucks 3.25A constantly at 12.1V (current battery state) for that light, which is not a lot more than a single CFL puts out, but is mostly focused in one direction. Roughly 40W of power. It also gets too hot to touch in a fairly quick time.

The CFL does not get hot (just warm), but heat still ages parts, and will probably affect this, too. It only draws 380mA for BOTH the CFLs together, INCLUDING the inverter power of 100mA, for a total of 3.8W + 16.5W = 20.32W, for even more light output than the halogen, and little heat.



Oh, and this is basically what my old CCFL headlight looks like inside: