SPINNERS.

This is a good representation of my slow but steady improvement in making basic BEAM bots that dont do too much... just spin.

Lets start off with my old Symet, built from the Book instructions (Junkbots, etc). WOW what a klunker!!:

That is a 1/4" grid graphpaper, so you can see just how HUGE-UH this thing was. its actually kinda silly looking nowadays. The thing was, I couldnt find any low voltage 4700 Caps (like the one in the transistor testor) at the time, and used all I could get: 10volt ones. I know now they are simply MUCH too heavy to make a solar powered thing that actually uh.. does anything.

Above it is the qeue cards I started making for myself, little reminders on circuit designs of stuff I may come back to later and need a quick reminder on what goes where.

The motor is a pancake motor I got from a Cassette walkman from the 80s/90s- I did what the Book reccomended, and asked my coworokers if they had any old walkmen tapedecks laying around that they didnt want anymore.. and BOY did they start coming in! I got like 5 of them to tear apart for the rather excellent motors to be had within (this one ran on 1.7 volts, drawing only 35mA- with some pretty good torque, by way of example). The Solar cell is one of several I mail ordered from Solarbotics. These poor cells are having a hard living, but they are resin encased, so, except for the printed circuitry tabs tearing away, theyre pretty much indestructable.  BTW: that little cell, measuring 37x33mm.. is a 6 volt, ~50ma (!!!)

This side view shows how it is supposed to work- the pulley (smeared in dried school glue for better grip) sits at an angle, propped up on the edge of the Capacitors, just barely not dragging the case on the ground. What this does is when the motor turns on, say, clockwise, like this the symet will slide towards me, until it runs into something, tips anoter way, and now the turning wheel will send it skitting in some other direction. Pretty cool, but all my klunky old thing can do is twitch. (and UGH the lousy cold welds on the casing!!!)

But anyway, that is the first I ever built.

Next is one from a failed experiment. I call it "1Wing":

This one has the smaller 4700 cap, and a different solar engine than the first Symet (that was a flashing LED solar engine). This one is a fancier 1381c solar engine, using a special voltage trigger chip- one of those transistor looking things crammed in between the capacitor prongs. That little black blob with the red diode is indeed the entire engine.

This is "1Wing" because it was supposed to be one side of a pair- in an attempt to make a Photovore that didnt actually have any eyes, yet still tracked towards a light due to the solar engine getting the most light firing more often, turning the bot to it (by running the opposite side motor). The blind photovore failed as a prototype, because for some reason one wing worked extra well, the other maybe 1/3 as well... meaning it didnt do what I wanted it to do. bummer.

 

But I kept the good solar engine, put the motor on its own wing, and made it a sort of spinner. This was my forst working solar engine that actually... worked.

 The cell is actually one of the big ones, cut down the center, where the two arrays of cells inside the resin are separated. I realized that the 6V was really just 2 3v ones wired in series, so that actually meant I could make 2 cells out of one!

 

Heres a rather boring video of it doing something... but what makes me grin is that "look Ma, no batteries!", and it really is running off of the desklight.

Yeah.. I warned you it wasnt very exciting, dont worry, the rest are much more active, as I DID get better at making these things.

 

 

So what was next... OH my "little engine that could":

Remember that the grid is 1/4" squares, so thats why its called "little". It uses another cell from Solarbotics, a 22x24mm one, (3v, ~20mA), a tiny pager vibrator motor, and uses the solar engine printed on the back of the card, seen in the next pic.

Kinda messy with the Hot Glue holding it all together. But you may wonder what the point was. This little engine was the end result of me tweaking this and that to take this cell, that Cap, that motor, and make the Best Darn Engine I could out of it, squeaking the most performance out of the limited power trickling in from the daylight. I tweaked mostly just the weight of the chassis, the arrangement of the "wheel" (a glob of tacky hotglue), and the timer capacitor (tan thing) that controls how long the voltage trigger stay "triggered". This is a fine line- between either draining the Cap completely and a slow recharge of the Cap, or a too rapid drain, getting not much motor activity and leaving a full Cap all the time. So you see, even with such few components, something as simple as a timing Cap can make ALL the difference!

 

 

Heres a video showing the best performance I was able to get: the lightest possible setup, the most direct wheel to ground drive, the best "power curve" of pulses:



 Yeah.. pretty Active.. if I do say so myself, running under a 100watt desklight. But why is it the "Little Engine THAT COULD"?

 

Because it could "turn over"!! The charge/discharge cycle, if given enough light, could cycle in between the time it takes for the motor to coast to a stop.. so... it runs continuously!

This is a big deal for me, because its important to know that the cell, with its trickle of current, could NEVER direct drive the motor on its own, directly. But with a Solar engine, and a millisecond short cycletime of pulses, it could in fact do the job!

 

 

Now that just warms my Heart. This little gizmo, about the size of a quarter, would run nonstop everyday until the end of time, or until a breakdown happens (so take THAT Zombie apocalypse! LOL). Maybe I will have it encased in a plexiglass domed display case on my tombstone for all the world to marvel at... too much? ah well, the inner geek in me got carried away.

 

But next lets see what a SERIOUS solar powered spinner can do: This one is bought from Solarbotics, and is called a "Battle Symmet" from an Instructables article(http://www.instructables.com/id/Solar-Powered-Battle-Symet-BEAM-Style/), and comes in a "solder it yourself" kit bag of parts. Lets see... linky:  http://www.solarbotics.com/product/60010/

When I saw this parts list, the somewhat BEAM educated geek in me went OOoooH! over some of the parts: a coreless induction pager motor, a .33F (thats like 330,000uf) SuperCapacitor, some wheels that fit on paperclips, etc... I went a little overboard, and bought like 6 of them.

So, if you clicked the linkys above, you know what its supposed to basically look like. I modified mine a bit, 1 for looks, and one for performance (of a sort):

 



I think mine looks meaner, more sleek, more well, just geektastic I guess. I built 3 of them, to battle it out in a slighly bowl shaped styrofoam plate, and kept track of which one was the "champion" by either being most active, hammering the other battle bot around more, or even BREAKING the other bot with a nasty tangle. The losers got disassembled for parts for other things, and the winner got some finishing touches, and a permanent place in my "cool stuff" tacklebox.

In addition to the blade "weapons" on the ring (these are the striking edges, afterall), what makes this little demon a bit more custom is the little scratch you see to the left of the motor, in the printed circuit strip along the left side. If you look closely, you can see tiny green wires in an X cross connecting the corners. What this means is that the two 3v cell arrays in the panel are wired in paralell now, no longer series. So instead of a 6v,~40mA, its theoretically a 3v, ~80mA... that doesnt work so well in less than optimal light (that was the drawback, but I figure all battle arenas will be lit... right?)

So, looking back at ol' 1Wing in its sedately pulsed spins around and around... how does one with some serious performance BEAM components do in comparison? The supercap (the blue chrome thing.. TINY for so much power) takes a bit of time to build up a charge... but when the voltage trigger sets it loose... well, lets just watch:

Pretty much awesome.

 

Thats it for my spinner Phase of learning (oh! I made a rear view mirror spinner, in my truck! details on that later.), but now we come to a bit of sad part of this Hobby and Learning experience. After eagerly absorbing all I can on BEAM robotics, technology, tricks, and events, and many many internet searches for more, more MORE... I noticed something unfortunate... most BEAM related websites havent been updated since roughly 2002!! Meaning the world has apparently "lost interest" YahooAnswers on this subject informed me that the age of discreet electronic components was giving way to integrated components, leaving little things like the voltage trigger in its transistor package a thing of the past- consumer elctronics simply dont have them inside anymore. Nor are these things called "cassette tape players" that need high efficiency motors around anymore.

 

So, bummer. My mean little blade hammer Battle has no one to battle. The timed dragrace solaroller I was designing has no events to compete in.  So these Gizmo's are ultimately just for my own personal "giggle factor". But so be it! Giggle, I Shall! and keep on building!

 

After this slightly disheartening discovery, my focus drifted a bit... but to other neat things. Like Arduino. More on that later as well, because that has some great robotics aspects as well.