This miniball project has its roots in the old BEAM Miniball kit published by Solarbotics. It's still a cool kit, so we're going to show you how built a simpler version. This project is spearheaded by Mr. Jerome Demers ( aka Robomaniac ), our intern at Solarbotics!

This robot uses a solar engine circuit. A small solar cell by itself generally doesn't have the power to make a motor move, so you have to store this power up in a capacitor, which is a small battery-like storage device. When the circuit sees that there is enough power stored, it releases it in a burst to the motor, getting useful work.

With this project, our solar engine will be powering a small car in a large plastic sphere!

This technology of using minimal electronics and simple mechanical design is call BEAM robotics.

The Miniball itself was originally invented by Richard Weait of North York, Toronto.The Miniball is a amazing robot - it uses a simple circuit and the robot itself proves to be very capable, rarely getting stuck. The Miniball is mechanically complex and electronically simple. (But don't worry - the mechanical part is still pretty easy)

In this case, we aren't going to build the original Miniball, but a smaller, more basic wannabe version. This robot is extremely simple and can take a beginner less than 2 hours to build.

The original Miniball has a geared motor that moved as a counter weight around a fixed shaft inside the plastic ball container. As the motor tries to move the weight forward, the ball starts to roll in that direction.

In our case we have a motor with wheel, which spins the ball forward as it runs.

Imagine this like a hamster in a ball - it's almost the exact same thing! But in this case, we're feeding our hamster with photons!

Step 1: Parts You'll Need

Mechanical Parts
1 - Transparent Plastic Sphere (80mm - get from craft store or hobby shop)
1 - High-efficiency Coreless Motor (Solarbotics part #: RPM2)
1 - Motor Mounting Clip (Solarbotics part #: MMFC)
3 - Rubber Wheels on Nylon Hubs (Solarbotics part #: RW)
2 - Paper clip

Electronic Parts
1 - 37 x 33mm Solarbotics Solar Cell (Solarbotics part #: SCC3733)
1 - 0.35F 2.5V Capacitor (Solarbotics part #: CP.33F)
1 - 6.8uF Tantalum Capacitor (Solarbotics part #: CP6.8uF)
1 - 3904 Transistor (Solarbotics part #: TR3904)
1 - 1381 Voltage Trigger (Solarbotics part #:1381C)
1 - Signal Diode 1N914, 1N4148 (Solarbotics part #: D1)

1 - Length twisted red/black wire

Tools Required
- Soldering equipment (soldering iron / solder / cleaning sponge) (HVW tech soldering tools)
- A pair of Needle-nose pliers (HVW tech part #: 43060 or 43061)
- A pair of Flush Cutters (HVW tech part #: 43040)
- Safety Glasses - VERY important when clipping and snipping! (Solarbotics part #: 5330)

We made a parts bundle of everything you you need to build this project (not including the plastic ball and hand tools). You'll have all the mechanical and electrical components to start making this neat lil' robot!

Click this link to get the bundle.
<p>nice work</p>
<p>nice work</p>
<p>Boo - not working. Diode is correct; used a magnifying glass to inspect my soldering and I don't see any overflow. Switched motor leads but then read elsewhere that just changes the direction of the motor. Tested the motor again and it works. I am using a 1381e instead of 1381c but didn't think that would matter. Thinking it has to be a short and I just can't see it. How do I test? Thanx all.</p>
<p>Thanx for the easy follow along!</p>
<p>very cool</p>
Too cool.
I really have to try making one of these!
Ok. Can I use hook-up wires instead of using breadboard wires. If I can't. Where can I buy a breadboard wire?
Working on this with my 10 year old.<br>Heads up on the breadboard wire. This is not in the parts list but it is essential to keeping the wire from contacting the board.<br><br>We are headed over to Radioshack to find some breadboard.
&nbsp;how do you get the ^sphere^
I when to my local art store, they use those sphere for home made Xmas ornaments.<br /> <br /> They are really cheap, they where on sales for 0.99$<br /> <br /> They had 2 size, small like the one in this instructables and much bigger. (4 inch )<br /> <br /> have fun!<br />
opps missed can you come here an read up one , oh ill copy an paste would a square work or does it not power enoght to flip over?
i dont think it will have enough power so try using the ball/capsules from the toy dispenser thingys.
i hate being dumb an lazy could we just trade ive lots of stuff taken apart lol you could build amys , live vid cam races sounds fun , oh wait it rains here to much .
<strong>how many workerballs can i get for 50,to 100 ft of cable wire , my dad collected junk too lol</strong>
arts an craft stores sell the P.balls , would a square work or does it not power enoght to flip over?
here's the one i bought http://www.createforless.com/Darice+Fillable+Shape+Plastic+Ball+80mm/pid163942.aspx
Adding up totals now... im at around $23 for electronics and another $11 for sphere
Will the robot work in artificial light?
How much do all the part cost?
this is sick!!! i'm Definitely building one.
Is there a remote controll?
Can I get a circuit diagram for this?<br />
here it is&nbsp;<br /> <a href="http://www.instructables.com/files/deriv/FKK/DB74/G5W7JD5L/FKKDB74G5W7JD5L.MEDIUM.gif" rel="nofollow">www.instructables.com/files/deriv/FKK/DB74/G5W7JD5L/FKKDB74G5W7JD5L.MEDIUM.gif</a><br />
Spiffing, thankyou :)<br />
Hi i was wondering if you could use a 1F cap instead of the 0.35F; would it just take longer to charge and have a longer burst of power?<br /> <br /> Thanks for your help<br /> Mdob<br />
&nbsp;yes it will have longer burst but will take longer to charge.
This is great so far! The only roadblock I've come across may sound amateurish but this is new to me:<br /> <br /> I&nbsp;bought the bundle from the website.&nbsp;I&nbsp;can't tell the difference between the two black pieces (the transistor and the voltage detector) to be able to know where they go. Any advice?&nbsp;They are not labeled at all.<br />
&nbsp;I never say non label transistor! I check the roll of the 2N3904 and 1381 and they are both mark.<br /> <br /> The 1381 is writting 381, the 1 is really hard to see/missing.<br /> <br /> You can test the transistor because there is a diode between the base and emitter.<br /> <br /> Take you multimeter in diode mode, then put the component flat side on the table. Touch the middle pin and the right pin with your multimeter and you should read around 0,6V. If you don't that is the 1381.&nbsp;<br /> <br /> Good luck!<br /> <br /> <br />
&nbsp;Mine does not work. I am measuring a short across the leads of the .35F cap and I get a short. Bad cap?
How do you measure your short? With the beeper on the multimeter or ohm?<br /> <br /> I used the beeper and I heard a beep too! I took the ohm and got 4M on a 4700uF cap.&nbsp;<br /> <br /> Be sure to check all the connection and polarity of all the components.<br />
When I finished my &quot;miniball wannabe&quot; it didn't work. After staring at it for awhile and looking at the setup of the &lt;a href=&quot;http://www.instructables.com/id/Solar-Powered-Battle-Symet-BEAM-Style/&quot;&gt;Solar Powered Battle Symet&lt;/a&gt;, I realized that I put the diode on backwards. I wanted to note to anyone else trying this instructable that the diode needs to have the dark line towards the bottom (in the orientation of the picture above)<br />
&nbsp;Hey, I added a note in the picture so people do not get confuse.<br /> <br /> Thanks<br /> <br /> I am happy that you where able to find the problem on your own! Great job!<br />
kal00: Adding a second capacitor doesn't take over charging while the first is discharging. The solar cell simply keeps adding its power output to the power being dumped by the MSE circuit. <br /> <br /> What it <em>does</em> do is let you store more power before activation, for a more impressive power burst!<br />
Sorry, the link is:<a href="http://www.instructables.com/id/Solar-Powered-Battle-Symet-BEAM-Style/" rel="nofollow">www.instructables.com/id/Solar-Powered-Battle-Symet-BEAM-Style/</a><br />
BTW if you weigh the driver down it wont tip unless it has tremendous speed<br /> probably about 0.5 kg would do it <br />
&nbsp;Yes but remember that the pager motor has no torque, so 500gr is WAY to heavy and the pager motor will not be able to roll the robot around.<br /> <br /> You really need to make that robot light and have that third top wheel.<br />
oh well mine has about 2 kg torque so it can withstand it <br /> <br /> <br /> it looks exactly the same a well(the motor)<br />
&nbsp;Just here to say remember <a href="http://xkcd.com/413/" rel="nofollow">THIS</a>?&nbsp;
Who doesn't!!!<br /> WICKED!!<br />
total cost?<br />
Not much if you just take the components out of old broken devices. ; D<br />
FREE!<br />
some parts can not be find in broken stuff...<br /> <br /> euh...<br /> <br /> if you search really long you might find all the stuff.<br /> <br /> the plastic ball will be the hard part.&nbsp; The 1381 is second, solar cell comes in third.<br /> <br /> You could make a solarengine with a other type of circuit because the 1381 is hard to find, I never found one in more then 10 years.<br /> <br /> good luck!<br /> <br /> <br />
If you can't get a 1381, this should work ( I have not tried it yet )<br /> <br /> http://www.solarbotics.net/library/circuits/se_t1_fled.html<br />
step 2 <br /> this link<br /> <br /> http://www.solarbotics.com/products/60010/<br /> <br /> 23$ and you will also need some paperclips, 3 cm of wires and the plastic sphere.<br /> <br /> Then you have everything to rock and roll!<br />
Is it tightly sealed??<br /> <br /> PLEASE, PLEASE&nbsp;put in in the water, I&nbsp;want to see a video!<br /> <br /> _l<br />
mmmhh delicous photonss.......<br />