My latest robotic creation is a 1lb fighting robot that competes under the name Algos. Algos replaces a basic 2 wheel drive wedge robot named Kobalos.

The concept for Algos came about when I decided that I wanted to switch to a robot with an active weapon.

I had a few key requirements in mind when designing Algos-

    It must have an active weapon capable of damaging the opposing robot
    It must be able to fight well even if the weapon is disabled
    It must be capable of absorbing a great deal of damage

These requirements led to a few key decisions. First, the weapon needed to be light to allow for the damage absorption and disabled weapon requirements, so I chose to go with a small diameter, high RPM spinning disk. Second, if the robot is going to be capable of fighting even without the weapon, it needed a passive attack system, which led to the general wedged shape and the use of the same drive system as Kobalos, my old 1lb wedge robot. Third, and finally, being able to absorb large amounts of damage while being light enough to stay within the weight limit meant exotic materials would be needed, so I built the entire robot out of 6al-4v (Grade 5) titanium in 1/16 and 1/32" thicknesses. Luckily, due to the size the material cost for the chassis was only $100 for enough material to build two complete chassis.

With the initial concept determined, the next key thing in the development process is deciding how you will make it. I often see people design the parts, then figure out what tool they need to make them. I typically follow the opposite approach and decide upon the manufacturing method before the first component is modeled.

In the case of Algos, I have chosen to use an abrasive waterjet to manufacture all of the components that are not pre-fabricated. The decision to use waterjet from the start influences many of the decisions made when designing Algos. Using 2d part designs reduces potential tolerance stack-up issues as all of the machining can be done at the same time, by the same machine, on the same piece of material for any given part thickness. Using all waterjet fabrication also means that replacement components are relatively inexpensive due to the minimal material waste and speed at which the parts can be made which reduces both material cost for any given part and reduces labor costs if the parts are being fabricated by a company like http://www.bigbluesaw.com/ or http://teamwhyachi.com/.

Parts List:
Fingertech Robotics-
11:1 Silver Spark Gearmotors (2)
TinyESC v2 (2)
Channel Mixer
Lite Hubs with Lite Flite wheels

Turnigy Park 300 brushless outrunner, 1380kV
Plush12 Brushless ESC
R410 OrangeRX

Robot Marketplace
Thunder Power 325mAh 3S LiPo - G6 Pro Power 65C Series

Cad Files:
This contains .dxf drawings of all of the components made for Algos including both generations of center rails.

Algos has competed in three events so far. At Clash of the Bots 3 Algos went 2-2 with several axle failures. At Dragon*Con Robot Micro Battles Algos placed 3rd with the upgraded weapon system. At the Atlanta Mini Maker Faire in the first Atlanta Robotic Combat event Algos went undefeated to take the 1lb championship. Video of Algos can be found at http://www.youtube.com/playlist?list=PLa4DDbMiSUTUSAMtKEfMFhywgw-Bp6Rv-

Step 1: Component Selection

There are a number of components that I have standardized across all of the 1lb robots I have built in recent years. These components are:

Fingertech Robotics TinyESC v2

The TinyESC is, in my opinion, the best insect weight esc available today. The high voltage capability, current limiting and light weight make it a great option for robots up to 3lbs.

Fingertech Robotics Silver Spark gearmotors

The Silver Spark gearmotors have proven to be incredibly reliable when combined with lite flite foam wheels. The gearboxes in Algos have been through 5 full tournaments across two robots without failure.

Fingertech Robotics Lite Hubs

These are the lightest hub adaptors I know of for lite flite wheels. They're inexpensive and they work well.

R410 4 channel Spektrum compatible receiver

They're light,  tiny, and work with DSM2 and DSMX transmitters.

Kitbots Nutstrip

It's available in a range of sizes and allows for easy assembly of waterjet cut panels.

For the remaining components on the robot, there was a good deal more decision making to be done. I knew I wanted a high RPM weapon, but with sensorless brushless motors there are occasional issues with starting torque, so a balance of torque and peak RPM was necessary. The style of weapon and motor mounting location also meant it would likely see some abuse, so low cost was a priority. When low cost is the goal, Hobbyking is the go to source for components. I eventually settled on a 1380kV outrunner from Hobbyking ( http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14398 ) for the weapon. At 11.1v, the rated voltage of the 3s lipo I was intending to use, the motor would theoretically spin at 15,318 rpm which works out to a tip speed of around 90mph with the 2" disk.

The motor suggests a 10A rated ESC for typical use, seeing as there was very little weight and size increase, I opted for the 12A Plush12 ( http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2161 ) brushless esc to give extra breathing room on that portion of the electrical system.

There's not really a set rule for battery selection, however with lipo batteries, one goal is typically to not drain the battery completely during a match. Matches for 1lb robots are normally 2 minutes long, so I wanted to make sure the robot would have plenty of battery to last a full two minutes. In combat situations, you have current spikes intermixed with low and intermediate draw periods. The TinyESC's limit each motor to 2.8A each, or 5.6A total. The weapon motor claims 7A peak, so when added together, you have a theoretical maximum draw of 12.6A. If through a strange string of circumstances you managed to stay at peak draw for an entire match, you would need to supply 12.6A for two minutes, which converts to a 420mAh battery ( (1000*Amps required) / (minutes of fight/60) ) however, as this is an extreme worst case scenario, a smaller battery can be chosen. I opted for a 325mAh battery under the assumption that 50% average draw would be an extreme case in actual use. I opted for a high end battery pack in this scale, a Thunder Power 3s 325mAh pack ( http://www.robotmarketplace.com/products/LP-TP325-3SPP65J.html ) rated at 65C continuous output, which translates to 21.1A.

The final piece of the puzzle was the mounting of the weapon disk. There are plenty of options on the market today, after looking at several options I chose to try the lightweight set screw hub from ServoCity ( https://www.servocity.com/html/lightweight_set_screw_hub__3mm.html ) and have been pleased with the results.

I use a custom power switch for my robots, however there are several off the shelf switches that have been used successfully and removable links are common in the small weight classes. Fingertech Robotics has been developing a small power switch that should be an ideal solution in the future.
<p>Hello, and thank you for the detailed write-up :) I'm designing a robot (first one ever!) that is similar to yours, and Algos was pointed out to me. I wanted to ask, since you're using 11:1 motors, do you find you have enough torque to push the opponent robots around? I was looking at the 33:1 motors (with larger diameter wheels) thinking I would want to balance the speed and torque. Any insight? Thanks! </p>
An increase in wheel size is going to offset an increase in torque.
<p>any video </p><p>send me on +917779069937</p>
<p>you have any video ? how to made it?</p>
is that any video of your robot
is that any video of your robot
<p>How much did this cost?</p>
<p>what type of motor did you use?</p>
<p>Could you tell me the total cost, thinking about building it!</p>
This looks soo Awesome....
<p>Its even more awesome to see it work in person.</p>
<p>what are the dimensions of the base? the cad files are not proportional </p>
<p>Using similar electronics, do you think it would be possible to get rid of the blade completely to make it just a wedge?</p>
Absolutely. It's occasionally fought as a wedge after the weapon was damaged to the point where it couldn't be fixed mid event.
Oh cool! One more thing (sorry I ask so many questions) where did u get your metals cut from and which pieces t which thickness
<p>Think i could use the gold spark 20:1 for this or no</p>
Silver Sparks would be the better option. Gold Sparks are more for low impact setups.
Oh didn't know that. Thanks!
<p>what gear ratio is the motor</p>
Drive motors are 11:1 silver sparks
Thanks. Sorry to keep bothering you, but what would you say the top speed is?<br>
<p>It should top out right around 10ft/s</p>
<p>what gear ratio is the motor</p>
<p>what size wheels r they</p>
The wheel size is normally in the 1.4-1.5&quot; range. I start with larger lite flite wheels then turn them down on a lathe.
<p>would this http://www.pololu.com/product/2820 servo be able to power a 150 gram ant weight robot? Or would this http://www.pololu.com/product/2149 one be better? Any recommendations?</p>
ok..like the algos.....its quite brilliant........but i use anything other than titanium which is as well as strong and cheap and light
On the second version of this can you tell me the dimensions of the width, top length, and the bottom length. Also a picture or two of the inside like the weapon motor setup.
Hi! <br>What kind of plug the Thunder Power 3s 325mAh pack has? did you bought any adapters to recharge it? <br>Thank you!
Im in the same type of thing at my school except we are making 15lb bots. I cant really make an instuctable because im late in the building process. but very cool man keep up the good work.
that is great <br>
I thought this robot looked familiar. I was at the maker faire and as a huge robot enthusiast was blown away. I would love to build this robot and I admire people like you for inspring my young generation to push forward with technology.
Great bot! Do you have any footage of it fighting?
Never mind, I found it. Looks like your design worked great!
very informitive! i have always been curious about battle bots.

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