Let's Make Robots!

cordless drill electric brake + stepper motor = saving power while not moving?

Hi All,

I've been trying to find out how the electric brake in cordless drills work, but am having no luck.  The appear to be able to stop the drill motor instantly with no wind-down.  

If anyone knows how this system works, can you provide a brief description or point me in the direction of where to go and learn about it?

What I had in mind was applying this type of braking system to a stepper motor of a balancing robot, so that I could save power, during those moments when the balancing robot is balanced and the motor is not moving.  

PLA 3D Printer Filament.

Hey all,

Long time no see. I've been on an adventure starting my own business, Citizen Scientific Workshop. We've just got some air in our wings with new products and such, and one of them is PLA 3D Printer Filament. If you visit my site, you can see all of the pretty colors


smart way of turning around

I've seen these 1 motor walkers before, with the big disavavantage that they can only walk straight forward.  Look how smart this is solved on this robot by adding an extra wheel :)

Homemade Remote Controlled Walking Robot: http://youtu.be/zrbTm6BFO_U


Charging a Lithium (LiFePo4) battery in place


Groucho's (a wheelchair based robot) battery is a monster 90 lbs of battery (24v, 100 amp-hr).

I'm hoping to be able to just turn off the robot and then disconnect the load (the battery is connected to the power distribution system via an Anderson PowerPole) and hook it to the the charger.

Hopefully this is not risky.

What I want to eventually do is to have Groucho plug himself into the wall socket himself. For that I'd need a lot of things to happen in the right order, with testing.

Rover 5 Explorer board Question

Hi, I am currently assembling my Rover 5, I have connected the Motors, encoders and the batteries  (6 x NiMh AA,s).

I plugged in a 12vdc 1amp plug pack, and flipped the power switch to charge, After about 15 - 20 seconds, I noticed a smell and turned the charger off, I went over both sides of the board and all looked fine, I did find however, the Resistor directly behind the power switch, was warm to hot.

NEW Metric Precision Stainless Steel Shafting

We just added Metric Shafting to our Actobotics

PopPet is on Kickstarter!

It's finally here, the day has come, PopPet is on Kickstarter!

This has been months in the making. But finally, all the verification on Kickstarters end is over and now comes the wait to see if PopPet is as good as everyone says :).

So, if you have some cash to spare and would like to support me, you can check out the campaign by clicking on the link below.

Chassis material

Hi builders

I just brought the Tamiya Dual Motor Gearbox with a pair of wheels. While waiting on the set to arrive, I wondered from what i should build the chassis of. My first throught was LEGO? I really just want to hear your thoughts and what how you build your chassis! :-)



Arduino UNO R3 SMD or IC

Hi All, I am very new to this hobby, I am looking to buy the UNO R3 board but have noticed there are 2 types, one with Microproccesor as an smd , the other with a plug in chip version of the proccesor,

Which one of the 2 is preferable please.



Electronics question: LEDs on a slightly unpredictable power supply

Hi guys, Way off topic, but you guys have been so helpful in the past, and i KNOW you know the answers, so one cant but ask!

We are doing a camper van conversion, and i have found some sweet "decking lights" for internal lighting.

They are sealed, "3LEDs and a resistor", units, designed to run at 12V (off a transformer, the junction box is a simple parrallel arrangement)

Problem is, the vehicle battery will produced between 11 and 14V depending on charge condition and if the alternator is running.

Advice on servo motors

Hello everyone! my and a friend are working on a project for making a replice of the sentry turret from a game called Team Fortress 2, although the specific details of that dont matter xD we are currently having trouble in locating servo motors for different purposes of the build, so i was wondering if anyone had any advice or links on where i could find servers with the following specifications:

Dagu Trex Controller Issue [SOLVED]


I create a new forum to talk about a trex controller issue I encountered after one hour of use of this controller. I mounted the dagu trex controller on the dagu wild thumper chassis with the 30+6mm given spacers . For testing purposes, I connected the trex controller in LV and no external switch mode (2 jumpers on) with Zippy LIPO 2S batteries and a D8RII FrSky receiver. The batteries are in series on the batteries input. The channel 1 and 2 of the receiver (which I programmed to be throttle and direction on the 9XR TX) are connected on the TX/RX pins of the controller.

Solar outlet Power

Hey friends! Work is still slowly going on my robot project but something else came up that I could really use some ideas on...


What I'd like to build is a solar powered AC outlet (110v US standard). Ideally it would take in power from the sun, store in a battery, and go out to an outlet. A friend of mine is doing some major go-green efforts and I wanted to help out, however Im a bit rusty on my electrical engineering lol.


secondary level arduino electronics kit?

i'm wondering if anyone sells a kit of components for like a secondary level of hobbyist... like a next step up from an arduino inventors kit.  Something that includes a bunch of components such as:

LPC dev tools first release

Some of you are aware of my ongoing project to develop a good toolchain for the NXP LPC1114 and related processors.  I have finally posted an initial release of what I have so far.  It is really rough, but mostly works.  If you are interested in getting a head start or if you just want to take a look at what I'm doing, the files are here:


Feedback is welcome.  Please don't tell me "your documentation sucks," I already know that :-)


Move robot along curved path (with differential steering)

I am building a robot that looks roughly like this:

(Image taken from this site and modified by myself.)

Dagu Micro Magician Robot Controller V2

Hi All, my Name is Peter, this will be my first post.

I have this controller, Micro Magician,  and was woundering, to run an I spy tank or similar, do I need to add a Motor controller or can I just use the motor out terminals on the Dagu Micro Magician Robot Controller V2



Adding a switch

Hello all.

I was just wondering how I would add an on/off switch to this circuit so I can turn the power from the batteries on and off?


Frying Up Some Pi

Ugh! Someone I was trying to help with a cheap L298N h-bridge pointed me to this video from TheRaspberryPiGuy.

At 10:41 of the video he plugs the 5V line into his RPi's I/O pin.

What type of projects are you using your BeagleBone black for?

My daughter and I have started building a robot with our BeagleBone black.  You can see our robot here http://letsmakerobots.com/robot/project/my-first-working-robot. I was wondering what others were using their BeagleBone black for to give me ideas for other projects we could also work on.