Let's Make Robots!


Navigates around using IR.

 Update: 26 June 2009

 A bit of a hiatus

Pager motors arrived from Solarbotics. Then thay sat on a co-workers desk for a week before he decided to tell me they had arrived.

Holonomic wheels causing problems so have opted to go for table tennis balls/polymorph. Thanks to emuller for proving this concept with Three wheeling doover.

Have built quad motor driver (2 x L293D) board, processor (28X1) board and sensor (IR LED & Receiver) on strip board(s).

Software tested both in simulation and with above boards. Need to tweak IR sensor for reduced range. Other than that, all good.

Update: 4 June 2009

Good things and not so good things

Cellphones arrived. And upon dismantling - no vibrating motor. Hmmm!? Brochure says they have vibrate mode. Damned if I know. Scored some NiMH batteries though! And tiny 8ohm speakers. Displays no good though. Oh well!

 Have ordered pager motors from Solarbotics. GM6's would not fit in lower body.

 Holonomic wheels coming along. Polymorph is great stuff. Having so much fun with it. And an artist (sculpture) friend has taken some away to play with.

Have ordered L293Ds, 38kHz IR receivers and a couple of other bits from Surplustronics (a local PICAXE and other good bits supplier) here in NZ.

Now, if only had a little more free time to continue with the build.

Update: 27 May 2009

Traction - How to make it go

After a lot of thought, and having looked at the RS Tri-Bot, I have decided to use three motor/gearbox combinations (Solarbotics GM6) to drive three holomonic wheels.

As I have not been able to find 30mm dia. holomonic wheels I will have to make my own (ouch!). Will be playing around with a couple of ideas over the next few days.

I have designed a Dual L293D H-bridge motor controller board to control the motors and LEDs in the legs. 

I have also finished the design for the main processor pcb. The processor has changed to a PICAXE 28X1 or 28X2 to allow more program space for controlling the motion of the robot.



Update: 25 May 2009

What's Inside

IMG_0083.jpg   IMG_0084.jpg

Upper Right: On/Off button  Centre: Head shell  Upper Right: Bulkhead with contact arcs

Lower Right: Bezel.                                          Lower Right: On/Off switch & pc

The contact arcs mate with two contacts on battery compartment (below)


 IMG_0085.jpg   IMG_0086.jpg

Upper Left: Battery compartment (3 x AAA)  Upper Right: Rubber 'torso'

Lower Left: Lower bulkhead. Secures 'torso'  Lower Right: Vibrator Motor


 IMG_0087.jpg   IMG_0089.jpg  

 Body with motor assembly                          Body without motor assembly 

                                                                                   Wires are for LEDs in legs


 IMG_0090.jpg  IMG_0098.jpg

      Body and legs from below                                Lower Body Shell


IMG_0093.jpg   IMG_0097.jpg

LED assembly. Leg mounting flange                            Leg internals          



                                         Disassembled Leg

It Begins

Update: 22 MAY 2009

Atom Massager lit up

Have four cellphones on their way to recycle for motors and batteries (and whatever else I can harvest from them).


  Having spent a bit of time looking at the many creations here on Lets Make robots, and on other websites, I still wasn't sure what type of robot I wanted to build. Then I stumbled across the Atom Massager at a local DSE (NZ) store.

 At this point I have disassembled the massager, removed the motor and am measuring up the space available.

 The plan is to install two pager motors (preferably with planetary gearboxes) controlled by an L293D (PWM controlled) via a PICAXE14M. I have also been spending some time developing the code I think will be needed.

 Quite a bit of work will need to be done on designing the traction system. I have received some good suggestions from Nebster and Oddbot on this.


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Bidding on four of the same model now. And definitely going to use the batteries in a project - maybe this one or another project I am slowly developing.. Thanks for the suggestion. Cheers
Nice job... cant wait to see a video of it.
Cheers but it is still in the "how do I get this to move" design phase. More info coming.
Thanks for that Unforunately I only have a maximum wheel width of 5 - 6mm. Hve found some interesting info that should enable me to make my own with polymorph and some beads. Hope they work. Cheers

Hey we're twins!


I tried to add a picture, but I'm not sure what happened, so instead, I Just added a page for a little robot that is simlar too what I think your design here is.  I made it a little while ago and it just uses a three  74AC240 IC to sense light and to be motor drivers. I don't use ominwheels, just the three little balls that rotate at a speed that is proportional to the strength of the light hitting the sensors in the top part - the result is that the robot follows a spotlight - and on a good day, it moves towards the brightest thing in the room, which is usually the window.

Fortunately, I have a wooden floor, so the three ball-wheels can slip and slide as they need to.


Just posted onyour blog. Thanks for the great video. What is the weight of your bot?


It's pretty light, very light actually, but somwhere in the range of 100-200 g I think.

The bits are:

3 micro servos, 3 74AC240 ICs, 3 wooden balls, 1 big clear ball, 1 4v camera batt, 6 LDRs, bits of wire, plastic. I think the big ball is about 10cm across, so not so much. The guts of it is pretty packed.


In retrospect, I think I'd use three ~3v  motors to make it really zip around. the servos just turn too slowly to make it very interesting.

Also, I'd work harder at balancing the 3 ICs - there are some biases in the outputs, I suppose it has to do with variations of the resistances of the LDRs, but there's not really much room for balancing pots.