SolaHex (Simple Hexapod Clone)

Let's Make Robots Robots
1

Update: Few images uploaded.

 

 

I always wanted to build a hexapod, and after pdg37 posted his Simple three-servo hexapod walker I told myself: "This is the best design to start!". ShC v1 by spacebird and Hexapod Clone by BruuD convinced me that the initial thought was right. So, to robot itself. I decided to go slightly beyond simplisity and add some features to my SolaHex, that is how I name it, and from name alone you could suspect it will have something to do with solar power... Bingo! Was not that hard, was it? :D So, what SolaHex is going to do:

  • Walk on 3x 8gr servo powered legs (implemented)
  • Detect obstacles with Sharp 10cm range sensor (implemented)
  • Produce sounds with piezo speaker (in progress)
  • Seek for light by LDR sensing (to be implemented)
  • Know if the battery charge is getting low (to be implemented)
  • Recharge with solar cells (to be implemented)
  • Signal with blue LED (to be implemented)

Parts:

  • Picaxe 28x2 low voltage microcontroller
  • 3x 8gr Micro Servos
  • TO BE UPDATED

 

 

23-Apr-2010

Most of work on mechanical side is done. He can walk forward-backward and detect obstacles. You can see it on first video. The best thing is... I have whole weekend to work on SolaHex, take pics, shoot vids and post them! :D 

25-Apr-2010

I have been working on hardware part today (solar cells and LDRs are installed) as well as making some photos. So, the story goes:

Here SolaHex is in electronics design phase. I had all parts connected on breadboard.

Next photo showing a plastic container I intended actually to fit everything into...

And everything were going well, I installed a piezo speaker on the bottom, then glued NiMH cell and servos on top...

But when I made cuts for legs in upper part and tried to fit my PCB in, I had to leave this idea. I left lower part intact though... Anyways... Legs were made from thin rods taken from old broken umbrella. Some heatshrink "boots" made :D After couple of minutes of digging in my junkbox, I found pretty nice CD dummy they put below all CDs when sold in stack. Bolted it to lower body with some mecano parts and few screws. This basically constituted the chassis. Today I glued solar cells and LDRs below my transparent hood and connected everything. Ohhh... what a mess with wiring... Next time I will first design my pcb properly instead just getting a small piece of it and designing "as it goes" :D  Below you can see how SolaHex looks at the moment (Click on images to see enlarged pics)

Now SolaHex only goes forward, till it sees obstacle and backs off as you saw from first video. So next time I have free time, I'll do some coding for turning first, then LDR measurements processing. Keep tuned :D

Walks around so far

  • Actuators / output devices: 3x 8gr Servos
  • Control method: autonomous
  • CPU: Picaxe 28x2 (Low Voltage)
  • Power source: 3.6V NiMH, 2 x SolarCell 4.5V 18mA each
  • Programming language: Picaxe basic
  • Sensors / input devices: Sharp IR, LDR
  • Target environment: indoor
This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/solahex-simple-hexapod-clone
2

looks good, but i doubt a

looks good, but i doubt a cheap and small solar panel will provide enough power for three servos, the sharp sensor, and leds…

3

I’m not planning to power it

I’m not planning to power it with solar pannels, only recharge a 3.6V 300mAh NiMH accumulator wich will be the power source. And pannels itself will be 2x 4.5V nominal voltage solar pannels from SolarBotics connected in parallel.  They should provide me with 36mA of current in sunlight (as per datasheet) which looks to me is sufficient for slow-charging my accumulator. I will need to do more optimization with regards to “sleep” mode power consumption, for example I’ll probably power up sharps trough transistor to be able to shut’em down.

4

Nice

I have been experimenting with solar until winter set in. Solar assist is easy. I reciently picked up a pack of cells that will put out 1 amp at 6 volts but you have to build it. Learning PICAXE may also come this year. As by watchnig you guys it seems to take little power. I can run a Basic Stamp on a 9 V 200 ma solar pack. They are 2 packs 2" x 6" each. Epoxy coated and tough.I got those off ebay for around $20. I think 1 amp for motors is a good start. Much more impressive then the steam iron.

5

Nice project, isotope. The

Nice project, isotope. The new pictures are awesome. The photovoltaric array seems to be very small. Did you measure the voltage in sunlight and ambient light (I ask because you have mentioned idoor use)? As I can see, you would have enough place above the CD top to assamble larger photovoltaric arrays.

 

6

Thanks :smiley: Yeah, there plenty

Thanks :smiley: Yeah, there plenty of room there :smiley: But for now I want to keep everything under the hood :smiley: Not yet, Working week just started, so I do not have much sun here in evening :slight_smile: the weather’ve been pretty cloudy in here anyways. So, I have to wait till weekend, or do some programming and take SolaHex with me to work to show off and take measurements during sunny lunch :)))

7

Turn right and left?

I like your design! Three servos for a hexapod robot. I jsut wonder if it is able to turn right, left and around with this configuration?

8

Thanks, but design is not

Thanks, but design is not mine. I got inspired by this. You can find all info there. And yes, it can turn :slight_smile: Unfotrunately I had to stop working on this project and disassembled the robot.

9

turn right and left

Actually this configuration works quite well at turning _ i used a similar config in mine a few months back and it turns on the spot !

I do find that the servos eat the batteries though

if you’re interested https://www.robotshop.com/letsmakerobots/node/26783

 

 

 

10

turn right and left

Actually this configuration works quite well at turning _ i used a similar config in mine a few months back and it turns on the spot !

I do find that the servos eat the batteries though

if you’re interested https://www.robotshop.com/letsmakerobots/node/26783