my first quad

Lynxmotion Legged Robots
1

Hi there,

This is my first attempt of a quad. I just managed to get all connected last night, well… most of them, still waiting for some parts. Is based on LM’s 3DOF leg design and I am using a 3" aluminium channel (ASB-503) and 4 offset servo brackets (ASB-11) to build the main body.

Already ordered an ARC-32 for control (now using just a mini controller from Pololu) and planning to use Xan’s code (thank you Xan for sharing your work with all of us ^_^) and change it for a quad. Planning some changes on the leg design, something inspired from Zenta’s famous T-Hex but with 3DOF to keep it more compact.

I’m also considering using a WiFly module for communication (wi-fi, up to 11Mbps, etc) as I do plan to add a serial camera (from 4D Systems) on it and also I’m interested in a two-way communication and eventually environment mapping. Did anyone here tried something else than PS2 and xBee?

I got a very rough gait (RB-RF-LB-LF) with some COG shifting on it to get it walk last night, but is far from something stable. Some pictures for reference:

http://nasulica.homelinux.org/wp-content/gallery/robots/3dofquad-front_small.jpg
http://nasulica.homelinux.org/wp-content/gallery/robots/3dofquad-top_small.jpg
http://nasulica.homelinux.org/wp-content/gallery/robots/3dofquad-leg_small.jpg

2

We’ve started a WiFi project using the Lantronix module:

lynxmotion.net/viewtopic.php?f=30&t=6770

You might consider using it.

Kurt has been busy with the Bees, and some of us use the BlueSmirf modules.

Alan KM6VV

3

Thank you Alan, unfortunately I already have few WiFly (RN-111B) modules. I managed to get one connected to an Arduino microcontroller and talk over wi-fi with a PC. My only issue for now is using the SoftSerial to connect to it on high speed. I need to use HardwareSerial instead.

4

I notice that you are using DFR15MG servos. How do you find those work?

5

To put it simple: I regret paying the money on them. I actually changed them after I took the picture…
I tried using them with 5V and 6V, different servo controllers, etc and still the jitter is annoying, some of them are basically moving non stop. The accuracy and repetability are far from expected, etc…