View Full Version : Drew's Quad Walker

09-10-2011, 10:56 PM
Hello all. I am finally getting around to documenting my simple quad walking robot now that I have it working reliably.

Quick specs:

4 legs, each 2DOF, using slightly modified MG996R servos
2 cell 1mAH LiPoly battery
Turnigy 15A ubec
Pololu 8-channel SSC and XBee radio for control
Frame made from waterjet cut steel, and dremel-tool cut aluminum tube and copper tank float
Radially symmetrical, top/bottom symmetrical design can walk in any direction or upside-down.

The project started out as something to do with leftover servos and other parts, and turned into a fun thing to do to entertain people at conventions and shows. The design is nothing terribly original or clever. The walking gait is a fast amble gait which is inefficient and really hard on the servos but gets the robot moving fast. There's essentially no on-board intelligence, but the control scheme mapping the joysticks to the legs has a lot of flexibility, which lets it do tricks like rolling over or sitting back on its rear legs and waving at people.

More of the details are over here: http://drewsrobots.blogspot.com/

09-11-2011, 04:57 PM
Just took a quick glance at your blog Drew - definitely liking what I saw! Best wishes on your project.


09-13-2011, 01:00 AM
That is an awesome bot... And the vids are great, too. I've not seen that style of walking before, but I think I understand how it's working, and will probably toy with implementing that on my own quad for fun.

08-04-2014, 10:45 AM

The old version of this bot was beaten to death over the course of many demos at conventions, and was retired with stripped servos and flaky electronics. I've just finished rebuilding a new version of it from scratch, using eight HXT900 micro servos, a custom-made radio control board, and lots of 3D-printed plastic parts. I'm working on a full write-up of the design and construction process.

I really didn't trust these HXT900 servos to hold up under this kind of walking cycle, but they're impressing me. I've put over half an hour of walking on the bot so far and haven't had a single failure. I'll be taking it to GenCon next week, which will let me really torture-test the design.

08-05-2014, 11:55 AM
Here's a short video of the robot walking (not terribly well, the floor was too slippery) at a friend's house. Her cat decided to assist with the demonstration.


08-29-2014, 09:19 AM
that's a very nice working quad.
I like the way it moves, it has some animal behavior