Motorized Walking ATAT using Servos and Arduino

Details

After printing all the parts, install the servos into the frame by snapping them into place. I designed the frame so the servos can only go in one way. Each servo is labeled for where it is connected to the Arduino. I used the Sparkfun Edge board : https://www.sparkfun.com/products/14525 as it was easy to solder on 3 pin headers for the servos. You will definitely need to use an external 5v regulator. The Edge will handle 800ma but the servos tend to run > 100ma each while running.

After the servos are installed, use the HomeServos.ino program to get them all to 90°. Then put the arms on as shown in the photos basically in line with the servo and all point towards the outside of the frams. Double and triple check you have the servos connected to the correct connector on the Edge board.

Add the small single arm that came with the servos and use the included screws to attach the Long and Short Arms to the servos.

Test it upside down without more than the upper "thigh" legs attached. when you are ready, you can attach all the parts below the knee.

Watch until the FR side of the frame lifts the shoulder. You should see the shoulder rise in this order : FR, RR, FL, RL.

The program is a basic sin wave servo motion action. I watched the mechanical version many times and just tried to emulate that. You can certainly tweak the program and show me how to do it correctly!

https://www.youtube.com/watch?v=F8O341sPUUk

This is a remix of this: https://www.thingiverse.com/thing:1083338

The Detailed body pieces are here: https://www.thingiverse.com/thing:4641541

The Servo Frame and push rods are here: https://www.thingiverse.com/thing:4651937

You will need some M2 x 8mm screws :)

Here is the graph of servo motion...

Files

WalkingATATUsingServos.ino

ino - 6.08 kB - 11/16/2020 at 03:07

Download

HomeServos.ino

ino - 834.00 bytes - 11/16/2020 at 02:56

Download

Project Logs

Collapse

Improved Height and more Servos Per Leg

Luke J. Barker • 04/14/2022 at 13:38 • 0 comments

An improvement has been on the design board to increase the size of the legs and use the 1980 ATAT toy as the body, add the servo legs, and get the original toy to walk. I added a servo to the knee joint in my first print/test. Now 3 servos will control 1 leg. The photo shows the old body, old leg and the new servo controlled hip and leg.

Discussions

dinho1967 wrote 05/05/2023 at 11:13

Hi Barker, tks for sharing such amazing project, recently I built your project and is so cool, I m now thinking to use same concept on AT-ACT or AT-M6....I d like to see the progress for your increased size version.

Are you sure? yes | no

markus wrote 04/15/2022 at 19:13

Do you know this at-at walking model?

https://youtu.be/ti6OQO0SqTc

Are you sure? yes | no

mharper68 wrote 04/13/2022 at 17:46

maybe add a heat seeking sensor, so it follows you around like a puppy. a really slow clunky puppy. this design is great. thank you.

Are you sure? yes | no

dinho1967 wrote 01/18/2022 at 02:12

congrats for the project...after some try outs with gears I gave up...and now I have a chance to make it happen...thank you so much...by the way I m planning to use arduino nano...lets see

Are you sure? yes | no

Luke J. Barker wrote 03/18/2022 at 13:46

The Nano should work! I also tried the gears and gave up but only after 3 tries!!! LOL. Luke

Are you sure? yes | no

miklos.bohuss wrote 08/06/2021 at 15:48

Hi All!

I am newbe here

Can I use arduino nano instead of SparkFun Edge Arduino somehow ?

Can anyone help with this?

Are you sure? yes | no

Luke J. Barker wrote 09/02/2021 at 15:26

I believe you can use the Nano, but you will need a servo connection shield or breadboard your own. As long as the Servo.h library works with the Nano, it should work.

Are you sure? yes | no

Steven R Ketelsen wrote 02/07/2021 at 18:09

got the servos working pretty well. testing it out, i had to adjust some of the servo arms to force better/more symmetrical contact with the surface. gonna cut up a ruined magnetic bed for the magnets you suggested. Hope to be done this weekend when we go into the snow.

Are you sure? yes | no

marazm wrote 01/26/2021 at 17:41

It walking trought snow?

Are you sure? yes | no

Luke J. Barker wrote 01/26/2021 at 17:46

We just got some yesterday.... I should try that :)

Are you sure? yes | no

marazm wrote 01/27/2021 at 18:25

This is the basic functionality. Destroy Rebellions.

Are you sure? yes | no

Steven R Ketelsen wrote 01/05/2021 at 21:18

...how do you secure the body & head to the frame? It just seems to rest on top. Am i missing some parts?

Are you sure? yes | no

Luke J. Barker wrote 01/13/2021 at 17:19

I glued magnets to the body and the frame and that seemed to work. Original had small peg and hole that easily broke.

Are you sure? yes | no

Steven R Ketelsen wrote 12/30/2020 at 06:35

This thing is fantastic. I've got everything printed and all the components laid out; servos are installed and the frame is assembled/screwed. I see there's a spot for the buck converter/voltage regulator, but there's servo leads coming out of it. do you just use standoffs to mount the regulator?

Also, I assume you're just dropping the 7.4v to 5v before you give it to the board? or are you doing something on the board itself?

Thanks!

Are you sure? yes | no

Luke J. Barker wrote 01/13/2021 at 17:21

Yes, I power the board with the regulated 5V by just wiring directly to one of the 3 pin connector 5V pins. Sorry about the holes through the depression for the regulator. I added a piece to Thingiverse to attach a battery and the regulator to the inside of the body.

Are you sure? yes | no

Ricky Burnett wrote 12/23/2020 at 17:14

I started printing this project today. I have ordered and received all the servos and other needed parts. This will be my third robotic project. I also started learning Fusion 360 for future projects I have in mind. Nice design and build Luke.

Are you sure? yes | no

Luke J. Barker wrote 12/23/2020 at 22:42

Have fun with it!! Let me know if you have any questions.

Are you sure? yes | no

craigdperl wrote 12/01/2020 at 00:19

Looks like a part or 2 are missing from Thingiverse. A lever that connects the servo arm to the leg and a cap that covers a servo arm connection to the shoulder.

Are you sure? yes | no

Luke J. Barker wrote 12/07/2020 at 15:01

Be sure to download both the Servo and Detailed Thingiverse repositories when printing, I just added the lift arm caps to the Servo Frame Thing.

Are you sure? yes | no

Luke J. Barker wrote 11/27/2020 at 16:27

With the SERVO.H library, you can run a servo from almost any Arduino Pin. All 8 are independent servos and motion. See the graph of movement, out of a full cycle of motion, each Shoulder is phased 1/4 of full motion from the next Shoulder.

Are you sure? yes | no

zatgun wrote 11/27/2020 at 05:04

I think I understand .. all 4 x legs and all 4 x shoulders are driven at the same time but the gears are arranged such that only 1of4 actually engage at any time .. is that how it works? So do we arrange the gears by trial and error or is it an intuitive thing?

Are you sure? yes | no

zatgun wrote 11/27/2020 at 05:01

Hello .. it looks to me like there are only the 2 x servo channels used on the Red board, one drives all legs and the other drives all knees. Have I got this right pls? If so .. how does this work .. the 4 x legs appear to operate independently ??

Are you sure? yes | no

markus wrote 11/26/2020 at 19:14

How about this movement:

https://youtu.be/ti6OQO0SqTc

Are you sure? yes | no

Luke J. Barker wrote 11/23/2020 at 21:40

I fixed the links in the Details.

Are you sure? yes | no

Mike Szczys wrote 11/23/2020 at 15:44

Looking awesome! It's funny how most walkers are trying to make smoother, organic kinematics. But these walkers were big an clunky in the movies. A different target to hit but looks like you've achieved both movie-like motion while also successfully walking forward.

Are you sure? yes | no

Luke J. Barker wrote 11/23/2020 at 16:16

Thanks. I have some ideas to keep it from rocking but I too love the movie-like motion. :)

Are you sure? yes | no

Mike Szczys wrote 11/23/2020 at 21:20

PS- Your thingiverse links above have some extra words in the embedded link which takes you to a 404 page when clicked.

Are you sure? yes | no

Sunil wrote 11/18/2020 at 20:04

I tried printing and assembling the detailed At-AT remix on thingiverse, but the timing of the gears were off and the walk cycle didn't quite work. Super disappointing after all that work. I will try your edits as I have most of the hardware already. I have a couple of these PWM Servo Driver boards I will use instead: https://www.ebay.ca/i/264299924590 . Thanks for sharing, as it will be great to resurrect this project!

Are you sure? yes | no

Luke J. Barker wrote 11/23/2020 at 16:15

I had the same problem with the gears and after 2 builds, I moved on to the servo idea. More fun this way. And it can walk backwards if you want ;)

Are you sure? yes | no

Luke J. Barker wrote 11/17/2020 at 01:52

LOL, it's all gravity. Another designer came up with that, I just modified to servos. The Knee is loose and when the shoulder moves up and the leg forward, the knee just does it's thing according to Newton... When I scale this up.. and I will... I plan to put servos in for the knees and then do some crazy moves. :)

Are you sure? yes | no

Dan Maloney wrote 11/16/2020 at 23:08

Neat. What's the knee joint like? IOW, how does it lock when it needs to?

Are you sure? yes | no

Motorized Walking ATAT using Servos and Arduino

Description

Details