Brat with 209 torso

Lynxmotion Legged Robots
1

Hi

I’m considering building the brat with a 209 torso (BT-02). I’m quite impressed with the one at youtube.com/watch?v=4fy01Zop … playnext=1

Are there any plans or instructions to build a brat 209? I did look on the Lynxmotion site in projects but couldn’t see anything related, although the BT-02 text indicates that there was a project for the 209 brat.

Also, will this acheive 4 DOF by using that torso along with the leg extensions? Would the HS-645MG Servo be sufficient for a build like this? I haven’t yet built a brat so probably would start with Biped BRAT Combo Kit (Autonomous) BotBoard / Basic Atom Pro (BRATCB) with a view to changing it to a 209 with extended legs later, so I want to get servos that would be OK for this.

Thanks in advance for any advice!

Peter

2

645’s are the best servo for the BRAT. We did build a similar and made a video of it walking.

We used a slightly different approach as we didn’t use the offset brackets. (ASB-11) We never made an assembly guide for it, but it’s not very complicated. I believe all you need is a set of ASB-04 and ASB-11 to add the 4th DOF.

I really like the looks of the legs with the ASB-11 there. :wink:

3

Looking at that gait, is it necessary for the ankles to tilt at all?.. your video is *NOT helping me *NOT go buy one!@ :slight_smile:

–Aaron

4

The ankles do need to tilt.

Sorry Aaron lol

5

my ankles don’t tilt when I walk :open_mouth:

I could try but I would look like a goober.

6

Or like a Web-Foot!

Alan KM6VV

7

That video looks pretty good to me!

What would be the downside of using the 209 torso? I’ve heard that the battery is difficult to access. Also how would you add a panning sensor, e.g. the Sharp GP2D12 IR Sensor, with the panning kit (or something else)?

Is there code around (e.g. for the walking) that has been modified for use with a 209 setup with extended legs and hip rotation?

8

For some unknown reason evolution never eliminated the ankle. I’m pretty sure your ankle does tilt when you are walking even if it’s a small amount. :wink:

9

We’ve never built one beyond what the video shows. You will have to decide the best way to go. I’m sure there are pro’s and con’s with many solutions.

We can look for the code used above for you. :slight_smile:

10

Found it!
ps2mscout1.1.bas (17.6 KB)

11

Before you get too attached to the idea of using a BAP28, you might want to take a look at the new BotBoarduino. The language(in my opinion) is much easier to learn and gives you a foot in the door to the real world of C programming. Did I mention that the Botboarduino is cheaper than the BAP28 + BotBoard? No? Well the BotBoarduino is about 50$ cheaper than the BAP28 + BotBoard combo.

If you’re interested I can mod my PS2 BRAT code for the BotBoarduino to take advantage of the 4th DOF.

12

maybe this should be a race to eliminate all basic micro stuff and stick with Arduino style code. I’m a little over a month and a half into C++ and I think its great!.. and it certainly compiles a lot faster too!.. along with the itch to build a brat/scout I could use the code in C++ if anyone has it

13

hey the brat 209 walks great! looks good!

14

Its interesting… I’ve been spending a lot of time looking at the Phoenix code and I haven’t even looked at others… It looks like all the brats code is just a bunch of canned servo positions.
again NONE of this is helping me not want to buy another bot.!@

Is there brat/scout C++ code available for an arduino… honestly it would be neat to see a teensy 2.0 embedded in a servo controller all in one, without two boards.

–Aaron