Let's Make Robots!

Robot Cat Quadraped (In Progress)

Walks Around Navigating obsticals
AttachmentSize
48_servo_controler_rmk2_.1.brd165.72 KB
48_servo_controler_rmk2_.1.sch564.73 KB
Robot_Cat_Small_Figures.xls10 KB
Robot_Cat_Files_1_.zip2.4 MB

Robot cat started out as a sketch-up model to work out the dimensions and get a feel for how i could mount the servos together an soon turned into quite a complicated project its a work in progress an quite slow moving due to the quantity of custom parts.

i have included the model and pcb files in the attachment 'robot cat files 1.zip'

photo cannoncam061_zps65059fcc.jpg

The Servo body is made from 25mm aluminum box section

it took about 3 hours to build the first one of these hip joints i cut 2 of each part so i can hopefully use them as a template

 

i will use a 6800mah lipo battery eventually as shown in the sketchup model but for now the nicad will do for testing mockup purposes

the body and hip servo joints coming together

 

i have included the eagle files for my 48 servo controller using an atmega 2560 microcontroler it is unfinished at the moment but if you want to have a look you will need the microbuilder & sparkfun component library's inluded in the zip file (eagle version 6.1)

as of the actual pc im not sure if i will use a raspberry pi or a via pico itx board for image recognition with open cv and ros if i can ever get my head round it

 

 

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Thanks everyone.

I had dreams of building a biped originally an then looking at my cat thought actually that solves some of the balance/stability issues I was considering.

the futabas are just for mock-up and trial fitting they were im my box of rc gear

I have been looking at these servos 13kg of torque is quite good for the price at $10 a piece

http://www.hobbyking.com/hobbyking/store/__27556__Turnigy_TGY_S901D_Metal_Gear_Digital_Robot_Servo_13kg_0_14sec_58g.html

anyone have any experience with them?

I was thinking of adding some springs or latex tubing to some of the servo joints to try and help off load some of the strain on the servos

as for sketchup stick with it there’s been countless evening's sitting with a micrometer and a handful of parts and lots of head scratching my advice draw a part and make use of the group/explode tool it helps a lot copy and pasting and moving parts about that and the sketchup warehouse is a great resource and can save a lot of time I didn’t draw the raspberry pi or the hitec servos

 

 

Nice project and yet another style. Mostly we see hexapods with their specific leg design. That cat leg design is quite interesting.

I am sure MarkusB would love your aluminum brackets...i do love them too.

Please keep posting more details, pictures, videos...we are hungry for that information.

Indeed I do love home made aluminium brackets. I would love to see it fall from 5m and land on its feet :)

This is the most unique walker we've seen in a while. I hope the Futabas are up to the challenge. I can't wait to see video-the kinematics will be fascinating.

I don't want to sound negative because this is such a beautiful piece of work and I want it to succeed so badly, but quadrupeds have a degree of freedom in each limb that I don't see here-namely one at the shoulder/hip hemicircumscribing the spine. When you watch a cat navigate a "turn" it usually involves crossing one forpaw across the spine's axis. That's not to say that this beast won't be able to corner, but it might make things more difficult, and it probably won't exhibit some of the cat-like motions you might expect as a result. It will probably almost have to effect some kind of balanced differential gait.

Looks like some precise milling and riveting. Good work!

Wow! That's just too cool.

Have you figured out what servos you'll use? I think those top leg servos are going to need to be really strong.

That's an amazing sketch! I'm just starting out in making designs for my robots in Sketch Up!