I started building a BRAT few weeks ago. Since I am using Pololu SSC rather then Lynxmotion SSC (too expensive here) I had to go the hard way and learn to make it work by myself. Anyway, I was not that happy with the way it walk, so I’ve been experimenting a bit on the leg configuration (3DOF, 4DOF, 5DOF…) but I decided to stick with 4 DOF for now, until I’ll be able to handle the IK part (still trying to understand the theory and all this names).
I tried the using the 209 torso but accessing the battery was a pain, not too many options for adding other servos for pan/tilt to be able to detect obstacles, etc make me look for a different configuration. This is how I come up with this one. Look a bit unballanced to the back (still waiting for some brackets to arrive), but is actually quite ok for now. There will be some additional changes coming soon
I managed to get some of the sequences working quite well, like: walk fwd, walk backward, turn left, turn right, squat, stand, etc. I am working now to hook this up to a “home made” arduino controller so I can controll it remotelly and hopefully get into the IK part.
Nice picture. I dont understand why you say the SSC-32 is to expensive? It’s only $39.95 less than the cost of eating out one night if you look at it that way.
Anyway, it sounds like you are making progress which is good. I look forward to seeing more in the future.
Thank you, SN96
Well, I am on the other side of the world, here no one is selling SSC-32… Anyway, add another 39$ for Sequencer, another 50$ for shipping and is no longer cheap. I can buy Pololu for 30$ here, including the Sequencer and some more, is running on USB and serial
I’m considering going back to a 5DOF configuration… Once you get it walk looks really great
I just did a small configuration change last night, to use the Lynxmotion’s torso (BT-01) turned 90 degrees as a base. Now I can still use the hip rotation and also put all my electronics and an additional li-poli battery to power up my microntroller and servo controller, beside the battery for servos.
Managed to get all running wireless, controlled through my Arduino (bot commands, code upgrades, text-to-speech, etc)
Wow! that’s a clever way to use the biped BT-01 torso! The design looks very nice, neat, and compact! Great project. I’m Very impressed with how you used the torso.
The hip rotation is a great feature. I look forward to seeing a video of this design walking and turning. I really need to blow the dust off my biped and get him built. I have the BT-01 torso and one 4dof leg complete but I need to get another two sets of ASB-09B brackets to complete the other leg and to add arms. I miss experimenting with my brat, but for my next biped project, I really want to try the full size biped.
Sorry Mike, I already dismantle the bugger. I did some other attempts but I realise that I need better servos to be able to control properly the walk. I just place an order for some 5645 servos and some other LM brackets. Will take a while to get them, so in the meantime, I am working on a quad using some cheap the servos I bought (and now regret of doing it ^_^).
Anyway, planning to use ASB-15 as a base for hips and with 2 “L” brackets to get an aluminium channel attached to it like a spine then attach the hands and head to it
Also, I took your advise and I ordered a SSC-32 together with the brackets. Now waiting for it, thank you.
