I was trying many different SES configurations and I just could not seem to find a sigle configuration that allowed the head servo on the same plane as the shoulder servos using the brat base 3 position channel. So I settled with this configuration that required cutting and drilling.
Although this configuration works after the mods, it’s a tad to crowded. I had to pry the bolts in the head servo and for this reason the assembly is tilted slightly. Here are some pictures of it with the new micro servo arms.
The shoulder servos are bolted directly to the channel. The head servo bracket had to be cut so that the hinge side was cut narrower to allow room for the other shoulder servo. The hinge side also had two holes drilled to match the holes on the channel for mounting. http://i627.photobucket.com/albums/tt358/botwire/Brat202.jpg
I didn’t want to cut or drill any of the brackets but I was not able to avoid it. I have to say, holding the asb-04 inches from the compound miter saw with my bare fingers was scary! It did the job though.
I need to re-do all my sequence steps since I connected all the servos on different pins. I decided to change the order of the BB2 and the SSC-32 mounting. Before, I had the SSC-32 mounted first, then the BB2, but it made changing jumpers for RS-232/TTL comms difficult. Now I have it so that the BB2 is installed first then the SSC-32 last, so I have access to the jumpers. I also added a second 3 position channel bar so the board carrier has a place to mount to.
One of the micro servos jammed up and stopped working. I also had a problem with the board carrier screws “go loose” on me, so I decided if I’m going to have to tear down the brat half way to fix the loose screws, and remove one of the arms to get to the bad servo, I might as well start over.
I have a biped “pete” torso waiting to be used. I bought it for when I was ready to graduate from a brat to a more complex biped. I really love the biped brat, but I think I’m ready for something a little different. I have a great idea that will re-use the brat legs and add an extra degree of freedom by using the hip servos in the torso. The legs will have 4° of freedom vs. 3°.
I have all the servos in the torso but I need a few “C” brackets to attach the legs to the torso.
I will return to the brat a different day, but right now I think I want to try the “PETE” style torso.
have you seen the Biped Pete Jr.? You mention you would like to modify the BRAT legs a little and it made me remember Pete Jr… lynxmotion.com/images/html/proj103.htm
Yes, I have seen that one. I am going to do the same except the legs will have the servos on end instead of flat, so it will be almost the same height as a regular biped “pete”.
Here are some pictures of the torso assembled ready to mount to the legs. I re-clocked the top servos of the brat legs so they are on end rather than flat. I have the channel mounted only to hold the legs in place. Picture the legs without the channel.
Here is a picture of me holding the torso in place to get an idea of height. Again look past the channel bar and you will see the legs will be taller than the standard brat.
I will attach an “L” bracket to top leg bracket and then attach that to the “C” bracket connected to the torso. There are two types of “L” brackets and I am going to use the thicker version for the added strength. I think this 4° configuration will work very well.
I changed the thread title since this project is no longer a BRAT class robot. With the addition of the humanoid torso and the added DOF to the legs I felt it was time to shift gears from a BRAT to full humanoid.
I’m gona call my new project “Vector Bot”. This was my original name for this type of project before I got involved with the brat.
i cant wait to get the rest of my parts to get my take on pete jr. out there, im only doing one servo set on end/vertical(brat style) because i dont want to high of a center of gravity, you might want to consider that, i have some other ideas but youll have to wait to see them
Yeah, I thought about that, but I want to try the servos on end first to see how it will work. I can always revert back to the flat BRAT style legs if it proves to be too unstable.
I don’t post em all. 