First Real Look At My Ez-b Controlled Full Size Lis B9 Robot

Dave I am so impressed with your work. It is truly amazing what you have accomplished. I for one can't wait to see how the arms get built. The arms will be the most challenging part of all I believe. I have not worked on my robot Magnus for quite some time now. I bit off more than I could chew. So I put him on hold till later and have been working on smaller bots.

I would definitely like to help you with this phase of the build because it will ultimately help me with the arms on Magnus later. So I will be glad to help you research the design and help brainstorm. I am sure others will pitch in. This is the best forum ever! There is so much talent here.

Dave I'm sure you have seen this but, here is a link to Bob Greiner's B9 build. He had experimented with a couple of designs. Not quite as much functionality as you need though.

Also Jerry Chevalier's build has a neat way of moving the arm up and down.

@Danger! I think, had an arm design he was working on for his B9. Maybe he can help out.

When I get home this weekend, I'll try to post a picture of what I have so far. It is still in the prototype stage, but you may get some ideas.

@rgordon, thanks for the offer and kind words. I'm always open to advice, ideas and critical criticism. Any help at all is welcome. I have visited Jerry's and Bob's site often and have gotten advice directly for each several times. Much of my build is based on what these guys (and others) have done before me. I'm not sure but from what I've heard him say I think Jerry seems dissatisfied with the method he shows in that vid. By watching it I can see there may be too much pressure and weight on the one rotating pivot point he's showing. Only way I'd be happy with that method is to install some type of ball bearing unit on the motor shaft the slot could roll over and of course it would have to be machined.

@Danger, Cant wait to see your pics and what your coming up with. I've been looking at many designs on robot arms that have been designed already for both the B9 and other robots. B9 is unique in that it need so slide in and out, bend at the solder and elbow and have the claws open and close (and maybe even spin). Along with all that it is very heavy and it needs to be built to support load and have motors capable to lift it. I'm estimating 10lbs each if using good strong but light weight materials like aluminum or some type of plastic.

@Dave what are the dimensional specs and info for your B9 arms? -Inside diameter of rubber arm -Length when fully retracted -Length when fully extended -Distance from torso arm opening to the elbow bending point -Distance from elbow to the wrist joint -Mounting method to robot torso -How much room is there inside the torso for mounting shoulder motor -Any other info that may be helpful in determining various arm designs -Do you have dimensional drawings of the arm opening? -Does elbow need to bend 90 degrees? -Does shoulder need to rotate more than 90 degrees?

With this info I may be able to build a full size model out of wood to functionally test out ideas. I have some small linear actuators (50 lb pushing force) that may be able to move the elbow but I am not sure how fast you want it to move. These are strong but not really fast. For the elbow I am thinking something like a Backhoe arm....

I have some rubber arms that I had ordered for Magnus to help with the simulation but, I don't know if it is the same as yours until you get me the dimensions.

Hey rgordon,

Let me get these specs together and get back to you. I've been wanting to gather this info anyway so thanks for the push. I like the backhoe idea. I operate one every so often at work so I'm understanding where your going with this.

Thanks for the interest. Dave

Please feel free to call me by my first name... Rex... if ya want. I would be honored.

Here are some more questions and items to ponder:

-Will the arms be used just for animation or will they be required to lift more than their own weight? -How fast do they need to move? -These arms will be heavy even if we use aluminum, PVC, wood or combination of these materials. Will need to have strong structural support at the shoulder joints. -Is there enough room inside the torso for wheelchair motors? Gonna need a lot of torque for the shoulder joints. -Need to think about how to get the wires through the shoulder joint area to the other motors and servos inside the rest of the arm. ServoCity has some great bearing, hollow tubing, and gearbox arrangements to consider. They have a lot of application photos of their products that would be good for you to look at to get ideas.

-How will you remove the torso for working on the central support structure with the arms in place? I had the arms on Magnus so that I could open a small hatch, pull one pin, disconnect a multi-pin connector and the arm would slide right out. However, I don't think you have that much room inside the torso. I will find the the pictures of the arms I had started on just to show you what I mean. I was using some 400in/lb torque motors, chain, sprockets, and pillow block bearings.

-Will all this extra weight be a problem for your torso rotation motor, lazy susan and limit switch setup? -Worst part is realizing that this is gonna cost quite a chunk-a-change eek But I think if we do get it to work well, then, it will be a revelation for all B9 Robot builders everywhere 'cause I have never seen a completely functional B9 arm in all my travels on the web. Most only extend and retract. Some only move up and down. I have not yet seen one with 5 DOF. (Shoulder, extend/retract, elbow, wrist and claw.)

Rex,

I'll be getting all the info and some pics today or tomorrow and post here. I have a couple new puppies in the house to keep under control and that keeps me jumping. eek Also have to take the mother-in-law out for her birthday dinner tonight. tired

In the mean time; I only need them to support their own weight but I'm sure someone down the road will try to hang something on the claws or have him hold something.

I would like to see the speed fast enough to simulate natural relaxed human speed but not frantic.

I should have enough room in the torso to hold wheelchair motors and was looking at the ones Tony is using on his Lexi build. However the elbow motors may not need to be that big. Toymaker sent me a few nice worm gear motors that may work there. What ever the size the whole rear end of the assembly will have to pass out through the 5" (approx size) arm hole when I disassemble. I'm looking forward to seeing your pics.

My plan is to mount these arms is much like yours. I need to remove them by reaching in from the outside and unscrew them before I unassailable the rest of the robot. My rubber arms have a nice flange at the end holding them in place and I just pull them out of the opening to remove and reach in. I have a central support system that is free from the main torso. I plan to attache there. That will keep the weight off the torso and transfer it down through the skeleton. I'm sure my heavy duty lazy Susan and motors will accept the extra load. Routing the wiring shouldn't be a big problem.

Money? Well, I work a lot of overtime at work and this has helped a lot with funding this build. I don't see that changing. I'm in this far and committed to go the distance to realize my childhood dream.

Thanks for the interest and help Rex!