Roko.ca

Today I got my sheet of Carbon Fiber in the mail, which I’m using for some structural and cosmetic parts on the Quadruped. I whipped up the base plate/battery tray this evening, which worked out awesome. The picture to the left does not do it justice! Carbon fiber just looks plain old cool.

Although I haven’t had too much time to do more work on the robot since my last post, I have done up the axles for the joints in the prototype leg. I still need to get the boring tool for the mill (it’s on order) to properly seat the bearings and gears to finish the leg, however. Even without the bearings, the motion is very smooth and stable, but hey, for less than $1 a bearing, why not?

In the picture to the right, you can see some details of the joint, and how I’m routing the flat flex cable for the motor controller (I’m offloading one motor controller onto each leg, to control the two motors in the leg). It took a lot of thought in the design phase on how to route the cable. The design requirements were for minimal strain on the cable, and minimum interference to other parts. That meant routing the cable as close to the axles as possible, so that they don’t bow out as much. This, however, means keeping them out of the gears. The control cable is a 0.5mm pitch, 10 pin flat flex cable.

After a lot of thought, I settled on using roll pins and e-rings as guides to keep the flat flex as close to the axles as possible, and away from the gears. It works really well, and the robot maintains a full range of motion without any interference from the cable. I still have to route the power cable, but that will be a more resiliant and should be easier than routing the flat flex.

I’m ready to order the waterjet cut parts for the next three legs, and am hoping to get that order out sometime this week. Hopefully by the end of February, I’ll have the entire body of the robot completed, then can concentrate on getting it to walk…..