Sylvie 2021 - Complete Bipedal Robot Lower Body

cults3d

Videos hosted on our zeronet platform: https://ngnoid.tv/?Channel=quantumkitty@zeroid.bit And check out our zeronet STL repo: https://3d.ngnoid.tv/ Description: Current status: Mechanically strong enough to balance on one foot. Great bending and stretching torque. Needs accelerometers before we can start walking! Parts for Sylvie 2021 Bipedal Robot Lower Body. Most parts will need to be printed flat/horizontally then glued together for maximum strength. The only parts that should NOT be glued together are the Tops and Bottoms of the major Leg and Thigh pieces where the stepper motors are supposed to slide in. If you glue those together, you will not be able to install the stepper motor.. you have to use the clips provided, and then use the cover to also help hold those two parts together. Check out my other things for the gearboxes. Update: Added missing piece that joins Gearbox B to Gearbox A (leg, to foot) To-do-list: Start experimenting with and place gyroscopes/accelerometers in various different locations. Use the waist Size C gearbox (Nema 23) as well as the thigh gearboxes in order to balance the robot on the X and Y axis, using gyroscope data. The M3 hole arrangement in the current hip parts are incompatible with the new version of the Size B gearboxes. You will have to remix the model and add new screw holes into them, or just drill them manually.. for now until I release the new version of the bipedal legs this Christmas Keep in mind that you also need 50mm M3 screws with nuts to hold the Size B gearboxes with their bearings in place.. the Z axis gearboxes that connect the hips to the legs. Otherwise, they could easily delaminate if you try lifting one leg. A bit of speculation: In my to-do list I mentioned that once the Y-axis gearboxes are reintegrated, they should be positioned as close to the center of gravity as possible. In other words, they should not be parallel to the leg, but slightly skewed to the center. Almost touching each other. Why is this? Well, in effect, those y-axis gearboxes will be acting like a crane that will support the full weight of the upper body. Ouch! The further away those gearboxes are from the center of gravity, the more torque they will require in order to hold the weight of body without collapsing sideways. Imagine how hard it would be for this robot to walk if her legs were 1m apart from each other! Try holding a broom in your hand. Hold it at the very tip, and see how hard it is to lift. Then hold it right by the brush cap and see how much easier it is. Theoretically - the closer together the hip gearboxes are, the less torque output we can get away with. Check out the 2nd photo I uploaded of HRP-2 to see what I mean. Notice how those joints are even smaller than the ones on the shoulders? Impossible! Aren't these gearboxes too slow for a bipedal robot? No, I only slowed them down for safety reasons. And yeah, it's even slower if you only get a few steps every time you press a keyboard key. The code will need to be rewritten so that the stepper motors can move for as long as the keyboard key is pressed, and then stop upon release. So rather than.. move 5 degrees, stop. Move 5 degrees, stop. Move 5 degrees, stop.. you should be able to move 5-6-7-8-9-10-11-12-20 degrees.. RELEASE KEY, stop. (Only for manual control. With the gyroscope control, they will be moving constantly) Another thing that SHOULD speed these up, as I mentioned before.. is to use STM32F103 modules instead of Arduino Nanos. The microprocessors of the Arduino Nanos will limit the amount of steps that you are capable of producing per milliseconds due to their slow speeds. (And that's even worse if you try to operate more than one stepper motor using one Arduino.. which is the reason I was using one Nano per stepper motor!)