"Walk N' Roll!"
Introduction: "Walk N' Roll!"
I've designed, 3D printed and assembled a number of rolling and walking mechanisms, but never a rolling AND walking mechanism, so "Walk N' Roll!" is my first attempt at a walking and rolling "transformer" mechanism.
Two cams control when the mechanism rolls and walks, and the same two cams create the walking motion for the four legs. Each leg contains a "one way" wheel that allows each wheel to roll when the leg moves from back to front and lock when the leg moves from front to back. This allows the model to walk forward. By simply reversing the polarity of the battery, the model will roll backwards then walk forwards.
As usual, I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make plenty of mistakes.
Designed using Autodesk Fusion 360, sliced using Cura 4.12.1, and 3D printed in TPU and PLA on Ultimaker S5s.
One final note, I receive no compensation in any form for the design, parts and/or materials used in this model.
Supplies
* Soldering iron and solder.
* Thick cyanoacrylate glue.
* Double sided tape.
Step 1: Parts
I acquired the following parts:
* One "uxcell 16mm DC 6V 60RPM Speed Torque Gear Box Electric Motor for Robot".
* One 3.7V 1200mAh lithium battery (https://www.adafruit.com/product/258).
* One JST PH 2-Pin Cable (https://www.adafruit.com/product/3814).
* Four 9.2mm lengths of 2mm diameter music wire (used as leg wheel axles).
Unless noted otherwise, I 3D printed the following parts in PLA at .15mm layer height, 20% infill and no supports.
* One "Arm, Left.stl".
* One "Arm, Right.stl".
* Two "Axle, Cam.stl".
* Four "Axle, Leg.stl".
* One "<PERSON>, Left.stl".
* One "<PERSON>, Right.stl".
* One "Chassis Base.stl".
* One "Chassis, Left.stl".
* One "Chassis, Right.stl".
* One "Gear and Axle, Wheel (2m 12t).stl".
* One "Gear, Cam (1m 48t).stl".
* One "Gear, Motor (1m 12t, 2m 12t).stl".
* Two "Gear, Wheel (2m 12t).stl".
* One "Leg, Left, Front.stl".
* One "Leg, Left, Rear.stl".
* One "Leg, Right, Front.stl".
* One "Leg, Right, Rear.stl".
* Two "Wheel Well, Left.stl".
* Two "Wheel Well, Right.stl".
* Four "Wheel, Foot.stl" in TPU on a TPU raft.
* Four "Wheel.stl" in TPU on a TPU raft.
This is a high precision print and assembly model using at times very small parts and in very tight spaces. 654
Prior to assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on you printer, your printer settings and the colors you chose, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth. I used small jewelers files and plenty of patience to perform this step.
The model also uses threaded assembly thus an M8 by 1.125 tap and die will assist with thread cleaning if necessary.
Step 2: Chassis Base Assembly.
To assemble the chassis base, I performed the following steps:
* Slid the wires from the JST connector through the small tunnel in "Chassis Base.stl".
* Pressed the motor into the base assembly, then soldered the wires to the motor such that the motor runs clockwise when viewed from the motor shaft end of the motor.
* Pressed "Gear, Motor (1m 12t, 2m 12t).stl" onto the motor shaft.
Step 3: Chassis Left Assembly.
To assemble the chassis left side, I performed the following steps:
* Placed "Arm, Left.stl" into "Chassis, Left. 784