Working ball robot II

thingiverse

This is a working ball robot model whose internal mechanism is very similar to Sphero. It is 96 mm wide and its easy to asemble and fast to print and you can open and close the sphere without removing any screw. I will complete the existing instructions soon. Scroll down for almost complete instructions! More projects here: https://juangg-projects.blogspot.ca Print Settings Supports: No Resolution: 0.2 mm Infill: 25-30% Notes: Supports are required only in Ball_a. I strongly recommend to print it in abs. How I Designed This I designed this using FreeCAD, wich is a free, easy to use, 3d design program. At first it was a bit tricky to enclose all the parts within a 44mm radius ball, but it became simple as I designed all inside a sphere, so I could see if the wheels were at a proper height and so on. Proyect: Working ball robot II From the begining, I´ve had problems of all kinds to solve, and in my view, I´ve learnt a lot from my mistakes. Starting from this design, the main aim of this is let students modify it in order to improve an learn from their mistakes. I think this proyect could be convenient for secondary education students, wich just a few knowledge of electronics, arduino and CAD design, being sure that having completed this, they will have greatly improved not only that skills, but from mathemathics to physics. The current desing can be completed within four or five hours, without 3d printing time, but you can keep improving and re-programming until you get bored. At the end, students should have succesfully completed an operating model, at least slightly different than the original design, and expose it saying what changes they have made and why. Also, you can try this on your own, as a personal proyect,and learn lots of things! Scroll down for instructions to complete the current desing. INSTRUCTIONS: a)3d printed parts: Just print each one once or twice if the name of the file ends in (x2) b)Non 3d printed parts: 2 standard flat side dc motors. 4x68 mm brass shaft (you can 3d print one) 2x10 mm wood screws. Super glue (or similar) Acetone (If working with abs) Silicone (Any kind) Soap (Used to work with silicone) An arduino nano, a L293D motor driver, a bluetooth module... c)Asembly: -The sphere: Take one of this.(Ball_a) Remove supports. Disolve them in acetone, we will use that later. Sand the inner side. Brush it with the acetone +abs mix. Glue that two pieces. Sand the excess of material. Brush all with acetone + abs. Do the same on the inner side and repeat all the previous steps with the other halve of the sphere. -The driving wheels: Print that piece, brush the internals with acetone for better results, let it dry, then, brush some soap with water inside. Fill the mould with silicone. Flat the silicone with your finger and some soap. Let it dry overnight and remove the tyres. Glue them to the inner piece of the wheel. -Internals: Parts needed. Glue the two motors in place. Glue the small gears to the motor shafts. Cut the brass rod, put it into the frame and then put the big gears on both sides. Glue the driving wheels to the big gears. Glue that stopper in place. Screw that piece on the upper side of the frame. Take one of this and put those shafts in place. Place that wheels on there. Place the other part over there. Screw that to the main frame. d)Printed Circuit Board Dowload the design (PCB.xps) and print it at 1:1 scale. Transfer it to a standard, single copper layer PCB with a permanent marker and remove the unwanted copper with Hcl. With this result. Now remove the ink with alcohol and make the holes needed. it should look like this, or hopefully better. All the conectors and the 5v regulator soldered. With the arduino Nano and the bluetoth module Fixed to the frame with the battery (Sorry for low quality photo)