My Robot Ivan

[LesHall 95]

This is vapor ware - just getting that clear right off the start.  I have only designed the concept model in 1,000 lines of OpenSCAD CAD language file.  Here is an illustration of the robot operating (click for animation):  

This robot, who's name is Ivan, has many fine features :)which I will attempt to describe here.  First of all it is entirely 3D printed plastic except for the motors, fasteners, and electronics - and the fasteners are few and few in type.  The motors are NEMA 17's, the venerable 3D printing motors used in almost every enthusiast 3D printer including the Ultimaker.  The control electronics are simple - arduino or arduino via computer link.  The entire robot is designed to be printable on an Ultimaker with a 200 mm build volume (or smaller in a scaled down version).  

Ivan is configurable with optional components including an optional rotating base, a necessary first stage, an optional second stage and an optional third stage.  The third stage, naturally, is only useful if the second stage is installed.  This illustration shows Ivan with the third stage installed (click for animation):  

Ivan has planetary gear mechanisms at each joint with a selectable gear reduction.  These planetary gear joints also function as bearings, so no metal bearings are required.  They are one of Ivan's key Identifying features and are derived from AVA's Gear Toy 2, a popular children's gear toy of my own design.  Here is the Thingiverse page on the design (my apologies to the YouMagine fans among us, I simply MUST post the design to YouMagine soon!):  

AVA's Gear Toy 2

Kids who grew up as toddlers with AVA's Gear Toy 1, youngsters with AVA's Gear Toy 2, and pre-teens with AVA's Gear Toy 4 will fallen love with AVA's Gear Toy 8, which is Ivan's code name in the series of AVA toys.  After all, each joint in Ivan is an AVA's Gear Toy 2 or similar.  

Besides being an educational and fun kid's toy, Ivan is serious business.  There are many applications for Ivan, despite his limitation of having only two degrees of freedom.  With three stages Ivan's third stage spins freely so it always points down.  This is useful for picking up items with an electromagnet or other actuator that is aligned by gravity.  With two or one stages Ivan can paint or deposit concrete, mud, or other material onto a shaped form to create dome homes for human living spaces, from kid's tree houses made of plaster-of-paris to mud huts in India for the poor, to concrete living spaces for the homeless in America or Europe.  Of course being a 3D printing robot, Ivan can steer his direction to shape windows and doors as well as thicker wall features, and can build the walls in thin layers for drying purposes.  There are many applications that I have envisioned for Ivan to perform.  

Ultimately though, Ivan exists to be a robot toy for kids of all ages including us adults parading as children.  The wise never grow up.  Take a trip back to childhood with Ivan the robot - you won't regret it.  

Les

p.s. shall I post the design to YouMagine even though it is vaporware?

Edited February 23, 2017 by Guest

[anykey 0]

Are you going the share the openscad files? Would love to take a look at them

[LesHall 95]

Yes everything including the book will be open sourced. I have released AVA's Gear Toy 1,2, and 4 on Thingiverse already, and I am working on Ivan and the book. I can share the current Ivan source code with you if you want to have a look at it now, with the understanding that you will keep me informed of developments.

Les

[LesHall 95]

Ivan has evolved so far since that design described above. Key new features include PVC connecting rods, larger gear boxes, all four joints have motors, many smaller details, and a trigonometry-based control system that plays the "touch the ball" game shown if you click on the following image.

In that image a red ball is randomly positioned within a thick spherical shell around the robot. Then the software runs one algebraic and four trigonometric equations to calculate all of the motor angles. This puts the tool almost directly not the ball almost all the time, a nice innovation that circumvents the mathy forward kinematics and the algorithmic inverse kinematics. I'm not sure but the trig i mentioned may be similar to the distilled-down math behind the forward kinematics for this robotic solution. Anyway, it always gets within a tolerance of the ball position.

I've started to work on the electronics and the software, running the motors at 5V to limit their current (they are 12V 2.5A motors so at 5V they should draw under 1A, allowing them to be driven by one motor chip each and controlled by one Arduino equivalent. Later I'll add ESP8266 for WiFi control.

Les