Servo-Stock

I am hoping to get a bunch of people up to speed with BowlerStudio so I am offering an introduction to BowlerStudio. This will be a set of classes where i will walk you through the process of building robots with BowlerStudio. I will be recording these sessions for anyone that comes later, but if you want to ask questions and get help you will need to attend the final class time. I have posted a when2meet to gather interest, and when a time is selected i will post back here.

http://when2meet.com/?5958587-1PWB2

As for prerequisites, this is *not* an introduction to programming class, so the ability to read and write object oriented (or functional) code is a must. I will be instructing using Groovy (Java) in most of the classes for the sake of consistency. I will briefly introduce using Python, Clojure and creating a custom Domain Specific Language. We will cover the scripting system, the git-as-filesystem architecture, the kinematics framework, the CAD engine, the physics engine, Arduino code and Bowler Protocol integration, offline headless deployment all while exploring the BowlerStudio Integrated Development Environment for full-stack robotics.

So i have been busy at work building the UI system for this and a whole bunch of other robotics hardware i have been working with over the years. Introducing:

BowlerStudio!

Its the printer controller, cnc controller, kinematics engine, and now has image processing, a bunch of AI libraries, and a 3d CSG cad system similar to OpenScad, but java. It makes all this available to the user through a scripting platform based on Groovy and Jython.

As for the ServoStock, it is not forgotten! we have been making progress on the servo control system in the NASA Sample Return Challenge robot, and with this years competition over, i can start to port back some of the fixes.

This the Peek-a-Bot, he is installed on Front street in Worcester MA, across from the City Hall. Paula Rudy made the puppet and I used the ServoStock frame on its side as a puppet holder. Those rotated free arms are helping keep it stiff under a lot of load. I think, however, i will need the third upper arm...

In the video you can see the task space axis tilt to one side as it moves. This was caused by low rigidity in the vertical arms. I added stiffness to them and made the bottom thicker. I also shrunk the pulley for the linear axis to increase the achievable task space resolution.

https://github.com/Technocopia/ServoStock-hw/commit/2baef74771851634ed8c7448e6b900df52d9fbd5

The extruder had a few features the interfered with the free arms and needs the design tweak, printing will have to wait for that to be done. 

In the mean time I found a long standing bug in how the centering value was calculated and applied the center calculation. It was being calculated as the middle of the 2 hysteresis bounds. This turned out to be ok, but it was being applied after the bounding values. This meant that the upper value was always high, and the lower was always low. I am now getting much faster settling times with lower I gains.

We are printing out the ServoStruder with the hopes of making the first print today! The servostruder is neat because it used the knurling on the output shaft of a standard servo instead of a traditional hobbed rod. This means one of the major custom metal vitamins from 3d printers can be totally dropped. Also, because of the encoder running on the filament not the motor, we can detect stalls (filament jams and out of filament events), and pause a print. There are no complicated switches or line break sensors, just the servo and the encoder. 

With luck we will have our first print by the end of today!