After the great week I had in the KeerBot project, I had to spend some time in the weekend to really implement all of the ideas I though during the week.
The main change I made is to transfer my bot from using timing belt to use wires and spools. There might be little decrease in the precision, but it lacks the need for counter weights for keeping the belt tightened which is a big advantage. So I tried using a fishing wire that was good in the term of strength but not good in elasticity (the robot jumped like a spring after each movement), I tried cotton wire (too thick) and finally found a wire from my wife’s sewing kit, (can bee seen in the picture).
I tried the supplied graphics within Dan’s project and learned a bit about canvas sizes and all – and even had a chance to load few graphics of my own.
After TOM gave me the starting code on how to implement Drawbot on my creation, (thanks for the phone support ! Like !) I started digging into the code – generally understanding there are 3 parts:
Java – Runs on the PC and load G-code drawings into the system
G-Code – The actual code that says the Drawbot where to move to
Firmware – The code that runs in the Arduino, and operates the motors
I found that the parts that needed to be changed are the Arduino (since I am not using Adafruit’s Stepper shield, but Pololu’s driver) which is a bit different.
beside that I need to insert the physical dimensions of my system and then to compile and run the code. Sounds easy hope it will be that way.
So I found the CORE:
The original code is calling an Adafruit’s motor shield (arduino.ino): static AF_Stepper m1((int)STEPS_PER_TURN, M2_PIN); static AF_Stepper m2((int)STEPS_PER_TURN, M1_PIN);
and then gives orders to one of the motors: m2.onestep(dir2); m1.step(1,M1_REEL_OUT);
I need to replace the motor commands by simple orders to the motors (digital out 1 or 0 for direction and 1 for step) that will use the same parameters as the Adafruit’s functions.
that will make the code shorter, thinner and without hassle
Tom says:”As a publicity project for the new makerspace “XLN Haifa” I started workingon my own implementation for the Drawbot polar-graph robot. I designed my own carriage to fit “expo” style whiteboard markers, whichare relatively heavy and tend to point upwards, so it needs a bigcounterweight which will not erase the markings. Next step is to design a new carriage with servo mount and implement pen up/down.”
Its already quite late, I guess this is what it takes to build a site while working full time (see About page), glad to do this – wonder where this will lead the project – trying to build a community site instead of a product site (following the reading of Chris Anderson’s book “Makers“)