Movement Issues with Custom Polargraph

[Anonymous]

Hey guys,
I’be been working to make my own custom machine and have all the hardware functioning, but am having some software issues I believe. Imma try to include as much info as I can about what I have done so please bear with me.

My hardware setup is I have two steppers controlled by two pololu_a4988’s, connected straight to my arduino mega. I have verified that the steppers work as expected in terms of polarity (if I command them to rotate in opposite directions, the plotter head moves up/down, likewise in like directions, the P.H. moves left/right) I skipped using one of the motor controller boards/lcds in favor of using the software on a PC and I can connect fine to the firmware.

My issue shows its ugly head when I try to draw anything. !! Every Movement Is Rotated 90 Degrees Clockwise. !! Using the manual driving revealed a little more. If I command G00 X10 Y0, the PH moves down. A command of G00 X-100 Y0 gets up. The most interesting part is if I kept inputting G00 X0 Y10, the PH would move to the right in decreasing increments, approach an asymptote of sorts, and eventually start moving left!

I have started digging in the code to check this out but am wondering if someone could think of a starting point.

Firmware wise, I have deleted the following files because I figured I wouldn’t need them: board_ramps/rumba/sanguinolulu/teensylu.h’s
lcd.ino
every robot prefix file that isn’t the polargraph .h and .ino files
sdcard.h/.ino

I have removed the deleted files’ relevant includes and defines and I moved the dir/step pin #defines to the motor.ino file so pins would still get instruction.

I have changed the config.h to suit my motors.

Other than these changes I didn’t touch anything. If you’ve read this far, thanks for reading my book, and if you have any advice or suggestions that would help me out a ton as I am not a coder by education lol.

Thanks,
Derek

Extra info: I recently tried just starting dry with the firmware as intact as I could, leaving all the board files and everything in there, defining pins from the board_rumba.h. The results were worse somehow, the PH only moves up and to the left, and down to the right. Still has that weird mirror effect if Y directions are input.

[Dan]

rotated clockwise? sounds like you have your motors backward AND one is reversed.

if you use the software and settings > jog motors, left in should drive the pen holder towards the left motor, and left out should drive the pen away. same thing for right in and right out.

I recommend…

* create a fork from github for your changes.
* make a new board_[yourname].h and put your pin definitions there.
* in configure.h, use your new board (see other boards as example)
* uncomment #define HAS_LCD in polargraph.h

that will disable the LCD and let you use your pin setup without smashing the existing code, plus it will make life easier when I update things and you want to roll those changes into your fork.

[Anonymous]

Yeah I figured that somehow I turned something around somehow, I’m just not sure how I managed that.

I tried the settings jog and I think you guessed right, the left command wasn’t even controlling the left motor. So I switched the motors and now am gonna check out how one got reversed. Also I’ll check out the github thing.

Thanks for the advice and your code, it’s allowed to me to learn arduino pretty much

[Author]

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