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The author is one of my favorite hacker/ingeneer. Mathias's projects when he was still in high school during the 80's: Primitive plotter: http://www.sentex.ne

by pmarin 8y ago

The author is one of my favorite hacker/ingeneer. Mathias's projects when he was still in high school during the 80's: Primitive plotter: http://www.sentex.net/~mwandel/tech/plotter.html http://www.sentex.net/~mwandel/tech/plotter.html Primitive 1-pin dot matrix printer: http://www.sentex.net/~mwandel/tech/printer.html http://www.sentex.net/~mwandel/tech/printer.html Primitive Commodore 64 drum scanner: http://www.sentex.net/~mwandel/tech/c64scanner.html http://www.sentex.net/~mwandel/tech/c64scanner.html Home made wooden Joystik: http://www.sentex.net/~mwandel/tech/joystik.html http://www.sentex.net/~mwandel/tech/joystik.html

amelius 8y ago
The author seems to be unaware that there are cheap stepper motor controllers available that handle all the tricky details of moving an axis to a given position smoothly. And they are implemented in hardware, so you don't have to sacrifice any CPU cycles to this task.
- darkpuma 8y ago
  He probably knows, but he's pretty thrifty and likes to reuse hardware he already has.
- WestCoastJustin 8y ago
  Do you have any links for this stuff or what they are called? I wouldn't mind checking that out. Thanks.
  - Animats 8y ago
    The bottom level tends to be basic Arduino shields that just switch power, but don't have a current limiting controller. Those need digital signal lines to tell them when to step. They waste a lot of power and can't be used with larger motors. The next step up is a current limiting stepper motor driver.[1] These can handle more voltage and current, and have the sensing to avoid burning themselves out. You still have to provide pulses for each step. Go for at least this level. Stepper motors use considerable power when stopped, and you need current limiting on all but the tiniest motors. Otherwise you get to choose between overheating and too weak. Next are drivers and controllers on the same board. These accept commands over USB, I2C, or a few other data paths, and take care of operating the motor.[2] If you're not into really low level programming, this makes life simpler. [1] https://www.pololu.com/product/2968 https://www.pololu.com/product/2968 [2] https://www.pololu.com/category/212/tic-stepper-motor-controllers https://www.pololu.com/category/212/tic-stepper-motor-contro...
    - WestCoastJustin 8y ago
      Awesome, thank you!
- bsder 8y ago
  That is true now. That was not so true in the 1980's. In fact, a Commodore 64 or a TRS-80 Color Computer were some of the cheapest "microcontroller development kits" at the time.
- alex_hitchins 8y ago
  I’d say he is well aware of this. A lot of the things he makes are from reclamed materials with a mimimal amount of new stuff. He is awesome.

by pmarin 8y ago

amelius 8y ago

The author seems to be unaware that there are cheap stepper motor controllers available that handle all the tricky details of moving an axis to a given position smoothly. And they are implemented in hardware, so you don't have to sacrifice any CPU cycles to this task.

darkpuma 8y ago
He probably knows, but he's pretty thrifty and likes to reuse hardware he already has.
WestCoastJustin 8y ago
Do you have any links for this stuff or what they are called? I wouldn't mind checking that out. Thanks.
- Animats 8y ago
  The bottom level tends to be basic Arduino shields that just switch power, but don't have a current limiting controller. Those need digital signal lines to tell them when to step. They waste a lot of power and can't be used with larger motors. The next step up is a current limiting stepper motor driver.[1] These can handle more voltage and current, and have the sensing to avoid burning themselves out. You still have to provide pulses for each step. Go for at least this level. Stepper motors use considerable power when stopped, and you need current limiting on all but the tiniest motors. Otherwise you get to choose between overheating and too weak. Next are drivers and controllers on the same board. These accept commands over USB, I2C, or a few other data paths, and take care of operating the motor.[2] If you're not into really low level programming, this makes life simpler. [1] https://www.pololu.com/product/2968 https://www.pololu.com/product/2968 [2] https://www.pololu.com/category/212/tic-stepper-motor-controllers https://www.pololu.com/category/212/tic-stepper-motor-contro...
  - WestCoastJustin 8y ago
    Awesome, thank you!
bsder 8y ago
That is true now. That was not so true in the 1980's. In fact, a Commodore 64 or a TRS-80 Color Computer were some of the cheapest "microcontroller development kits" at the time.
alex_hitchins 8y ago
I’d say he is well aware of this. A lot of the things he makes are from reclamed materials with a mimimal amount of new stuff. He is awesome.