3 ms·

> Here if you zoom it a bit, you can see a very slight wobble in the pen tracks because it catches a bit of the paper's grain, and depositing ink, the paper "dr

> Here if you zoom it a bit, you can see a very slight wobble in the pen tracks because it catches a bit of the paper's grain, and depositing ink, the paper "drinks" the ink which fattens the lines a tiny bit. I think you're misattributing things. Plotters use stepper motors and so have a minimum distance they can move along each axis. Due to this, they don't produce perfect lines at an angle and do introduce similar artifacts to what you'd see on a screen.

chantepierre 3y ago
You must be right, there also must be mechanical steps or wobble at play here. I was hesitant because my 3D printer (lower-end than an Axidraw) seems capable of smoother angled/curved lines than what we can see here. On the other hand plotters I've seen (a long time ago) seemed to not eliminate all vibration in the pen.. but I did not see a mid to high end recent plotter running.
- alpaca128 3y ago
  FDM 3D printers squish molten plastic onto the previous layer, and that probably helps balance out the limited "resolution" of stepper motors. Also I'm guessing the inertia makes the extruder movement a bit more continuous, after all it's enough to cause artifacts like ghosting when printing at higher speeds.
globular-toast 3y ago
That's disappointing. I had assumed these devices were analogue and able to draw true curves. This makes me not so excited about them.
- Infernal 3y ago
  No true draftsman
- phkahler 3y ago
  An analog one could be built with 3 phase motors, but that's another project.
mkl 3y ago
IME older plotters use DC motors and optical encoders rather than steppers, and do seem to produce perfect lines at angles. They can't do curves perfectly, as even when you specify an arc or bezier curve, the plotter breaks it down into small straight segments.
sleepybrett 3y ago
the step resolution is such (80 steps/mm) on the axidraw v3 that this isn't really an issue. From their product page: * Native XY resolution: 2032 steps per inch (80 steps per mm). * Reproducibility (XY): Typically better than 0.005 inches (0.1 mm) at low speeds.

chantepierre 3y ago

You must be right, there also must be mechanical steps or wobble at play here. I was hesitant because my 3D printer (lower-end than an Axidraw) seems capable of smoother angled/curved lines than what we can see here. On the other hand plotters I've seen (a long time ago) seemed to not eliminate all vibration in the pen.. but I did not see a mid to high end recent plotter running.

alpaca128 3y ago
FDM 3D printers squish molten plastic onto the previous layer, and that probably helps balance out the limited "resolution" of stepper motors. Also I'm guessing the inertia makes the extruder movement a bit more continuous, after all it's enough to cause artifacts like ghosting when printing at higher speeds.

globular-toast 3y ago

That's disappointing. I had assumed these devices were analogue and able to draw true curves. This makes me not so excited about them.

Infernal 3y ago
No true draftsman
phkahler 3y ago
An analog one could be built with 3 phase motors, but that's another project.

mkl 3y ago

IME older plotters use DC motors and optical encoders rather than steppers, and do seem to produce perfect lines at angles. They can't do curves perfectly, as even when you specify an arc or bezier curve, the plotter breaks it down into small straight segments.

sleepybrett 3y ago

the step resolution is such (80 steps/mm) on the axidraw v3 that this isn't really an issue. From their product page: * Native XY resolution: 2032 steps per inch (80 steps per mm). * Reproducibility (XY): Typically better than 0.005 inches (0.1 mm) at low speeds.