Hi all, Sandy,

The Polargraph SD finally arrived the other day and I quickly assembled it on a A2 picture frame with the glass and backing paper inside-out. It worked like a charm as soon as I figured out I had to add the SET HOME command before drawing. Duh.

I started out with a vector drawing of ol' Frankenstein with a felt-tip pen and I'm really loving the results. The small imperfections and squiggles really add to the aesthetics of it all. What a machine you've made Sandy! (even the wifey thinks it's really cool)

I also had a quick go at the random scribble function which leads me to a question: When the gondola was traveling with the pen up between scribbles, it moved with the same slow stuttery movements as when drawing, i.e not direct. Is this normal? Should it "pen up" at all when doing the random scribble as opposed to doing the whole drawing in one go?

Also another question while I'm at it: what's the life expectancy of the motors? At the moment I'm doing a lot of experimenting and doodling around, just playing, but maybe I should save it for more completed/thought through pieces?

(next questions will be in the appropriate sub-forums, sorry 😯 )

Hi Andy, welcome to the forum 🙂 Epic first drawing and classy looking setup!

Mr Kongorilla is 100% correct, the pen lift isn't used at all for "pixel" drawings except when you've got "lift pen over masked pixels" selected in the "render pixels..." dialog.

NOW, the question is, why is it lifting when there's still density to be drawn? I guess it's a mask colour thing. This is where you can choose a particular colour to be ignored from the generated pixels.

If you hit "i" then there's a box for "chroma key colour", and you can change it with the "choose mask colour" function. As you click on a particular colour (from the underlying image), you should see particular pixels that are that same colour disappear from the pixel preview. Maybe that even makes sense, it sounds much more complicated than I thought it was.

And yes, don't worry about wearing the motors out. If you manage to, then you must accept some more motors as a prize 🙂 Seriously the only issue I've ever had isn't from running all day, but keeping them locked and still all day. Which is why they have the safety cutout - after 10 minutes of doing nothing the machine will lift the pen (if it isn't already up) and cut the power to the motors. When I was running the machine in spectrum arts' window all day, the motors got so hot the sprockets softened and started spinning on the motor shafts, the motors smelled like insulation and were almost too hot to touch (old style polargraph with adafruit shield and lots of volts, and something going faintly wrong). Still worked fine afterwards though - they are robust. I'm using ABS plastic for the sprockets now rather than PLA, so they don't soften as easily, and I also cut a groove in the motor shaft, and have a tooth in the sprocket to make the connection a bit more positive.

skillin'
sn

Lift pen over masked is the default behaviour, the issue is more that you might have something masked that you don't think you have masked.

The servo is a slightly different story - they are not expensive ones, so out of any one batch, the quality varies pretty wildly. I've only ever had one fail on me during actual use, and that had been working for a long long time, but I would not be at all surprised if any particular one stopped working. If it does of course I can send you a spare - they don't cost much.

I would love to have a better quality servo (ideally more _quiet_), but while these ones are less than $10, it's not difficult to pay four times that for a quality one, and the benefit just didn't seem proportionate, and even then there's still no guarantee of longevity/accuracy/noise.

For multi layer vectors, or for things which need to be placed "just so", I do use a template around the layers like you say. Place it (move vector) at the top left corner of the machine, and then use "resize vector" to get it to match the size of the machine - or whatever size you're happy with. Then make sure you "save", now any svg you load in will have the same origin point, and scaling factor. Note that selection area is not used for vector drawing anyway, but instead the page size is where the vector is cropped to. That's fairly non-intuitive, I know. Why do you need to restart the controller between layers?

Re the touchscreen issues - that's a bit worrying, it should be either working or not working, and restarting shouldn't make a difference - the software is such a thin layer that there's almost nothing to go wrong. I'd appreciate it if you kept an eye on that and let me know if you can spot a pattern, or if it's getting worse. Electrically, the LCDs are the most fragile piece of the machine, but I've never actually experienced problems with them myself (that I couldn't eventually track down to me being a eejit anyway).

Glad you're enjoying it!
sn

Cool - glad that helped. The first three "free" commands that are preloaded are

set penwidth (C02,<penwidth>,END)
set speed (C31,<motor max speed>,END)
set acceleration (C32,<motor acceleration>,END)

so unless you also restart the machine itself, you don't need to resend them. If you _do_ want to resend them, hit the "send pen tip size" and the "send speed" buttons on the SETUP tab to regenerate them. Those three commands are pre-loaded because they aren't otherwise saved to the EEPROM (persistent memory) on board the machine itself. It'll always reset to defaults (0.8, 400, 600 afaicr).t

No way to manually enter codes into the queue through the controller. You could import a queue from a txt file if you wanted to do that.

Did you reload the firmware on the machine or anything? The issue I recently had with the touchscreens sounds quite similar. It manifested as the touchable area being contracted to over the left hand side of the screen. It was possible to get the buttons to activate, but only by pressing somewhere else on the screen. That was to do with a badly calibrated library! Was ages until I figured it out, I was going crackers.

sn

Harvey's stuff is outstanding - it draws in a kind of "organic" way that is very much the kind of thing that I was shooting for when I started - not deterministic so much, not just following instructions, but interpreting them. One day polargraph will be as good!!