Feature Request: pause & recalibrate pen

[3LD]

My crayola markers keep going dry 3/4 of the way through drawings.

Requesting a 'pause after x pen down distance' or even just a manual pause button on web interface.

[nikivanov]

How long are your drawings taking? I used to have this problem with the older prototype of Mural that was really slow, but once I switched to the Nema steppers I didn't find the pen running out / drying out to be a problem.

This isn't a trivial change, unfortunately. The software architecture isn't meant to pause the drawing and run user-interactive stuff mid-way. I think FluidNC might make it easier. I know there's a GCode command for pausing for user input. That would be an easy hook to do a pen change / recalibration.

[3LD]

I try to keep my drawings at around 100m pen down distance, anything much over and I get noticeably incomplete drawings. After 100 meters a fresh pen is bone dry. Not timed any of them but probably averaging 4 or 5 hours.

I think I'm using the same pens as you, 'Crayola Ultra Clean Washables'. Are you getting much different results?

[nikivanov]

I've done 250m+ and it didnt look like it was fading. I think what's happening for you is that you have a lot of pen movement, and if you lift and lower the pen over and over again into the wall it gets blunted and stops drawing. I've seen this happen on my end when I was trying to render an SVG that was essentially a bunch of little dots. Or maybe your wall surface is too abrasive?

[3LD]

.... if you lift and lower the pen over and over again into the wall it gets blunted and stops drawing. I've seen this happen on my end when I was trying to render an SVG that was essentially a bunch of little dots.

I think you've called it. I pulled a couple 'bone dry' markers out of the bin and they actually still work fine if held 45° to the wall. Its just the tip thats non functional.
I wonder if I'm setting the pen 'wall contact depth' too low and wearing out the marker tip prematurely.
Have you experimented with angling the pen.stl so the marker is held slightly off wall normal?

[nikivanov]

I don't think a slight angle would fix this unfortunately. It'd just blunt it slightly on the side.

[nikivanov]

This is actually the reason the servo movement is slowed down - I don't just send it at full speed down because I think it smashes the tip in.