Thoughts on pausing prints when filament runs out.

[cjdavis618]

As we all know, the Rostock has a wonderfully large build volume, which can lead to Looonnnngggg prints. So I was wondering what could be done to pause prints when filament jams or runs out. I figure with so many people on here using the system it has probably already been done.

I would say a simple contact switch should do the job, but how would we trigger the Rambo or Pc to pause the print. I'm not sure there are unused input options on the Arduino that Rambo is not using, but I am not a wizard on the programming of it either. I haven't stayed at a holiday in express lately. lol

Looking at the schematic at http://reprap.org/mediawiki/images/7/75 ... ematic.png, and the connecter view here, http://reprap.org/wiki/File:Rambo-conn-all.jpg, I can't really tell if all of the ports are used. I "Think" that some of the analog ext ports are open.

The question is whether we can find a solution that is PC based (Which can be done through software and usb sensors) or a way to do it when using an SD card as well. I would prefer a machine option rather than a clunky PC based system.

Has anyone done this yet with their Rostock or Orion?

[Tinyhead]

It would be nice if there was an open Digital input. You could print a simple setup for the filament, toss a bearing limit-switch in place (such as http://www.ebay.com/itm/10-pc-TEMCo-Mic ... 1125050152) and when the filament stopped passing through, the switch would open and it could give a 'pause' command. It would at least allow you to splice in a new roll of filament. I don't know how well the pausing and starting affects the actual print though...

[cjdavis618]

I agree about the paused print and resume. Primarily, I am trying to prevent burning my hotend up due to overnight prints where I run out of filament. Supposedly the Makerbot software will let you swap filament mid print to change colors, replace filament, etc. My son likes to make "Rainbow" parts on his flashforge and they seem to turn out ok so I guess it works with it.

Never tried with repetier or the rostock. Got to put that on the calendar I guess.

(I'm utilitarian with my printer and get accused of never making anything fun.. lol.. That's probably why I have never tried it, so he is probably right.. )

[Eric]

There are gobs of unused pins on the Arduino, and many of them are broken out for you. In the case of the Rambo, the items labeled: Analog Ext (analog pins can be used in the normal digital mode also), PWMExt (ditto, you don't have to use them in a PWM fashion), Serial, Motor Ext, Extension 2(if you don't have an LCD panel using it), I2C,SD/SPI, and of course anything else you aren't using in the normal fashion. Some of those may not be populated with connectors, but that's a detail you can correct.

In particular, very few people actually use BOTH min and max limit switches, so right there are 3 inputs available to repurpose, with connectors already set up for individual switches. Most of the work required would be in the software modifications.