G-Code fix for leaking second extruder?

[roykirk]

I know I saw a thread about this somewhere recently, so forgive me if I can't find it right now. I've finally found a use for dual extrusion, but I'm running up against a significant issue already. The main color of my model is black, with some white engraved text near what would be the end of the print job. Both extruders want to be on during the entire print, which is causing little specks of white filament (from the other extruder leaking a bit) in what should be all black parts of the model. Has anyone discovered a fix for this?

[Geoff]

I know I saw a thread about this somewhere recently, so forgive me if I can't find it right now. I've finally found a use for dual extrusion, but I'm running up against a significant issue already. The main color of my model is black, with some white engraved text near what would be the end of the print job. Both extruders want to be on during the entire print, which is causing little specks of white filament (from the other extruder leaking a bit) in what should be all black parts of the model. Has anyone discovered a fix for this?

2 Ways..

1. The easy way.
Use makerware and it will generate walls to wipe the dribble off.

2. The harder way
Gcode Retract Rates

http://wiki.solidoodle.com/setting-a...ing-your-gcode

[Mjolinor]

Why do both extruders need to be on for the entire print?

[roykirk]

Why do both extruders need to be on for the entire print?

That's the default

[Geoff]

Why do both extruders need to be on for the entire print?

Because you need to keep the side that is not printing at the print ready temperature, even if you are not printing.

Yes, it would make sense if the printer only used what colour it needs when it needed it, but the firmware isnt that smart, you need to do your own programming to really start sorting that stuff out, I know how to do it, just not where to start...
First thing I'd be doing is converting to marlin or sailfish (i haven't used salfish) and then going through the code and seeing what does what, the line commenting is great, you can't go wrong.

[Mjolinor]

I still don't see why they should both be hot. If the print takes 50 hours and it is 48 hours until your white nozzle is needed then turn it on at 47 hours 58 minutes and 15 seconds or so into the print. Most slicers allow for tool change G code that will let you stick the instruction in there and all you to wait for temperature and wipe before continuing. "Wipe" is the reason I stuck an inverted brass brush at head height at the extreme of the travel in mine

[Geoff]

I still don't see why they should both be hot. If the print takes 50 hours and it is 48 hours until your white nozzle is needed then turn it on at 47 hours 58 minutes and 15 seconds or so into the print. Most slicers allow for tool change G code that will let you stick the instruction in there and all you to wait for temperature and wipe before continuing. "Wipe" is the reason I stuck an inverted brass brush at head height at the extreme of the travel in mine

As I said, yes it would make sense ... I am not disagreeing with you

I print more dual extrusions than anyone I know (i'm one of those wierd people that actually want to use it.. ) and yes, it's annoying as hell to print a plaque that has 2 solid colours, 1 top and 1 bottom.. and yet it still uses both nozzles all the way. And if I don't use makerware and the dribble walls, replicator G leaves little bits.

[3DPBuser]

So no slicer knows to leave the one nozzle off until needed? Leaving it on will cook the plastic, in addition to dribbles.

The inverted brass brush sounds neat; first time I've heard this. Maybe it could be an option or standard item for printers, and the brush could be over in the corner.

[Mjolinor]

Here is the brass brush. It mounts on the carriage so no matter what Y is I just need to move X to wipe.

[3DPBuser]

Is a neat solution if it works; should be promoted more.