Standalone Operation - Unloading Filament

I've gotten to the point that I rarely have to use Pronterface with my Tantillus. Printing from the SD card is a lot easier and more fool proof than depending on having my Mac connected to the printer all the time. I can do 'almost' everything necessary from the Tantillus front panel.

The one exception that I've discovered so far is unloading filament completely. When I unload the filament stops about 80 mm short of completely exiting the extruder. The move axis control only provides for extruding filament, not retracting it. So, to get the filament completely unloaded either have to tell it to unload again - which runs the extruder a lot longer than necessary - or hook up Pronterface.

Am I missing or overlooking something?

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Lem Fugitt
3D Printing Dreams
Robots Dreams
"The map is not the territory."

Agreed.. It's a small issue, but annoying. It could be solved in a couple of ways. You could go tweak the firmware settings to change how much gets retracted when unloading... Perhaps 700mm or 750mm might be enough. Conversely perhaps Sublime could add a "Retract" option directly below extrude in the move axis menu.

I would like some more feed back on what you guys would like. For now I do have instructions on how to adjust the length [www.tantillus.org] under step 4.

I was also going to add an entry to the first part of the prepare menu for purge and if people would like I could add a retract button as well.

I was also thinking about making the unload function first extrude 15mm and then retract the set length to ensure the flared end of the filament is melted and will come out of the tube easily. Have you guys found this to be needed?

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A purge and also a retract menu option would be good.

I've never tried extruding before retracting when unloading, but it makes sense that would help it come out more easily. I'd say go ahead and make that change.

Sublime Wrote:
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> I was also thinking about making the unload
> function first extrude 15mm and then retract the
> set length to ensure the flared end of the
> filament is melted and will come out of the tube
> easily. Have you guys found this to be needed?

Great idea. Definitely useful.

For example, I had a situation where the unloading filament came out of the hotend with a long string then a blob on the end. When it passed through the extruder the string broke trapping the blob between the hobbed bolt teeth and the extruder body. I didn't notice it when it happened and tried loading new filament, which jammed it up. So, I had to disassemble part of the extruder and clean out the debris. Extruding some plastic first before unloading would probably minimize the possibility of this happening.

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Lem Fugitt
3D Printing Dreams
Robots Dreams
"The map is not the territory."

I have added Purge and Retract to the Prepare menu as well as the purge before Unloading.

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Sublime Wrote:
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> I have added Purge and Retract to the Prepare menu
> as well as the purge before Unloading.

Looks like I better change my gears and get my Tantillus configuration in line with the latest units so that I can take advantage of these improvements.

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Lem Fugitt
3D Printing Dreams
Robots Dreams
"The map is not the territory."

Robots-Dreams Wrote:
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> Sublime Wrote:
> --------------------------------------------------
> -----
> > I have added Purge and Retract to the Prepare
> menu
> > as well as the purge before Unloading.
>
> Looks like I better change my gears and get my
> Tantillus configuration in line with the latest
> units so that I can take advantage of these
> improvements.

The only thing that changes with the herringbone extruder gears is the max E speed is lower which makes the retractions a little slow compared to the regular gears.

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver