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Scalable extra prime

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Having realised that one issue with my prints is oozing after travel moves I configured the standard priming feature to great effect. I then realised that I was having additional oozing after large travel distances. This isn't so noticeable when you're using small nozzles, but becomes far more of an issue with bigger ones as the voids left are rather more significant.


Upon searching I discovered that the scalable extra prime add-on existed and I readily installed it but hit upon a snag. The settings do not show up when enabled.


Initially I tried this with Cura 3.2.1 and after having problems discovered that the 3.3 beta existed, so I tried that and still the problem persists.


In my Cura print setup the tick box to enable 'Scalable Extra Prime' appears, but when I select it the additional settings do not show up. They should do, as I've made sure that they are set to be displayed in the overall settings, but whatever I do, no dice, no settings appear when I enable scalable extra prime.


I'm working with a Creality CR-10.


I've tried creating a new CR-10 profile and this doesn't help either. I've tried looking at the default settings that Cura creates for the CR-10 and can't really see anything there that would prevent them from showing up either. Is there something I am missing here or could try? It seems odd that the tick box to enable SEP shows up, but when enabled, the extra settings to not.


Many thanks,



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No ideas.  I have been 3d printing with ultimakers for 5 years and figured out how to stop the leaking long ago (for example print cooler and slower)


I've never needed extra prime and don't know what "scalable" extra prime is for.  I never liked the extra prime feature - it implies you are leaking in the first place or something else is wrong with your hardware.

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Well I would say I'm not the only one with this problem as someone went out of their way to create a plug-in specifically to solve it.


The plug-in should work, it's even one of the bullet points, worth a mention, for the beta 3.3 version. The trouble is simply that when enabled the settings do not appear on the configuration panel.


The leaking may have been solved for you but when using large diameter nozzles the problem becomes significant. I didn't even notice it occurring with my 0.4mm nozzle, but with the 0.8mm, yup, which makes sense.


It's not even really the oozing that's the problem, its when the print nozzle moves over an already printed area, skimming over the surface, the material just within the nozzle gets drawn/wicked out onto the print. The printer then goes to print in the new area, assuming that material is flush with the nozzle exit hole, but it's not. So prints nothing for a short distance.


Extra prime is for priming a little bit of extra material into the nozzle to make up for the bit that was lost during the travel and it works really well. The trouble is you need to prime different amounts depending on the distance travelled and this is what the 'scalable' part of the plug-in solves.

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Hi, you can try search it. Four of It showed up right after I typed "prime". I changed the "Max Extra Prime" value to 1 (was 0 before which I think It wouldn't work). It does modify the G-code. For the calculation probably you already knew it from GitHub:


extra filament = ((actual_travel - min_travel) / ( max_travel - min_travel)) * (max_prime - min_prime) + min_prime



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Welp.. It seems there's a horrible bug in this plugin. It also modify extrusion values in the "End G-Code" lines. It adds the retraction value (E-2 and E-3 in my setting) with the last offset value (116.58898 in this case).
For me, I'll delete the retraction command (E-2 and E-3) from the "End G-Code" to fix this.

I hope this would not happen to others ^^




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I noticed this same bug.  I didn't realize what was causing it until reading this post.  Sure enough... disabling the extra prime stopped the glob of filament being extruded at the end of my prints.

This plugin is very useful for prints with very large travels so hopefully they can figure out a way to not make it apply to the end gcode.

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