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Posted · Retract before wipe?

I’m new to the group and relatively new to CURA, so please pardon me if these questions are too “beginner”:

When both wiping and retraction are enabled, is there a way to force CURA to retract before wiping rather than the reverse?

Also, is there a way to force the wiping to occur on an inner wall rather than an outer?

Thanks in advance for any clarification. 

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    • 3 weeks later...
    Posted · Retract before wipe?

    I’m still wondering why the sequence seems to be:

    wipe-retract-lift

    instead of:

    retract-wipe-lift

    which seems like it would be much more effective at “hiding” any unretracted material in the interior of the active island so that it doesn’t end up as strings between islands. 
    However I wanted to let everyone know that my stringing problems have disappeared after changing one parameter: moisture. The basement where I store filament and print is about 70% RH. So, even though I’m only using PLA, I found that once I started storing my filament in bags with desiccant at about 10-20% RH, the prints have become string free despite the odd order of retraction. 

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    Posted · Retract before wipe?

    This is unexpected.  I hope someone else can confirm this.  I do find different brands and even different colors string different amounts.  Certainly larger nozzles string more.  White filament in particular (regardless of brand) seems to string more and have different characteristics.

     

    I store many spools of filament with large amounts of desiccant, but not my PLA.

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    Posted · Retract before wipe?

    For the record, the filament I’m using is eSun PLA+, grey. 
    Prior to drying the filament I had tried dozens of combinations of settings. Some seemed to help a little, but even the best still resulted in wispy, hair like strings instead of outright blobby ropes.  When I dried the filament, the wispy hairs vanished. 

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    Posted · Retract before wipe?
    58 minutes ago, sricha said:

    When I dried the filament, the wispy hairs vanished. 

    Interesting.

     

    In general, the colder the nozzle temp, the more viscous, the less stringing.  More importantly, printing slower helps as there is lower nozzle pressure when printing slower.  But these are trade offs.  Improving one thing may hurt another (namely speed).

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    Posted · Retract before wipe?

    An important fact when creating a dry box (which I did):

    ==> water vapor (H2O) is only about 60% as dense as (ie is LIGHTER than) dry air (O2 & N2) <==
    The density ratio isn’t orders of magnitude but it’s significant enough that in a very, very still environment (such as a sealed container sitting on a shelf for weeks) a stratification will develop with drier air tending to sink down. Since we usually put desiccant at the bottom of a dry box, we are essentially drying the portion of the air that is already drier than the rest. It’s like trying to heat a room by putting an electric heater on the ceiling: yes, diffusion will cause the whole room will be warmer than if the heater wasn’t there, but its intuitively much more effective to place the heater in the coolest zone rather than the warmest.

    Using two hygrometers I can confirm that there is an RH difference of about 10% in a box only 25cm tall without active mixing. 
    After installing a small fan, the RH is uniform throughout.  A cleaner (and quieter) solution would be to find/make a desiccant container that can be mounted toward the top. 
    -And dryer filament will noticeably reduce or eliminate that last bit stringing that the normal methods just can’t seem to get rid of. 

     

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