how to stop stringing and bad surface textures when hopping

[DdeWaard]

hello fellow delta users,

i have the rostock max an it works beautifully.the only problem i have is that it makes a lot of strings and uglyness when hopping from one "part" to the other when there is space between them.

anyone have any idea why? is it because the extruder is so far away with the bowden tube in between that it takes some time for the filament to retract? also i noticed that, while hopping, the hotend "leaks" a littlebit of filament sticking it to the part it's moving towards.

I really want to make this dragon sculpture: http://www.thingiverse.com/thing:246198 but i think that when i will start it it will turn out very ugly when it has to do the hopping between the neck and the wings. and this same counts for all multiple part prints.

perhaps you could share your slic3r settings that deal with this.

thanks in advance,

Demy de Waard

[bubbasnow]

you will want to investigate wipe and retract settings.. they differ from the different types of material

[rymnd]

For me, it was enough to play with the retraction settings (speed and length), making sure my nozzle diameter and filament diameter settings were right, and lowering the hotend temperature to prevent oozing.

In my case, it turned out the stringing was due mostly to over-extrusion

My settings:
retraction length: 4.5mm
retraction speed: 50mm/s
hotend temperature: 227 C (lowered from 230) for ABS

[Tonkabot]

I Also am having bad stringing ( although it got worse after adding the PEEK fan and I don't know why) [yes I redid the PID calibration after PEEK Fan]

I tried to focus on the stringing in this photo, but I can see I had some motion blur. time to get a real tripod for the camera, and/or a ring flash.
Actually other than the stringing, these minions and the single minion I made with these settings have very nice finish.

I saw some posting that said I need to calibrate the extrusion. So I tried. If I hit the extrude 10mm button 5 times on Rep-host it looks like about 35mm of filament goes into the extruder. That seems way off, and when I tried to make the extrude factor 1.4 in slic3r it seemed to over extrude really badly.

I am still running all the [slicer] defaults that I downloaded from the link in Gene's manual. I see posts like the below, but I have not seen any definitive instructions on how to calibrate extruding, or what changes to retraction I should be trying.

I also saw someone calibrating their extruder based on measurements of a thin-walled box, so that they get the width of the thin wall equal to the width setting. this seems like a reasonable thing to base it on. Although an explanation of where these settings go, in slic3r or int the EEPROM or what would be nice.

Help!

For me, it was enough to play with the retraction settings (speed and length), making sure my nozzle diameter and filament diameter settings were right, and lowering the hotend temperature to prevent oozing.

In my case, it turned out the stringing was due mostly to over-extrusion

My settings:
retraction length: 4.5mm
retraction speed: 50mm/s
hotend temperature: 227 C (lowered from 230) for ABS

[rymnd]

I Also am having bad stringing ( although it got worse after adding the PEEK fan and I don't know why) [yes I redid the PID calibration after PEEK Fan]

minion_silk.jpg

I tried to focus on the stringing in this photo, but I can see I had some motion blur. time to get a real tripod for the camera, and/or a ring flash.
Actually other than the stringing, these minions and the single minion I made with these settings have very nice finish.

I saw some posting that said I need to calibrate the extrusion. So I tried. If I hit the extrude 10mm button 5 times on Rep-host it looks like about 35mm of filament goes into the extruder. That seems way off, and when I tried to make the extrude factor 1.4 in slic3r it seemed to over extrude really badly.

I am still running all the [slicer] defaults that I downloaded from the link in Gene's manual. I see posts like the below, but I have not seen any definitive instructions on how to calibrate extruding, or what changes to retraction I should be trying.

I also saw someone calibrating their extruder based on measurements of a thin-walled box, so that they get the width of the thin wall equal to the width setting. this seems like a reasonable thing to base it on. Although an explanation of where these settings go, in slic3r or int the EEPROM or what would be nice.

Help!

For me, it was enough to play with the retraction settings (speed and length), making sure my nozzle diameter and filament diameter settings were right, and lowering the hotend temperature to prevent oozing.

In my case, it turned out the stringing was due mostly to over-extrusion

My settings:
retraction length: 4.5mm
retraction speed: 50mm/s
hotend temperature: 227 C (lowered from 230) for ABS

For a systematic approach, you can try: http://reprap.org/wiki/Triffid_Hunter's ... tion_Guide

For over and under-extrusion, I've read that a lot of people recommend printing blocks at 100% infill. If your extruder/hotend is set incorrectly, you'll see either sparse layers or extra-goopy layers.

From your symptoms and image, I would say that you're probably setting the hotend temperature too high. Hopefully someone more experienced/knowledgeable will correct me if I'm wrong, but running the PID calibration has nothing to do w/ the true temperature of the hotend. You may have set your hotend at 230C, and it's true temperature is actually higher. Just spit-balling here, but my intuition tells me that your hotend around your heating element will get hotter after installing a PEEK fan, since any cooling effect that it has will cause the PID controller to increase its output. If the hotend is too hot, then the nozzle is more likely to ooze, and retraction will be less able to pull the filament back and prevent stringing.

Might be wrong and totally misguided, but that's my thought.

For me, I just did trial and error with a bunch of different retraction and retraction speed settings on the hollow pyramid test piece, and I found that selecting the right hotend temperature made the most positive impact on my prints.

Best of luck!