[Troubleshooting] Big stringing problem with flsun SR and Orcaslicer

Anticorp, 17 days ago

Dry your filament

Rangelus, 16 days ago

Hey mate, I keep my filament in a dry cabinet at 5ish% humidity, and I’ve had the same results with two different filaments in there. I even chucked my filament in a food dehydrator at 40C for 12h with no effect. I’m pretty sure the filament is dry!

Anticorp, 16 days ago

Drat. I had the same issue as you and nothing was working, despite thinking my filament was dry since it was brand new. I finally dried it in a filament dryer and the problem went away. So, that’s usually my first recommendation. Sorry it doesn’t help you.

Rangelus, 16 days ago

It’s all good mate! Thanks for the suggestion. When I first started printing I had that exact issue.

papalonian, 17 days ago

• Dried filament and different colours, no effect

rambos, 17 days ago

lemann gave some good points. Since you already tried so many things like lower temp than recommended and drying, I guess bowden tube might be loose (there should be no play at all). Or just a bad filament? I know esun is quite popular, but I never tried it.

What size of the nozzle you use? Bigger nozzle = more stringing

It is hard to avoid stringing with PETG, but for PLA it shouldn’t be a problem at all. My bowden extruder with 3 mm retraction has 0 stringing with Polymaker Polyterra PLA. Even with 1 mm stringing is almost gone completely. I found Polymaker much better with stringing than DevilDesign or AzureFilm that I used before.

Rangelus, 17 days ago

I know esun is quite popular, but I never tried it.

I’ve generally had the best results with it. Ironically, before the upgrades I had almost no stringing.

I’m using a 0.4mm nozzle. I probably should have mentioned in the OP that I didn’t have problems before, but the upgrades have happened in addition to moving to Orcaslicer.

Now I’m worried if I’ve got my Bowden tube seated in the hotend correctly…

rambos, 17 days ago

Now I’m worried if I’ve got my Bowden tube seated in the hotend correctly…

Just pull/push the tube with your hands. If there is no play you are good, but if there is:

1. Inspect the bowden tube ends and cut them if they are worn out
2. Push the bowden tube in the fitting.
3. While pushing it in, press the collet down
4. Then pull it out with a nail and then zip tie it

I found original clips too thin, zip ties are much better IMO. It helped me remove stringing completely while using half of the retraction distance (using 0.6 nozzle)

Rangelus, 17 days ago

After sleeping on it, I remembered that my new heatbreak doesn’t feed the bowden all the way to the end of the nozzle like the stock one does, so I’m pretty sure I have it seated correctly. I’ll check it though, many thanks for the info! :)

lemann, 17 days ago (edited 17 days ago)

I had a similar stringing issue with PETG on my flsun Q5, where PLA was printing flawless without any strings whatsoever. Since your SR isn’t a bowden, that mostly rules out retraction distance IMO.

For me I narrowed it down to Z-hop: as the printer was lifting the nozzle slightly to move to another part of the print, molten filament oozed out - sticking to the print, and getting stringed across by the nozzle. I only noticed after recording the print (use at least 60fps to avoid the frame blurring you’ll get at 30> and watching what exactly was happening prior to the stringing. It took about 4 hours to get to that point 😭

If orcaslicer is based on Prusaslicer, wipe on retract with the initial distance set to 100% may not trigger a wipe. Try 70% or 80% instead. There’s another setting somewhere to force retraction when changing layers: enabling this will forcibly honor your wipe retraction preference when changing print layer.

I think you may still get stringing at the really spiky parts of the test print, given there’s no space for a wipe, and that volcano is going to hold way more molten filament than a V6 or similar

Hopefully someone with more experience can add their 2¢, it was pretty difficult to research info online when I had PETG stringing - everything just says “tune your retraction” 😤

Edit: I mixed up the SR with the v400! In that case, Another thing to check is your bowden tube pneumatic couplers - unload the filament and tug lightly on each to see if they’re fitting securely. If they’re loose, your extruder can end up moving the bowden tube itself back and forwards, which affects your retraction

Rangelus, 17 days ago

Thanks for the reply mate!

I didn’t think to mess with z-hop - I’ll give that a go, and I’ll do some testing to make sure the Bowden is seated correctly and the wipe on retract is actually happening - thanks!

The print in the image is a ‘torture test’, and just something I had on hand to illustrate the issue. I’m actually not fussed if there is still some stringing at the top, but other detailed prints were getting it pretty bad, including retraction towers.