Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
So I've moved from my old printer to this one to do general printing, but also printing a lot of miniatures (I've done it before on FDMs, perfectly acceptable quality, resin printers are not an option).
It was printing fine with the stock 0.4mm nozzle at 0.1mm layer height, but I've since swapped in a 0.25mm nozzle and I'm trying to print at 0.1mm layer height so that I can get some nice, fine details in the miniature prints. The problem is, it's stringing really, really badly. Both wispy strings and actual solid filament lines. I'm using Slic3r PE with the 0.25 nozzle printer profile and the 0.25 nozzle 0.05mm layer height profile. I've also tried tweaking it to no real effect. I increased retraction from the stock 0.8mm to 1.6mm which seemed to help a bit in the torture tests, but still didn't really solve the issue on actual prints. This exact same filament was fine with the 0.4mm nozzle and I've used it for miniatures before on another printer.
Here are some examples of the stringing I'm referring to. These are all printed at very slow speeds (20-30mm/s):
I've tried different temperatures (from 200 to 230's), different retraction, etc. Nothing helps.
Any ideas?
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Different filament, just to show that it's not filament specific:
(ignore the clump on the far-right arm on the right side model, that's caused by something else and can be ignored)
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
What settings are you using? In particular, what retraction settings?
Here are my settings for 0.25mm nozzle. I haven't done extensive testing, but I don't get stringing issues like that.
If you'd care to share a link to one of the STLs, I can give it a try to compare results.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Not much different than yours it would seem. I've tried both more (up to 1.6mm) and less (down to 0.4mm) retraction. I've turned Z-Hop right down for now because it actually made the issue worse (I was getting stringing even on the normal 0.4 nozzle because of it) which is why that's changed.
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
I've got a long print going, but after it finishes, I'll try the retraction posts using a 0.25mm nozzle for comparison, unless you've got a different STL to try. We're those results at 0.10 or 0.05mm layer height?
I tend to get some very fine silky stringing, not those big branches you're getting.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
0.05 layer height. Any object will work (the more gaps the better I'd guess). The best thing to use to make it obvious though is probably the 4 point torture test - https://www.thingiverse.com/thing:909901 - which is a quick way to test it.
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Just tried some other settings. 1.6mm retraction, 80mm/s on the left, Slic3r PE defaults (0.8, 35mm/s) on the right:
I'd tried 1.6 retraction before but it didn't help, looks like the speed is important. Will try again with the default 0.8mm retraction, but at the much higher speed.
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
I've found playing with nozzle temp almost as effective as retraction setting.
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Already tried nozzle temp, didn't help. Went all the way from just below the limit for the filament all the way up to 230. Mentioned that in the initial post.
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
I went as low as 180c ... settled on 185c for my specific job -- and never saw much difference on towers between 200c and 230c. You may have to stretch a bit to get the results you want. But - all filaments behave a bit differently.
Re: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Going below 200 on the two filaments I tried resulted in catastrophically failed prints with virtually no layer adhesion, the print surfaces looked like jagged waves, so that doesn't seem to be an option (I normally use PLA+ which has a recommended temp of 205-230).
RE: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Having this same issue, and as you state - It's printing fine with a .4 nozzle, but causes issues using a .25 nozzle. Specifically I'm trying .05mm height, but tried others too. I've also tried a lot of different retraction settings.
Were you able to find any resolution to the issue?
RE: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Having this same issue, and as you state - It's printing fine with a .4 nozzle, but causes issues using a .25 nozzle. Specifically I'm trying .05mm height, but tried others too. I've also tried a lot of different retraction settings.
Since this thread was originally posted, I've done a lot of work on reducing stringing. I've got full notes on the linked pages, but a quick summary:
- Make sure your filament is dry. Even PLA can absorb moisture over time, and environmental issues can make a big difference from day-to-day.
- Be sure you've calibrated your extrusion multiplier for each filament. For Prusament with the Prusa-supplied profiles this is less of a concern, but if you're using another manufacturer's product, it's worth doing some test prints to get this right. Any difference between your slicer settings and the actual printer and filament you print with can result in slight over-extrusion which will show up in prints as stringing.
- Consider printing a temperature tower to identify the ideal printing temp for each filament. I don't always do this, but I do try to stick to the low-end of printing temperatures where appearance matters.
- Verify your cooling duct is directed properly. Consider adding a silicone sock to your hotend to avoid thermal shock when the fan turns on.
Since figuring this all out, I'm able to use 0.2-0.4mm retraction, 0.4mm z-lift and disable wiping completely for my prints.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
Having this same issue, and as you state - It's printing fine with a .4 nozzle, but causes issues using a .25 nozzle. Specifically I'm trying .05mm height, but tried others too. I've also tried a lot of different retraction settings.
Since this thread was originally posted, I've done a lot of work on reducing stringing. I've got full notes on the linked pages, but a quick summary:
- Make sure your filament is dry. Even PLA can absorb moisture over time, and environmental issues can make a big difference from day-to-day.
- Be sure you've calibrated your extrusion multiplier for each filament. For Prusament with the Prusa-supplied profiles this is less of a concern, but if you're using another manufacturer's product, it's worth doing some test prints to get this right. Any difference between your slicer settings and the actual printer and filament you print with can result in slight over-extrusion which will show up in prints as stringing.
- Consider printing a temperature tower to identify the ideal printing temp for each filament. I don't always do this, but I do try to stick to the low-end of printing temperatures where appearance matters.
- Verify your cooling duct is directed properly. Consider adding a silicone sock to your hotend to avoid thermal shock when the fan turns on.
Since figuring this all out, I'm able to use 0.2-0.4mm retraction, 0.4mm z-lift and disable wiping completely for my prints.
O wow - you have quite a lot of information on your blog! Thank you for sharing that 🙂 I will be going through and testing things out accordingly based on your recommendations and testing!
RE: Severe Stringing With 0.25mm Nozzle and 0.05mm Layer Height
@bobstro
I created an account just to reply to this post, thank you. I just installed a 0.25mm nozzle to print miniature parts, and all I got was spider webs. following your short procedure, my prints are nearly perfect. I only measured the filament and adjusted the extrusion factor, so there is even more improvement possible. Thanks again!