Right off the bat, please note: I have researched all available post, threads, videos, and comments found relating Bambu PETG-CF and the X1C. Some are not included in here as they either are redundant (same user posting the same info) or they do not provide sufficient evidence for the settings
Please read what has already been done before commenting. This is long and comprehensive, but should provide a single resource to what is available on this topic
Like many of you, I have been plagued with the desire to use Bambu PETG-CF and yet, been met with the inability to have acceptable results. I hope to solve that here by providing what I have found, while also seeing if we can finally consolidate a definitive solution to this. I have titled this topic as such so that once a solution is nailed down, I can update this first post.
The purpose of this topic only applies to Bambu Lab Filament and the Hardened .4mm and .6mm Nozzles. If I donāt set that limit now, we will have too many other variables. Yes, other companies make good and maybe even better PETG-CF, but that does not solve the problem at hand. Feel free to mention them as a point of comparison, like āHere are my settings for Bambu but with ___ filament, I did not have these issues and used these settingsā. This could help us determine what the underlying issue at hand is.
The predominate issues many encounter seems to be:
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Blobs on the print - Small dots of defects either at the start/end of a layer or randomly in the middle
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Tearing of top surface - Rough or completely ripped top layers that can expose the infill or just be cosmetic. Can also accumulate on the nozzle.
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Nozzle collecting filament (not always the same as the blobs) - though related to blobs, this typically is much larger amount of filament that collects on the nozzle and will either randomly be deposited on the print, or can be manually removed/falls off. Either way, this results in areas lacking filament and mimic under extrusion only to be followed by a burst of filament (clog?)
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Poor Bridging and overhangs - Strong warping or outright failures on short bridges and strands hanging down on overhangs. (potentially a byproduct of these others issues so I will not be diving too deep into this)
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Failures on long prints - Some combination of one or more of these compounded, by long print times.
There are quite a large number of complaints/request for help when it comes to this filament on this forum and other outlets. Unfortunately, none seem to fully solve the issue. Here, I will compile the some of the solutions/suggestions I have found. These are not really in a particular order, besides first 3.
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Dry your filament - For some reason, this is a highly controversial and divisive topic. I am guessing it is because in the early bedslinger days, we rarely dried our filament. We also only had PLA and this is not a bedslinger. General recommendations seem to be 65-70 Ā°C for 8-12h. YMMV
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Calibrate your filament - PETG-CF seems to be hit or miss with the autocalibration. I have found that it can overestimate the values but I have also had several good calibrations. Calibration is needed because if the printer puts out even a small amount of extra filament, it will aggressively collect on the nozzle.
In general:
- Flow Ratio should be around .94-.96
- K Factor of 0.024
- Volumetric flow rate of 12-18 mmĀ³/sec
For reference, if someone has properly calibrated their filament, I will be referring to it as āFully Tunedā
- Create proper print settings - This one is going to have a bit of back and forth as some people have found great success with the stock profiles while others have had headaches. I believe this where many of the problems and solutions are.
I will be assuming the top glass is off for all of the prints as that is what Bambu recommends.
Print Settings:
I am not sure the best way for this to be formatted at this stage as we are still compiling the results.
Right now, I think melding the predominate issues (with links to their existing topics) and providing their listed solutions/what I have tried could be best. My thought is that if I link to the original post, but compile the solutions here, we can see what worked and what did not.
As for how to handle the nozzle issues, I am not sure. At some point each will get their own section (or if it is determined the .4mm is not advised then just the .6mm will have one). For now, both will exist here so please specify what nozzle you are using
Blobs on the Print -
User @ant posted Help Tuning Bambu PETG-CF earlier this year and @Balint posted Bambu PETG-CF sticking to nozzle, unable to print
Their issues seem similar and many solutions were tried. For ant, the original settings were using a .4mm Nozzle, the filament was dried and fully tuned. .2mm layer Height, Nozzle 255C, and Gyroid Infill at 15%. They did have the lid and door closed at the start. @3DTech then provided good insight into why they recommended what they recommend.
Their suggestions were:
- Min layer height of .2 with a .4mm nozzle and .18 with a .6mm nozzle
- Bridge Speed of 30 mm/s
- Cooling Min/Max of 40% - 20s and 90% - 6s respectively.
- Disable Slow Printing down for better later cooling
- 25% overhang threshold with 90% Fan speed.
This was then followed up with ant saying new testing using these settings found success (see his post for credit to other users)
- Rectilinear infill. Overhang Speed Reduction of 0-20-20-10. Reduced Chamber fan speed (no value given). Seam Rear. This was using stock PETG-CF profile for the .4mm nozzle.
For Balint, they seemingly had tried most of these already with little to no success. The filament was not specifically calibrated as they stated they found no difference. Below is their settings and I am confused as to why all failed.
- switching nozzles: 0.4mm and 0.6mm
- switching layer heights: 0.2mm nozzle, 0.24mm and 0.3mm with 0.6mm nozzle
- the nozzles are not clogged, damaged and very clean when starting the print
- coating the nozzle with PTFE lubricant
- wall order: outer walls first
- wall speeds: 60mm/s outer, 80mm/s inner, 100mm/s infill
- infill type: gyroid
- infill overlap: -2%
- chamber fan set to 100%
- part cooling fan set to 10-30%
- everything else stock Bambu PETG-CF profile
- everything else my print profile based on these Bambu print profiles:
0.3mm Strength (0.6mm nozzle)
0.24mm Strength (0.6mm nozzle)
0.2mm Strength (0.2mm nozzle)
Tearing of top surface-
@kragghc posted PETG Tearing Top Surface where the filament was dried for 12 hours, calibrated, and tested using various settings on a P1P with .4 Hardened Nozzle. I will say, their listed flow ratio of 1.03 and PA of .032 seems to be too high IMO. Nozzle 265C and Max Vol Speed of 13.
Cooling is similar to what 3DTech had recommended in the other post with the addition of Retraction 2mm and Z Hop of .4mm (the Z Hop should be useless as the default is already .4mm. Retractation default is 1.4mm)
There was also a claim that sparse infill was being printed lower than the main print layer. This is the only time I have seen this mentioned, but could be worth exploring before just dismissing.
This is the first time that major changes to the print settings were done. Here are the ones that I believe would actually effect the print:
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Top/Bottom Shell - 5, Bottom Surface - Archimedean Chords, Internal Solid infill - Mononic Line, Disable Ensure vertical shell thickness, Enable Infill Combination, Enable Avoid Crossing Walls, Gyroid 50%, Wall Loops - 4, Support Style - Snug, Bottom Z Distance .35 (.2 Default), Top Interface Spacing .1 (.5 Default),
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For speeds(default value in parenthesis): Gap 200 (250), Inner Wall 200 (300), Internal Solid Infill 200 (250),Outer wall 140 (200), Sparse infill 200 (270), Top Surface 150 (200).
It later became suggested that the issue was due to partial clogging of the nozzle due to the Aux Fan. This never fully proven, but is now the 2nd time that has been suggested. The failure also occurred on a sparse infill layer.
@wiremeup came in to suggest settings that are similar to what we saw on the Blob section, but with the changes/additions of: Grid infill and patterns that avoid sharp movements like Concentric.
Retraction should be āhighā (which later was suggested to be 4-5mm) and fast, with flow ratio ālowā. I disagree with the Grid infill as my testing shows it to be harming in all cases and all filaments. And others did as well. Just adding it for posterity. They also later stated you must use the .6mm Nozzle.
They were really institant on Grid Infill and did back their claim with many photos of very nice parts, but it was all printed on another printer/filament.
kragghc later stated they tested Rectilinear but found no benefit. They also tried 50% print speed, 2-6 walls, 25-50% infill, lower Vol Speed to 10, and using the Generic PETG profile but still failed. Not sure if these were at one time or not.
No real solutions were had, just these suggestions.
Nozzle collecting filament
We have now reached the existing megathread by @ohrenstoepsel Mega Thread
This is currently at 106 post, so any summery is next to impossible. It also makes finding solutions time consuming.
Many of the suggested solution are similar to what we have seen above, but here are the major ones:
.4mm Nozzle
@djeZo888 suggested Nozzle 265C (which was later dropped to 255C), Bed 80, PA of .032. Reduced speeds the same as in the Top Surface with the addition of Support Interface 60 (150), Support 100 (150). Print with door and lid closed. (the example print provided is the BentoBox which is small and has very little infill)
3DTech is back again. They suggested the Slice PRP paint but did also state they do not use Bambu brand PETG-CF. They also added changing Retraction settings to:Length = 1.1 (1.4), Z hop = zero (.4), Retraction speed = 40 (30), Deretraction speed = 30 (30), Travel distance = 0.6 (Not sure if this is the Travel Distance Threshold or the Wipe distance?).
We are also back with 20% infill and Rectilinear/Gyroid suggested.
@s.3 makes a lot of contributions here and does a large amount of testing. The main issue is that they are using a cht bimetal high flow nozzle, so a variable to keep in mind.
They did suggest two things strange early on: slightly pulling down the silicon sock and Printing the first layer at 200C Bed 90C. This did seem to work for them and they are the first major long test of a blob free 7 hour print.
Balint also provides some new insights after their original post. Again, drying and tuning are stressed and using Rectangular (Maybe meant Rectilinear?) infill,
What is new is: Reduce Infill Overlap, Disable Vertical Wall Thickness, Match Inner/Outer wall speeds, change wall order to Outer/Inner and Inner/Out to compare, Enable Arachne,
.6mm Nozzle
wiremeup This is now were we finally get more suggestions with the .6mm Nozzle. I am going to use his photos for these because there are so many changes. These are quite the departure from what has been previously suggested.
ohrenstoepsel later follows up with some more .6mm changes suggesting:
- 260C, Gyroid 15-20%, Aux Fan 20%, Chamber Fan 70%. The rest is stock profile.
@r00t did more testing and stated they found disabling Z Hop on layer change and before travel (not sure where these settings are), increasing retraction distance and speed, and raising the temps to 270C help them the most on their P1P. They decreased Flow Ratio to .89 and decreased line width (not value provided).
@kungpaoshizi suggested a gcode addition ( G29.1 Z0.03 ) that is also mentioned as a solution to the top surface/long print quality. Now other threads comment on where this should be made, but the general suggestion seems to be at the very end of the Filament Start Gcode.
The final major addition is by XxBonnyxX (I ran out of allowed tags) who used principles from this Bambu Wiki Page for PA-CF on the PETG-CF to seemingly good success. Wiki Page for PA-CF. I am not sure what exact here they did besides drying and printing at a max of 100 mm/s.
Again, all of these have been suggested but no real consensus has been made.
Whatās Next? and TLDR
This is where you come in. Hopefully since all the OPās and those who contributed to all of these post have been tagged, we can get everyone in one topic and hopefully stay on topic to get this solved.
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While there are a few post I have not mentioned here, the major post have been. There are also post on Reddit but they do not seem to give much detail or provide the same input seen here. Same with the Facebook group besides one on their mods who always has great PETG-CF prints.
- This is what I have tested. However, after compiling this I think I need to make changes.:
- I have tried many of these settings to limited success. Drying and Calibration are assumed, Nozzle seems to be either .4mm or .6mm, but I am using the .6mm.
- Gcode additions have not decreased blobs for me
- Lowered Temp to 250C (First layer 240C)
- Aux fan 0, Chamber 70. Part Cooling 0-20,75-15. Slow Printing Down enabled, Overhang threshold and speed 10% and 90%
- Retraction set to 2mm, Z Hop .4 (it seems I should disable this), Enabled Retract on Layer and Wipe while Retracting, Retract amount before wipe 85%.
- Layer Height of .24, Classic Wall, Inner/Outer/Infill/, Avoid Crossing wall 400%.
- 2 walls, Cubic Infill 20% (doesnāt seem to help), disable Infill Combi, Enabled Ensure Vertical Shell
- First layer 35, infill 55
- Outer wall 80, Inner 120, Sparse 100, Internal Solid Infill 120, Top Surface 100, Slow Down for Overhangs 0-25-15-10, Bridge 20, Gap Infill 250.
- This is what I have tested. However, after compiling this I think I need to make changes.:
TLDR
- The main consensus seems to be as follows
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dry filament and calibrate (potentially drop flow ratio to .89?)
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Change retraction distance and speed on .6mm nozzle (anywhere from default to 4-5mm, Speed of 40mm/s all the up to āhighā which was never given a value)
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Edit cooling values of both the part cooling (Min/Max of 40% - 20s and 90% - 6s), Aux Fan (anywhere from 0-30% ), Chamber fan (suggested anywhere from 30% to 100%
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Add G29.1 Z0.03 gcode (not proven)
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Disable Z Hop?
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Drop all print speeds potentially down to 100mm/s with very high bridge speed tested in one post.
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Rectilinear infill is repeatedly mentioned. I really think this is where the problem stems from
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These are the settings that repeatedly came up. It does not seem to be that temp is playing a massive role here as those have been changed with the issue persisting. It mainly seems to be that the infill is causing this, but I am not sure what the solutions is.
I believe we need to run a orthogonal (Taguchi) array to isolate variables here. With a standardized part (that takes sufficiently long to accumulate an error), nozzle size, and settings, we could all run a single test but compare them via a point system to see what changes things and while still allowing for two variable changes at a time.
Thanks for reading and I hope this wasnāt too boring.