When I try to print regular, generic nylon with the p1s, I am unable to get a parts with knitted layers. Basically, the layers just peel apart like a French pasty. I have tried temps from 260 to 290 C; Preheating the chamber; All fans off. What am I doing wrong?
PS:Good point. I dried the filament first
have you dried the nylon first?
Good point. I did dry it first. ( plus, brand new spool)
If itās definately dry (brand new spool doesnāt mean itās dry, so Iām hoping thatās not what you mean) - then what are you running for speeds?
You may be running too fast to get heat into the filament properly, although with 300c thatās unlikely vs moisture.
I had it two days in the dehydrator, but I just realized the temperature was only 50Ā° C. Do you think that the drying temp could be the problem?
On the side note, I did rehydrate one of the prints, and it Still flaked apart.
For the settings, I just used the generic PA at the silent mode (50%).
Can you post a picture of the fail and/or a screen shot of the sliced file?
Layer separation is generally a case of bad interlayer adhesion. The first thing that comes to mind is AMS printing with an incompatible material at the same time. For example, PLA and PETG are not compatible and will weaken the layersā adhesion if printed at the same time. The purge canāt be long enough to get all of the other filament out without being super wasteful, so youāll end up with weakened layers until all of the second filaments remnants pass through.
Another thing that comes to mind from your description of the problem is āSilent Modeā. Taking too long between layers will also weaken the adhesion. Hot layers bond well together, cold layers donāt bond and only have a weak connection. Consider, running it in normal.
Good point about the speed. I will try a faster mode.
What do you mean about the AMS? Are you saying I should use not use it with nylon?
(Note. This is a single material print with no support).
It is a small part. Attached is the PC printed version. The garbage was picked up today, but I have a shedding one at work that I can post, soon.
50c is nowhere near enough to drive moisture out of nylon, 70-80c minimum
More so talking about mixing of materials contaminating the part, causing poor adhesion. But if you are only using one material that shouldnāt be an issue.
Most Nylons/PAās are fine in the AMS, just watch out for the brittle ones. Theyāll break and clog up the PTFE pathway.
I finally got to dry the filament at 85Ā° C for 23 hours. The prints still came out weak. However, I ended up slowing down the speed to 3 mm3/s and increase the temp to 300Ā° C. Cosmetically the parts look terrible, but when I flex the part, the break lines are showing that knitting between the layers is occurring. I guess I will order a different brand to try to prove out that it is just not a limitation of the P1S. (Also, I soaked the prints in water which improved the flexibility of the part).
Thanks for your help.
Thereās still something weird going on there, I print nylon at 4x that speed and it comes out with great strength.
Iāve only used the BBL Nylons, and like Phillip mentioned, itās been great on my converted P1S. Beautiful finish, uber strong parts (Iāve used it for a DYI CNC spindle mount), printing at the BBL profile speedsā¦ I just canāt complain. But if the brand you are using isnāt as good, that could constitute why you are having issues.
There are no other good reasons that I can think of right now, that would explain the bad layer adhesion. Things to look out for in general are contamination of the filament (mixing of incompatible filaments in the nozzle), printing too slow (which could be a part of your problem), and poor extrusion where the extrusion isnāt consistent which causes poor bonding.
The thing that continues to make me think your issue is the filament is the poor finish. This just suggests to me there is something very off in the system. Unlikely the printer, as long as the temps are getting to the level that the system shows. For example, if the nozzle is printing at 250C when the system thinks itās at 300C odd things like this could be occurring.
I didnāt see on Bambuās lab site that they sell regular nylon, only the filled versions. Maybe the P1S canāt do regular nylon?
It tried a new brand gizmo dorks nylon. I had similar results. Still weak but the finish ant temps above 270C looks like the fuzzy mode was turned on.
Does everyone turn off all fans during your prints?
For nylon, yes, no fans, hot chamber.
If it looks fuzzy, your nylon is wet, simple as that.
I hate to be dismissive, but this is not your problem. Its possible your description of the problem is not what we think is. Do you have a pic of the bad looking part?
I also donāt know what Pa I am getting. Maybe Iām buying PA 11 and BBLās Pa-CF is using PA 12 or vice versa.
The layer photo was at the generic default temp and the complete part was 300C. Layer adhesion is better but the fingers still snap right with little layer line knitting.
Your pic clearly shows that you are extruding too much filament.
This ripple look only appears when there is too muchā¦
Try this for a change: The calibration mode 
I had a very old spool that simply would not print good no matter what setting I tried.
After calibrating the prints came out fine.
Ok, I will try the cal again.
What sizes did you process with the BambuLab PA in the surface? I have a part with about 10cmĀ² and have concerns about the print bed adhesion. The plan is to use the High Temp plate with BambuLab PA glue stick, possibly also on the textured plate.
Apart from no cooling and a closed build space, do you have any tips for me?
Iām currently looking for parts for a provisional build chamber heater, but I donāt yet know whether this is necessary.
My use of PA (PAHT, PA6 GF, PA6 CF) has been pretty seamless. The largest part wasnāt massive, approximately 120mmx120mmx150mm, but it stuck really well and was virtually flat. One print and I was done with that part.
I use the basic profiles on the textured bed with glue. But note, the infill on my parts were only 15%. I did use 4-6 walls for strength though.
I havenāt tried recently, and I do think things have changes on the cooling side of the profiles, so I canāt confirm things are still super simple. However, is adhesion is the main problem, there are some simple step that will put you in the best place to start.
*Bonus - Dry Nylon before use (during use if the print is really long). Nylon can get back to 70% full of moisture in a matter of hours in relatively high humidity.
