I have tried twice now, a simple part printed using PC. Both times they failed. The first with warping and surface finish, the second, surface finish only.
I dried the filament each time for 12 hours at 70 degC - maximum my creality dryer goes to in terms of temp.
I was wondering if people could help identify what the actual failure mode is and any help on fixing it. I started of with by far the most simple of the units I need to print which is very concerning for when I get to the others.
To go along with what @JonRaymond suggested … Make sure to heat soak the print chamber by bumping the bed temperature up to 100c+ and turning on the auxiliary fan. Let it sit until the chamber hits at least 45c and then start the print. You might also adjust the bed temperature to something higher than default. I usually just do 90-100c for smaller parts and 100-110c for larger.
Ok so the surface of the component raising up and touching the tip of the extruder?
I only have the PEI plate. With PLA and the first attempt using PC I’ve only washed hands with fairy liquid and then cleaned the plate with the same and hot water. Then dried with lint free tissue.
Due to the warping the first time around I then added a skirt and brim to the print. I bought Kaizuo glue stick from Amazon and applied it to the PEI plate.
I also did some research and did a few other bits as you mention.
preheated the bed at 110 degC and allowed it to warm up the chamber to just over 40 degC, 42/43 I think.
Changed speeds and thickness of the first few and last few layers.
I’ll pile on. PC is one of my favorite filaments. I continue to have great luck with it. But I really had to do a lot of testing and calibration to understand its nuances.
Here’s what I can see from your print.
You’re on a textured plate. Don’t do that, use a smooth high temp plate and you’ll get much better bed adhesion and ultimatly better results.
It looks like you may be trying to print at too fine a layer height. I have found that I cannot go lower than 0.20 otherwise I get results similar to yours. See this example.
I also guess the groove around the part won’t help with warping.
There was mention of using rafters but wasn’t sure if this would help.
The first time I tried printing two of the diagonally opposite each other to allow them to be made as two separate parts rather than layers of both at the same time as read that can help.
Second time I only printed the one part central.
Would it be better to position it centre left in front of the aux fan, I’m still new to this but I believe the large black fan is the aux fan? I wasn’t sure if it was a cooling fan but I may be thinking of the fan in the head?
Thanks Olias, so I need a smooth plate, assume that’s the bambulabs engineering plate? I did like the effect the carbon triangular type plates but believe these aren’t to be used with high temps.
And still use glue stick?
I did dry the filament and will do it again just before printing.
I increased the layers to the max for first few and last layers - 0.4mm as I’ve been using the 0.4 mm head. I did also get a 0.6mm hot end but yet to use it. You are talking about all the other layers in between as I have a feeling I chose better detail - 0.16mm I think. So this needs to be at least 0.2?
I use the dual sided engineering plate and high temp plate. Truth be told, I ended up coating the engineering side with Kapton Tape. AKA Polyimide tape, Ostensibly for the purposes of getting a specular smooth finish. It started off being an experiment that I’ve now been using for months.
The engineering plate does state that it supports PC printing but you want to use glue, not as an adhesive but more as a release agent to allow for the model to come off the plate. You may find yourself having to stick the plate in the freezer for 5 minutes to get the model to shrink a little if you have trouble removing it. But that’s the whole reason for using a smooth plate, to get much better adhesion.
Yes, as I mentioned above, glue for release liner purposes, not so much for layer adhesion. You don’t need a lot either, a thin smear is all. In fact, if you are using past glue stick, rub some on then take a wet paper towel and smooth the glue around to achieve a thinner more uniform affect.
Yes, 0.16 was the threshold that my models failed at. In fact the image above of the black oval was at 0.16. 0.20 faired much better and one doesn’t really see that much of a difference. In addition, going too thin with PC actually makes for a weaker part as the layers tend to be weaker. 0.20 and 0.24 where the best results for me but the filament and how well it’s tuned will have even more affect that layer height.
Ok I just need to try and source one now. The bambulabs uk store doesn’t even list the high temp plate / engineering plate. A place called additive-x.com shows 4 in stock until you go to the cart, then it says it will need to be back ordered so I’ve emailed them. It’s 2:18am here so most normal people are asleep.
You’ve given me a way forward, thank you.
For other adjustments like in the settings pictures in one of most posts above, do you change pattern form, infill %, brim size, speeds etc?
Or by changing the build plate and the layer thickness with all the other bits I did the second time around, with aux fan on too from the guys recommendations above too, be a good next step and go from there.
I did come across you on other threads saying you use hairspray instead of a glue stick?
Yes, I do use hairspray. It’s a bit complicated, and if there is interest, I suppose I could post in another thread on that topic. In a nutshell, one has to acquire a marker applicator to put the decanted hairspray in. You can’t simply use it out of the can. It involves carefully piercing the can of hairspray, ideally when it’s ice cold, unshaken, and has been at rest for 24 hours. Then, pierce the metal top rim with a can opener to release the accelerant slowly. Allow the small pinhole to release the accelerant until it’s gone. This is best done outside. After the accelerant has escaped, you can open the canister the rest of the way. The fluid inside has carbonated-like properties. You don’t want to use it right away. That’s where decanting comes in.
Again, that’s just a summary, if there is interest, then I can post a tutorial.
The advantage of using hairspray in a marker applicator is that you get the benefits of liquid glue but in a much thinner applicator and you get much finer control. Hairspray is of course a legacy adhesive harkening back to the days when 3D printing used glass plates so it’s a proven technique. Plus, one wants to use the cheapest hair spray as that will be devoid of any unnecessary additives and oils that would otherwise interfere with plate adhesion. The last really nice benefit is that it wipes off totally clean with just soap and
water or you could use IPA as a solvent. Consider that fancy liquid glue adhesives for so-called “engineered for 3d Printing use” are $20 for 3oz. Whereas a cheap can of hairspray is 11oz for $3 and you can see the appeal. But admittedly some people just like to say that their stuff is “Ultra designed” whereas I say… yeah… my AMP goes to 11 too.
I used to use that on the build plate of my Makerbot Replicator “back in the day”. One of the better materials especially when the build plate didn’t get all that hot and there was no enclosure and I liked to print with ABS. You can just tell by the way it feels that stuff’s going to want to stick to it.
Warping happens because the print cools as it is being printed, that cooling isn’t uniform (for any number of reasons including the shape and fill and print speed and build plate temp and extrusion temp) and since plastic shrinks as it cools the shrinkage isn’t uniform. The print tends to cool fastest/more further away from the build plate, so the higher up regions shrink more. That pulls “in” on the sides of the print, which pulls “up” at the bottom of the print. A potato chip warps when it’s cooked for the same reasons.
My first impression when I saw the OP’s picture was “too hot”. Before doing anything, I’d to manual flow, PA and temp tower cals.
My trick to minimizing warping (I print mostly in ABS, ASA, PA and PETG all of which shrink a lot as they cool and so, tend to want to warp more than PLA which shrinks less) is to minimize temperature deltas. I run the build plate a 110ºF and I calibrate the filament so I know I’m running it at the lowest temp I can. And especially for larger prints that are more prone to warp, I let the build chamber heat up to at least 40ºC before starting the print (and I run the aux fan to “stir” the air and ensure everything is heating fairly evenly. It can take a while).
Also, given the defective area is predominantly on one side, assuming the Aux fan isn’t running, I’d check the nozzle to make sure it’s not bent. If the Aux fan is running, shut that sucker off. The only thing it’s actually any good at is ruining prints.
Technology Outlet is a great place for Bambu Lab stuff, in fact, I bought my X1Carbon Combo from them, and other printers!
They seem to have things in stock that the BL UK store is always out of stock.
Thanks! I managed to locate it on Amazon UK although it is nearly twice as expensive as the .com one, I think it is worth it though over buying 3D LAC bottles
I wanted to add a led riser to also make room to insulate the top glass.
I printed one out in PLA first which went fine.
Once my bambulabs pei smooth / engineering plate arrived I added glue and went about printing the riser in PC. A few layers into the infil, one of the angles came away from the plate…am I using too much glue? Too hot a temp?
Started again, cleaned up residue glue, added a brim, something else then happened. Looks like it all got too hot?
I started both times by heating bed temp to 110 degC (am I getting the temps mixed up with Fahrenheit, uk we use Celsius), and I was sure the recommended temps from Bambulabs was the same but as I’m writing this I feel less confident so need to check this.
With the bed heating I let it soak in until I saw a chamber temp around 45 degC. Then started the print.
This was what I tried to print: -
The model I used seemed to load values in, I chose the abs profile as it was closer to PC values. But then chose the PC filament from ams.
It did also ask after if I wanted to save the modified values at the end and I did get asked something at the beginning but the wording or I was confusing so wasn’t an obvious choice at the time. It was getting too late at that point to be carrying on after failing the first time.
goes to 11 too. 
