When Printing Bambu ABS (Black 1.75mm) filament, and following all procedures (Glue stick, engineering plate, bed leveling, ABS profiles/temps/door closed…) the ENGINEERING plate actually lifts off the X1C bed (at the corners) when printing a large/flat object. The printed object does not separate from the plate. THE PLATE SEPARATES FROM THE BED in the corners
I know ABS “shrinks”, but does Bambu engineering have a work-around, or a “specialized” THICK RIGID plate in development?
Welcome to the forum.
In the “olden days” before magnetic beds we used binder clips to hold glass to the bed.
Tiny C clamps are now available on Makerworld.
Thanks for the rapid reply. THAT’s what I always had to use on my Ender3 !
As you know, you really need a low profile clip to “keep it out of the way”
George
I’ll do your clippy idea…
What? OLDEN DAYS!? 
Back when you had to 
to the printing gods every time you started a print… otherwise… 
Youngsters have it so easy these days… Don’t even have to level the bed. (Shakes fist)
I still get that bed leveling on my Qidi XMax 3. Keeps that brain in shape. 
For large ABS prints, it’s critical that you get the build chamber up to temperature before you start. Run the build plate heater manually while you’re setting things up. Wait for the chamber to reach at least 40ºC before starting. I run the Aux fan on high during my preheat. Takes longer to get to temp, but that’s the point.
Don’t reduce build plate temp at all during the print. You want the build plate to run as hot as it’ll go, and you want your extrusion temp to be as low as it can be and still give you solid interlayer adhesion (which you may need to evaluate with some test objects).
Chamber fan off of course, for both preheat and print.
From some reports I’ve seen, it might help to put some blue painter’s tape around the chamber door seams to seal it off and reduce how much cold air can leak in. I haven’t had to do this, but my printer is in a warmer room in my house so it doesn’t matter as much for me…
I’m surprised that the tape on the door makes a difference seeing as there are big holes on the back side of the printer.
I’ve considered trying some of the chamber blockoff plates.
Thanks for the help ! Will do all of what you suggested!
Geogre
As a guard against collision, I did some experiments recently and proved to myself that it can be done with tape,
though more as a short-term stopgap measure and probably not a good long-term solution.
Can’t thank you enough… will do
George
Dumb Question: You mention Chamber fan OFF (how about Aux fan & Device Fan)?
Thanks
For ABS bridges and larger overhangs, you probably want some part fan cooling. But the Aux and Chamber should be off for the entire print.
The part warps because the higher layers cool off faster/more than the lower layers. ABS changes size significantly as it cools (5% or more). So the upper layers shrink and pull inward on the lower layers. But the inward pull is constrained by the print’s adhesion to the build plate, so it’s only the “Z” component of the force that can do anything, and the perimeter of the print pulls “up” in response.
So maximizing the ambient temp and minimizing the delta between the build plate and filament extrusion temps minimizes the amount of shrinkage that can occur during the print, which reduces the “Z” force and so, the warping effect.
Fans move air, moving air will speed up the plastic’s convective cooling process that accelerates warping. So no fans.
Mechanically constraining the build plate can help, as others have suggested. A strip of painter’s tape along the edges would probably be somewhat effective and fairly quick/dirty to evaluate (and easy to remove). You could probably also print some clips to lock the plate in place. But constraining the plate might just result in the model pulling free from the plate. So while this approach may be worth trying, it may not prove effective (enough).
A little ABS dissolved in Acetone and brushed on to the build plate (and allowed to dry) can significantly improve how well the print sticks to the build plate. But it’s kind of a pain to prep and use. And I can’t say for sure if Acetone won’t attack the build plate material. So try this as a last resort. But this, in combination with a mechanical constraint to keep the build plate from pulling up, would likely ensure success. This is how I used to do it in the early Makerbot days of FDM printing.
I use these:
https://www.printables.com/model/537896-rounded-bed-clamps-anti-warping-low-profile-for-ba
Thanks for posting. Don’t you need some kind of spring to be a part of the clamp? Or does the printed plastic instead provide the needed springiness to the clamp when you tighten the screws down? Or…?
There’s not much margin for error when it comes to placement of the clamps. The X1 does its filament purges almost on the very edge of the plate.
If you print the clamps in ASA or PA, they will have enough flex to be effective, you screw them down. Chamber fan should be on 0 for ABS and ASA. The aux is off by default, and the cooling fan should be auto as well. You need to disable the chamber fan in Gcode.