More print knocking problems :(

prints getting knocked over is becoming the bane of my life :frowning: .

This is my latest print and no matter what I do it always seems to get ripped from the bed about this point - and I dont know what to do :frowning:

Ive added a raft - slowed things down, turned zhop to normal - adjust supports and angles.

I dont know what else to try. Would anybody have any suggestions?

I can send the file if it helps

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When you set your Z hop and the other stuff up, are you also shutting off the reduce infill retraction?

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Without seeing the whole model I can’t completely figure out why there is so much support material underneath the model. Seems like that is a very weak area under the print. Maybe this is how you print it on your other printer, maybe try a different orientation.
Mark

hi - where do I find that option?

thanks
N

what’s the best way for me to share the .3mf? Im sure ive set it up all wrong as im really new to all this. The last print the model actually split away from all that support (at the usual place)

hi - yeah printing on the textured plate. Im cleaning every so often. Whilst ive had adhesion problems in the past - I think this is a different issue as I hear a cracking sound at the same place every time where the prints being ā€˜ripped’ from the plate :frowning:

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When you’re in bamboo slicer, and you go over to options where it says, quality strength, speed support, and in others all the way down at the bottom of the page it says G code output reduce infill retraction on select that… not sure if that’ll work for you. It seems to help me.

it was already ticked :-/

here’s a link to the file - hopefully it will work.

thanks for your help!
N

Deselect that option on check it.

Try this: Dropbox - sampleprint.3mf - Simplify your life

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hi

yeah I was just about to post, I have been able to print it upside down, but ive really been trying to avoid any support scarring :frowning: . When I printed it this way up it left it not too pretty on top.

Would you have any tips on how to avoid the support scarring at all?

thanks again for your help - much appreciated :pray:

@nickholl, Here are the two main variables that I recommend changing based on your posts:

  1. Change to tree support (slim) in the orientation that you actually want. I’ve posted a good amount of information about tree support and what settings to adjust in regards to that.
  2. Add.02 to your support interface spacing. The default top interface spacing is usually .2. Make that .22. This will eliminate most imperfections that you are looking to avoid.

If your using an AMS Lite, use a different material (filament) for supports…PLA & PETG won’t stick together. Model PLA use PETG support…Model PETG use PLA support.

If you are using grid infill switch it to gyroid. Grid crosses itself at the same spot and is notorious for knocking over prints. Also let Bambu slicer orient the model so that most of the movements are on the X axis vs the Y

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Use ironing in the slicer for top layers. That usually cleans things up
Mark

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I was having fits printing multiple-at-a-time PETG models. Printed singly, they always completed. Printed more the one at a time, the odds of failure went up significantly as a function of how many things I was printing.

What I discovered was that if I’m over-extruding even just a little bit, over time a booger of filament builds up on the nozzle. At some point, the booger gets snagged and is deposited on the model. If I’m only printing one thing, the layer time is short (these are tall/thin objects). If a booger gets deposited, it’s still somewhat malleable on the next layer pass, the nozzle can push through/past it. When I’m printing multiples, the layer time is much higher. That gives the booger longer to cool, so that when the print head comes back around and hits it on the next pass the blob is as hard as a rock. Nozzle snags, print gets knocked over.

My failed knocked-over prints always had a blob on the top layer when I retrieved them from the build plate.

My clue was that the problem was worse with white PETG vs. a red and blue. Auto-calibration is never going to be perfect of course, but the Lidar appears to have extra difficulty with this white PETG, it calibrates with too much extrusion every time.

Once I manually calibrated and carefully tweaked flow and PA so there was an absolute minimum of excess plastic being laid down, the ā€œmy print gets knocked overā€ problem went away.

The thing I’m most amazed by is that this must have happened better than a half dozen times before I figured it out. The nozzle never got bent. Lucky I guess.

Observe the booger. :slight_smile:

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I dont have the AMS - beginning to wish I did :-/

yeah ive seen that blob as well - this happens when printing the piece singularly as well though for me

Separate the top part where it overhangs (top of the handle?), then split the rest of the model in half lengthways so they print flat on the bed. You can add connectors and/or just glue the pieces together.

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