this post was submitted on 21 Nov 2023
49 points (100.0% liked)

3DPrinting

17269 readers
259 users here now

3DPrinting is a place where makers of all skill levels and walks of life can learn about and discuss 3D printing and development of 3D printed parts and devices.

The r/functionalprint community is now located at: or [email protected]

There are CAD communities available at: [email protected] or [email protected]

Rules

If you need an easy way to host pictures, https://catbox.moe/ may be an option. Be ethical about what you post and donate if you are able or use this a lot. It is just an individual hosting content, not a company. The image embedding syntax for Lemmy is ![]()

Moderation policy: Light, mostly invisible

founded 2 years ago
MODERATORS
[email protected]
[email protected]
[email protected]
[email protected]
49
What is happening in that corner? (and only that corner!) (feddit.de)
submitted 1 year ago* (last edited 1 year ago) by [email protected] to c/[email protected]
8 comments fedilink hide all child comments
 

EDIT: I've followed [email protected] 's suggestions and I have rerouted the bowden tube. Tomorrow I'll start another print and see the results. I'll report back.

Here's the whole printer during that print...

https://files.catbox.moe/smtxlj.webm

...and here's a detail image:

The printer is a Creality CR5 Pro HT running Klipper - although I doubt this is too relevant. The extruder is of the "push type" with the hotend only including the heated nozzle. Current speed is 70mm/s in the layers but at the moment of the video 35mm/s due to the top layer.

I have no idea why, with a relatively symmetrical print just this corner is so messed up and underextruded. Any idea would be nice.

top 8 comments
sorted by: hot top controversial new old
[–] [email protected] 6 points 1 year ago (1 children)

Two guesses:

Someone else pointed out that your Bowden tube looks a little pinched in some of the corners, I can't tell which corner is underextruding from the video but possibly there's filament slippage from that?

Is there any oozing from the nozzle? If the corner with the problem is the "start" corner, any plastic that oozes out during travel isn't making it into the print. Depending on your slicer you should be able to randomize the start location per layer to try to hide it, but if that's the cause I'd try to figure out why it's oozing so much.

[–] [email protected] 4 points 1 year ago* (last edited 1 year ago) (1 children)

Someone else pointed out that your Bowden tube looks a little pinched in some of the corners, I can’t tell which corner is underextruding from the video but possibly there’s filament slippage from that?

Yep, it is exactly that corner where the radius of the tube reaches its minimum. I think that is a hot candidate for the main issue. Also after removing the print, it turned out the the outside had this issue as well and that was printed in the other direction. So, coming out of the slow corner the flow couldn't accelerate quick enough to get back to volume due to high friction. Thanks, see my edit, I'll report back!

Is there any oozing from the nozzle?

Yes, there is some. I have not calibrated retraction in Klipper yet, I know I should - however, this shouldn't be the cause of this with almost no travel between layers or different parts in this model. But it's on the list, you're right.

[–] [email protected] 1 points 1 year ago

Yeah, if there's not much travel distance between layers I'd say the Bowden tube is gonna be your culprit. Looks like if you just remove the tie connecting the tube to the cables going to the print head you'll probably be fine, definitely report back!

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago) (1 children)

Looks like lots of underextrusion, but I don't know why it'd do it only in that corner.

[–] [email protected] 2 points 1 year ago

Yes, definitely underextrusion. See edit for idea, test following tomorrow.

[–] [email protected] 1 points 1 year ago (1 children)

Bed leveling could be the problem, under extruding due to a low spot on that corner.

[–] [email protected] 1 points 1 year ago

Bedmesh was created right before the print and applies, I'd rate that second after underextrusion due to the bowden tube getting bent hard. We'll see though!

[–] [email protected] 1 points 1 year ago

Check your bed bearings. I had this happen when one of my bearings started to let go. I also found a deformation in the bearing channel, so I switched that unit to MGN12 rails and the issue went away.