Heavy vertical parts will always fail

This part failed two times for me. On slightly different height but with same nozzle position

According to traces it failed when nozzle was moving from wall to infill.
Both times brim still was on build plate and part was thorn out.
Seems that at some point vibrations are getting so strong that nozzle crashes into the part. And I don’t know how I can fix it without editing of hotend accelerations.


Did you try adding a modifier to that area to slow it down?

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I’m not sure that simple decreasing speed will be enough, vibration is produced by fast accelereations\decelerations. I’ts not small area, it’s about all upper 1/3 part of detail where most mass is concentrated(design is not great, but it’s not mine). If I’ll have enough plastiq on that spool after all printing is done - I’ll try.


There are multiple possibilities.

  • The printer moving quickly and stopping to change direction cause the top of the print to wobble and throw of the print.
  • another, and looking at your model I believe this is more likely, the infill pattern is crossing lines and eventually there is a bump that gets hit by the nozzle.

I would try,

  • slowing down the speed
  • enable avoid crossing wall
  • try a different infill pattern, such as cubic

I am a bit ashamed to say, when I had the same problem months ago, I just printed the part on my slow Prusa. The part was just a 40mm long 6mm diameter shaft being printed on end and after failing a couple times on the P1P I gave up.

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The Gyroid looks like @ 30% infill can cause a lot of shaking with a tall part like this. I would change the infill pattern.

We don’t know what filament you are using so maybe go with a rectilinear or any none overlap pattern.

Lay it down? Change speeds in case resonance is an issue? Or add side supports to stabilize?

I think I read that the part was disconnected from the brim—what is your brim gap? Try not to have a gap. Try using glue if you aren’t.

My guess is that the part detached from the print bed and then the nozzle collided with the top of the print that lifted. The taller your print is the bigger the temp differential is between nozzle and the build plate which can lead to warping and then detachment from build plate.

I’ve had prints that warp and warp the build plate, but did not detach! Really have to take into account how material behaves.

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With my third try I finally placed it horizontally. I wanted to avoid horizontal printing because top plane is angled and horizontal printing produces awful-looking ladder. But for now that filament is ran out and I’m stopping experiments.

Gap is 0.1 mm, brim is connected to part well enough.
As adhessive i’m using this glue
dissolved in alcohol in proportion 1/3.
It’s best 3d-print adhessive I’ve ever tried(proven by many people)
When build plate is hot - it’s nearly impossible to remove part, considerable should be applied(and when it’s cold - part is detached almost by itself). I din’t see the moment of failure, but I’m sure - crash was epic.

Slowing it down is a great tip for this IMO, but I’m curious… is this a PLA print? And if it is, do you have the machine closed up fully while printing?

I’ve never had a problem printing with the printer fully closed up, but I have noticed that PLA stays very malleable at the end of a long print. The softness does allow a lot of movement and oscillation of the part. I have seen a few occasions when it brushed the part, but it’s never failed a print for me. But your issue looks very similar to what could happen.

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Try infill combination with gyroid, less nozzle drag, just as strong and faster print times

I don’t use it on all of my models but would definitely select it for the model you are printing

I use infill combination more often than not just not when there’s lots of overhangs

Tall parts are hard, and parts with high infill are hard. I actually doubt any other printer will print the part particularly well. I spent a lot of time testing high infill parts and reducing internal part stress to improve bed adhesion. Here are the two issues:

  • The part is very tall, which often has problems because the “rigidity” of upper layers relies entirely on the rigidity of the part itself. This particular part is pretty rigid so I don’t think it’s the primary issue, but for very tall, thin structures, sometimes the only option is to create a sacrificial “I-beam” connected to the part temporarily to keep it rigid for printing, and to mechanically separate it later. Supports don’t really help unless they continually connect with the part.

  • Increasing the wall layers or infill density much beyond the defaults are difficult, as they produce significantly larger warping forces. They are even worse for tall parts. At some point, high infill parts produce so much internal stress that no glue, no matter how strong, can ever handle the stress. And even if you did have a magically perfect glue, once you do get the part off the bed, even after cooling, the entire part will warp and curl due to the internally stressed plastic.

  • What’s happening is the part is slowly peeling off the bed (despite even having the best adhesive out there) due to extreme stresses, and the nozzle starts banging on the part more and more.

  • Your best bet is to reduce perimeter shells or reduce infill. Shells first.

  • If you don’t want to reduce that infill, your only option is to reduce the thermal stresses inside the part. Unfortunately, this can be an (expensive) guess and check procedure. I assume you’re using cool plate. You should print the part like an ABS part, except targeting much lower chamber temperatures (35-45C). The aux fan can help to equilibrate throughout the chamber, though for a tall part the chamber temperature might vary a bit too much. My guess for this part is you want the cool plate up to 40-45C. Unfortunately the more plastic you have, the more perfectly the temperature needs to be dialed in. Basically, you want the bed temperature and the temperature of any new layers to be roughly the same, but for very dense parts (I have tested this on literal 100% infill, 20mm thick parts) you end up needing to be very exact, down to a few degrees C, to reduce the stress enough that bed adhesives can handle the curling.

  • Significantly slowing down the printing can also help part temperature equilibration.

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No, It’s PETG, part is not getting soft, seems that it was simply just too tall and too heavy at the upper end

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No, It’s engineering plate and PETG. For now it’s the only part which was failing constanly, earlier I’ve succesfully printed Hydra AMS w\o any issues at full speed(which is also tall and massive). Unfotunatelly, this part should be pretty rigid to resist constantly applied force, so I cant print it with less perimeters or infill. For now I’ve finished my experiments with this part and simply printed it horizontally.

Cool you was able to get your part done also it will be stronger horizontally I figure you was going vertical do to the middle shaft hole needing to be perfectly round.

I had a part like this on my big printer it had a shaft hole and the part was very tall and had to be perfect round so I printed it on a raft with no gaps I used 16 bottom layer and when part was done I used my chop saw and cut the raft off and sized the part :rofl:

The things you have to do to get 3d parts sometimes :+1:

Have a good one :v: S.V.D

The funniest thing is that it hasn’t. Ive modified original part to use 8.8mm carbon bow arrow as a shaft(it was cheap and pretty aesy to get). So I’ve easily fixed roundness of the shaft hole with 9mm drill. I wnated it to be printed vertically just because of upper surface. It looks not really great being printed horizontally

Here is an explanation from Prusa about how the nozzle can hit the infill.

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What z hop height do you have set? I increased mine to .4mm z hop. I also have the avoid crossing perimeters turned off so there is no nozzle dragging through infill during travel moves. I also increased retraction distance to .8 for some filament which resolved a lot of issues I had. I mainly use less infill at thicker width to avoid too many movements and longer print times, and I just increase top layers so it can bridge across the infill correctly once it does all the top layers.

I also noticed you have a lot of perimeters, so you may want to try lowering perimeter count and increase width so it equals same thickness you want. so if you did 3 walls at .4 you could do 2 walls at .6mm instead. Then infill you can just lower % and increase width to .6 and then increase top layers. Just an idea.

Oh, one more thing, try cropping your model using the splitting tool and start it just before this failed section so you can see if changes make a difference without wasting all that time and filament printing the entire thing just to find out it made no difference.

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The problem could simply be movement of the actual model. Tall thin models are unstable and can move while being printed. Even CoreXYs still impart a little movement on tall thin models from the friction of laying the plastic. You can generally see this in the print quality of the upper layers just before the failure. If you see offsetting of the layers (subtle layer shifts), you’ll know if the model is moving. To fix that, you can slow down the trouble sections with a modifier or add stabilizing supports to the upper area.

However, your model doesn’t appear to be showing the telltale sign of the offset layers. If you don’t have those signs of a swaying model, try what PEZ3D suggested and add a little more (or enable) Z-Hop.

I was having problems printing some very tall, very thin spirals. I also was attempting to print a thin bell-bottomed tube with slots through the side walls near the bottom of the part.

I made sure that I was retracting for every move even when on infill and things were still toppling. I studied the failures and came up with a cure that worked for me; it is a new type of support that worked better than expected.

I wrote up my idea on http://cocoonsupports.com
so that people could experiment with it.

This part that the original poster was fighting with is perfect for this type of support.

I hope this works for you, I could help you with the modeling of the support if you need it.

Good luck

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