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I have been trying to print the same dinosaur model for several days and all my attempts have failed in the same place. On every attempt, the tail falls off the supports. Sometimes there is a little black fleck at the point of failure.

I've varied the print temperature +/- 5 °C. I've tried cooling at 60, 70 and 100 %. I've tightened the extruded gripper thing. I've dropped the print speed to 40 mm/s. On my last attempt, I increased flow to 105 % but no joy.

I got the furthest with infilled support, despite the tail falling off.

Tail falls off support

Tail came away during print

I'm using an AnyCubic Mega S with PolyTerra PLA. Model is printed with 25 % infill, printing temperature is 210 °C, 0.2 mm layer height, 3 walls @ 1.2 mm, 50 mm/s, 100 % cooling, default Cura support and raft for adhesion. I have inspected the nozzle and it is clean.

Does anyone know what I could do to prevent the tail from coming away from the supports during print?

Edit

The model is the carnosaurus from https://www.myminifactory.com/object/3d-print-dinosaurs-pack-200076.

I've been printing it as orientated in the file -- balancing on its tail almost vertical. Is this orientation unusual?

enter image description here

I wonder if this way up is best suited to resin printing and whether I'd have better results if I laid the dinosaur flat.

Update

I decided to print something else. The new model, which I'd printed successfully three times before suffered from the same layer adhesion problems.

I re-printed the carnotaurus last night with a new, 0.25mm nozzle. It came out perfect. I suspect the original problem was down to the nozzle after all but haven't had chance to test another 0.4mm nozzle.

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  • $\begingroup$ Yes, that orientation is very unusual and will waste extreme amounts of material on supports. I would print it with the feet flat to the build plate (likely best visual quality), or lying on its side as close as possible to the build plate (likely best strength). $\endgroup$ Jan 11 at 13:45
  • $\begingroup$ I will try a different orientation. One thing I have noticed about the tail down orientation is that the layers look like natural contours of the skin when they're printed that way. I wonder if that's why the designer chose the orientation. $\endgroup$ Jan 11 at 21:48
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    $\begingroup$ Perhaps. Anyway, it should work, albeit being a waste, in that orientation, so if it's not, something is going wrong with your layer adhesion, and you probably need to spend some time trying to understand what's going on by reproducing the issue with simpler models. $\endgroup$ Jan 11 at 22:24

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If part of the print is only attached to the buildplate through support structures, and it keeps coming off, the support structures are either not adequately adhering to the print, or they're geometrically insufficient, in the sense that they only attach at small points around which the print sitting on top can tilt like a lever with forces from the printing and eventually work its way off. If that's the case, you might have to fool around with the slicer's support generation settings until it gives you ones that look like they're geometrically reasonable.

If the problem is just poor adhesion between the part and the support structure, you probably just need to adjust some settings in the slicer, like the Z distance between the support and the part, and any options that might be affecting integrity of printing the support. For example Cura has an option, on by default, to skip retractions in the support structure. This causes both heavy stringing and underextrusion of the supports, so that they're weak and don't adhere well.

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  • $\begingroup$ Do you know what that option in Cura is called? I increased the support interface size to 1.00mm but the tail failed yet again. $\endgroup$ Jan 9 at 22:44
  • $\begingroup$ "Limit support retractions" I think. $\endgroup$ Jan 9 at 23:11
  • $\begingroup$ I switched to regular support and doubled the interface to 1.6mm. The tail printed out intact this time. However, when I removed the supports, the tail came apart in exactly the same places. This leads me to suspect that the true problem is layer adhesion. I've tried printing @ 195C, 205C, 210C and 215C and all prints are weak at the same points. Any ideas? $\endgroup$ Jan 11 at 9:54

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