Help on how to print these please

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1

Hi all

I have some spikey stuff I’m trying to print and it fails constantly, often after 12+ hours of printing. Printer is an X1-C that other than this runs flawlessly.

The problem comes from it being multicoloured. I’m saying that as if I print them in just one colour, they work fine.

Essentially, at some stage one, or more, come loose and take the others out with them sometime later. Even when I’ve caught one in time, and skipped it, another is bound to go later. I’m getting less than 10% working.

I think somehow the print head is knocking them off, rather than them just gently coming loose. However, that’s just the feeling I get and it may be wrong.

Also, I often find a layer shift at some point, mayve 0.5 mm max. My feeling on this, though it is a guess, is that the plate has shifted as the errant spike is shoved around. I think this as it’s not always the same height, and if it’s ther,e it will be on every single object.

Other things to note:

  1. I don’t have any printing problems other than this one model. Even then, it’s only the multicoloured version.

  2. I print with a brim. The brim stays put when the object(s) dislodge. I’ve even made the brim larger but that doesn’t matter as the brim stays on the plate and the onbject detatches.

  3. Ones that haven’t dislodged seem firmly fixed to the plate.

  4. Slow first layer and all the usual stuff to improve bed adhesion, such as a gluestick.

After so many failures, I even changed the model, as in the photos, so the base isn’t the tube but has a solid bottom layer, which I would then have to remove with a blade. This didn’t help at all.

I used to have a little more success with this, but still with many failures. I upped the walls (from 2 to 4 I think) and increased infill. That didn’t help and may have made things worse. I’m not sure about that though but it might help someone suggest a solution.

On the rare occasion one has printed properly, it’s come out really well.

Photos attached to show you the basic object. I print them with the tube upright and the (newly added) solid round base on the plate.

Has anyone got any suggestions as to how I can print these successfully?

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2

I could be wrong, but could it be that your cones are floating? That the black and green filaments are not mixing, causing the printer to try to print in midair? The problem doesn’t seem to be limited to the top; even the bottom cones look broken.

Have you ever tried pulling the cones back a little bit? Or was it a ready-made model that you downloaded? If the inside doesn’t matter, I would even pull it in completely with the green paint on the back of the cones for a better hold.

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You didn’t mention what kind of infill you use? I hope it’s not one that constantly hammers against the printed object, but something like gyroid, for example.

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Hi RetroSharky, and thanks for going to so much trouble with your response.

It is my own model. I get what you are saying about the cones and I’ll try what you suggested.

NEW INFO: Just looked at the model and the spikes do go back right to the inside of the tube, so I can’t embed them and deeper. However, I do have the spikes and the tube as separate objects (as that made the multi could printing easier) so I’ll try combining them into the one object before creating the stl/3mf file.

I’m not sure that’s it though because the single colour version prints fine and also originally they did print will less failures. Still failing but less so, so I wonder if I’ve tweaked some other setting the wrong way.

However, I am absolutely going to try what you suggest and see how that goes. thanks! It should be easy to do as I have the original model in Fusion I put together.

As for the infill, I didn’t know that had implications, so thanks for that pointer. I’m using rectilinear. Is that one of the bad ones? I’ll switch to gyroid as well as the change above and see if that helps.

I’ll post back here with results.

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No, not to my knowledge. Bad infills are, for example: Grid - lead to nozzle scraping or abnormal noises due to collisions with the model.

Rectilinear doesn’t stand for high quality, but for speed, but that shouldn’t be a problem in this context. I would still switch to gyroid or even 100% infill.

Silly question, have you activated the prime tower? Just ask again, because I can’t see it in the photos.

And while you’re at it, make sure your nozzle is wiped clean when changing colors. It can’t hurt to keep an eye on it.

5

You probably should lower your “object-brim gap” to 0 as the space currently is too large to adhere the brim to the model.

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Yes, do use a prime tower.

Nozzel wipes clean ok, and as it happens I just upgraded that slightly. So, that should be as good as it can be and it does appear to wipe clean. It’s interesting you said that though as I have wondered if a lump of filament was what knocks over the model, but haven’t seen it actually happen.

Thanks for the infil information. Great to know.

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7

Thanks for that Jon. I hadn’t spotted that option. That sounds like a definite change to make. Fingers crossed that will do it!

8

Would those green cones happen to be PLA silk? Silk PLA has a reputation of not sticking very well to regular PLA. Try replacing the green with PLA metal or sparkle, and you’ll likely get a better print with a similar effect

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This looks like a holiday cookie with fancy chocolate chips. I agree w/ Retros advice. I’d also like to add to reposition your models a few cm higher in Y so that the brims dont print overtop the calibration spaghetti. It obviously works, but it can create a string/booger that gets carried around later

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10

Thanks 3dEd … yes it is silk but that photo is a little misleading.

The actual problem is that the whole thing detaches from the plate, usually about 12 hours into the print. That’s all standard PLA. When I’ve had the occasional successful one the silk is binding really well to the standard, or actually it’s matt, PLA.

11

I agree with you about the calibration lines. I do always keep them clear of that. Bt accident I hadn’t this time because I made the brim extra wide and forgot to move them back a bit. I was actually surprised that it worked.