My self-made models cannot be 3D printed correctly. Bulgs on different Levels

Hello, I need help as my self-made models cannot be 3D printed correctly.

Whenever there are several levels there is a bulge on the outside.

With this model I made an edge offset and extruded it downwards. At the point when it becomes hollow on the inside, this bulge appears on the outside. What can I do against it?

Thank you so much

It appears to be happening at the same depth on the outside as the recessed inside?

Does it happen on all prints? or just that model? Is it always at the same height?

It looks like a layer shift. What material, bed temp, nozzle temp?

I’ve had it happen before where 1 or 2 layers on all objects are larger by about that same amount. I used to print the gear bearings for my girl’s children clients. The whole batch wouldn’t turn. Grrrr!

One more question, is the bulge outward all around the print?

Yes the bulg is on the same depth as the recessed inside.

That just happen with shapr3d models when i use edge offset and extrude it downwards, so that a level is created and the inside is hollow above.

I have no problems with Layer shifting all other models or models witch are created with Fusion360 are printing will. I think thats a bug of Shaper3d.

Yes the bulg goes all around the model on the same hight.

Thanks for youre replay. Sorry for the bad english its not easy for a non nativ speaker to find the right expressions.

You English is fine. I want to be sure I understood your problem. Can you give us step by step screenshots of your method to create the box? A similar and smaller version?

So far my Shapr models print flawlessly.

I agree with Oregonerd that Shapr models do print flawlessly. To troubleshoot, create the same body in Fusion360, 3D print and compare with the Shapr model. If the same result then your 3D printer needs tuning (like belt tightening).

Another thing to check is the model you created in Shapr3D. Make sure it one solid body, meaning parts may appear to be attached but could be separate adjacent bodies. Make sure all is Union’ed. Some 3D printer slicers don’t like multiple parts within a body that you think is only one body. I hope this wasn’t too confusing. Again, it is not a bug in Shapr3D.

Thank you! Good idea to show the problem with screenshots.

As a new member i just able to add one picture, i hope you can see it.

There is just one body nothing to union.
I hope than helps.

Thank you for youre reply. I will give it a try to create the same model in fusion now. Than i will compare them. It will take some time to print the model again. i will tell when its finished!

To make sure that there is no problem with my printer, before I read your reply I printed a model that is the same height as the model that had the problem. But this time I didn’t extrude the middle downwards. It should now be clear that there is no problem with layer shifting.

The next thing I do is print the two models that I created once with Shapr and once with Fusion.

I will let you know directly.

So what program did you use to create the model? And what slicer are you using?

The model in my last comment, was created with shapr3d but the difference is only that there is no extrution downwards in the middle.

It was sliced with PrusaSlicer.

I use Prusaslicer too.
Now that I see your 3D model with a simple recess in the center. The anomaly occurs height wise at the inner surface (at the water line so to speak, looking at your last Shapr pic). That is a printer, filament, slicer settings issue and not a 3D model issue. Don’t bother to redo in Fusion as you will have the same issue. I too have come across that same ‘bulge’ problem.

Possibly a bed temp or nozzle temp issue? it seems to be at the transition to the thin wall. I thought maybe increase the number of perimeters, or decrease bed temp and or nozzle temp a bit.

If it’s a slicer issue he should be able to see the anomaly by zooming in on the side of the object at the level where it occurs.

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Sorry but i think that is a model Issue i created models a long long time with fusion an never had a problem like this. Thats the 3. time i have this problem with with different models and different filaments and different temperatures.

In prusa slicer i cant see this bugle.

if you already came across that same bugle problem, how do you solved it?

Here is an other example created as the same way.

i dont thinnk that could be a temp problem, bed and nozzle temp changed while printing.

Frustrating. And you have recently created something in Fusion and it prints fine? I may just be coincidence since changing to Shapr.

I recommend checking bed belt tension. Make sure belt it is not rubbing from tracking off the belt idler and the belt gear is tight on the stepper. Check bed shafts.

Make sure the is some slide resistance on the bed bearings to reduce lash. Make sure there is no play x & y oh the bed.

These are the most common causes of this problem.

This happened to me on 2 print jobs and then not again.

Oh and check extruder filament tension.

The fusion model is still printing at the moment.

Just a question may be my thinking is wrong, or didnt unterstand you.
If the tensions of the belts are wrong, why did this just shows up when the height is reached where the inside is hollow? And after a few layers every thing is good?

Tomorrow i will check the belts and tighten it up a little bit than i will print it again.

Thanks for youre time!

All things change over time. Much reading on the subject says checking these things can solve this and similar issues. As to why at a certain height? Who knows.

Even leaving a door open mid print changing room temp can affect these printers. I keep a dehumidifier running continuously in my 8 by 12 office. Keeps it warm and fairly constant temp and humidity

The same models that printed wonky printed correctly later so. :man_shrugging:

But keeping your printer tuned is essential. I’ll be doing a tear down and bearing lube after 25 more prints for a job.

Okay i give up. It realy seems to be a slicer problem.
Youre last post motivated me to overhaul my printer again. My prints are realy nice at the moment.

I already asked the people from prusa forum about this problem and they told me that is a problem with prusaslicer. Some one usesed simplyfy3d and the problem didnt accoured. Than he used prusaslicer with the same file and the problem accourse.

Thanks for youre nice help!

I’m in the middle of a job that I don’t want to fail. I will not updated to the latest drivers and slicer until it is finished. Call me cautious! If it isn’t broke don’t fix it!

Your print did look a bit wonky. The green block, where the square hole is in front, didn’t look like it was printing surface around the hole perimeters correctly.

Have a look at this:

Before you tear into your printer, you might want to try a different filament and make sure it is DRY. Better yet, try a new spool if you can. All filaments should be dry. PLA is more forgiving and PETG is more problematic with stringing and such if not dry. Also tweak your slicer settings. There is a wealth of info online for troubleshooting printing issues. I would do test prints with a scaled down version of your current model to save some time.

As I mentioned, I too use Prusaslicer for slicing. I have a Prusa i3 MK3S and a Prusa Mini. Both are great printers.

Good luck, Mike