I have a mystery Stl file that changes completely when I print it.

I made a simple little lid for a box in Tinkercad which I have used quite often that looks ok in the slicer until I slice it and then it changes completely I have never had this happen before and though this tiny little print is not important to me I am just wondering what is going on. If anyone wishes to take a look at it and tell me why it does this here is the file. I did it in both Prusa and Cura with the same results. In fact as soon as you slice the stl file you see the change.

lid_box.zip (435 Bytes)

I found part of the problem: the model is not sitting flat on the build plate. It’s tilted up on the left end. I tried rotating it so it is flat, but it still has issues. I would redo it. I suspect you accidentally rotated it in TC and that issue promelgated through the whole model.

Aha! I knew you would find the problem. I shall do that and see what happens. It is strange though because Prusa is supposed to lay things down.

I tried and tried and restarted but it is basically just the same. A bottom and no sides. I started new with a solid box and a void box which I lifted up 0.4 to make the bottom centered them on 2 axes and grouped them. As usual it looks fine when I import it to the slicer and when I slice it I only have the bottom, no sides.

Cura also has the option to “drop models to the build plate”. However, if the model is off kilter from the start, that won’t help. In Cura I had a bottom & 4 sides, but there was a small section completely missing from the left corner of the front edge.

Here are some images of what I got:

[ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:6114}[/ATTACH] This shows the left end off the build plate.

[ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:6116}[/ATTACH] This is how it sliced. Notice the front left corner.

[ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:6117}[/ATTACH] This is after I layed as flat as I could manage.

[ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:6115}[/ATTACH] And sliced after laying flat.

I tried and tried and restarted but it is basically just the same. A bottom and no sides. I started new with a solid box and a void box which I lifted up 0.4 to make the bottom centered them on 2 axes and grouped them. As usual it looks fine when I import it to the slicer and when I slice it I only have the bottom, no sides.

How about this. Seems to have fixed it.

CE3PRO_lid_box_fixed.zip (456 Bytes)

oops sorry didn’t fix it after all my bad just flattened it and nothing else.

Ok i don’t know what you did to that model but you did a REALLY good job of it ?

@Larry, seems you got the same result I got. It is odd for sure. I tried the Mesh tools in Cura 4.8. They made some improvement, but didn’t fix the basic issue.

@roon4660, if you post the specs, I’m sure 1 of us can create a working STL for you.

I really don’t give a damn about the stl file other than the fact that I don’t know what went wrong. I was making a lid of OD 38.6 x 51.6 x 12.4 with a wall od ).4 mm. in Tinkercad. Since Tinkercad is the only thing I know how to use I would just like to know what I did wrong.

I have never used TC, so I’m no help with it.

I explained further up exactly how I did it. It’s always worked before for me. I’m puzzled.

In trying to learn how to use Tinkercad I did lots of similar little projects but I have never had this happen. It couldn’t be an easier project. I redid it from scratch 3 times with no cigar. I was just about to try a much more complicated project but until I figure out what is wrong…hmmmm I wonder if I reboot my computer that might help. I have a habit of leaving it on all the time. I know that tinkercad can bug sometimes with a little help from my old macbook pro.

It seems pretty unlikely that a reboot would help, but what harm can it do?

It didn’t help at all. I’ve already redone it, it appears perfect when I bring it into prusa and when it’s sliced the sides disappear.

Just for kicks, why not try just bringing the solid box into Prusa & slice it; see what happens.

I know it is flat on the bed. I can’t imagine why it doesn’t work. Maybe I’ll try two cylinders the same way.

I’ll try the cyclinder first and see what happens.

The cylinder cup I just made and imported to Prusa did exactly the same thing.