Microgap Layer Between Bodies. Why ? Repair ?

[cmoher3]

Greetings to all of you. I hope these troubling times find you well.

I've attached a couple of files of a part I have made that keeps messing up on the 3D printer. I started in Sketch mode, drew to concentric circles and proceeded to extrude them, unevenly. I'm basically just making a cup. If you look at the rendering, you may squint and see a very fine plane develops between the vertical sides and the horizontal bottom. This plane is at the top of the bottom disk, if you will, right where the vertical walls first intersect the flat horizontal bottom. It is probably the width of a paper.

I don't know what it is I've done that created this layer. I intended that the sides and bottom be all one fused part. When printing in a 3D printer, sure enough that fine layer of nothingness, shows up in the print and the vertical walls shift there. A very pronounced seam line can be seen.

I'd love to know what it is I'm doing that created that break in continuity and now that it's there, how I might get rid of it ? Perhaps this newbie needs to discover a tool that fuses features together ?

As usual, thanks for your help and yes, I washed my hands before attaching the files.

[davebYYPCU]

Body 1, did you forget it was there?

Seems to have been hidden then duplicated ignored with 2nd and 3rd extrude. 

3rd extrude should have joined it into one body if it was visible at the time.

Check the operation type is what you need before ok.

How was this sent to the printer? 

All 7 bodies as one file?  That would do it, just don't send body 1.

I would join all with Combine Join, but don't know what you want.

Body 1 was never needed or used, but the printer sees it twice.  

Might help....

[cmoher3]

I can't remember how I made this, nut I think I just drew those 2 circles and extruded them. As far as I can tell, the two separate extrudes resulted in two bodies: One for the thick disk like bottom, and the other for the vertical walls. when I just delete Body 1, other down stream features disappear that I guess were referencing it. I'm really confused now and may just do this all over again.

[davebYYPCU]

I didn't mention Delete, its bad for a Timeline.

Hide or Remove it, but as you say other stuff could probably see it.

Make it as one body, with Joins, but Remove Body 1 at the end of the timeline, doesn't break anything.

Might help....

[cmoher3]

OK I hid Body 1 and then used Combine, which I think is what you meant by join, and selected all my model. I've now Exported as an .stl. Hopefully I'm good and hopefully that problem is gone. I did also Remove Body1 per your instruction.

[davebYYPCU]

That should do it, 

Extrude > New Body, or Cut or > Join - decide which way you need it at the time before pressing Ok, 

There are good reasons to use all those, but you have to think ahead.

3d Printers work best with one body at the end of the time line, how you get there, - no right or wrong method.

[cmoher3]

I was a little too fast to write this off as Resolved. Doing the print now and you can see in the image, as it is being made, there is still that distinct layer line.

[davebYYPCU]

What Slicer are you using, - that’s a no plastic type error, where the floor and wall changes over.

Does it show in Slicer preview?

Something in the Gcode, Maybe.  I didn’t see anything in the Fusion model to do that if Body one is sorted out.

Can you zip the Gcode and the Stl File it’s running, and add it here?  I will check a clean model here and my Slicer preview will show that sort of stuff.  Seems like it’s still doing a top or bottom layer at that point, older file with the two bodies?

[davebYYPCU]

Saving the file as STL without fixing the body 1, does this, 

there is a line / gap / anomaly here. 

Fix hide remove body 1, leaves just body 2 - one piece - error is not here, Saving Body 2 as STL

Is the trick.

Might help...

[cmoher3]

I'm not sure I understand you and wonder if I sent the wrong file or something. I removed Body 1. Why is it showing in your display ?? Maybe I need to save again... 

[cmoher3]

Jeez... where did the post go between #8 and 9 where I sent you the files ? I'd like to see what I sent you. There was no Body 1 when i saved the files in Fusion. I removed it per your instructions.

[davebYYPCU]

I am working with the first file sent, 

not to confuse you, just that these last two pic, do explain why there is a trace line at the height of the inside floor, 

A close look, will show that there are overlapping / duplicate triangles that don't align, certainly would show up in a print.

I knew that you had removed Body 1, but I wonder if that was the file being printed.

Hope that clears it up.  Mainly its about how you saved the STL.

Might help...

[cmoher3]

Sorry Dave ... still very confused. In post 8 you requested file copies. I replied and sent those but in the very next post you are posting analytical images of what I thought were the files I sent you. Post 9 should be my reply with copies of the files, unless for inexplicable reasons, the post did not go through ???? In any event, in Message 10, I have sent you 40mmCap v9.f3d. I will attach a fresh version of the .stl in this message. When I clicked on Export to create it, there is only Body 2 under the Bodies tab. If you can suggest any undertaking or book such that I too can analyze my own files for these anomalies and flaws, please do let me know.

[cmoher3]

I'll attach a fresh file here. I'm not sure what, in saving the .stl or what in the slicer settings would cause this. I've got to assume that in the first two extrusions the disk intersected the second extrusion, that being the outer vertical walls and where that intersection took place, is where this imperfection is taking place. I went back and looked at these extrusions to see if somehow they could be redone without messing downstream operations up but I just don't know, with my current skills, how to do that ? Should I delete one of these extrusions and try and do it again ? Any pointers on that process. I'm almost at the point of just redrawing this from scratch but I put so much work into the fine detail of the inner central terminal, I'd hate to have to do this again.

[TheCADWhisperer · Accepted solution]

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@cmoher3 wrote:

 I'm almost at the point of just redrawing this from scratch but I put so much work into the fine detail of the inner central terminal, I'd hate to have to do this again.

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This would only take a few minutes to do the entire part over from scratch.

Sketch1 isn't fully defined? 

The circles are different sizes and no location of the smaller circles defined?

Sketch2 no size or location dimension?

Beginners should never ever do Move.  (There is almost always a better technique.)

Plane1 is not needed (I would use the BORN Technique).

Sketch 5 missing size and location?

Sketch 6 missing location? (And extraneous line.)

None of your sketches fully defined?

Do you have a picture of a real world part you are attempting to model?

Notice that all of my sketches have lock symbol indicating fully defined.

[cmoher3]

I'll attach a photo of the defective part, at some point.... thought I had earlier.. I'm printing another, that may remedy the situation. Sorry , but I don't understand many of your points as I am a novice. I'll take a wait and see approach for now.

[cmoher3]

Photos attached. That layer line is not as bad a I remembered it and I can live with it. You can, in the second photo, see the seam. Those square port outlets are badly deformed as I printed it without realizing that they were not sitting flat on the print bed, so they lifted up during printing. 

[TheCADWhisperer]

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@cmoher3 wrote:

.... I don't understand many of your points as I am a novice. 

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Step 1. Download my Doodle.f3d

Step 2. Go through the timeline step-by-step and reproduce it on your own.  Ask questions at on anything you do not understand.

[cmoher3]

That is a remarkably efficient process. I need obviously a lot more experience to get there. Your points weren't clearly understood as I still haven't wrapped my head around the point of constraints as I find them far more often annoying rather than helpful. I also did not understand your point about not having dimensions on some of the sketches as to the effect that would have on this seam. Anyhow, I just printed another part, after doing the things Dave had asked me to do, but it is still there and I still don't understand how to get rid of it via editing. Your idea of doing this with rotation sure looks like a remedy, so I will close this off with thanks and gratitude.

[TheCADWhisperer]

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@cmoher3 wrote:

1. I still haven't wrapped my head around the point of constraints as I find them far more often annoying rather than helpful.

2. I also did not understand your point about not having dimensions on some of the sketches 

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1. Geometry constraints are the foundation of absolute and predictable, robust control of geometry.

2. Dimensions are  used to control the size of geometry in the CAD world and used for measurement, inspection and control in the real world.