"Fault line" on print

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piwi42
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Joined: February 26th, 2021, 3:02 am
3D Printer(s): Anycubic Proton Mono SE

"Fault line" on print

Post by piwi42 »

Hi, I'm a newbie to 3D printing and hope you can help with a fault which is happening on my prints.

Am trying to print a holder for a controller. Have designed the shape myself in Sketchup, but each time I try to print it there is a "fault line" all around the shape at the level where the front wall ends.
Print1.jpg
There is a noticeable indentation of the back face just below the fault line (as shown in this photo).
Print2.jpg

I printed a scaled down version of the shape in case, by coincidence, there was a fault with the screw rod at that level, but the fault is always at the level where the front wall ends, irrespective of the height of this level.
Print3.jpg
Also, the print below the fault line is rougher to the touch, as shown in the photos. The back face above the fault line is smooth and flat.

Any ideas what could be causing this and how I can prevent it please?

Printer: Anycubic Photon Mono SE with "Wham Bam" flexible plate attached
Resin: Elegoo Standard Grey
CAD: Sketchup
(The shape is made up of simple rectangles. Base is laid first then the back, sides and front are built on top, each as a single rectangle.
On the front, the full height pieces on the edge were built first, then the gap between them closed with the lower-level front wall).
Prep: Chitubox was used to position the model on build plate and to re-scale the model for the test print.
( The shape was positioned with its base on the build plate).
Photon Workshop was then used to slice the model.
(There is no visible distortion at the fault line when looking at the individual slices in Photon Workshop).
Print Settings: I used the default ones in Photon Workshop.

My previous printing experience: Have successfully printed some basic test pieces including "Benchy Boat" and the "Twisted Rook", plus a human figure.
Also designed and printed a smaller, wall-mounted holder for a mini wi-fi router. This was a similar shape to the models in the pictures, but did not have a full-width front, just diagonal pieces in the front corners.

Thanks in anticipation.

peter
Lez0
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Joined: October 8th, 2017, 10:21 am
Location: Spain
3D Printer(s): JGAurora A5S, Anycubic Photon, Saturn 2

Re: "Fault line" on print

Post by Lez0 »

Is there a hole in the box so the resin can drain. if not this may be causing a suction effect.
Could you attach the 3d file so we can look at it.

Lez
piwi42
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Joined: February 26th, 2021, 3:02 am
3D Printer(s): Anycubic Proton Mono SE

Re: "Fault line" on print

Post by piwi42 »

The box is open, just a base and sides (each 2mm thick). Hope the attached .stl file is Ok.

Thanks
Attachments
Sketchup Digitrax Controller Holder.stl
(19.56 KiB) Downloaded 207 times
Lez0
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Joined: October 8th, 2017, 10:21 am
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3D Printer(s): JGAurora A5S, Anycubic Photon, Saturn 2

Re: "Fault line" on print

Post by Lez0 »

OK, I've looked at the box and I have some recommendations.
First I think the problem is the box is closed and you are getting a suction from the resin as It lifts this is causing the wall to flex a little. So when it changes profile on the print there is no tension on the box area.
Solution 1: move one of the holes down so it is inside the box, this will create a flow for the resin.
Solution 2: If you can move the holes, put a small hole (3mm) at the base of the box so the resin can flow during printing.
Solution 3: turn the box 45° and print it. 3D printers work better as one certain models. It means the print area is smaller. It's easier to show you.
Attachments
Drip pan.png
piwi42
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Joined: February 26th, 2021, 3:02 am
3D Printer(s): Anycubic Proton Mono SE

Re: "Fault line" on print

Post by piwi42 »

Ah yes, your explanation makes sense. I had not thought of the suction.

Will modify the shape and try again.

Many thanks
Lez0
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Posts: 400
Joined: October 8th, 2017, 10:21 am
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3D Printer(s): JGAurora A5S, Anycubic Photon, Saturn 2

Re: "Fault line" on print

Post by Lez0 »

That's OK.
Let me know how if it works.
piwi42
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Joined: February 26th, 2021, 3:02 am
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Re: "Fault line" on print

Post by piwi42 »

LezO

Yes, you were correct about suction causing the fault line and the rough surface.
The new print is fine as you can see from this image.
Print4.jpg
There is still a very faint line at the same level as before, but you need to look very hard to spot it and it does not matter for this project.

Many thanks again for your help.

Peter
Lez0
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Posts: 400
Joined: October 8th, 2017, 10:21 am
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3D Printer(s): JGAurora A5S, Anycubic Photon, Saturn 2

Re: "Fault line" on print

Post by Lez0 »

Glad I could help.
I have only been using the resin printer for just over a year, and I'm still learning.
I remember at the start being frustrated with failed prints, I still get them now and again but at least I know where to ask for help.
I'm sure one day you will be able to pass on your knowledge to help someone.
Enjoy your printing.
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