Printed Threads Layers Not Bonding

[Sybergeek]

I printed this SD card holder on Thingiverse and the base printed beautifully. However, (you knew that was coming) when printing the top, the threads inside the top printed so most every print line was visible and distinct. The rest of the top printed great. The top was printed as oriented in the Thingiverse images with the open side facing the print bed.

What pointers or configuration suggestions might you have to achieve solid threads on this top?

My printer is an Ender 5 Pro with a 4.2.2 board running bugfix 2.0.x from February 21 and BLTouch. Cura 4.8 is the slicer. Print temps are 200C (nozzle) and 60C (bed). The filament is Overture PLA space gray.

Much appreciated,

Sybergeek

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[Gramps]

I think I would print the lid with the threads facing up

[Geit]

yeah, I would place it with the flat side down, too. I also would increase the temperature a little.

It looks like your bonding issue is caused by to fast cooling. The part cooling fan is pushing air down and since you create a ring, the air gets blasted around the inner part, where the thread lives. So the lines probably cool down before bonding with the previous layer. With more temperature the cooling takes longer and the plastic can melt together.

Having a temperature of around 210-215 is not bad in this situation.

[Alan]

I second upping the print temperature and you might also want to try the adaptive layer setting in Cura.

Cheers

[Sybergeek]

Thanks everyone. I will give those a go and post the results.

[Sybergeek]

You ever have one of those situations that once you figure out the solution to the problem, you feel like such a noob? Well this is one of those circumstances. I must admit I’m new to this 3D printing world (since Jan 2021), but I’ve worked with technology long enough to know that something wasn’t adding up. That something in a word: supports. My face is red and with a lot of egg. (facepalm) So I did some custom supports. The support are a bit tough to break free, but the threads are in good shape. My Cura file is h​​​​​​ere. Would one of you support gurus be willing to take a look and give the noob a few pointers? I have also attached the latest print after removing the supports.

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[Ender5r]

If you print this top side down, as @Geit suggested, you should not need supports for this model.

[Alan]

Why use supports? I like the design–thank you!–so figured I’d give it a try. I flipped it over.

Cheers

[Sybergeek]

The lettering on the top gets marred when printing top-down. In the interest of improving my knowledge of supports, any suggestions on the custom support settings?

[Ender5r]

re: supports: a tree support right in the middle of the circle might work. But, if you were to print it top side down on glass, I suspect it would print even better.

[Sybergeek]

A link to my Cura file with the supports and settings is in post #6