Bottom and Perimeter Separation Problem

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CCRN
Posts: 178
Joined: Wed Jun 01, 2016 6:15 pm

Bottom and Perimeter Separation Problem

Post by CCRN » Mon Mar 13, 2017 4:32 am

I am having some issues where the bottom layer is not connecting well to the perimeter.
IMG_0268.JPG
I am ruling out filament, reprinting with some eSun PLA Plus right now. I have tried changing the number of bottom/perimeter layers to 3 from 2. My layer height is 0.2mm and I am using the stock 0.35 mm nozzle.

Would much appreciate some ideas to try and make this intersection a bit stronger.

Thanks,

Jerold

CCRN
Posts: 178
Joined: Wed Jun 01, 2016 6:15 pm

Re: Bottom and Perimeter Separation Problem

Post by CCRN » Mon Mar 13, 2017 4:33 am

My temps are 215 nozzle, 70 bed. I am printing on boro with hairspray.

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Jules
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Re: Bottom and Perimeter Separation Problem

Post by Jules » Mon Mar 13, 2017 6:51 am

Looks like the layers are being under extruded a little bit - there are pretty distinct lines between your threads, and you can see the layer below.

Check your extrusion multiplier, make sure you have the gap set correctly, and make sure that you have enough Outline Overlap on your Infill (about 15%). :)

CCRN
Posts: 178
Joined: Wed Jun 01, 2016 6:15 pm

Re: Bottom and Perimeter Separation Problem

Post by CCRN » Mon Mar 13, 2017 2:03 pm

Thank you Jules!

I printed the design with the eSun PLA+ with 2 outlines and 2 bottom layers, and did not get the separation like in the picture. It is strong and appears durable. The filament that gave me the weak join was 3D solutech PLA. I verified my infill outline overlap is at 15%. There isn't really any infill used in this design. It is simply a tray with a bottom and border edges. My gap was just set so I know it is good and the bed was leveled.

I am going to try another print, maybe use the 3D solutech at 220 and see if it is any better. Somehow I ended up with four rolls of the 3D solutech apple green so I have to use them up, but only if I can get them to work.

Jerold

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sthone
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Re: Bottom and Perimeter Separation Problem

Post by sthone » Mon Mar 13, 2017 2:51 pm

I bought a roll of that solutech once and I wasn't that impressed with it but if I remember right it does call for it to be printed hotter than normal PLA settings... so yeah the 220 might be a step in the right direction.
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CCRN
Posts: 178
Joined: Wed Jun 01, 2016 6:15 pm

Re: Bottom and Perimeter Separation Problem

Post by CCRN » Mon Mar 13, 2017 3:26 pm

I was impressed with the color and at the time, there wasn't anything comparable on Amazon.

Looks like I have a variation in my openSCAD design. The failing one fails on both filaments. Now to figure out what I did to mess this up....

Phil
Posts: 188
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Re: Bottom and Perimeter Separation Problem

Post by Phil » Mon Mar 13, 2017 3:35 pm

Could it be your STL file? I have printed items from customers that had errors in STL files which resulted in similar problems. When they built the files in their CAD programs, they did not click the "Merge Result" or equivalent button, and it left a part as two separate pieces, rather than an integrated whole.

CCRN
Posts: 178
Joined: Wed Jun 01, 2016 6:15 pm

Re: Bottom and Perimeter Separation Problem

Post by CCRN » Mon Mar 13, 2017 3:56 pm

I think I may have an idea what is going on. It is very counterintuitive and I have no idea why this happened. Fortunately I saved a factory file from the working model and have the settings :D

A few days ago I made the decision to print 2 outlines instead of 1 that I had been printing. I suppose I did it thinking it would strengthen the print. Here is what it looks like in the S3D print screen. I can press on the side of the tray and it snaps with little effort.
Screenshot 2017-03-13 08.38.32.png
My older working design only has a single outline and for some reason is stronger. I can press on the sides a bit harder and it does not separate. Here is a pic.
Screenshot 2017-03-13 08.37.42.png
What is super odd is the outline width on both models (1 vs 2 layers) is the same. It seem like the single layer design is connecting with the bottom layer better or the bottom layer is a bit wider. I am not sure which.

It looks like this is a situation where more outlines actually weakens a seam and does not strenghten it. I am not familiar with the settings that control how the bottom layer and outline join. Again, I am using 0.35 mm nozzle and 0.2 mm layer height.

Is there anyone smarter than I am that can tell me why the two outline slice is not connecting to the bottom layer as well as the single outline one?

Thanks,
Jerold

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