doug_scott
Posts: 28
Joined: Sun Sep 29, 2019 9:37 am

outside edges not sticking

Sun Jan 03, 2021 12:15 pm

I am having an issue with the outside edges not sticking. The overall print is very good, even the edges that are not sticking are perfect in appearance. When the print is complete you can pull the vertically printed edges aware from the object itself. If I printed with 2 shells, I can take two individual shells off. 5 shells, 5 individual shells can be peeled off. These are complete shells that are fused to every layer down the vertical edge. when removed and laid flat on the table you would swear they were printed horizontally, that is how good the fusion is between vertical layers.

Is this something as simple as just print 1 shell, or even 0 shells?

zemlin
Posts: 341
Joined: Mon Feb 01, 2016 11:36 am

Re: outside edges not sticking

Sun Jan 03, 2021 3:52 pm

You need to increase your extrusion multiplier so you're putting out more material.
I run a test part with an extrusion multiplier starting at 0.85 and going up to 1.05 every 3mm in height by using 20 different processes. Then I peel the skins off until I find where I'm getting bonds I can't separate. I think set my extrusion multiplier to 2% higher than that point. It works for me.

doug_scott
Posts: 28
Joined: Sun Sep 29, 2019 9:37 am

Re: outside edges not sticking

Fri Jan 08, 2021 7:35 am

zemlin wrote:
Sun Jan 03, 2021 3:52 pm
You need to increase your extrusion multiplier so you're putting out more material.
I run a test part with an extrusion multiplier starting at 0.85 and going up to 1.05 every 3mm in height by using 20 different processes. Then I peel the skins off until I find where I'm getting bonds I can't separate. I think set my extrusion multiplier to 2% higher than that point. It works for me.
I am not sure I am understanding what you are saying. Are you saying that you will increase the number of Outline/Perimeter Shells to a number high enough to ensure you can peel off the loose ones down to a point that they stop being able to be peeled off?

I printed off a L-shaped tray that slides into a box. The vertical part fills in the side of the box and has mounting holes that attach the tray to the box. If I print the tray with 100% fill and 4 Outline/Perimeter Shells, I will get a 3mm solid vertical wall as expected. The tray portion is also solid. For a small part like this it is ok to run at 100% fill.
I printed it off again, this time with 75% fill. The result was poor. The vertical part is now open or un-sealed at the top edge, allowing me to fan through the individual "sheets". It looks and behaves like when you have a stack of $10 bills in your wallet and you open your wallet, then use your thumb to flip through the top edge of the bills. If I manage to get my finger in between the sheets I can peel the entire sheet off. By this I mean the entire 5cm tall sheets. Each Outline/Perimeter Shell has no problem sticking to the ones applied on top of them, but seems to refuse to stick to the one before and after it on the same layer. Printing all items at 100% fill as the solution cannot be accepted as a fix.

I have tried the Extrusion Multiplier at various levels both below and above 100%. I have also tried decreasing the z-axis offset to the point that it barely manages to print the first layer. Also done those two adjustments together in the hopes that it would make the width wider enough to force it to connect with its neighbor row. Did not work. The rest of the print is near perfect.

User avatar
dkightley
Posts: 2302
Joined: Tue Mar 10, 2015 4:09 pm

Re: outside edges not sticking

Fri Jan 08, 2021 7:55 am

Can you attach a factory file for the "failed" print.....and a photo showing the defect you are describing.

I think that your diagnosis method of "changing anything and see" may have resulted in a print setting that needs some investigation.
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

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