Topic: Layer Adhesion

I just got done with a 4+ hour print, and have to trash it, bummer!

Most of the print seemed fine, but in some areas, the layers just did not adhere to each other.

I am using ABS and have the hot end set at 200C.

Am I running it too hot, too cold?  When I run into adhesion issues (like in the attached photo), how do you properly troubleshoot the problem?


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Re: Layer Adhesion

What did you slice that with?  It looks like there are bigger problems- is that a lot of strings and stray loops pulled out the sides?  The solid layers don't look right either, and there are a lot of them.


Re: Layer Adhesion

I sliced with skeinforge.

I am working on trying out a new, complete, software installation on Ubuntu.  Right now I am running everything via a Mac.

Any ideas on how to clean things up in skeinforge?



Re: Layer Adhesion

First off, Merry Christmas (eve) everyone!

Okay, I've tweaked my slic3r settings to where I am now getting fairly decent results.

If you look at the item that was printed in purple, vs the gray ones (in the photos), you can see a HUGE difference.

However, if you look at the top of the X-Wing and the columns, it seems that wherever circles are being extruded, I am still having problems - even larger circles like the top 1/3 of the X-Wing.

What settings can I tweak to make the columns and circles look better?

So far, I've been tweaking the settings in the "Retraction" area of Slic3r.

What settings can I tweak to make the columns and circles look better?

I am printing at 195C with the bed at 100C.  (kind of bummed too because I am printing on glass and it just cracked).

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Re: Layer Adhesion

For the small features, you are going to have better results if you can get a fan on them.  Slow-down cooling is good up to a point, but if you slow the layers down too much (with higher minimum layer times) the nozzle itself is going to keep the plastic soft so lower layers get pushed around.

The retraction speed in the Solidoodle profile is 75, but the extruder speed is capped in the firmware at something like 45.  In Repetier, go to Config->Firmware EEPROM Configuration and change the Max Feedrate for E to something like 150.  Turn up the feedrate for Z as well.   The row of blobs is either from the nozzle moving from the external perimeter to the infill, or from the nozzle sitting still while Z moves to the next layer.

A rule of thumb for retraction is to keep the distance small and the speed as fast as you can get it.  Since retraction doesn't involve pushing plastic through the nozzle, it can go pretty fast.  Try pushing it to something like .75 distance and 100 speed.  Also set the minimum travel to .5.   That is the minimum distance the nozzle is going to move for retraction to be activated.  For small columns, it may not be moving far enough for retraction to turn on.


Re: Layer Adhesion

Awesome, thanks.  I will try all of that out.

Btw, I do have a fan on... I used this one: http://www.thingiverse.com/thing:30828

It is constantly on right now, I may end up putting it on a switch.  Controlling it via gcode looked a bit daunting to get it all setup.



Re: Layer Adhesion

That could be why you are getting poor adhesion. If it runs all the time, it might cool it too much. Do you run with a cover?


Re: Layer Adhesion

No, I don't have a cover for it.