1 Topic by mobius1ace5

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Topic: Extruder contacting print during moving

Wondering if I am the only one experiencing the extruder knocking the print as it moves to another location.  I figure this is a zheight offset thing? but I have already set it +.1 from factory which seems to give the best prints for me.  I am only currently able to print in .3mm because of this issue and some thin prints will de-laminate during contact.  I am using glue stick as an adhesion agent.

It does not appear that my bed is tram either, even after multiple calibrations and such I still find the layers towards the back to be more squished than ones in the front.  I really don't want to have to level it myself but will do so if needed.

2 Reply by trayracing

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Re: Extruder contacting print during moving

I've had parts get knocked off too. This causes the overhang to curl up a bit. With each layer, the extruder pushes it back down and the overhang starts to curl back up as the new layer cools and shrinks. Then the race is on to see if the part straightens out before it stiffens enough to be dislodged by the extruder. Fascinating to watch, but not terribly satisfying.

3 Reply by thatdecade

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Re: Extruder contacting print during moving

What can be done to prevent the curling up on the overhand edges of a print?

4 Reply by TickTock

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Re: Extruder contacting print during moving

Have you tried reducing the flowrate?  Extruder hitting the print is usually caused by too much material being applied for me.

5 Reply by mobius1ace5 (edited by mobius1ace5 2015-01-26 15:47:37)

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Re: Extruder contacting print during moving

TickTock wrote:

Have you tried reducing the flowrate?  Extruder hitting the print is usually caused by too much material being applied for me.

I am down to .6 for my extrusion multiplier, getting good layers, infill is lacking slightly, but I did turn up the speed to 50 on that, so that could be my fault.  I figured maybe it was the z offset or even the auto-leveling stuff moving the bed up and down?  What are you running?

6 Reply by DePartedPrinter

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Re: Extruder contacting print during moving

thatdecade wrote:

What can be done to prevent the curling up on the overhand edges of a print?


Add a fan to blow on the print.

SD2 with E3D, SD Press, Form 1+
Filastruder
NYLON (taulman): http://www.soliforum.com/topic/466/nylon/

7 Reply by monitron

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Re: Extruder contacting print during moving

DePartedPrinter wrote:

Add a fan to blow on the print.

Wow, this will really stop overhangs from curling up? I have the exact same problem. Please pardon my ignorance, but before I go crazy modding, can I try this out by simply leaving all doors open and pointing a cheap desk fan into the front of the printer? smile

monitron's Website

8 Reply by DePartedPrinter

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Re: Extruder contacting print during moving

monitron wrote:
DePartedPrinter wrote:

Add a fan to blow on the print.

Wow, this will really stop overhangs from curling up? I have the exact same problem. Please pardon my ignorance, but before I go crazy modding, can I try this out by simply leaving all doors open and pointing a cheap desk fan into the front of the printer? smile


It really depends on how bad your overhangs are but a desk fan should work fine. You might have a hard time keeping the bed at temp doing this and it might also cause more warping on the bottom layers.

The key is to fully cool a layer before the next layer is applied.

SD2 with E3D, SD Press, Form 1+
Filastruder
NYLON (taulman): http://www.soliforum.com/topic/466/nylon/

9 Reply by lueman

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Re: Extruder contacting print during moving

Ditto to everything that (dearly) DePartedPrinter said,

In my case I experimented by changing flow-rate & Z-Offset, I finally got great prints when I set my flow-rate to 80% with Extrusion Multiplier at 1, my current E-Steps were 122 so I figure if I set E-steps to around 97-100 I'll be in the ballpark. As to Z-offset I set mine so I am a +50% of my Layer Height so I set my extruder at .22 mm* from bed.  50% of .3 is .15 so .22-.15 =.07  I like to press just a little more so I set my Z-Offset to -.09 to -.1 Yours may vary depending on how accurate your calibration is & how well the filament sticks to the bed. 

* For those of you who don't have feeler gauges: After many attempts I gave up on them!  Try using a straight razor take off the safety edge (do so at your own risk, but really if you cut yourself you really should take up a different hobby) and just use the flat razor body, mine measure exactly 220 mil  , they are very consistent accurate & inexpensive.

good luck!

SD4 with E3D V6.

Those who don't know ask, those who don't care comment,  those who comment without answers  hide ignorance for fear of asking. Be fearless!

10 Reply by lueman

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Re: Extruder contacting print during moving

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Those who don't know ask, those who don't care comment,  those who comment without answers  hide ignorance for fear of asking. Be fearless!

11 Reply by CobbCrawler

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Re: Extruder contacting print during moving

thatdecade wrote:

What can be done to prevent the curling up on the overhand edges of a print?

with overhangs using support can help to hold a print down as well as up, plus it gives a little more cooling time for the print