Over Extrusion issue (help)  

RE: Over Extrusion issue (help)

1.0mm 20x20.3mf

RE: Over Extrusion issue (help)

In my experience a 100% infill will give over extrusion, depending on the model. Just a few percent too much filament and no where to go will eventually invite trouble.

I never go beyond 80-90% infill to avoid the problems with over extrusion. If I want a stronger part I raise the perimeter count and make top/bottom ticker.

RE: Over Extrusion issue (help)

@area51

Thanks for the reply. 

Even before I get to my infill I’m having issues though. I can hear and see that the nozzle is scrapping across the top of the first layer. Is it possible my Z steps are incorrect? 

RE: Over Extrusion issue (help)

Not sure if that’s a thing? But I’m guessing the motor moves could be slightly out just like the E steps can be? 

RE: Over Extrusion issue (help)

@grimmy579

... the nozzle is scrapping across the top of the first layer.

Overrextrusion expands in 3 dimensions, your layers are effectively too thick.

Why are you using 100% fill?  It is very rarely necessary; a few voids within the structure usually make a part tougher and more resilient.

Cheerio,

RE: Over Extrusion issue (help)

@grimmy579

Printing a cube with exact measures will tell if the step calibration in X, Y and Z is correct. Use a setting with low infill and measure it.

Be sure that the first layer Z calibration is correct and Z is not too low.

If the problem is visible, uploading some pictures will make it easier to help.

RE: Over Extrusion issue (help)

@diem

It not usual for me to use 100% infill to be honest but I was printing something which is only 1.2mm high. Most of the time it’s 10-15% infill but this is happening on my first 2-3 solid base/perimeter layers as well. 

RE: Over Extrusion issue (help)

@area51

Yeah finished printing my cube and X,Y are pretty good (19.9) but the Z is 19.5 Could that be enough to effect my layers? 

RE: Over Extrusion issue (help)

Posted by: @grimmy579

@area51

Yeah finished printing my cube and X,Y are pretty good (19.9) but the Z is 19.5 Could that be enough to effect my layers? 

That gives around 3% over extrusion and 0.5mm too much in the height that has to go somewhere.
If infill where to be set at 95% it would compensate for the missing space and still give a nearly solid infill.

To check the height of the first layers, a print of 2-3 layers (0.4 - 0.6 mm) could be made and measured with at caliper to see if first layer z-height is off and how much.

RE: Over Extrusion issue (help)

OK. Have you measured the actual diameter of your filament? If the true value is a little off you can enter the measured diameter (in Filament Settings) and help the slicer that way.

Alternatively you can tweak the Extrusion multiplier, also in Filament Settings, until you are happy.

Hmmm, and if your nozzle is worn you might have related issues.

Hth, Cheerio,

RE: Over Extrusion issue (help)

@diem

Yep. Measured the filament in 10 places and taken the average. Printed the .4 extrusion multiplier cube and made that slight adjustment as well and now that’s spot on. The nozzle is brand new 🤷🏻‍♂️

RE: Over Extrusion issue (help)

I’m a bit lost as to what it could be, if it’s not the Z steps? If that’s a thing 

RE: Over Extrusion issue (help)

@area51

It’s under height not over? I’ve also checked my bed height and printed a .2 20x20 to check the first layer and it’s perfect. 
I’ve just found a YouTube video on adjusting the X,Y,Z steps so I’m going to give that a try and I’ll report back 👍🏻

RE: Over Extrusion issue (help)

@grimmy579

I know very little about Ender 3, but be sure that everything mechanical is tight - stepper couplings etc. I find it unlikely that the z-step setup should be wrong as it is defined by the mechanical parts. Measuring it won't hurt, but often the problem is found in loose mechanical parts like grub screws and belts not tight enough.

RE: Over Extrusion issue (help)

@area51

I've checked over everything twice. It's all nice and tight. 

I've had a go at calibrating my Steps with the cube and I've now got it within .1mm on the Z so thats good but its not helped with the over extrusion issue. I've rechecked the extrusion multiplier and that perfect at .4 walls. Not really sure what to try next. I suppose I can reduce the extrusion width for infill if I really need 100% infill but its not going to help with over extrusion and scrapping on the first 3 layers. 

RE: Over Extrusion issue (help)

This guitar pick is only .8mm and already the over Extrusion is pretty bad. You can see where the nozzle has scrapped across it before I stopped the print 

RE: Over Extrusion issue (help)

The extrusion width in the tests is only the same size as the nozzle = 0.4mm. I use extrusion width of 0.45 mm for the same nozzle size, which gives more controllable width and better layer adhesion.
Maybe you could try printing a test box width 0.45 mm extrusion width and measure if that still holds the measure for single wall.

Other than that there is only Z-Level (maybe to low) and extrusion multiplier (maybe to high) to dial in.
Another try is to lower the extrusion multiplier about 5% from 1.00 to 0.95 - this is the standard Prusa Printer setting for nozzle size 0.4 mm and it works very well.

RE: Over Extrusion issue (help)

@area51

Right I’ll try the extrusion width at .45 first and recheck the multiplier 🤞🏻thanks Area51. I’ll let you know how it goes 

RE: Over Extrusion issue (help)

It could be the filament or temperature you are printing.

If you print with less temperature , it could help, but model could become more brittle.

If you  check adjusted the printer and everything is OK, then use the extrusion multiplier, this normal to use this.