Horrible print results.Help needed?

siblues

I am using a .3 nozzle and I have adjusted the settings you mentioned other than the thermistor value.I am using a Semitec thermistor.I will try to print two parts so as to give them sufficient time to cool.I also turned off acceleration and jerk control in Cura and I am just slowing down the outer wall speed to 20.0 mm/s and disabling tree supports.

The thermistor value should be changed from
M305 P1 T100000 B4725 C0 R4700

to
M305 P1 T100000 B4725 C7.060000e-8

JamesM

FYI...I have gotten plenty of filaments that even though they arrived in a vacuum sealed bag with dessicant, they had moisture in them and had to be dried. Mainly PETG and definitely Nylon. Also I just received some prilon Carbon PC yesterday, perfectly vacuum sealed with dessicant and had tons of moisture.

So if it's petg I would thrown it in an oven at it's lowest possible temperature for 4-6 hours or a dehydrator at 60-65C for the same time and dry it.

Dugee

going to make a suggestion that helped me - make sure the filament size in the printer setup in cura is set to 1.75mm. I had very brittle prints and a lot of wierd issues because of this.

even though I had set the filament size in the slicer at the correct size the printer profile was set to 3mm and was overriding the filament set up.

basically gives the same effect as massive under-extrusion.

probably not this but worth checking.

siblues

I am going to look into a dehydrator and the last time I checked it was set to 1.75 but I will make sure.

The thermistor line in config.g should it be written like my second example?

Phaedrux

@siblues said in Horrible print results.Help needed?:

The thermistor line in config.g should it be written like my second example?

Yes, you can leave off the R value and the Duet will use the default, which is fine.

As for the moisture, usually you can hear some hissing and popping or bubbling as you extrude into free air if it's really bad.

I don't know where you live, but if there is high humidity it's more likely to be an issue.

siblues

I live in NJ also known as the armpit of America.I don't hear any hissing or popping which isn't definitive proof of dry filament.I tried lowering the temp to 210 before making all of the adjustments mentioned in this thread and there was much less stringing with the Esun PLA+ so maybe with the adjustments and some temp tuning I will get better results.

JamesM

I'm in NJ as well...I thought it was petg you were printing....I've never really had a moisture issue with PLA+. I used to use Esun but wasn't a fan and switched to Sunlu PLA+. Now for PETG I primarily use Esun.

siblues

Nice to know there are more of us on here.

I am using a few different brands like Esun,Inland,Amazon,Sainsmart and Fox filament.I have used quite a few rolls of every brand except the Esun stuff.Inland always seems to work well for me so I always have a few spools laying around.I am having similar issues with both PETG and PLA+.I may try using a PT100 for more precise temperature control and just to make sure the readings are actually what they say they are.

I'll post up some pics of the two parts I am currently printing for some more advice.

Here are the two pieces I just finished with the new settings and printed at 210 degrees.I printed them at .2 layer height and the layers are really noticeable'I would love to get a smoother finish if possible.This is for a new fan set up so that it can be used with my standard V6 and my Volcano that's in the mail.I think one of the issues is the part isn't getting a strong stream of air from the cooling fan the way it is right now.

dc42

@siblues said in Horrible print results.Help needed?:

I'll post up some pics of the two parts I am currently printing for some more advice.

The first one in particular looks to me that is was printed way to hot and/or with insufficient print cooling. Suggestions:

Check your M305 thermistor settings. Your second example is correct if you are using an E3D thermistor.
Try a lower temperature. Most PLA filaments print OK at 190 to 200C.
Try a higher print cooling fan setting.
Tall thin towers like those are often a problem because each layer doesn't have time to cool before the next one is printed. Most slicers have a "minimum layer time" to help with that. Try increasing that setting.

Phaedrux

I didn't see that you'd edited your post with your results. I don't think the forum sends a notification on an edit, nor does it show up as an unread post, so I totally missed it.

Those pictures look much better than the first ones, so I think you're on the right track.

Now that you have the correct thermistor values, you should rerun a PID tune on your hotend heater. https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control#Section_Setting_the_model_parameters_by_auto_tuning

Then I think it would be a good idea to retune your e steps. Choose a temp you'd normally be printing at, like 210c. Mark your filament at 110mm above where the filament enters the extruder. Use G1 E100 F60 to slowly extrude 100mm of filament. When it's done, measure the distance from your mark to the extruder body, and use old_e_steps * (100 / (110 - distance_to_mark)) to find your new e steps value. You may need to redo this a few times to get it dialed in.

Lastly, you'll want to calibrate your filament flow value for the slicer to fine tune your flow rate. Usually this is done by printing a small single wall object to get your extrusion width right. Something like this: 0_1555018807413_100mm rounded.stl

Print it in vase mode or spiralize contour mode in Cura. Set your extrusion width to match your nozzle size and print at something like 30mm/s. For your 0.3 nozzle a layer height of 0.15 would be ideal. Set the flow rate in Cura to 100%. Then once it's printed use a caliper to measure the wall thickness at the top middle of all four walls, take the average thickness and use Old Flow Rate * (Expected Thickness/Measured Thickness) = New Flow Rate.. You may need to redo this a few times to get it dialed in.

Another good way to tune the flow rate is to print a large square (same STL as above) and watch the solid infill lines. If your first layer height is accurate, you should be able to use the extrusion multiplier slider in the DWC or PanelDue to adjust your line thickness until you're getting a nice first layer. Take the resulting percentage you set on the slider and use the same formula as above to find your new flow rate.

Another good way is to print that same STL with zero infill, zero top and bottom layers and 2 perimeters. Use the same speed for inner and outer walls. Extrusion width same as the nozzle for both. Layer height 50% of nozzle width. Use a brim to keep it anchored. This works best when you're already close to having the right flow. Let it print several layers and watch the two walls reduce the extrusion multiplier until you can see a gap between the walls then slowly bring it back up until the gap is gone.

You can use the same method to adjust your print speed by adjusting the print speed up or down with the speed slider until things are starting to look smooth. Then using the resulting percentage to scale the values you used in the slicer.

That same STL can work well to dial in your first layer height once the flow rate is distilled in too. Baby step until it's putting down perfect layers and adjust the z probe offset accordingly.

Once you've got the temps and extrusion rate nailed down I think you'll notice a big improvement in print quality.

A good way to help with the part cooling for such small parts is to use no heated bed at all if you can get away with it. Pointing a small fan in the general direction of the parts on the bed can help a lot too.

siblues

I tried everything you mentioned above Phaedrux and the prints look much much better but there is definitely some room for major improvement.I am currrently printing at 200 degrees.This is my first PLA+ roll so I am not really sure if 200 is good but I am going to print a few test cubes at different temps to see which one gives me the best results.I printed an empty cube with a .3 wall thickness in spiralize mode and the results where amazing.I will print another and post results.

Here is the last print

Phaedrux

Still looks over extruded and maybe still too hot. Try 195c and reduce the flow rate 5 percent.

siblues

I had already started another print at 190 so I will post those results when they are done printing.The parts pictured above are really strong and have almost eliminated the crazy amount of stringing so the results are headed in the right direction.I raised the minimum layer time from the 5 second Cura default to 10 seconds.I don't know if that should be adjusted a bit higher?

Phaedrux

Minimum layer tone can have a negative impact as well if there isn't adequate part cooling because it slows down so much that the nozzle is just hanging around keeping things hot with not enough fan to cool it of. 5-10 seconds is a good setting. And min speed or 10-15mm/s. Then get some part cooling in there.

Another way to force some layer cooling in there is along the lines of printing more than one of the small parts. You can add a simple cylinder a way away from the part. That way it has to travel over to the cylinder every layer giving the main part a chance to cool. Especially useful with models that have tall skinny sections at the top.

fcwilt

Hi,

I suggest you stick to printing PLA test cubes until you have the basic values in your firmware and slicer working well.

Then you can try other test objects aimed at testing stringing, bridging, etc.

Don't try to do too much at once.

I have tried several brands of PLA and I have found that 190 works best for me. But my 190 might be different than your 190 depending on how accurate our respective temp sensors are.

My hotend is a stock E3D v6 being fed filament by a Zesty Nimble. I highly recommend the Nimble.

And for PLA I run my bed at 60.

Just out of curiosity why the 0.3 nozzle?

Thanks.

Frederick

siblues

I started with one on my original printer and it worked really well for me so I continued using it.I have a few volcano set ups coming in the mail and about 15 nozzles in varying sizes from .6 up to 1.20 so I will try that out once I get the printer working as it should.I will start testing temps with the test cubes next.I will keep this thread updated and I will be back with retraction and jerk settings questions.

siblues

Here are a few more pictures of some of my prints.I am currently printing these with the same settings as before but at 185 degrees.

Phaedrux

That's not too bad really. Maybe a little bit of over extrusion still. Otherwise it's much cleaner.

Are you happier with the results?

Veti

are you sure that you have a semitec thermistor on your hotend?

185 for pla+ seems a bit low.

did you correct the m305 entry?

siblues

I posted the config above and it is set for the Semitec. I also had adjusted the flow to 95 percent for the last set of prints pictured. I can drop that down to 90if that would help?