Guys, having an issue I have not faced in a long time and at

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(Brandon Satterfield) #1

Guys, having an issue I have not faced in a long time and at my wit’s end. Running Repetier 1.0, slic3r 1.1.6, and E3D v6. The filament is PLA and running at 186 degrees. My feed is adequately pushing as I am leaving slight marks on the filament. I have perfectly tuned retraction, and esteps/mm.
The issue is, the machine randomly skips layers. There is no consistency, such as z ribbing or high acceleration or jerk would provide. The filament is running perfect out of the nozzle on test and calibration pieces, but when I go to print the model I have this issue. The image shows all the skipping layers behind the support.
Looking for any ideas here.

(Stephane BUISSON) #2

skipping steps could be due to motor overheating, happen to me too, in with this hot wheather.
Solved with a fan onto motors !

(Jim Wilson) #3

Also worth trying a few completely unrelated slicers to narrow it down to hardware or software.

(Matthew Satterlee) #4

I had a “sticky” bearing on my z axis cause something similar. The stepper was having a hard time hitting positions accurately which caused a lot of weird looking stuff in the z axis.

Good luck, I hope you find your issue!

(Eric Lien) #5

Ever since I put superlube on my z shafts and lead screws a lot of what I thought was z ribbing has gone away. I think you are correct that ease of bearing motion on Z is critical so microsteps hit the mark.

(Brandon Satterfield) #6

@StephaneBUISSON thank you for this suggestion. I have been monitoring my motor temps. I have not had any temp issues post tuning my stepper sticks, thanks again for the suggestion.

(Brandon Satterfield) #7

@Jim_Wilson this is what I am afraid of having to do. I have used Slic3r since day one. I can get a lot out of it, never have had something I can’t do with it. Lately the thought of changing and learning a new slicer has been weighing heavy. I really like the new pillar supports, in slic3r, they snap off like a dream. But alas I suppose it is time to try something different.

(Brandon Satterfield) #8

@Matthew_Satterlee I have not looked at this. I will decouple my z tonight and assure of smooth travel. Thank you.

(Brandon Satterfield) #9

@Eclsnowman I fought this same issue, I have been packing my bearings with a heavy marine grease since. I will try the suggested tonight.

The only reason I am slightly hesitant about it being a z axis travel issue is due to the fact I can print a 50 mm tall hollow box and it is seamless and flawless. I can print a 20mm filled box in one corner and a hollow in the other and still flawless.

I have tried heavy z retracts, additional added to length post retraction, varying temp to filament, speeds, accelerations, layer heights. The issue remains.

I am leaning towards attempting to redraw, manually support, and run through cura and kisslicer. Just a little discouraged as I have always been able to get my printress to act right. The only change this time is the supports (pillars) and a brand new V6 hotend, I really hope it’s not the latter.

(James Rivera) #10

@Brandon_Satterfield it might just be a combination of friction and stepper motor/drivers overheating that might not show itself in short test prints but will in long duration prints. Heat sinks on the stepper driver chips (and/or a fan blowing on the board), plus similar treatment to the steppers themselves may be worth the effort. I found that putting heat sinks on my stepper chips (and ultimately slowing the print velocity and acceleration down) fixed a similar problem I was having.

(Jim Wilson) #11

@Brandon_Satterfield even just making a copy of your slic3r directory and restarting from defaults may help you ID the issue, if you don’t want to stray too far.

(Brandon Satterfield) #12

@James_Rivera great suggestion. This community is extremely knowledgable!
My current set up has two fans directing air over my stepper sticks that all posses heat sinks (gadgets 3d RAMPS 1.4 setup). I have checked them over a 6 hour print and stayed cool to the touch.

(Brandon Satterfield) #13

@Jim_Wilson ha, did this last week. Great suggestion, this has helped several times in my printing life in the past. I sometimes will make far too many changes and this is the easy resolve. Thanks!

(Patrick Ryan) #14

Is your extruder overheating? I found my aluminum extruder was getting warm enough to cause the filament to slip and not extrude properly, and only realized that was my problem after it actually got warm enough that the filament visibly bent around the drive gear. Pointed a fan directly at the extruder and problem solved.

(Brandon Satterfield) #15

@Patrick_Ryan I am hopeful this is not the issue. Stated above the only changes I have made are Slic3r and a brand new hotend. I greatly want to lean on the slicer, I truly believe in the hotend product due to great support from a guy on here, Sanjay M., and the v5 hotends I ran were a little finicky on PLA, but once tuned, amazing.

I have done a number of cold pulls and really seems the filament is staying cool till the transition zone, but will look at this again tonight. Thanks again for another great suggestion.

(Markus Granberg) #16

Try cura. Its super simple to get going. I think its a must to dubble check the g-code before starting with hardware changes! Its a pain to modify your printer only to find that its software related…

(Sanjay Mortimer) #17

What do you mean by skipping layers? Is plastic missing? Or is the Z axis not moving?

If you post images of the sides of your prints up closer and tag me in I’ll be able to see if it’s an extrusion issue or hotend related.

(Brandon Satterfield) #18

@Markus_Granberg I sliced with curaengine last night. It really was beyond easy. Post slicing I ran through the preview in Repetier layer by layer and found a funny layer around 67 of 580. The layer shows a solid, but travel does not line up. I was hesitant to proceed, resliced with Slic3r and tried a few other things, same results, so I guess I’ll try to run it as i do not have much to loose.
@Sanjay_Mortimer , you have to be that companies greatest asset. I will start a new post, you guys excuse the mess I’ve been pulling my hair out.

(Chris Thomson) #19

I wonder if it is a feed rate issue, a small test box does not require a lot of plastic to go through the hotend quickly, perhaps due to minimum layer time settings, or other features of the model, whereas that bigger part does.

Try bringing the print speed down or putting the temperature up to see what happens.

I’m putting pla through a 1.75 v6 at about 250 degrees at the moment to print large objects quickly. Yes it seems very high, but it also seems to work.

(Brandon Satterfield) #20

@Chris_Thomson you know, I did stop bumping the temp up at 208. I have previously ran this same filament at 217 but through a .25 nozzle. For speed I am only running a max of 48 mm/s and on a .4 nozzle, this is slow for my set-up.
I typically will check my set-up for speed and temp by manually extruding through repetier. I load the filament and quickly push 200 mm through. If it stop or locks temp goes up, and I repeat. I then keep raising the temp and do 50mm out and 20mm in, too high a temp and I swell in the heat break and lock. I drop the temp post this experiment and that is my temp band for that filament.

I’ll redo this tonight, perhaps just too cold.
Thanks for the suggestion!