Fillament skipping on Parts of the print with close perimeters  

RE: Fillament skipping on Parts of the print with close perimeters

If you are changing nozzles, which guide did you follow to ensure it was done correctly?

RE: Fillament skipping on Parts of the print with close perimeters

@tim-2

I guess your new guide would come  in handy here....

@amidar. Not much to go with from your description. If you save your project as a 3mf file, zip it (IMPORTANT), and attach it to your post, we'll have the model AND all your slicer settings to work with.

RE: Fillament skipping on Parts of the print with close perimeters

Creating and Posting a project file

RE: Fillament skipping on Parts of the print with close perimeters

print

Here it is

RE: Fillament skipping on Parts of the print with close perimeters

@tim-2

i followed the guidlines from the prusa knowledge base, there was this video that shows how to do it

RE: Fillament skipping on Parts of the print with close perimeters

@amidar

Nothing wrong with the model that I can see. 

I would not print external perimeters first. You'll have overhang issues.

I would not print infill before perimeters.

I would retract always - this may be the setting that is causing clogs.

I don't understand why you are slowing down print speeds so much. Is there a reason?

Why did you change perimeter overlap? That seems like a bad idea as it reduces strength.

And you've changed a bunch of filament overrides. Again, please explain your reasoning.

If it were me, I'd just undo all the changes you've made except perimeters and try printing the part using defaults.

RE: Fillament skipping on Parts of the print with close perimeters

@tim-2

The speed settings i changed in my first attempts to get rid of the clicking- my thinking was i am extruding to fast for my old machine

the order of the perimeter is also experimental just to see if it changes anything - as ik noticed that the clicking only happens with the perimeters

In terms of retracting i actually think that is the main reason it clogs, just a whole punch of up and down rapidly might cause it to get stuck somehow idk it was just another guess/ attempt to fix it

and perimeter overlap i also changed in the suspicion that it might overpower the steppermotor if there is to much overlap forcing the stepper motor to work much harder - i know its unlikely but i have been trying to fix this for a while now before i turned to the forums.

In terms of my own investigation efforts- i now managed to print just the upper section of the gear without clicking- with the settings that can be seen in the file i sent. Right now i am printing the big version again in the hopes it finally goes throught completely. For the sake of completion i will also test out default settings on just the upper gear model afterwards - lets see if that works.

Also to note: my printer is quite old, i got it as soon as it came out and then upgraded it to a MK3s a year or so ago - which makes it - i think - like 4 yrs old by now. Tho i did at one point completely replace the entire hotend assembly due to a particullarly bad clog caused by some cheapo Nylon X. 

PS- i am printing with Prusa PLA right now, so its not the fillament

RE: Fillament skipping on Parts of the print with close perimeters

@amidar

When you changed nozzles - did you use the E3D-V6 procedure? I've seen too many cases of folks not using that procedure and end up with clogs. Also - it seems the heat break thermal compound Prusa was (or wasn't using) using degrades over time and needs to be refreshed. Then there's the issue with the Prusa MMU compliant heat break itself causing problems.  But primary concern here is that the heat break is set in the heater block the proper depth, and tight in the heat sink.  

RE: Fillament skipping on Parts of the print with close perimeters

@amidar

I did find a problem with the model in the area where you are saying the problem begins.

this effects the first two layers of that area.

I've attached a .3mf project file with the changes I would make to increase your chances of a successful print, you will have to fix the model yourself if that ends up being the issue.

Körper3_Swiss

Hope this helps,

Swiss_Cheese

RE: Fillament skipping on Parts of the print with close perimeters

@swiss_cheese

i am aware of this issue it happend during design but its only 3 layers and the problem doesnt "start" there even if its halfway done with the upper section and i switch out the fillament (which usually fixes it) it still starts to click after a while.

RE: Fillament skipping on Parts of the print with close perimeters

@tim-2

I just red through the article again, just to double check, and although i did use the procedure with the 2 spanners it coulkd be that when i first installed the new hotend assembly that it got a bit loose or something like that, tho i changed the nozzle after i had the clicking for the first time, thinking it was an old nozzle that had just excessive wear in it. In terms of the thermal compound i looked up when i bought the new hotend It was almost a year ago at this point, idk if thats enough fo rit to degrade. 

*But primary concern here is that the heat break is set in the heater block the proper depth, and tight in the heat sink* <- How would i check for that?

In terms of what i did in the meanwhile: the print completed without clicking this time but obviously with such little retraction it looks bad and has a bunch of blobs on the top surface where i think many unrectracted pieces added up into it. But apart from that it seems good it even meshes with the other gears.

Behind me I am printing the upper section of the the gear with normal setting (0.15 PLa quality settings) With the only changes being the shell count and infill pattern: 6shells and rectilinear 30% Just now it started clicking again, so i pressed down the fillament a bit to help the stepper motor- it currently is at like layer 6 and apart from that bit of clicking just now keeps ongoing. 

Note that i only changed print parameters not the fillament settings- i forgot to use the OG ones but atleast it will narrow the issue down a bit more.

Thanks for helping me out BTW guys

RE: Fillament skipping on Parts of the print with close perimeters

Update: THe print finished and it clicked the entire time, the section where the bearing is supposed to go has tons of small gasp where the fillament skipped, but atleast it didnt clog upm combletely - i am still at a loss for what causes this the only thing i changed in terms of fillament override was retraction length and speed - 30m/s and 2.7mm retraction

RE: Fillament skipping on Parts of the print with close perimeters

@amidar

Visual inspection ...

RE: Fillament skipping on Parts of the print with close perimeters

That looks new!

RE: Fillament skipping on Parts of the print with close perimeters

Factory fresh ... read about too many cases of rats nests turning into blobs. So I bought spares.

RE: Fillament skipping on Parts of the print with close perimeters

@tim-2

i just opened my printhead and it does look like the distance there is larger than it should be, i do have calipers though, how much should the distance be? (in mm)

RE: Fillament skipping on Parts of the print with close perimeters

Posted by: @amidar

@tim-2

i just opened my printhead and it does look like the distance there is larger than it should be, i do have calipers though, how much should the distance be? (in mm)

it seems to be 2.5mm right now after i tightened it a bit

RE: Fillament skipping on Parts of the print with close perimeters

@tim-2

I always keep a brand new one in the parts box also. 

RE: Fillament skipping on Parts of the print with close perimeters

@amidar

That is pretty close to what I am getting.