Good layer, Bad layer

[aaron81006 2]

Hello,  3D print newb here.

 

I have a model that I can't get a complete print of.  It prints really well for a while,then does a crappy layer (or a few), then it prints good again for a while, then screws up again. It appears the bad layers are not adhering and "pulling-in" on itself. I don't see any bad layers in the gcode.  What gives?

 

I did the design in Fusion 360 and the slicing in the free version of Cura.  The material is PLA.  Printer is an Ender 3. V1

 

Any suggestions are appreciated.  

 

Thanks

Edited January 26 by aaron81006

[Slashee_the_Cow 269]

*scratches head* About the first idea to come off my freshly scratched noggin' is to make sure you're not printing too fast, but even then that should be either a consistent problem or slowly get worse.

 

I think the blue in the pictures is a light (or something) somewhere but the filament itself seems to turn white in spots? (Correct me if I'm wrong, there's a few bits which look bright because there's light reflecting off them. Make sure you're printing using the correct speed and temperature for your material (most spools will have it listed on the side).

 

My other guess is "hardware problem" either the hot end gives up after a bit for some reason (does it always happen at the same height?) or possibly the motherboard just decides to have a seizure (can happen in early model Ender-3s).

 

And if you're looking for a workaround (which you're not, you're looking for a solution, but a workaround might work in the meantime) it's pretty simple. Cyanoacrylate. More simple when I call it "superglue". Just regular old superglue. PLA loves the stuff and you can get pretty good adhesion after holding things in place for only a few seconds. Print sections that work and then break out the glue and make sure you don't get any on your fingers accidentally (it can be a pain to get it off there - literally).

[aaron81006 2]

Hi Slashee.  Thanks for your feedback.   

I think the colors you are seeing are just from the lighting.  I don't see any discoloration. 

I needed a new hotend for my other printer so I have 2 on order, they will be here tomorrow.   Hopefully that will help.  I will confirm the suggested temp on the spool.  TBH, I only know its black (facepalm). 

The height of the defect seems to vary. I did a previous print and it only had one defect at a different height.   

My unit is a (used) Marlin V 1.0.1.  If it is a motherboard issue, there is a guy selling a new one on FBM.  Would this work in my machine? See pic

 

[Slashee_the_Cow 269]

8 hours ago, aaron81006 said:

My unit is a (used) Marlin V 1.0.1.  If it is a motherboard issue, there is a guy selling a new one on FBM.  Would this work in my machine?

Not sure it's a motherboard issue, it could be an "almost anything" issue, down to a cable between the mobo and hot end on the fritz. (Un)?fortunately I've never dived into the world of printer mods (most of mine don't survive long enough to make it worth it) so you might have to ask on an Ender related forum or something to see if that mobo will work.

[aaron81006 2]

Ok.  I did install the new mobo and have a new hotend coming today.  After I get it installed, I will give the print another go.

 

I will post the results.

 

[jwilsonvt 0]

Hi- I'm really interested in how this turned out for you? I'm really new to this too and am having the same issue.  Several layers totally fine than  stings for 3/4 of an inch then corrected itself and back to normal.  I'm using a Anycubic Kobra thats about 2 months old.  

[aaron81006 2]

I put that new mother board in and it works great!

[Slashee_the_Cow 269]

1 minute ago, aaron81006 said:

I put that new mother board in and it works great!

Awesome to hear!