Uneven, imprecise seams


#1

Hello, I had this unusual problem today with a piece from a client; it seems like the final filament deposition for each layer doesn't really know where to finish, and creates this messy seam effect. The settings for the seam were default and the layer height .29microns. I checked back the model in ZSuite but everything looks fine to me.

I don't know the reason for this, I have never had any accuracy issues with my Zortrax. Does anybody have a clue? Thanks a lot!


#2

Hello, can you attach the file ?


#3

Sure, thank you so much!


#4

Hi,

Try to use Random Seam in Z-Suite (Advanced Settings).


#5

I considered that option, but dont understand the difference. Is it that you don't see the vertical seam line in the final object? I will try that.


#6

I don't know why the Z-Suite is set like this, but when a cylindrical shape is printed, the extruder circles back and forth, not continuously in one direction. That creates the seam. The random feature should "hide" that.


#7

Try a new nozzle, Lucia. Random seam will probably have the same problem, but scattered all over the print instead of in a straight line.


#8

Thanks all for your advice. why do you think it might be the nozzle? It had never happened to me before. I will try the random seam anyway, and post the result just in case it was an isolated failure. I really trust the machine, don't want to believe something is wrong with it...


#9

I had a very similar issue about a year ago, I think I may have even posted about it here. After much hypothesizing about various complicated reasons for the problem, I found that changing the nozzle fixed it completely.


#10

I see, I am cleaning the nozzle hard just in case. Hope it works...


#11

It didnt. Changed to random seams and same problem. I will change the nozzle as you say Julia, thanks a lot for the advice, I think I would have never reached that conclussion on my own.


#12

Also try to run a twist drill, I think the hole is 4mm, by hand (actually you need a pair of pliers) through the brass pipe the nozzle fits into. There might be some old debris in there as well. The hot end must be fully heated. Be careful not to damage the white plastic tube in the hot end (if you have it).

Best of luck!

John TangerÃ¥s 


#13

Thank you John, I will try as well with the wire provided.


#14

Thank you John, I will try as well with the wire provided.

No problem, but the thin wire is for the 0.4 mm hole in the nozzle only. Use the twist drill (broca helicoidal) to clear the tube that the nozzle enters. Also clear the nozzle from the back with a twist drill. If you use only the wire, you may open a hole in the residue in the nozzle, but you won't remove it. The twist drill method will remove it. Mist drills have a tip angle of 118 degrees, hence the bottom seat in the nozzle too. Using a drill (in addition to the wire) will clean the nozzle (and tube) effectively.

Hope it works out for you!

John


#15

I've never had to ream the feed tube (which is stainless, not brass). It is 2mm in diameter, not 4.

Reaming the nozzle from the back, if done, should be performed with a 1.6 - 1.8mm bit, with the nozzle heated by a torch or heat gun to soften any plastic inside, and carefully, so as not to gouge the interior of the nozzle.

While nozzles can certainly be cleaned and their lives prolonged, in this case Lucia is debugging a printing issue, and the only sure way to eliminate a nozzle problem is to use a fresh, unused OEM nozzle.