Suddenly poor print quality on two SV08's - solved with extruder idler gear

Sovol SV08
1

Since about 2 weeks I observe a great difference in print quality on both my sv08 printers.
Despite using new petg filament from my trusted supplier the print contains large amount of blobs, zits and stringing. Also after the partcooling is enabled the top of almost every layer is rough

I tried cleaning the nozzle, different filament, some tuning with temperature, but alas no big difference

Maybe is the sv08 especially prone to colder weather conditions due to the high flow nozzle or is this my imagination ?

2 Likes
2

So things were fine 2 weeks ago, have you changed anything on the printer or slicer settings…??

3

No
otherwise I would certainly have doubted my own settings at first :wink:

Also the printers are at two different locations with different slicer computers

4

Hello,
Maybe to perform your tests, you should use the same environment on your 2 printers (location, slicer and settings).

5

1st: I would dry the filament.
2nd: I would try the print again, but slow the speed down.
Also, turn off Z Hop if it is enabled.

6

The filament is from a new sealed bag, but I ordered filament dryers already because of the same suspicion.
Also tempted to try an enclosure

Turning the speed down would maybe cause the symptoms to disappear but would not solve the actual problem that there may be.
I’m just curious what the cause would be that with the same slicer and printer settings the prints were flawless till about two weeks ago…

Maybe some colder weather and moist is disrupting the working of the high flow nozzle

I will try if turning the coolers down a bit will improve the prints

7

What happens if you just increase the printing temperature with 5 degrees?

8

It doesn’t matter if the bag is sealed or where it came from, you should treat all filament as wet out of the bag.

Watch at 2.20

9

I looked up filament profiles for my brand (nobufil) and apparently the temperatures need to be much higher for high flow nozzles…(255 to 265 degrees)
I think I just have been lucky before because of the higher environment temperatures.

10

The slicer profile should have compensated for the flow…that what profiles are for.
You temps might be the issue.

I have 1 roll of PETG I had all kinds of trouble with. I printed with my normal PETG temp of 235*, this brand needed to print at 270*. Haven’t had any problems since.

1 Like
11

with the higher temperature the print seems better, but still not good.
I’ll wait for the filament dryer boxes to be delivered and try again with those in place.

I’ll keep you posted

12

What fan speed are you using?
Some PETG can only be printed with a max fan speed of 20-40%,
and with a temp at 260-270

13

I did also try to lower the fan speed because of the lower environment temperature, but I haven’t tried larger prints with that.

14

You can also use your oven at low temperature (60°C max)

15

All the filament i tested today was previously dried in a food dryer and stored in vacuüm bags.

I think i found the issue on one of them in the extruder idler gear axle which had came out of the handle at one end. I guess the jerks on the extruder make it work it’s way out through vibrations, causing the extruder to lose it’s grip on the filament causing under extrusion.

I printed a small plate and glued it on the handle to prevent the axle from working it’s way out again.

Benchy are printed fine again in different filaments, now started something bigger.

16

And guess what, the other printer had the exact same issue.

IMG_20241025_090228
IMG_20241025_0902281920×2560 330 KB

After putting the idler gear shaft back in it’s place and securing it with a glued on disc of plastic the print was perfect again

IMG-20241025-WA0005
IMG-20241025-WA00051920×3413 537 KB

2 Likes
17

I wasn’t sure exactly what you were talking about the first time without a pic.
Now seeing the issue, I have to say…I’ve never seen this one before. :upside_down_face:

18

On my side i did not had this trouble (yet ?). Maybe it’s better to print it… just in case :stuck_out_tongue:

I found that few time ago but i did not understood well… now it’s more clear : SV08 Extruder fix by Valerie Moore | Download free STL model | Printables.com

1 Like
19

I had exactly the same, and I remembered this fix from my sv08 search on printables and thingiverse.

It took me some time to realize this was my issue though, because I would have never suspected this to be the cause of the artifacts I was getting.

20

For comparison :
right with the idler gear shaft out of place, left with the gear secured again.
Exact same filament and slicer settings.

under extrusion
under extrusion1536×2048 454 KB

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