Notifications
Clear all

VFA Artifacts on X+Y Straight Edges  

Page 37 / 41
  RSS
CJD
 CJD
(@cjd)
Eminent Member
RE: VFA Artifacts on X+Y Straight Edges

I don't think so - the spacing was identical, just shifted 1/3 of the width or so every ~5 layers - long straights and I don't think there were speed differences as it got narrower. Should have snapped a pic before installing. Thinking of printing in a color so there's hope yet... just no printing today, too tired.

Posted by: @ratlet
  •  
Posted by: @cjd

This whole issue is so weird. I noticed on a handle reprint (added a fitting so I could easily swap tubes from a drier), which is a pyramid-ish shape, that vfa would temain aligned vertically for 5ish layers up the angled side, then shift a bit and again... 5 layers aligned till another shift. If it's belt related, it changes based on the relationship of the two belts to each other not just a belt over idler.

Might be speed related.  In my vfa towers I found the frequency of the artifacts increased with increasing extruder speed.

 

Posted : 11/06/2025 1:08 am
Teo84
(@teo84)
Member
RISPONDI: VFA Artifacts on X+Y Straight Edges

Yes, you are right about the negative pressure, the fact is that users have to think about closing the various empty spaces and holes as much as possible with modifications. In addition, an extraction filter also lets heat out and especially in a passively heated printer with a heated bed it is counterproductive, it already struggles to heat up normally. The ideal would be an internal recirculation filter but in that case the printer would have to be sealed because there is no negative pressure. The Prusa enclosure has a recirculation filter but the container is not at all watertight. It seems like they didn't think about it at all by putting the filter there with four screws without worrying about how it actually works. For the VFA, it is not expected to be eliminated completely but as you said that it should be reduced to the same level as other printers. I love the Nextruder in my opinion and it is one of the best extruders/hot ends and I hope for this reason that they can solve these problems.

Posted : 11/06/2025 10:06 am
1 people liked
Ratlet
(@ratlet)
Trusted Member
RE: VFA Artifacts on X+Y Straight Edges

The 1.5mm belts and pulleys have arrived, unfortunately I won't have time to test until next week at the very earliest, however I suspect if I got started right away my wife would batter me lol.

Posted : 11/06/2025 7:08 pm
vitaprint 3D
(@vitaprint-3d)
Eminent Member
RE: VFA Artifacts on X+Y Straight Edges

 

Posted by: @shushuda
  1. Loosen the belts as much as you can on both ends. One turn on the left, one turn on the right, one turn on the left etc. Do it in small increments to keep the gantry squared.
  2. Remove the left side metal panel.
  3. Remove the left side plastic panel.
  4. Undo 4 screws that hold the left motor.
  5. Lift the motor and lay it on its side.
  6. Remove old pulley.
  7. Place new pulley.
  8. Put the motor back in, taking care to catch the belt loop inside the plastic part.
  9. Screw the motor in.
  10. Retension the belts the same way as you loosened them but in reverse.
  11. Print a wall - perfect 45 degrees diagonal that goes from the front left to the back right. The exact same motion as when the printer does solid infill.
  12. Loosen the belts the same way as in step 1.
  13. Unscrew the motor.
  14. Lift the motor.
  15. Remove pulley.
  16. Put it aside together with the print. DO NOT confuse them all, you will have multiple pulley-print pairs.
  17. Repeat steps 7-16 until you run out of pulleys.
  18. Compare the prints and pick the best looking 2. DO NOT confuse them or you will have to repeat the process.
  19. Put those best pulleys aside, marking the absolute best with a marker.
  20. Now you can put those pulleys onto the motors for good. Use the absolute best pulley on the RIGHT motor.
  21. Reassemble the panels, retension the belts.

The right side metal panel is a bit tricky to remove. Just undo the rivets and gently drop the panel so it pops out and hangs onto the connected PTFE. Leave it like that and you can then reach the motor screws just fine.

which pulleyes do you bought? you have a brand name or link ?

 

Follow me on : twitch-vitaprint3d --- youtube-vitaprint3d --- instagram-vitaprint3d

Posted : 11/06/2025 7:22 pm
Shushuda
(@shushuda)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

which pulleyes do you bought? you have a brand name or link ?

Mellow. Here's the link, pick "16 teeth". Get at least 2 pairs, some are better than others. It's a lottery. They are still better than Prusa's.
https://www.aliexpress.com/item/33002989677.html

For the VFA, it is not expected to be eliminated completely

Mine were eliminated completely by the pulley elimination and swap.

Posted : 11/06/2025 7:58 pm
Cato Nord
(@cato-nord)
Member
RE:

I was just about to buy a core one then I found out about this issue. How positive are you about that changing the pulley will be a good solution?

Considering if I should buy a MK4s instead or "gamble" on the core one.

Posted : 11/06/2025 8:35 pm
Geoff Steele
(@geoff-steele)
Active Member
RE: VFA Artifacts on X+Y Straight Edges

 

Posted by: @shushuda

Get at least 2 pairs, some are better than others. It's a lottery. They are still better than Prusa's.

What makes a better pair - eg are you weighing them to get matched weights? Or is this something that needs testing on the printer to determine?

Posted : 11/06/2025 10:47 pm
Shushuda
(@shushuda)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

What makes a better pair - eg are you weighing them to get matched weights? Or is this something that needs testing on the printer to determine?

I see no difference between them personally, they look identical to my eyes. I just put them in the printer and print a test to verify.

I said "pairs" because Mellow's Aliexpress store sells them in pairs, they're not matched or anything, just sold by 2pc per listing. Personally I bought 2 pairs (4pc total) and got 3 good pulleys, although there were differences in artefacts' intensity. Just keep in mind I am min-maxing this. Most ppl would be satisfied with pulleys I'd consider rejects. I was after pristine smooth walls to match my MK4S' quality (which I achieved).

How positive are you about that changing the pulley will be a good solution?

I had the same issue on my MK4S, back then still a MK4. It showed excessive rippling at any speed above 25, so it manifested only after the Input Shaping update. It was also the pulley causing it. The artefact also follows the pulley in both cases, I swapped the pulleys on my Core One and the artefact switched angles. Same on the MK4 back when I discovered this - swap switched artefacts from Y to X axis. There were still some ripples left on the MK4 but I smoothed most of them out with a Y axis mod that centers the belt, replaces the idler with toothed and makes everything way more rigid. In the case of Core One the full fix came from pulley swap alone.

However, your future printer might have a different issue. Or it might have great smooth walls from the get go. I can't say that it will be affected only by the pulley issue and nothing else. I'm just saying that a lot of these ripple issues might be due to pulleys based on my personal experiences with 2 printers.

This is also why it'd be cool if more people tried the pulley swap and shared their findings and test prints. Atm it's mostly me and my 2 printers, so it's not a big pool of evidence.

My friend started going through his pulley pile today, I will ask him about his results once he's done and relay that if you wish.

Posted : 11/06/2025 11:31 pm
3 people liked
gb160
(@gb160)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

 

Posted by: @shushuda

What makes a better pair - eg are you weighing them to get matched weights? Or is this something that needs testing on the printer to determine?

I see no difference between them personally, they look identical to my eyes. I just put them in the printer and print a test to verify.

I said "pairs" because Mellow's Aliexpress store sells them in pairs, they're not matched or anything, just sold by 2pc per listing. Personally I bought 2 pairs (4pc total) and got 3 good pulleys, although there were differences in artefacts' intensity. Just keep in mind I am min-maxing this. Most ppl would be satisfied with pulleys I'd consider rejects. I was after pristine smooth walls to match my MK4S' quality (which I achieved).

How positive are you about that changing the pulley will be a good solution?

I had the same issue on my MK4S, back then still a MK4. It showed excessive rippling at any speed above 25, so it manifested only after the Input Shaping update. It was also the pulley causing it. The artefact also follows the pulley in both cases, I swapped the pulleys on my Core One and the artefact switched angles. Same on the MK4 back when I discovered this - swap switched artefacts from Y to X axis. There were still some ripples left on the MK4 but I smoothed most of them out with a Y axis mod that centers the belt, replaces the idler with toothed and makes everything way more rigid. In the case of Core One the full fix came from pulley swap alone.

However, your future printer might have a different issue. Or it might have great smooth walls from the get go. I can't say that it will be affected only by the pulley issue and nothing else. I'm just saying that a lot of these ripple issues might be due to pulleys based on my personal experiences with 2 printers.

This is also why it'd be cool if more people tried the pulley swap and shared their findings and test prints. Atm it's mostly me and my 2 printers, so it's not a big pool of evidence.

My friend started going through his pulley pile today, I will ask him about his results once he's done and relay that if you wish.

I've got to do an Aliexpress order for some other bits so Ive just put 2 pairs in my basket.

When you fit them, are you using the Prusa measuring tool thing to align the pulley on the shaft?

Posted : 12/06/2025 6:13 am
Scott
(@scott-18)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

I've got to do an Aliexpress order for some other bits so Ive just put 2 pairs in my basket.

WHAAAAAAT! I didn't read correctly, I ordered 6 pairs instead of 6 idlers...

Posted : 12/06/2025 8:12 am
gb160
(@gb160)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

 

Posted by: @scott-18

I've got to do an Aliexpress order for some other bits so Ive just put 2 pairs in my basket.

WHAAAAAAT! I didn't read correctly, I ordered 6 pairs instead of 6 idlers...

😂

Posted : 12/06/2025 8:13 am
1 people liked
chmax
(@chmax)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

Can't test myself yet (I am waiting for my kit to ship) but this difference in results with optically identical items is really an interesting issue. Could it be that the difference between a "good" and a "bad" pulley is in the center hole? Given how they are fixed onto the motor shaft, a slightly larger center hole could affect the centering, leading to the artifacts? 

Posted : 12/06/2025 8:22 am
ersvo
(@ersvo)
Active Member
RE: VFA Artifacts on X+Y Straight Edges

I agree, maybe its not changing the part for the another, but simply removing and placing the puller will improve the result, because it is, by chance, fixed at a better angle or position? 

Posted by: @chmax

Can't test myself yet (I am waiting for my kit to ship) but this difference in results with optically identical items is really an interesting issue. Could it be that the difference between a "good" and a "bad" pulley is in the center hole? Given how they are fixed onto the motor shaft, a slightly larger center hole could affect the centering, leading to the artifacts? 

 

Posted : 12/06/2025 8:27 am
1 people liked
Ratlet
(@ratlet)
Trusted Member
RE: VFA Artifacts on X+Y Straight Edges

 

Posted by: @shushuda

What makes a better pair - eg are you weighing them to get matched weights? Or is this something that needs testing on the printer to determine?

I see no difference between them personally, they look identical to my eyes. I just put them in the printer and print a test to verify.

I said "pairs" because Mellow's Aliexpress store sells them in pairs, they're not matched or anything, just sold by 2pc per listing. Personally I bought 2 pairs (4pc total) and got 3 good pulleys, although there were differences in artefacts' intensity. Just keep in mind I am min-maxing this. Most ppl would be satisfied with pulleys I'd consider rejects. I was after pristine smooth walls to match my MK4S' quality (which I achieved).

How positive are you about that changing the pulley will be a good solution?

I had the same issue on my MK4S, back then still a MK4. It showed excessive rippling at any speed above 25, so it manifested only after the Input Shaping update. It was also the pulley causing it. The artefact also follows the pulley in both cases, I swapped the pulleys on my Core One and the artefact switched angles. Same on the MK4 back when I discovered this - swap switched artefacts from Y to X axis. There were still some ripples left on the MK4 but I smoothed most of them out with a Y axis mod that centers the belt, replaces the idler with toothed and makes everything way more rigid. In the case of Core One the full fix came from pulley swap alone.

However, your future printer might have a different issue. Or it might have great smooth walls from the get go. I can't say that it will be affected only by the pulley issue and nothing else. I'm just saying that a lot of these ripple issues might be due to pulleys based on my personal experiences with 2 printers.

This is also why it'd be cool if more people tried the pulley swap and shared their findings and test prints. Atm it's mostly me and my 2 printers, so it's not a big pool of evidence.

My friend started going through his pulley pile today, I will ask him about his results once he's done and relay that if you wish.

Ive ordered 5 from powge of aliexpress.  The 1.5mm pitch parts turned up and the quality looks very good so I ordered some of theirs.  Might as well get some other datasets in.

Also it means I don't actually have change the belt immediately whixh i wil if i go for 1.5mm pitch.  The thought of dismantle the nextruder does not fill me with joy.

 

A user on the core one FB group is reporting resolving the issue by changing the belts, but prints are 1.5% smaller on xy (can be fixed by shrinkage)

Posted : 12/06/2025 9:11 am
1 people liked
gb160
(@gb160)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

 

Posted by: @ersvo

I agree, maybe its not changing the part for the another, but simply removing and placing the puller will improve the result, because it is, by chance, fixed at a better angle or position?  

I don't think so, from what @shushuda has concluded, it appears that the VFA issue follows the 'bad' pulley/pulleys.

Posted : 12/06/2025 9:17 am
1 people liked
Jürgen
(@jurgen-7)
Prominent Member
RE: VFA Artifacts on X+Y Straight Edges
Posted by: @scott-18

WHAAAAAAT! I didn't read correctly, I ordered 6 pairs instead of 6 idlers...

So you are the one to blame that they are now sold out! 😉 

(You didn't order idlers but pulleys, right?)

Posted : 12/06/2025 9:45 am
1 people liked
chmax
(@chmax)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

exactly the reason why I was thinking about the center hole tolerances...

Posted by: @gb160

 

Posted by: @ersvo

I agree, maybe its not changing the part for the another, but simply removing and placing the puller will improve the result, because it is, by chance, fixed at a better angle or position?  

I don't think so, from what @shushuda has concluded, it appears that the VFA issue follows the 'bad' pulley/pulleys.

 

Posted : 12/06/2025 9:46 am
1 people liked
chmax
(@chmax)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges

I think it was me, when I placed my order I got the "last 2 pairs" ... now I usually tend to disregard the "oh they are the last one, hurry up, buy NOW!" messages but apparently it was real for once 😀 😀 

Posted by: @jurgen-7
Posted by: @scott-18

WHAAAAAAT! I didn't read correctly, I ordered 6 pairs instead of 6 idlers...

So you are the one to blame that they are now sold out! 😉 

(You didn't order idlers but pulleys, right?)

 

Posted : 12/06/2025 9:49 am
Jürgen
(@jurgen-7)
Prominent Member
RE: VFA Artifacts on X+Y Straight Edges
Posted by: @gb160  
Posted by: @ersvo

I agree, maybe its not changing the part for the another, but simply removing and placing the puller will improve the result, because it is, by chance, fixed at a better angle or position?  

I don't think so, from what @shushuda has concluded, it appears that the VFA issue follows the 'bad' pulley/pulleys.

Also, I think we are really looking for a problem on the tooth pitch level, not on the diameter level. In all pictures I have seen, as well as in my own Core One, the belt ripple seems to repeat steadily over extended surfaces of the printed part -- with no indication of a longer period that would map to the pulley circumference.

Posted : 12/06/2025 9:49 am
2 people liked
Scott
(@scott-18)
Estimable Member
RE: VFA Artifacts on X+Y Straight Edges
Posted by: @jurgen-7
Posted by: @scott-18

WHAAAAAAT! I didn't read correctly, I ordered 6 pairs instead of 6 idlers...

So you are the one to blame that they are now sold out! 😉 

(You didn't order idlers but pulleys, right?)

Oh no sorry! I think I will ask a refund for 3 pairs as soon as I get them, I don't plan to use as much pulleys (yes it was pulleys indeed, not idlers)!

Crazy, the shop keeper must have faint out seeing this much orders in a short period hahaha!

Posted : 12/06/2025 9:56 am
3 people liked
Page 37 / 41
Share: