Thumping sound when tilting vat returns to level position
 
Notifications
Clear all

Thumping sound when tilting vat returns to level position  

  RSS
WidgetCeramics
(@widgetceramics)
Active Member
Thumping sound when tilting vat returns to level position

After printing approximately 5 successful layers, the tilting vat begins to make a thump/bang noise when it returns to the level position. This noise eventually goes away after the next 20-30 layers finish. The arm that supports the build plate also jumps up/down violently when the tilting vat returns to the level position. The print failed twice. This is only my 2nd print. The first print (using the Prusa Tough Orange resin) of the miniature Josef Prusa test print turned out flawless - the best print I've ever seen. The resin I am using now is a custom, proprietary resin. The only thing I changed between 1st and current print is the resin, and I turned off the vat fill level sensor. At this point I am unsure whether it's slicing issue, a mechanical issue, a sensor issue, or a resin issue. I will trouble shoot.

Video:

Posted : 17/09/2021 5:06 pm
WidgetCeramics
(@widgetceramics)
Active Member
Topic starter answered:
Resin Sensor

So it turns out, disabling the vat resin level sensor caused the thumping issue. Re-enabling the vat resin level sensor fixed the issue - no more thumping or hammering. Prusa, can you please fix this problem in the next firmware release?

Posted : 17/09/2021 6:46 pm
JoanTabb
(@joantabb)
Moderator

can you post this on Github please?

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 17/09/2021 8:22 pm
WidgetCeramics
(@widgetceramics)
Active Member
Topic starter answered:
Github?

Hi Joan, I don't know how to do that, or why I should do that. Feel free to share this however you like though. 

-Jonathan

Posted : 17/09/2021 8:41 pm
WidgetCeramics
(@widgetceramics)
Active Member
Topic starter answered:
RE: Nevermind

I spoke to soon. The thumping sound persists. The problem has not been fixed. Same issue as before. My current hypothesis is that slicing a part with "Pad: None" is causing the issue, since the test print where the tilting vat did not thump had "Pad: Below Object" enabled on Prusa Slicer, whereas the test print that's running now (and making the thumping sound) was sliced with "Pad: None". I will test this to confirm whether it's the root of the problem.

Posted : 17/09/2021 8:51 pm
JoanTabb
(@joantabb)
Moderator

Hmmm... most of my prints are no pad, and no thump... 
I have done a couple of prints with pads.   

if I over adjust the initial bed position,(a bit High) i have had clunks...   but nothing recently... 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 17/09/2021 10:48 pm
JoanTabb
(@joantabb)
Moderator

can you try again with a lower value for the initial  exposure time? 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 17/09/2021 11:08 pm
ejberg
(@ejberg)
Trusted Member

Looking closely at that video, the vat never goes all the way back to level. It stops early, and then the clunk looks (and sounds) like the stepper motor being forced out a step.

Posted : 18/09/2021 4:04 pm
joeybronzoni
(@joeybronzoni)
New Member
RE: I had this problem and adjusting the exposure removed the sound on the newer SL1S

Yea... this was an issue I had today. Had a clunking/crackle sound. And I assumed it was the base/print pulling from the FEP foil after the exposure. I tend to over expose my layers with the original SL1 but I've upgraded to the SL1S(speed) and still cranked up the exposure on the first and rest of the layers. I am trying this print again with the default exposure and while the clunking/crackle/thump is gone when the tank bed returns home I am going to guess that the default exposure won't work for this print(I'll return once I get to 20-25% of the print to see it). At that point its just a matter of not cranking up the exposure to overkill.  But yes -adjusting the exposure removed the terrible sounds for me. *So thanks Joan -you've indirectly answered quite a but of questions I've had.

This post was modified 1 month ago by joeybronzoni
Posted : 20/09/2021 11:13 pm
WidgetCeramics
(@widgetceramics)
Active Member
Topic starter answered:
Long Exposure

For whatever reason, the clunking sound has gone away, which is great, but now I don't know what cause the issue in the first place. I accidentally poured a full vat of resin into the INSIDE of the machine (a whole other story which I don't want to discuss), so I cleaned the inside of the machine, including the resin sensor. The clunking sound went away after.

So I increased the exposure to 80 seconds, disabled the resin sensor, and ran the print without resin in the vat to see if the clunking sound would return. I did not. Now I am wondering if the resin sensor is the cause?

Posted : 21/09/2021 1:36 pm
JoanTabb
(@joantabb)
Moderator

on early layers you can usually hear the FEP Peeling off the print as the tank tilts giving feedback when you can't see the model
regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 21/09/2021 7:22 pm
Andrew Luebke
(@andrew-luebke)
New Member
Fast tilt for me

I have these problems on my printers as well.  My current theory is that if the area of the layers is big and the fast tilt is used the resin builds up and forces the platform up or the tank down, I see layers de-laminating when this problem gets bad so that's why I think the fast tilt is too fast to get resin out of the way.  I've had good luck switching to the slow print profile on the printer or changing the percentage under area fill from 45 to 35 for slow tilt.

Posted : 21/09/2021 8:13 pm
Share: