Frequent clogging with Verbatim BVOH  

Page 2 / 3
  RSS
KaraLT
(@karalt)
Active Member

@ssill2

Good to know. I will try increasing the purge even more next as well. Can you explain more about the idler bolt modification you mentioned? I haven't heard of removing that.

Posted : 08/06/2021 8:16 pm
ssill2
(@ssill2)
Honorable Member

@karalt

yeah I think the first two are basically required to have any good luck with it.  if you use the buffer there's a similar mod to use M10 connectors.  I've never used the buffer myself, these sunlu filament dryers work great to function as a buffer and you can dry your filament at the same time.

The big thing that I found made the load/unload more reliable was the idler bolt.

See mine.

on the mmu they are flush

and on the extruder it should look like this right below the hex window side of the extruder

Posted : 08/06/2021 8:22 pm
ssill2
(@ssill2)
Honorable Member

I'm sure I'll be doing something with BVOH again soon now that the MMU is not being a b*tch 🙂  I'll let you know if I see any issues with it, but the bvoh was the main reason I got the filament dryer.  and then I discovered that it functions well as a buffer so I bought 4 more lol

Posted : 08/06/2021 8:24 pm
KaraLT
(@karalt)
Active Member

@ssill2

Ahhh okay I see what you mean. So, I should also try playing with my idler tension?

I'd be very interested to see what your results end up being with a BVOH print! Looking forward to hearing how that goes.

Posted : 08/06/2021 9:33 pm
ssill2
(@ssill2)
Honorable Member

yeah I have another one of the owls printing but maybe later this week I'll try something with solubles again.  Support told me that with the problems I was seeing the idler tension was the only thing left lol.

Posted : 08/06/2021 9:38 pm
KaraLT
(@karalt)
Active Member

@ssill2

That could very well be my problem. I have never really paid much attention to mine. The bolts are ~0.1mm below the printed part for my MMU2S and the extruder one is a little complicated. The bondtech extruder comes with a very different idler, especially when paired with the MMU2S. Did you use the standard Prusa procedure to get yours just right? I recall it being something along the lines of holding filament in the extruder, making the gear turn from the menu, and tightening it until it just barely grabs the filament. 

I guess one reason I have not given it much attention is I do not understand why it is so important that it is just right. In my mind, it either controls the filament or it doesn't. If it grinds, I imagine the true cause of that problem would be a jam or something else stopping the filament from moving. 

Many others seem to be having success by tightening their extruder and MMU2S properly, so I must be wrong in thinking it couldn't possibly matter THAT much. If anyone could explain the reasoning behind it to me, that would be appreciated.

Posted : 09/06/2021 9:49 pm
ssill2
(@ssill2)
Honorable Member

@karalt

I’m only tell you what support told me in troubleshooting my mmu issue a couple days ago lol.  I was in the same camp as you.   But apparently it matters a lot 🙂

Posted : 09/06/2021 9:52 pm
Mdjuan
(@mdjuan)
New Member

If it is too loose or too tight the filament sensor will have errors. 
also, if the idler is too tight the idler motor will return a high voltage to board, so the printer will say there is a jam. 

Posted : 09/06/2021 11:31 pm
ssill2
(@ssill2)
Honorable Member

Ok just finished prints of this.  so I'm confident the mmu is working well.  between the two prints it's over 3k filament changes lol

I'll try to come up with something to test the printing of supports with bvoh and see if I have any issues there.

Posted : 10/06/2021 12:45 pm
ssill2
(@ssill2)
Honorable Member

ok first small test with bvoh and pla.  That worked ok.  going to do something more extensive next.

Just kicked this off.

PETG + BVOH

Posted : 10/06/2021 6:39 pm
KaraLT
(@karalt)
Active Member
Posted by: @mdjuan

If it is too loose or too tight the filament sensor will have errors. 
also, if the idler is too tight the idler motor will return a high voltage to board, so the printer will say there is a jam. 

This was really helpful for me to imagine what was going on with my extruder. I noticed that my IR sensor was rather unstable, the part that held it liked to jiggle and the light I have soldered in would sometimes fade in and out. I didn't notice this when printing before, but it might have been happening when I wasn't looking. 

I modelled and printed a part to hold the IR sensor cover in place better. I also noticed that there was a nut missing from the part and when I replaced that nut, the screw held it much more steady during printing. I have high hopes that my next print will be at least better than my last.

For the motor high voltage thing, can you help me understand more about why the idler tightness causes this? What I don't get is, if there is something blocking the way, wouldn't the gears keep trying to push the filament and the motor would return a high voltage anyways? Regardless of idler tightness?

Posted : 11/06/2021 2:24 am
KaraLT
(@karalt)
Active Member

@ssill2

The owls look so good! I've only ever done small multicolored PLA prints, like a 5 color benchy. Very impressive the scale you were able to print without any issues!

I'm loving the look of the LCD part upgrade, when I've seen it on other machines. I think that will be one of my first prints once I get this working!

I've played with my idler tension and fixed a wiggly IR sensor cover, so I have also started a print and am waiting to see if it works any better than the last few.

Posted : 11/06/2021 2:28 am
ssill2
(@ssill2)
Honorable Member

@karalt

Had a few interventions so far with the bvoh.  I upped that temp by 5 deg which seemed to help

Posted : 11/06/2021 2:32 am
KaraLT liked
KaraLT
(@karalt)
Active Member

Nothing is working any better. Still grinding in the extruder and failing on the PLA load.

Posted : 11/06/2021 4:23 am
KaraLT
(@karalt)
Active Member

I feel like there are teeny tiny failures on the IR sensor that are small enough that I am not seeing them. I am toying with the idea of hooking up an arduino nano to the extruder, feeding the IR sensor connector with the GPIO pins on the arduino and programming the arduino to read the IR sensor signal line. I figure I could program it to ignore any short 0's, kind of work as a debouncer?

Posted : 11/06/2021 4:28 am
KaraLT
(@karalt)
Active Member

@ssill2

I'd be interested how many interventions you end up with, I have been able to print with lots of interventions. But it is really bad, like once it starts happening (usually only a centimeter into the print) it just happens over and over and its unbearable to sit by the printer, intervening on every second layer.

Posted : 11/06/2021 4:30 am
ssill2
(@ssill2)
Honorable Member

@karalt

Well I will say, I did NOT have good success with PETG and BVOH overnight and I ended up having an unrecoverable print.   I think I'm going to need to play with the temperatures.  I was using paramount3d PETG and verbatim BVOH.  I was getting blobbing yesterday evening that required interventions.  over night it stopped and it got into a situation where the stringing in filament path 1 prevented the selector from moving over to filament 5.  at that point the mmu thought the selector was on path 5 but it hadn't gotten over there due to a filament string preventing the selector from moving over there.  I couldn't see any way to recover the print so I had to kill it.  Maybe I'll fiddle with it some more this weekend.  The paramount was roll right out of the shrinkwrap so I know it was dry.  and I had the filament dryer turned on for the bvoh.  I feel like this is mostly temperature related at this point I'll have to do some small prints to try to dial in the temp to the temp needed for the filament swaps to work reliably.   I was excited after the success with pla, so this is disappointing.

Posted : 11/06/2021 1:42 pm
Mdjuan
(@mdjuan)
New Member

Bvoh is nor for pet, the printing temperature is different. 
you might try hips with abs. 
hips is soluble in lemonene

Posted : 11/06/2021 2:56 pm
ssill2
(@ssill2)
Honorable Member

Ok, so I made a small change to filament path and updated the verbatim temp by 5 deg.  Seems to be better.   I also reoriented part.  Feels like an improvement.  I'll post the .3mf once I get some success with this.

Posted : 11/06/2021 7:21 pm
KaraLT
(@karalt)
Active Member

Sounds good. Yeah, I got about as far as you did in your PETG/BVOH combo, but when I was doing PLA/BVOH. What are your PLA/BVOH settings?

Currently I am printing a temperature tower with my PLA on 50% speed. Will see how low I can go with that, and repeat for the BVOH. Then I will try a 50% speed print and see if it makes a difference.

When I run a print on reduced speed, from the LCD menu, does it reduce ALL speeds? For example would it effect my ramming settings etc?

Posted : 11/06/2021 10:50 pm
Page 2 / 3
Share:

Please Login or Register