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MK4 Factory Assembled - Bad Bearings?  

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Thejiral
(@thejiral)
Noble Member
RE: MK4 Factory Assembled - Bad Bearings?

 

Posted by: @jeremy-3

1 - Input Shaper is still having the issues I mentioned several updates back. They are finding more variance between machines than anticipated so their "generic" algorithm isn't providing the best output. They're going to continue to work on it but the end result will have some "smoothing" effect to fine details. They do plan on having an accelerometer available at some point down the road. The actual public stable release of IS sounds like a long ways off.

So, there is too much variance between machines, even their factory assembled ones for some "generic" algorithm to perform well (not even talking about the kit), who would have thought. I am all for innovation but I don't quite get it why Prusa is trying to reinvent the wheel, just to save on two ADXL senonsors which cost and weigh basically nothing and some wiring. If IS in the Mk4 is a long way off, one will have to start judging the Mk4 on its merits without it and that would be an unfortunate downgrade.

Non-optimally adjusted input shaper eats away details and corners, that's why it needs to be well adjusted. I do know that they are still working on it and I am giving them a few months of slack given how new the product is (even though that key feature should have been implemented before the launch IMHO) but afterwards I would expect a proper input shaper implementation, or something that works as well as what we have in Klipper. I would not even say there needs to be an ADXL based calibration. What needs to be there is the possibility to calibrate input shaper at least with a dedicated calibration print and entering the calibration values in the firmware or in the Slicer.  In Klipper that is also an option which delivers good results as well. That second option is a lot less sexy for sure but given that you don't have to and also should not calibrate Input shaper often, it would not be such a big deal in reality and also give a real world confirmation of input shaper performance rather than a theoretical one based on sensor readings. 

Mk3s MMU2s, Voron 0.1, Voron 2.4

Posted : 27/04/2023 6:45 am
Antimix
(@antimix)
Reputable Member
RE: MK4 Factory Assembled - Bad Bearings?

@Jeremy,

look at here:  https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-hardware-firmware-and-software-help/very-loud-first-layer-vibrations-x-axis/

It sound me the same sound from the X axe. On this user the vibration and scratches are even worse.

Regards

Posted : 27/04/2023 3:16 pm
Jeremy
(@jeremy-3)
Trusted Member
Topic starter answered:
RE: MK4 Factory Assembled - Bad Bearings?

I've posted a large update in the master thread.

https://www.reddit.com/r/prusa3d/comments/12sgny2/known_mk4_design_flaw/

Posted : 28/04/2023 4:16 pm
iftibashir
(@iftibashir)
Honorable Member
RE: MK4 Factory Assembled - Bad Bearings?

Saves users from moving over to Reddit:

Posted by: @jeremy-3

Update 14:

1 - Between those that observed issues right away and those that later had progressing issues, the number of complaints is more than half of the shipped units, thus the halt to shipping. Prusa expects to start shipping MK4s again within 7-10 days (maybe a trickle of them sooner). The change in part tolerances and fittings are being tested and then new parts have to be retrofitted to existing "ready to ship" stock.

2 - Prusa will be posting early next week (if not already) instructions on how to repack and prepare to ship back MK4s for those with the print artifacts and resonance. Obviously one would still need to work with support to get the RMA setup.

3 - Regarding the prior Update 13 on Input Shaping - an alpha firmware update (v5.0 Alpha) should be available at some point to start getting external feedback on the generic/default values they're trying to fine-tune. Unfortunately, right now the spectrum of differences is pretty large even amongst their pre-assembled machines and the only options are either to slow-down the default profiles from what they originally planned, or to allow for faster speeds but more smoothing. More to come.

4 - The bed divit issue continues to create some noise, but Prusa has no plans right now to formally acknowledge it as an issue. Instead, they will treat the beds as consumables subject to wear and tear.

5 - There is much more I could continue to share (issues, XL updates, MK4 enhancement Top 10, etc), but based on the blowback over the past two weeks, I will refrain at this time. I understand some don't want to publicize issues or make Prusa look bad - but that is not the intent. My intent in sharing the very large level of frustration within many Prusa workers is to get attention on the issues so they get properly resolved and our MK4s can be just as reliable and accurate as our MK3s. Just because the PR side doesn't want to acknowledge issues, doesn't mean the dedicated tech teams don't want people to know what's going on and how it could impact them.

 

ORIGINAL PRUSA MK4 KIT - Full step-by-step video assembly guide!

>ORIGINAL PRUSA MINI+ Full video assembly guide!

Posted : 28/04/2023 6:10 pm
Jeremy liked
iftibashir
(@iftibashir)
Honorable Member
RE:

I didn’t realise they had halted shipping of all units? I’m off on holiday end half of May so I didn’t want to receive my MK4 Kit until June anyways, but at this rate I think July is a more prudent expectation!

Is this what they actually told you? They seem to be divulging quite a bit of info……. 

RE the bed divit issue - guess it’s not a wide spread enough issue for them to acknowledge just yet? 

 

Appreciate the updates - keep them coming!

ORIGINAL PRUSA MK4 KIT - Full step-by-step video assembly guide!

>ORIGINAL PRUSA MINI+ Full video assembly guide!

Posted : 28/04/2023 6:12 pm
Joshua Giacone
(@joshua-giacone)
Eminent Member
RE: MK4 Factory Assembled - Bad Bearings?

I know you said you'd stop updating on reddit, could you please keep updating in this forum thread?

Posted by: @jeremy-3

I've posted a large update in the master thread.

https://www.reddit.com/r/prusa3d/comments/12sgny2/known_mk4_design_flaw/

 

Posted : 28/04/2023 9:19 pm
Matthew Schultz
(@matthew-schultz)
Eminent Member
RE: MK4 Factory Assembled - Bad Bearings?

+1

Posted by: @joshua-giacone

I know you said you'd stop updating on reddit, could you please keep updating in this forum thread?

Posted by: @jeremy-3

I've posted a large update in the master thread.

https://www.reddit.com/r/prusa3d/comments/12sgny2/known_mk4_design_flaw/

 

 

Posted : 28/04/2023 9:21 pm
GeekintheOzarks
(@geekintheozarks)
Active Member
RE: MK4 Factory Assembled - Bad Bearings?

Yes, please keep providing updates as they are greatly appreciated 

Posted : 28/04/2023 9:23 pm
iftibashir
(@iftibashir)
Honorable Member
RE: MK4 Factory Assembled - Bad Bearings?

Is the rattling noise coming from the planetary gears in the extruded motor? Watched a YouTube Short where by pressing his finger against the motor where the gears are, the rattling stopped……until he let go again….!

ORIGINAL PRUSA MK4 KIT - Full step-by-step video assembly guide!

>ORIGINAL PRUSA MINI+ Full video assembly guide!

Posted : 30/04/2023 10:20 am
Jeremy
(@jeremy-3)
Trusted Member
Topic starter answered:
RE: MK4 Factory Assembled - Bad Bearings?

No, we touched every possible part, screw, bolt, tension, etc and the planetary gears themselves weren't making the noise.  It was a tolerance issue between the toolhead carriage, it's bearing mounts, and the planetary gear slippage.

Posted : 30/04/2023 3:16 pm
Rainer
(@rainer-2)
Reputable Member
RE: MK4 Factory Assembled - Bad Bearings?

To what extent are the great things affected?

How is it if you print out the parts yourself? I think there will be even more difference between different printers.

Because I ordered an MK4 kit, of course I am interested in the whole thing.

I already have a mini and I am satisfied with it. Of course, not everything went smoothly and I don't lift the Prusa company on a base.

Some things could have run better and, above all, faster. But basically I have confidence that Prusa tries to do the things right and not to fake early buyers.

I usually keep my printer for a long time. Then I don't care if Input Shaper is going really well in a year. Not great, but ok.

I am not sure whether it can be done without ADXL. On the other hand, the profiles for the mini are really good. My manual attempts with linear Advance did not bring any better results.

In any case, you have to find a really good solution with the input shaper, otherwise you will lose your credibility. If it doesn't work with the universal profiles, Prusa must have the eggs to give the mistake and find a solution. And in the interests of Prusa as soon as possible and as good as possible. In terms of marketing, everything else can wait in my opinion.

Posted : 30/04/2023 6:16 pm
Jeremy
(@jeremy-3)
Trusted Member
Topic starter answered:
RE: MK4 Factory Assembled - Bad Bearings?

Now that support has publicly admitted to shipments having been halted for a while, I assume I’ll get some apologies?

Posted : 03/05/2023 5:10 pm
Jeremy
(@jeremy-3)
Trusted Member
Topic starter answered:
RE:

Final Update:

Had a wrap up call with our account manager and the support team today now that we have 2 replacement MK4s we've put through the paces. Everything is looking good on the changes to the toolhead assembly.

Notably, the R1 design will be forever known as the "4 screw" design and the R2 design will forever be known as the "3 screw" design. With the necessary changes to the Nextruder assembly, the only visual reference between the two versions is the number of screws and the mount.

https://www.reddit.com/r/prusa3d/comments/12sgny2/known_mk4_design_flaw/

Posted : 08/05/2023 11:49 pm
kevman
(@kevman)
Estimable Member
RE: MK4 Factory Assembled - Bad Bearings?

So - besides the screw, what changes other changes were made? Or was that the only change and it solved the problem ?

Posted : 08/05/2023 11:55 pm
Jeremy
(@jeremy-3)
Trusted Member
Topic starter answered:
RE: MK4 Factory Assembled - Bad Bearings?

There are other internal changes.  I didn't take a picture of the R1 internals so unfortunately don't have a before/after pic to show.

Posted : 08/05/2023 11:58 pm
GeekintheOzarks
(@geekintheozarks)
Active Member
RE: MK4 Factory Assembled - Bad Bearings?

Be interesting when they update the MK4 files on printables to see the changes

Posted : 09/05/2023 12:05 am
kevman
(@kevman)
Estimable Member
RE: MK4 Factory Assembled - Bad Bearings?

I wonder if it is more than just printed parts, Jeremy mentioned that they were sent two full new units. Would be a pain if it was more to it.

Posted by: @geekintheozarks

Be interesting when they update the MK4 files on printables to see the changes

 

Posted : 09/05/2023 12:07 am
GeekintheOzarks
(@geekintheozarks)
Active Member
RE: MK4 Factory Assembled - Bad Bearings?

Just glad this is getting sorted out before my kit ships.. I do feel for the people who had issues..

Posted : 09/05/2023 12:10 am
SgtCaffran
(@sgtcaffran)
Active Member
RE: MK4 Factory Assembled - Bad Bearings?

 

Posted by: @jeremy-3

Final Update:

Had a wrap up call with our account manager and the support team today now that we have 2 replacement MK4s we've put through the paces. Everything is looking good on the changes to the toolhead assembly.

Notably, the R1 design will be forever known as the "4 screw" design and the R2 design will forever be known as the "3 screw" design. With the necessary changes to the Nextruder assembly, the only visual reference between the two versions is the number of screws and the mount.

https://www.reddit.com/r/prusa3d/comments/12sgny2/known_mk4_design_flaw/

Thank you for the update, I am also interested to see if the online designs will be updated. That should give us a nice overview of what changed. Nice to hear that your issues have been solved!

Posted : 09/05/2023 5:36 am
Jeremy liked
ManelTo
(@manelto)
Estimable Member
RE: MK4 Factory Assembled - Bad Bearings?

Maybe some user of the printer with the R1 design (the one with the four screws) could upload a photo with the interior of the Nextruder?And then Jeremy could maybe upload a picture of the new design?

Posted by: @jeremy-3

There are other internal changes.  I didn't take a picture of the R1 internals so unfortunately don't have a before/after pic to show.

 

Sorry for my poor English. I try to do my best.

Posted : 09/05/2023 6:43 am
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