MK4 Current Owners - Issues? [POLL]  

RE: MK4 Current Owners - Issues? [POLL]

My MK4 kit overall works fine (apart from known prusalink/octoprint current constraints), except ...

My first layer consistency (PETG on satin bed) has been sketchy. I had a couple of instances where a strand of PETG fooled the printer into air-printing and a number of instances of in-sufficient squish on the first layer. My bed is pretty clean, but it's not brand new -- might be my setup, but I think there are still some underlying issues.

I am using firmware 5.0.0. Seems to me that the pre-heat temp of PET should be higher than 170 if you want to melt the filament enough for the sensing to work. 

I assume that things will get better over time. I'm happy to be rid of the pinda.

RE: MK4 Current Owners - Issues? [POLL]

My first layer is never perfect. Load cell sensor replacement on the way. 

RE:

occasionally I have experienced that a print will not start due to a nozzle cleaning error. Typically I have resolved this by scraping the PEI sheet where the nozzle cleaning was done. There appears to be bits of filament at that spot that once cleaned, will allow for nozzle cleaning to process without error. 

The frustration with this issue is that the nozzle cleaning process deposits those bits of filament and causes the cleaning process to fail. 

Also no issues with the prints after this cleaning process failed. I am not convinced that the filament cleaning process, as currently implemented, is necessary. 

RE: MK4 Current Owners - Issues? [POLL]

So far liking the printer.

PETG not sticking to the textured build plate has been a thing.

I am having a hard time dialing in the Y belt tension. I get the homing failure and hate the pounding the stop to recalibrate or whatever. I would like to fixt that.

RE: MK4 Current Owners - Issues? [POLL]

Posted by: @sweetride

So far liking the printer.

PETG not sticking to the textured build plate has been a thing.

I am having a hard time dialing in the Y belt tension. I get the homing failure and hate the pounding the stop to recalibrate or whatever. I would like to fixt that.

Bedwise, make sure to clean it really good with 90%+ alcohol (I only use 99%)

Try to increase bed temp (what temp are you setting it to?)

RE: MK4 Current Owners - Issues? [POLL]

PETG not sticking to the textured build plate has been a thing.

Try one of these and tell us if it worked out.

https://www.printables.com/de/model/465185-prusa-mk4-fan-draft-shroud
https://www.printables.com/de/model/585199-prusa-mk4-fan-cover
https://www.printables.com/de/model/621216-prusa-mk4-fan-cover

It reduces the air turbulence on the bed, that's induced by the heatbreak fan

RE: MK4 Current Owners - Issues? [POLL]

I am using a fan shroud (the 3rd one listed) and a glue sticking the bed before printing.

I use one side for glue stick prints and one side for prints without a glue coating.

RE: MK4 Current Owners - Issues? [POLL]

The only issue I have is with PrusaLink. Once in a while (not very often), I'll use "upload and print" from Prusa Slicer and it will do the whole upload then say "Internal server error" instead of starting the print. I have no idea what triggers this, but I usually just reset the MK4 to clear out any cobwebs and it works fine on the next attempt.

RE: MK4 Current Owners - Issues? [POLL]

Same here, a lot of stringies (PETG) not tested other filament yet. Tried changing retraction, temperature... to no avail. A bit disappointed as my MK3S+ worked flawless. 

RE: MK4 Current Owners - Issues? [POLL]

Posted by: @tom-horsley

The only issue I have is with PrusaLink. Once in a while (not very often), I'll use "upload and print" from Prusa Slicer and it will do the whole upload then say "Internal server error" instead of starting the print. I have no idea what triggers this, but I usually just reset the MK4 to clear out any cobwebs and it works fine on the next attempt.

Just a quicktip: make sure you're in the main menu. It you're still in some status screen or the finish-screen of the last print, it'll result in that internal server error.

RE:

@sweetride:  Many users report the textured sheet (I have one) has a film from the factory.. Clean well with soap and water.. that will dissolve some stuff that alcohol won't.. in fact I generally find dish soap and hot water better than alcohol for cleaning. You might mildly scrub with a plastic dish sponge.. That should help adhesion. You might try increasing the bed temp 5 deg as well. You can get an IR thermometer to see if your bed is getting close to the proper temp. It won't be bang on what you dial because the sensor isn't at the top, but should be within 5-10 degrees everywhere.

RE: MK4 Current Owners - Issues? [POLL]

Currently no available hard nozzles, no available nozzle assembly, no available nylon print plate. nozzle marking the smooth print sheet, MMU paid and promised months ago not shipped. Still working on it.

new Prusa motto:

Way over promise way under deliver. Ship whenever some of the bugs are reduced, software updates to follow.

Print on tee shirts and hand out.  

RE: MK4 Current Owners - Issues? [POLL]

I think the printing on T-shirts accessory is delayed. ..

RE: MK4 Current Owners - Issues? [POLL]

My MK4 squeaks when printing PETG, some PETG squeaks less, some more, but it always squeaks. No one from support has been able to advise me how to fix this problem until today. 😢 

I was deciding between Bambulab X1C and Prusa MK4. MK4 I chose because it is less noisy compared to X1C, but wouldn't bambulab fans be better than squeaking..?

Video: https://1drv.ms/v/s!AkoWjpZFyViRgfwe-gnQZJiFOaMXjw?e=6oPxtR

RE: MK4 Current Owners - Issues? [POLL]

I loathe printing with my Mk4... i rarely good get results. I have to rely on my MK3.

RE: MK4 Current Owners - Issues? [POLL]

For PETG I lower the temperature to 220 both hot end and bed, that way I get very satisfying results similar to what I had with my MK3S+. Not sure if it is the temp sensor measuring wrong or the AD conversion in the firmware or I just have a broken sensor. As I can't measure the hot end temperature I'm in the blind here. I did read others had to do the same to get less stringing and blobs so it might be something that can be corrected in firmware. 

RE: MK4 Current Owners - Issues? [POLL]

I measured the hotend temperature and one of the sensors I got sent by them was 15°C off (hotter). They apparently have problems with the complete batch of sensors so it's quite possible that your sensor is somewhat malfunctioning. But you can just set the temp lower and you're fine.

RE: MK4 Current Owners - Issues? [POLL]

Have you contacted support?  Mine works superior to my Mk3S+ or prior Mk3.  Maybe they can help.  

Posted by: @jeffl

I loathe printing with my Mk4... i rarely good get results. I have to rely on my MK3.

RE: MK4 Current Owners - Issues? [POLL]

Have you reported the problem to support?  They might replace it.  

Posted by: @the-powl

I measured the hotend temperature and one of the sensors I got sent by them was 15°C off (hotter). They apparently have problems with the complete batch of sensors so it's quite possible that your sensor is somewhat malfunctioning. But you can just set the temp lower and you're fine.

RE: MK4 Current Owners - Issues? [POLL]

Thank you cwbullet for your reply. Looks like I'm in that situation. I'll get it to support like you suggest.