After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.  

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

The quality on my XL-5Head isn't as good as the MK4, which isn't as good as my Prusa-Mini.  I've been primarily working with the current firmware and not the alpha release, so I think it will improve.   The size increase is worth it for the MK4 or even MK3.  The XL is only worth it if you have a real NEED for the size which most folks do not.  

You can only use the wipe tower if all the nozzles are the same size, so just having one or two 0.4 nozzles for detail won't help.

A full set of 0.4 nozzles with a spare is $180.  Everything about this printer is expensive.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

The stringing issue can be 95% dealt with in slicer settings, so jumping out of line just because of that seems foolish.

You can print without a prime tower at all, but depending on the print that may not be advisable.

I've only ever used the alpha firmware in my couple weeks of ownership to great success. The only hiccup I've had, which also affects prior firmware, is one instance of the usb unreadable error which was solved by simply reinserting the usb and then successfully continuing with the print.

I did come across 3 minor QC-issues with the prebuilt nextruder docks: one missing spring on a nozzle sealer assembly, and two of the silicone sealer holders needed a little sanding to fully actuate in their holes. I had an extra spring from my MK3/MMU spare parts bags. So no big deal, but a little disappointing.

The details will be better with a .4mm nozzle, of course.

The MK4 and XL use the same extruder, so I'm not sure why you think one would be better.

The real issue is PrusaSlicer doesn't yet allow for differently sized nozzles in a print.

Even with a fully functional, zero-issue MMU you will not beat the speed, purity of color, zero-purge, nor ability to print multi-material that the XL offers. But its your money; I'm sure everyone in line behind you will be happier for you skipping out.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

I received my XL5 semi-assembled about a month ago.  My experiences have been very positive.  I have a little over 300 hours and 4300 material changes on the printer to date.  I really do not have stringing issues, but I do dry my filament.  Others have used lower temps to control the stringing.  I cannot complain about quality.  I actually a lot of silk material and quality has been on par or better than my MK3S+ printers.  Getting into fine detail like text is a little troublesome, but that is a function of the 0.6mm nozzles.

I tried using the alpha firmware and had fault half way through a print.  I am not sure what the issue was as I didn't have time to deal with it.  I switched back to 4.7.2 and have not had an issue since.  I'll probably try again at some point, but I am not in a rush for that.

The only "issue" I have had is my number 4 extruder position has had to be re-calibrated twice.  Fairly minor issue and I am not sure what is moving, but it only has happened at the beginning of a new print.  It takes a couple of minutes to fix.

Overall, I have been very happy with the printer and will likely looking at a second if demand requires it.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Im with Dante, I only have the dual head but positive experience so far. Printed a key chain with dual colors and the stringing was very minimal. I would not purchase if you dont need it for the size. The MK4 is the beast. 

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

I have 3 mk3 units and my 5 tool xl prints as well as any of them.   I had some slight stringing issues but fresh filament seems to have solved it. 

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Posted by: @o-knode

What are your experiences with the quality of print even at fine detail between mk4 and xl and do you think prusa can fix the problems with quality of the new extruders (build with loose screws and holes in printable parts by prusa) and with general low printing quality? what are the results using the new alpha firmware?

and last not least is it better for detail prints using a 0,4 nozzle at some extruders

Surface quality is worse than MK4 and I put down to lingering bugs in the slicer with 0.6mm nozzles. Despite having Arachne enabled there are visible artefacts in thin-walled designs (~2 perimeters) printed on the XL and curiously these artefacts are also visible in Prusaslicer. The external perimeter on the MK4 is smooth in both Prusaslicer preview and in the final print. The external perimeter on the XL is lumpy in both the Prusaslicer preview and the print; the lumps correlate with internal structures like nut captures and structural ribbings.

I'm guessing - but don't know for certain - it has something to do with extrusion width and the Arachne algorithm. With both the MK4 and XL at 0.20mm layer height the MK4 uses 0.45mm extrusion width whereas the XL uses 0.65mm extrusion width. I think the slicer has been fine tuned over many years for 0.45mm width and now with larger nozzles some of that fine tuning is broken. I want to experiment with a 0.4mm nozzle on the XL but haven't had time as yet.

The stringing issue is huge. Teaching Tech on youtube released a video last night where he dived into the stringing issue. He's a good content creator and I have confidence in his thoroughness. Despite a valiant effort he still can't solve the stringing issues.

Teaching Tech's experience is not unique either. Multiple youtubers who I trust and many people on this forum are getting these stringing issues. It's shockingly bad. Whether it's the slicer, the firmware, or the profiles, or variances in hardware, or the custom g-code, or a design flaw in the toolhead system. I can't say. I don't think anybody has a proper grasp on the problem yet. It's especially weird because some youtubers and Prusa themselves are turning out multi-material prints that look amazing.

As much as I hate to say it because I'm usually quite happy with Prusa products, the evidence is mounting that you should avoid the Prusa XL for now until when (or even if) Prusa can resolve them. Good companies sometimes turn out bad products and never fix them. Even big companies like Apple and Ford sometimes have massive blunders. I'm not saying the Prusa XL is a blunder - not yet - but they're burning a lot of goodwill right now.

RE:

So maybe I am just lucky, but with my 2 Head XL I actually thought my machine is broken. What I found out is that I need to print about 15-20°c lower. I know that shouldn't be the case, but it really is. With both heads consistently.

After I figured that out the machine works quite perfect for me. For detailed prints I use 4mm nozzles especially with Multimaterial/Multicolor, but for mechanical Parts the 0.6 Nozzles are great. I have printed these four really sturdy extenders in 7 Hours:

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Is that your first layer facing the camera, I think it is. If so there's good squish at the bottom and it lessens near the top of the part. 

My experience of the 5T XL is very similar to that in the Teaching Tech video.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Ohh no that is the top of the Part. Here it is from the first Layer:

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

My 5T XL is due to ship soon. Has anyone tried PrusaSlicer 2.7.0-beta1 released last night? It has new helical z-lift and travel ramping features specifically to address stringing issues. I hope Michael (TeachingTech) makes another update with the new PS version.

https://github.com/prusa3d/PrusaSlicer/releases/tag/version_2.7.0-beta1

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

I've tried it, stringing is much improved on the two tests I've done so far.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Typically the teaching tech guy is pretty good, but this time around he is showing his lack of toolchanging experience.

Speaking from three years with the E3d toolchanger….

1. z hopping is essential for multi materials. Turn that off and you will see nozzle crashing.

2. Increase “Retraction on tool disable” to 11.2 mm for each extruder. This Retracts out of the melt zone BEFORE the tool leaves the print. As such the 3d print dogs approach becomes irrelevant since the material is moved up and out before the tool moves. Retracting out of the melt zone also stops the drool on to the nozzle seal which stops the string there as well.

3. Use the correct temperatures. Prusa’s presets are way too hot. You have to operate so that the timing is correct to go to and from the melting point. Too hot and it takes to long to cool down.

All of the above makes for zero stringing with pla and no need for a prime tower. PETG has so not worked as well as of yet, but I’m workin on it!

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

What he showed is the Prusa released an undercooked firmware and slicer. He may have been able to try other things to ‘fix’ the issues but that shouldn’t be needed IMO. As he points out, the whole point of buying a Prusa printer is you get the whole package. Fine tuning yes, sorting basic problems that shouldn’t be there need to be shown to potential customers. 

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Yeah... I kinda get that and I really do not disagree with that at all. However, the unfortunate fact is in order to have a 3D printer that is flawless and as easy to use as a toaster actually costs a heckalot more than $4K. Even those that cost $50K are not as easy and flawless as a toaster. Yah... Prusa makes the sales pitch as though it will work that well. I've been seeing this from Jo now for over ten years. I expected exactly what I got and what I got is easily the most advanced FDM machine there is... except for the $50K Markforged, but that's a single extruder with limited materials.

In the meantime, I have found a completely different stringing problem and I think I know why it's happening... but that will be in the Multicolor PETG thread. I won't hijack this thread.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

I would like to see updates from prusa on what they have done or are doing to correct issues warped build plates bad assembles documented g-code updates. And i know they will get there.

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

Is there any Proof that all the measurements prusa do with all there Thermistors is correct or is it a batch problem? Means 190 really 190? And what happens you change a mk4 thermistor to an xl with slightly longer cable?

RE: After all the stringing problems i cancelled my order for xl 5 head so i must take a decision to renew it or to swich to an mk4.

I had trouble with a purge tower not sticking on the first 5 color PLA print, but in the other 4-5 prints, the tower has stayed put, or if each part is big enough (infill space) I dont’ do a purge tower and wipe it infill, with infill before exterior.   I’ll update to the latest alpha/beta set ups and go back to defaults and see where PRusa has taken us.  

After the MMU2 debacle, and the first problems with my XL, I was not encouraged.  The lates prints have been spot on.  Multipart, print-in-place, functional- but under 200mm cubes- have gone really well.  I did a USB cord organizer/winder in my daughters school colors and she said “Wow!”.  Made my wife an add-on for a birthday present.  I’ve said elsewhere that multi-color PLA prints were my minimum performance target, and the XL has met that.  I’ll use my MK4 for speed prints and my (now) twin Minis with REVO as my workhorses.  My Mk3s will be my experimental (REVO HT + Enclsosure) and if the MMU3 ever gets rolling for teh Mk4,I’ll use that for ‘filament-on-demand’ rather than as a true MM printer- which the XL is rocking so far.