Prusa XL Dual head - semi assembled build and first weeks experiences
As a background - I have owned the Prusa MK2 which I then upgraded all the way to MK2.5s eventually (inclusing MMU1 and MMU2). I still own that printer and it keeps going.
The I got a MK3 and built it on Bear frame and Bear upgrades… upgraded all the way to MK3.5S as it is today. Again works and keeps going.
I was contemplating the XL purhase for a long time and finally bought it now with June '25 campaign. There are two main things I hope to gain
a) build volume, especially cm2 for woodworking templatesb) dual printing of PETG material and PLA as supports as I do tend to need supports for many of the various tidbits designed and printed
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The build of the Semi-Assembled printer took about 7..8hours. Sure one could build it a bit faster, but I rather took it slow. It is also advisebale to read the Comments on the build manual and also wathcing build videos on Youtube gave some very useful hints (speeding though those at 1.5x speed is a good idea as many of the things are obvious for more experiences Prusa builders, but then every now and then is some very useful info bits that are new or XL specific.
Wifi Antenna assemply and position had two options - one I had was documented elsewhere in manual. I added comment, but yeah, took a bit time to figure it out as the cable did not reach where the guidance seemed to show.
Build documentation is generally good. The Semi-Assembled manual though ends very abruptly with hardware part done and no guidance on what next. One has to figure to look into Assembled printer manual to see the powering on, calibrations etc. I did add a respective note to the build manual now too.
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There is a lot of controversial info around internet about the XY belt tuning and importance of getting it right. So obviouly while building it I did wonder if and how much the XY belt tuning is pre done in factory or not. After all the XY gantry does come assembled. Yet this is a part where the manuals could do a better job. As is, there is not even a mention about XY belt tension. There should be at least a point at end of the "First run" section pointing to
https://help.prusa3d.com/article/adjusting-belt-tension-xl_401793
In my case, lacking info on XY belt situation I did decide to use the "Prusa Belt Tuner" app on iPad and carefully set both belts to green and +/-1 Hertz on both sides.
The printer then did it's checks and calibrations ok. It did crash and reboot itself while doing the offset calibration with pin - it did continue after reboot thiugh and finish it.
Now again one source that above page points to is the "Homin Tower"
https://www.printables.com/model/542670-homing-tower
I did try that and got the result on right - not satisfacoty at all… And this was with "Tuned belts"… I did follow the guidance and tightened both belts half a turn at the time… did it 2 times if I recall correct… print improved, so I stopped and started the print again - this time with orange PLA (both were the PLA rolls that came with printer). As is obvious things were good now.
After all this I do have a feeling that the factory setting was actually pretty close to optimal as with belt tuning I had loosen the belt tensions and now with this model adjusted them back.
Also note - the Tower model G-code is unique as it prints one layer then does the whole XY homing sequence in front left corner and go back and print next layer etc… All in all it takes a lot of time, but if it does succeed with this it does show that printer really has an optimum for belt tension.
Anyhow, my take is that printing this models should be part of the First Run as a step. Would probably avoid several customers hunting for reasons of unsatisfactory prints.
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How have things gone since then…
Printer a new dust shoot for Mitre Saw as one of the first trials - fine result
Decided to then try the extended printbed size with a dust shoot for Axminster AW table saw - again, fine with minor beaulty issues as I do experience some oozing from nozzle (using Prusa PETG, with Prusa own print profiles, not tuned yet).
Then printer the whole Voxel3D "Prusa XL - EnXLosure" partlist
https://www.printables.com/model/610843-prusa-xl-enxlosure
Note! - Aliexpress shipping to Estonia was outrageous (like 170 EUR range), but then I found I could order direct from
Blurolls Prusa XL Minimalist and Printable Acrylic Enclosure Kit with Fasteners Doors USA Free Duty,MK4 & XL & Core One
Got the acrylic + hardware for 116EUR total.
All in all I do like the design of this enxlosure better than Prusa original one and the price was also much better in end. Plan is to build an exchaust pipe and temp control for it as well soon - so that is to come.
Had one fail with layer shifting over doing all those parts
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Feedback to Prusa from experiences this far
- Assembly manual, no clear jump from mechanical assembly to "First run" for Semi Assembled printer type
- Belt tuning, being as important as it is the respective Support article should be surfaced better for new user, including the "Homing Tower"
- Info about the Homing Tower" on Printables com should also of course link back to support article already from "Description section" and also explanation why this *.gcode is special would be good.
- Why is the dual head printer restricted to material feed from left side only - Ideally I would move the rolls to right side, but the cable for the sensor block would restrict that. This could be considered as an option imho as people have varying space to put the printer in.
- Priority 2 ask would be to allow Dual Head users to place the head homes to positions 2 and 4 for example or 3 and 5. Software wise should be relative easy feature…. What it would give is the opportunity for tweakers to design a better print fan. The current design is very restrictive as heads are so closer to eachother. Yet as I don't plan to upgrade to 5 heads I would like the freedom to experiment… I believe that would be following the long staning Prusa ethos also - to allow community to come up with better solutions.
- "Pause for cleaning"…. As is the head moves towards back when one pauses the print - It would be great if there would be an option to move it where it also goes otherwise with "Auto Home" - ie front left corner. The Nozzle is better reachable there and would allow me to clean the Nozzle if I see it getting a blob on it due to oozing or some such mid print.
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Hopefully something useful for those yet to choose this printer.