Prusa XL belts - could use some nice advice

[Kurt Gluck]

Belts --- So I am doing my first regular maintenance.  Lots of learning (Prusa XL 5TH part assembled) -- The cell phone sound app https://help.prusa3d.com/.../adjusting-belt-tension-xl... told me that my belts were slightly loose.  I tightened them a little, and they now pass.    For the life of me I cant understand the "alignment" step.   I dont know what to grab and where, and why, or how... 

Anyway I printed some of the Prusa homing tower before tightening the belts and it had a layer shift.   Now post tightening I am printing it again, and I have a couple of artifacts so far... any ideas (the PLA  is from fillament.ca bought earlier this year and who have since gone belly up as a filament manufacturer so it could be old stock, and I dont own a drier so it could be some moisture issues)...   Or something else...

Any not too snarky advice would be appreciated....

[3D Printing Tips and Tricks]

I can’t tell from the pic… does the effect happen only in this area? Does this area correspond with the layer start and stops?

[Kurt Gluck]

Here is a short video:  https://share.icloud.com/photos/0d60U2BEL3xHjjM7XPHlLj8BA

It is a special prepaired gcode from Prusa - it kinda is designed to print poorly :-) you know to stress the belts.  

The defect in the center seems to be from the filament being way way too hot.  And maybe because it’s not dry :-). On facebook of course people all say I need to dry my filament.   On facebook if you complained that interest rates were too high to buy a house they would tell you to dry your filament :-).        

The defect on the face is only on one of the 4 sides, and seems to be where it starts and ends each layer.   As I said I have no idea how to perform the “alignment” step in the maintenance.   I will have to at some point contact prusa support.  I had an issue with not quite understanding how to lub the z screws (the video and documentation  for the coupler pins was very clear, but the z screws was not) - and after about a 50 minute wait the chat people were very helpful and walked me through it.    They also said they are improving that documentation. 

Belt tightening was straight forward (which means for me it only took a day - I am VERY slow, read it 3 times then read it again) - but for the life of me I dont understand what I am to do for belt alignment  step.   I will most likely contact support again, but family stuff is in the way. 

Kurt-A 

[3D Printing Tips and Tricks]

What are your filament temps? All the presets are way higher than the specs for each material.

[3D Printing Tips and Tricks]

Actually, imo…

Before saying “dry your filament” one should ask where you are! If you’re in the west where it’s dry than drying your filament is not likely your problem. Otoh, if you live where the cicadas sing loud, then yeah, drying the filament may be needed, although I doubt that’s your problem. My guess is you’re too hot.

[Kurt Gluck]

So... I now understand "Alignment" (Perhaps if I had built the printer instead of it being partially assembled I would have understood this, on the otherhand I would probably still be building it).

I contacted Prusa Support - turns out at 9:30 PM EST the person working is only at 8:30 PM, they are located in Columbia.  

It said 4 minutes but it took over 30, but thats what watching TV is for... I also spend this time prepairing in a notepad a complete description of my question.  

Anyway the support person said that they would make me a video explaining it, and a short while later I had a wonderful explanation of how to check alignment.  And YES I was out of alignment by a bit.

So, my suggested procedure is: Follow the Tension procedure https://help.prusa3d.com/article/adjusting-belt-tension-xl_401793  using the app: https://belt.connect.prusa3d.com/

When you get the correct HZ, switch to the other side.  THEN check the alignment by moving the toolholder to the center and pulling it all the way forward.  Then as per the video https://www.dropbox.com/scl/fi/yj1jb7609749fmu8vvkrw/f9510d19-22e1-41bb-a157-b200de6a6302.MOV?rlkey=qpckgu13c0e4neric1usdt8db&st=xofvaci3&dl=0. look at the left and the right and see if you see a small gap, if you do tighten that side till the gap goes away.  THEN go vack and redo the entire Tension procedure HZ check for both side, if still CORRECT then you can move on.

My next step is printing another portion of another homing tower: https://www.printables.com/model/542670-homing-tower 

You can see that one #3.  It is improved.  Now I have rerun the Phase Stepping Calibration - I will reprint some of the tower to see if it improves more....  

I will update whats next.

Kurt-A 

[Kurt Gluck]

The homing tower is a presized gcode from prusa on printables.  My printer panel says its printing at 220.

[Kurt Gluck]

I have a funny facebook reply where I ask = the guy who is suggesting this where he got his dehydrator then i suggest that I am going to put the spool in my 2017 Tesla S, with cabin overheat protection on on a a sunny day.  The car should stay around 100F 38C, and have plenty of air for the moisture to dissipate into -- I am going for a prize for most expensive fillament dryer, on the otherhand if it works it does hold more than 4 spools. 

[Kurt Gluck]

New Jersey by the way - so could be 

[Kurt Gluck]

By the way my strumming is giving me 83 left and 77 right Hz , which it says are both "just right" 

[Alan B]

I don't care for the resonant belt tension measurements, there are so many ways to have issues with them. I have had very good results from printed belt tension gauges, either the simple ones Prusa (and others) have published, or the much nicer units available from West 3D as kits or preassembled tools (and probably others). It's much easier to match tensions and results are not dependent on nearly as many variables.

Good luck with your adjustments.

On Sun, Jun 9, 2024 at 8:32 PM Kurt Gluck <kurt...@gmail.com> wrote:

By the way my strumming is giving me 83 left and 77 right Hz , which it says are both "just right" 

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