loading and unloading doesn´t work too well (not really at all)
I already hate me for upgrading to the MMU2S. The printer was working so well but the MMU2S just behaves like a cheap toy 🙁
As in my earlier post the filament gets loaded and instantly unloaded, I thought that might be a problem by the sensor but that one works well.. what you could call well slight ticking on the chimney lever already messes with the status of the IR sensor. What exactly was the reason for the change from the old sensor?
Now I managed to trick the feed to nozzle by pulling off the pipe feeding the filament while the MMU2S was pushing it, inserting the pipe afterwards. Anyway I started over with the first-layer calibration. This turned out terrible and I couldn´t solve it by adjusting the Z-position.
When it was finished it tried to unload the filament (Why for fxxxx sake?) however the unloading failed, the filament wasn´t pulled out and even if I "help" to get it out of the heating element the MMU2S isn´t able to push it out far enough so it would recognize it as being unloaded. It keeps running and running until it stops with "requires attention".
I have no idea where to start to fix this. I guess I will feed the filament directly and keep the MMU2S off.
Maybe I should have kept some of the gummy bears for this point of frustration 🙁
RE: loading and unloading doesn´t work too well (not really at all)
I had to move the chimney around to find the sweet spot. I also had to move the extruder abit to find it's sweet spot.
I hate the chimney, I have to find a extra tall fitting for the ptfe tube going to it.. I don't know what they where thinking
I have a Prusa,therefore I research.
RE: loading and unloading doesn´t work too well (not really at all)
Yeah I'm not happy with adding the MMU either. The only issue I had with the plain MK3 was the retraction issue with the stepped heat break and I had just ordered the parts to fix that when the MMU shipping notification came (which is not compatible with the mods I was going to do).
I got a successful single color Benchy from the MMU, but 2 attempts with lots of hand holding have still failed to produce a 2 color Benchy. The latest issue being that the retractions for the wheel house appear to have trigger the stepped heat break jam/clog issue...
RE: loading and unloading doesn´t work too well (not really at all)
If I´d know that the loading/instant unloading is caused by the chimney I´d mess around with it but yesterday I fed the filament directly and it was no issue, I was even able to do a nice first layer calibration print. So the issue is somewhere a the MMU. Since my package had one wrong bearing I ordered one now (to get it as quick as possible) to fix the MMU joint. This could solve some of the filament transport issues but I am not so sure. I think the bearings are just too slippy for the filament transport. Why isn´t this designed with gears? Now about the buffer, come on, really ? I mean this is like the 3rd or 4th revision of the MMU and then this? I mean couldn´t the sheets (5 of them) be at least of transparent plastic so you see where the filament is moving? I don´t even want to think about loading flexible filament, this will be a real pain.
I feel like a betatester right now.
RE: loading and unloading doesn´t work too well (not really at all)
make sure the "idler bearing cylinder is lined up. and if there is no extra tension from what ever is feeding your rolls. the 2 "springed screws" that hold down the cover only need to be just under flush.
I have a Prusa,therefore I research.
RE: loading and unloading doesn´t work too well (not really at all)
I had my mmu damned near perfect also before I did the upgrade. I only went "S" so I could use transparentish' petG easier. and now im doing allot more petG
I have a Prusa,therefore I research.
RE: loading and unloading doesn´t work too well (not really at all)
Ok I´ll try again once I got the bearing, just doesn´t make too much sense to search for the problem unless I fixed this issue.
RE: loading and unloading doesn´t work too well (not really at all)
@thomas-83 - I'm experiencing either the same or similar problems. I just finished assembling my MMU2s and I am unable to perform first layer calibration. Have you been able to complete that step with MMU feeding filament? (I saw you calibrated first layer by hand feeding the printer)
At this point I'm going to retrace my steps in manual and see if I missed something.
RE: loading and unloading doesn´t work too well (not really at all)
No not yet, I won´t do any more testing until I get that missing bearing about middle of next week. I have doubts that it will change anything but I want to exclude anything that could cause a problem. Maybe you already read it but I also had massive problems with flexible filament (TPE85A) with the new MK3S "printhead". So this isn´t just about the MMU2S.
RE: loading and unloading doesn´t work too well (not really at all)
I had to rebuild my extruder this weekend and I am less happy with this disaster.
It had filament broken off and stuck both in the heat break and the top of the PTFE tube. What I was really disgusted to find was that part of the shroud had warped pretty badly. My MK3 head had 2-2.5k hours on it and it still looks perfect. The 3S had maybe 40 hours and it shows heat problems???
And of course the with switch to the inferior IR sensor it didn't stop trying to print while it was jammed. Count me in the 3S is a downgrade crowd 😕
RE: loading and unloading doesn´t work too well (not really at all)
Okay here is my progress and what I did find out so far.
First of all I made a remix of the autorewinding thing so I just needed around 8-9 hours per spool instead of the 40+ 😉 I didn´t print the holders, I cut them from plastic with my cnc and put them on an old shelf board with engraved nut, will mount it to the wall later, maybe I have to increase the distance to the printer.
I removed all the pipes, they don´t make any sense at all, they just cause friction. I´d even like to remove the one between MMU and printhead and replace it with a wider one.
Why? Simple to explain, the printer tends to leave lumps at the end of the filament at the end of a print and because of that the filament gets stuck due to too much friction at the pipe beginning at the print head. Resulting in an error.
The blade in the MMU got drawn out of the holder, I don´t see any sense of it anyway. The whole design of the holder is complete crap (Sorry Josef Prusa, I have to say this.) Why mounting the blade with two bolts from the backside? Removing them is a real p.i.t.a. Why using a blade that got no mounting holes? Because it is just jammed between two plastic pieces it will never permanently resist the force on it once it needs to cut filament. There are so many types of blades out there and you have chosen the most inconvinient.
Besides what is it´s purpose? It only got work to do in case the retraction of the filament failed to work correctly. This should only happen if the filament gets stuck before the MMU, so in a pipe of in the buffer. I will try if this ever happens with the "component reduction" I did now.
Proceeding with some multicolor prints now.