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ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

lol, my text mistakenly had "on<nospace>load" in it.  So wordfence was complaining.  I understand why lol  that's an html keyword lol

Posted : 26/05/2021 9:04 pm
gglockner
(@gglockner)
Eminent Member
RE: Thanks to the Forums

I just got my MMU2S assembled yesterday. As I climb the learning curve, I have the following initial observations:

  1. The calibration seems more sensitive than the base i3. For example, there is a lot of flexibility in how you place a spool with the stock i3; with the MMU2S, you need to be careful to accommodate the feed and retract.
  2. Based on my reading, I was expecting to hate the filament buffer. In reality, I think it's a pretty good solution; many of the mods to substitute the buffer seem worse to me than the buffer. For my config, the only issue I have with the buffer is that I have to detach the printer-side (rear) PTFE tubes to feed them. If I keep the buffer, I may mod that to make it easier to detach the PTFE tubes.

Updates to follow.

Posted : 26/05/2021 9:20 pm
gglockner
(@gglockner)
Eminent Member
RE: Thanks to the Forums
Posted by: @ssill2

In this case, the IR sensor was not fully calibrated and the mmu kept sending filament because the IR sensor hadn't triggered and told it was there.

I understand that the MMU2 has a different requirement for the IR sensor, but I also believe it's less precise than the base i3 location. Hence the need to "calibrate" the IR sensor with the MMU2. I nearly skipped that build step, and I'm glad I followed it.

Posted : 26/05/2021 9:24 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@gglockner

there is a mod to the buffer to use festo connectors.  After you spend hours and hours and hours watching it, you'll definitely start to know when something isn't going to work or not.  Case in point, try feeding some tpu in 🙂

Posted : 26/05/2021 9:25 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@gglockner

Yes, you must use an allen key and do the calibration.  Same for calibrating the finda.

Posted : 26/05/2021 9:27 pm
gglockner
(@gglockner)
Eminent Member
RE: Thanks to the Forums
Posted by: @ssill2

@gglockner

there is a mod to the buffer to use festo connectors.  After you spend hours and hours and hours watching it, you'll definitely start to know when something isn't going to work or not.  Case in point, try feeding some tpu in 🙂

Thanks, I saw the Festo connector buffer mod. I like it in concept but the comments say that the designer changed the diameter. Because the original design lets you extend the PTFE tube into the buffer. So I may need to mod the mod... 😝

This post was modified 5 months ago by gglockner
Posted : 26/05/2021 9:28 pm
Baklin
(@baklin)
Reputable Member
RE: Thanks to the Forums
Posted by: @ssill2

So after the first intervention it SEEMS to be ok for now.

I did recognize these first layers as I had sliced this print a few times already, but never tried it yet.

Now that I have my setup almost like I want it, this was the time to try it.

Nine and a half hours so far without any problems or interventions.

I do this with 0.3 mm layer height so "only" 6-7 hours to go. 😉

 

Posted : 27/05/2021 3:44 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@baklin

Per usual lol mmu issues are often indiscriminate.  I've had prints that had over 600 changes go through without issue and then the next print, without having changed anything would fail on every other change.  My only point is that the number of people that the MMU works for flawlessly  is vastly dwarfed by those it doesn't work well for.  And the number that it works well for without significant modification is a fraction of that!  The fact that they are rewriting the firmware(which hasn't been updated on github in like two years)  sort of tells you that it's desperately in need of TLC.   I do have another set of 2mm ID  tubes coming so I can try to eliminate any bends when putting it back in the enclosure.  I've resigned myself to the fact that interventions will be needed sometimes.  But the fact that the firmware seems to wig out in some cases, killing the print, is just annoying.  THAT is a firmware issue.  as you saw with my last test the tubes were about as short as you could reasonably get and had very little bend.  This thing's days are number though.  As soon I figure out what multi-extruder printer I want to get, this printer is going back to a reliable MK3S+ I'll do the multi material prints on the new printer.

Posted : 27/05/2021 3:58 pm
gglockner
(@gglockner)
Eminent Member
RE: Thanks to the Forums
Posted by: @ssill2

My only point is that the number of people that the MMU works for flawlessly  is vastly dwarfed by those it doesn't work well for.  And the number that it works well for without significant modification is a fraction of that!

How do you base this claim? People go to internet forums to vent complaints far more than to post "all is fine".

As for mods, many people mod the base i3 (without the MMU) to improve its performance: enclosures, filament dryers, bed adhesive, nyloc bed leveling, etc.

What I've discovered in my first 3 months of 3D printing is that it's a hobby that involves tuning and tweaking. The MMU adds another layer to that. Clearly the MMU has room for improvement, far more than the i3. But I don't think it's a failure. As they say, "your mileage may vary".

Posted : 27/05/2021 5:18 pm
gglockner
(@gglockner)
Eminent Member
RE: Thanks to the Forums
Posted by: @ssill2

As soon I figure out what multi-extruder printer I want to get, this printer is going back to a reliable MK3S+ I'll do the multi material prints on the new printer.

Based on what I've read, a multi-extruder printer has different tradeoffs in terms of alignment of the extruders and costs, while gaining simplicity in terms of filament handling. Have you looked at the Mosaic Palette as well? That is simple in terms of extruders and filament handling, though it gets complex in terms of model slicing, and it's nearly as expensive as an i3 kit.

Posted : 27/05/2021 5:27 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@gglockner

That's fair.  The perceived number of people with issues is much higher for the reasons you pointed out.  On the other hand you don't to modify the base i3 in order to get it to reliably fulfill it's primary function.  With the MMU, virtually anyone that's used it will tell you, download and print these parts to get it to work.  Honestly the only mods I've considered making to the i3 printer is to change the color of the plastic parts.  The base printer is a wonderful machine.  And I'd buy another one in a heartbeat.  I think the i3 set the bar very high and thus when you get the MMU you're thinking you'll get the same sort of experience.

I will continue to try to get some more reliability out of this thing, but I don't think I'm alone in my disappointment with the MMU.  I'm glad that it's working for you and some others  that's great.  for 300 it's a bargain for being able to do multi-color prints.  and since I don't make anything to sell where failed prints are eating into my profits, it's almost good enough.  But I once I've figured out the print settings to get something to print reliably, I don't even have the assurance with the mmu that the same print would work multiple times over and that's kind of a problem. 

Posted : 27/05/2021 5:33 pm
gglockner
(@gglockner)
Eminent Member
RE: Thanks to the Forums

@ssill2

When I got started with the i3, I struggled with first layer adhesion, and I still have to tweak this every time I switch nozzles or bed sheets. While this doesn't require mods, it's far from plug-and-play.

Posted : 27/05/2021 5:39 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@gglockner

Yes, I'm going to do some research before I pull the trigger on something.  The other thing I don't like about the MMU is the amount of waste generated.  I hate throwing a large petg purge block in the garbage at the end of a print.  not only is it wasting money, it's filling up the landfill.  The ability to recycle print scraps is really wide-spread yet.  I'd love it if it was.  I'd happily sort my scraps in to tpu, petg, pla, etc.

I have looked at the palette.  In fact I know at least one person on here, fuscher I think, that has preordered the PaletteV3 pro.  I'm quite interested to see what he reports back on that.  But in my opinion that's still a kludge and even though it supposedly produces less filament waste, it I think it has it's drawbacks as well.   I think one stream of filament is a better approach than what the MMU does.  I don't have any first hand experience with one and I may hold off on the multi-extruder printer until I hear what is experience is with it.    If it's good, that might be good enough for me to pull the trigger one of those vs plopping down 2.7k or more on an e3d tool changer.  Since I don't make money with my prints, the palette is more attractive if it's functional.

Posted : 27/05/2021 5:43 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@gglockner

I've not had the occasion to change nozzles yet, but changing sheets is straightforward and it makes total sense why you have to have sheet profiles for them.  no problem.  But the fact that, for me, the mmu is hit or miss with out changing anything is what's so frustrating.   I recently printed a huey in petg with bvoh.   The fuselage printed fined, over 500 tool changes.  With the same settings and same spools loaded, I printed the main rotor and tail rotor.  intervention after intervention.....     got annoyed, took a day and came back to it and it worked.   that's the kind of thing I'm talking about. 

Posted : 27/05/2021 5:48 pm
Baklin
(@baklin)
Reputable Member
RE: Thanks to the Forums

I have added a few mods with I build it. I have done a color change so was printing all the parts any way.

I'm still happy with my MMU and would buy it again if I had to start over.

 

The 17+ hour print with 504 filament changes finished without and problems. Also no cut pieces in the MMU, so it didn't have to cut any filaments to keep going.

 

 

 

This is my setup now. All 2mm ID PTFE tubes and my remix of an auto rewind spool holder.

A buffer is easier and more foolproof as it has no moving parts. But I don't have enough room behind my printer to put a buffer and keep the tubes short enough.

 

 

Posted : 28/05/2021 5:14 pm
gglockner liked
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@baklin

Nice. I just got new tubes in. Should be putting the thing back in enclosure here in a bit

Posted : 28/05/2021 8:20 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

Ok, I'm trying this again after putting everything back in the enclosure with fresh tubes.  I did of course have it stop over night but I was able to recover.  I think the power may have blinked due to thunderstorms.  I have the printers on UPS, but I've found that the printer doesn't seem to handle it well.  I was able to resume the job after pulling the one filament and cutting a fresh tip on it.

Posted : 29/05/2021 12:43 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

@baklin

as I was typing the last message of course it hung up on the same filament again.   I think I'm going to have to try to shorten the tube length and do something like your setup to use some open space in lieu of using the buffer.

Posted : 29/05/2021 12:52 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

While I'm waiting for this print, I got the latest prusaslicer to build from source.  the mmu painting thing is a game-changer.

Posted : 29/05/2021 1:25 pm
ssill2
(@ssill2)
Noble Member
RE: Thanks to the Forums

ok, the blob on the purge block happened again.  And thus makes the print unrecoverable.  The nozzle starts to hit this and triggers crash detection.  Ok that was attempt 4 on this thing.  

Posted : 29/05/2021 1:37 pm
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