Don't make the MMU3 more difficult that it has to be...  

RE: Don't make the MMU3 more difficult that it has to be...

This is really how the MMU integration should have looked in the first place!

But I wonder why Prusa did not implement it that way, and went for the clumsy hood/blob/turret on top. Could it be that they do not trust the MMU to feed filament through the sharp bend in the PTFE tube? The main purpose of that ugly hood seems to be that the PTFE tube can lead straight into the Nextruder, after a large-radius bend.   

RE: Don't make the MMU3 more difficult that it has to be...

I agree.  While the coefficient of friction of PTFE is low and these Bondtech extruders are strong, the best path is always going to be the shortest and straightest.  However, It seems to work.  I only have issues with one specific spool of PETG stripping on occasion.  

RE: Don't make the MMU3 more difficult that it has to be...

The link shows the need to change parts on the Nextruder, forgive me for being a bit slow to work this out, but is this needed on the core one? I’m going to be pretty peeved if I have to start stripping the nextruder down after just building it to connect my MMU, once I’ve actually built it of course.

Thanks in advance,

Scott

RE: Don't make the MMU3 more difficult that it has to be...

There are a few changes yo need to make to the nextruder if you hadn't already done them on a previous iteration.

RE: Don't make the MMU3 more difficult that it has to be...

Right okay. I only finished building my C1 kit yesterday, so I’m hoping the necessary parts are already included in the build I put together. Maybe I’m missing something, but wasn’t the C1 meant to be MMU3 ready? Like I say, I’ll be pretty miffed if I have to strip down the gearbox/nextruder after just assembling it.

Scott

Posted by: @discojon

There are a few changes yo need to make to the nextruder if you hadn't already done them on a previous iteration.

RE: Don't make the MMU3 more difficult that it has to be...

Step 25 of the MMU3 kit assembly manual looks like it involves changing out the main plate of the Nextruder of the C1.

RE: Don't make the MMU3 more difficult that it has to be...

Posted by: @ssmith

Step 25 of the MMU3 kit assembly manual looks like it involves changing out the main plate of the Nextruder of the C1.

Is it possible to use the modified filament detector made for MMU without the MMU?

It could be a nice way to feed soft TPU without the ball type filament detector to pass through.

RE: Don't make the MMU3 more difficult that it has to be...

"Is it possible to use the modified filament detector made for MMU without the MMU?"
That's an interesting idea, looks like it should be. 

RE: Don't make the MMU3 more difficult that it has to be...

Yes, it is possible. You either have to push a little harder on the filament, or you can push the idler lever a little to the left while you push on the filament. You will see (on the display) and feel that the filament is feeding.

RE: Don't make the MMU3 more difficult that it has to be...

Is the o’ring mandatory?

Sorry, it’s a little off-topic.

RE: Don't make the MMU3 more difficult that it has to be...

The original plate is not designed for so many filament changes, hence the new plate comes constructed from a different material and the o-ring, and can handle a ton more filament changes - considering a single print could have hundreds of changes. 

Posted by: @scott-18

Is the o’ring mandatory?

Sorry, it’s a little off-topic.

RE: Don't make the MMU3 more difficult that it has to be...

Posted by: @scotttomo

The link shows the need to change parts on the Nextruder, forgive me for being a bit slow to work this out, but is this needed on the core one? I’m going to be pretty peeved if I have to start stripping the nextruder down after just building it to connect my MMU, once I’ve actually built it of course.

Thanks in advance,

Scott

Yes, it is still needed. 

The plate inside the extruder assembly needs to be changed, as does the filament sensor and idler swivel assembly. 

The idler side door is the same material so does not need to be changed. 

RE: Don't make the MMU3 more difficult that it has to be...

To @scotttomo point, why not just do this work on the Core One.   There really is no reason not to.  especially since you can't get all the parts for the remodel.  I am missing that stupid magnet.  No place to source it from what I can find.  

RE: Don't make the MMU3 more difficult that it has to be...

Posted by: @mander

missing that stupid magnet.  No place to source it from what I can find.  

Measuring the pocket for the magnet in PrusaSlicer, it looks like a 3mm x 1mm disc would fit. Partsbuilt sells a package of 4 3mm discs that look in the picture like 1mm thick, or Amazon will sell  a couple hundred for a few dollars more. Can't be sure those are of adequate strength, though.

RE: Don't make the MMU3 more difficult that it has to be...

Hi, don´t use the chinese 3x1mm magnets, they are weaker than the Prusa ones, so the filament sensor doesn´t work as it should be. And non-detection loading failures are really bad cause they mostly turns into clogging the nozzle and extruder.

If there is no Magnet Grade noted, then it would be anything, but I assume Prusa is using N48 Magnets, cheap Chinese ones might be N38 and below.

So try to get N48 Magnet or order the Prusa Magnets.

As alternative there are mods for the FS Arm with 3x3 magnet available, which are also working.

Greets Thorsten

RE: Don't make the MMU3 more difficult that it has to be...

Here you can see the difference of the magnet strength for the prusa 3x1mm magnet and some I purchased over amazon.

Both magnets are placed with radius upright, under a magnet indicater sheet, both with identical distance. On the left is prusa, right is amazon, you can see the differnt strong magnetic field.