MK3S Upgrade kit is HERE!!!!  

Re: MK3S Upgrade kit is HERE!!!!

It seems to me that the grinding problems should be less because the mmu2 unit doesn’t have to push into the bondtech gears to know where the filament is.

No, it does. According to what we've seen here on the last 2 pages, filament does have to engage the bondtech gears to trigger the sensor. It's the movement of the idler door after gear engagement that actuates the IR sensor. It's a setup specialised for the mmu2s for the mk3s extruder.

Re: MK3S Upgrade kit is HERE!!!!

It seems to me that the grinding problems should be less because the mmu2 unit doesn’t have to push into the bondtech gears to know where the filament is.

No, it does. According to what we've seen here on the last 2 pages, filament does have to engage the bondtech gears to trigger the sensor. It's the movement of the idler door that actuates the IR sensor specialised for the mk3s extruder for the mmu2s.

So, there are 2 key points when loading filament.

Firstly, the Bondtech gears are kept moving during the load process at the same speed as the MMU final load speed (except for the first load of a print, which is a real PITA)

and secondly the Bondtech ider door movement triggers a sensor which immediately disengages the MMU drive

This does not prevent stringing and its consequences; this is a different issue altogether. There are two major issues here (other than temp settings)

First, the friction through the feed path. This must be minimised to reduce stringing.

Second, there's the Bondtech gear alignment. This must be exceedingly precise. If it's out by 0.1mm, the filament will not feed straight when entering the PTFE which will cause high friction, initial unloads will have skipping and stringing will occur.

As one further note, the Bondtech tension can be higher than before to assist with the initial unload, but in this case, the first load may have to be assisted, because the Bondtechs are not turning (see above).

Peter

Re: MK3S Upgrade kit is HERE!!!!

As one further note, the Bondtech tension can be higher than before to assist with the initial unload, but in this case, the first load may have to be assisted, because the Bondtechs are not turning (see above).

Am I correct in assuming that the issue with the Bondtech not turning on the initial load is something that could be fixed in a future firmware update?

Re: MK3S Upgrade kit is HERE!!!!

Am I correct in assuming that the issue with the Bondtech not turning on the initial load is something that could be fixed in a future firmware update?

Don't see why not. In fact the constant turning/clicking of the Bondtech during a filament change is also a PITA. I have put forward the idea that the Bondtech starts turning when the filament gets close - for all loads, signalled by MMU.

Peter

Re: MK3S Upgrade kit is HERE!!!!

Ooh, I wants that. I stand corrected, I thought the MK3S parts available to print were the same thing.

😀 😀 😀

Printed parts are here: https://github.com/prusa3d/Original-Prusa-i3/tree/MK3S/Printed-Parts/STL

But look for the ones labelled MMU2s.

Peter

So are those parts different than the self-printed MK3 to MK3S parts? https://www.prusa3d.com/downloads/others/mk3-mk3s-upgrade.zip
Since the email about the MMU2S upgrade said it included the 3 to 3S upgrade (which is what my link is to), I assumed they were one and the same.

In either event, I downloaded and printed the 3 to 3S upgrade parts, and they have the places for the new filament sensor, ball bearing, magnets and swivel that the animations pictured earlier showed.

UPDATE:
I just downloaded the MMU2S specific ones that Peter linked to, and compaired the two in Slic3r PE. They are indeed different designs. Some of the parts from the 3 to 3S upgrade are still required though:

Re: MK3S Upgrade kit is HERE!!!!

So with the new non-light based sensors, I guess we can now have a 100% non-black extruder now.

Re: MK3S Upgrade kit is HERE!!!!

Here is a description of the design changes and nice comparrision of the differences between MK3s and Mk3s + MMU2s:

https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f61/new-printed-parts-c1-r4-mk3s-mk2-5s-mmu2s-t27888.html

Re: MK3S Upgrade kit is HERE!!!!

Here is a description of the design changes and nice comparrision of the differences between MK3s and Mk3s + MMU2s:

https://shop.prusa3d.com/forum/general-discussion-announcements-and-releases-f61/new-printed-parts-c1-r4-mk3s-mk2-5s-mmu2s-t27888.html

That's great, thanks for that info. Very handy.

Re: MK3S Upgrade kit is HERE!!!!

Hey Peter, did you print the upgrade parts yourself or did Prusa send them to you to test? If you printed them, where'd you source the threaded insert on the new FS cover?

Also, have you tried flexible material with the new setup? I've heard that the new sensor design makes printing with flexible material much more reliable.

Thanks for all the info and feedback you've been providing on this thread! It's really become a great "Ask a Beta Tester Anything about the upgrade" thread. 😀

Re: MK3S Upgrade kit is HERE!!!!

Thank you Prusa. I upgraded my printer and come out with better results than the kit I started with. My live Z is 0.00 and I have much less noise.

Re: MK3S Upgrade kit is HERE!!!!

I finished installing the MK3s extruder upgrade on a MK3. I did the firmware update, ran all the calibration steps. And... it doesn't work. It seems to be caught in a loop where it thinks it needs to load filament, and just wants to unload and load over and over again.
Did anyone else see this?

Re: MK3S Upgrade kit is HERE!!!!

I finished installing the MK3s extruder upgrade on a MK3. I did the firmware update, ran all the calibration steps. And... it doesn't work. It seems to be caught in a loop where it thinks it needs to load filament, and just wants to unload and load over and over again.
Did anyone else see this?

I haven't done my upgrade yet, but I seem to think I remember hearing that if the screws holding the sensor board down are too tight it may throw it out of alignment. Sounds like something simple to try to me...

Re: MK3S Upgrade kit is HERE!!!!

well, let me know when you've finished the install and firmware update. Curious to know if I'm a special case of if this is happening to other people.

Re: MK3S Upgrade kit is HERE!!!!

well, let me know when you've finished the install and firmware update. Curious to know if I'm a special case of if this is happening to other people.

Don't hold your breath. I may not have a window of time to do my upgrade for another week or two (by which time I'll probably have forgotten about this thread). I'm not trying to be mean, just honest. I know myself too well. 😉

Have you searched for the message(s) that I alluded to? (I'm not going to bother searching right now as it doesn't directly affect me yet.) Have you tried backing the screw off on your unit (from really tight to snug)? Seems to me to be a quick and simple thing to try. You built the kit, you should still have the tools lying around...

Re: MK3S Upgrade kit is HERE!!!!

During the assembly, there was a note to be careful about leaving the little lever loose so that it could move freely. I took a couple video shots of the assembly , and in the video it appears to be appreciably loose, but not sloppy loose.

Good luck on your assembly, I thought the kit was kind of fun. Watch when you assemble it on the horizontal bars, the lower linear bearing was a little tricky to get aligned right, the fit into the clamshell bracket was little tight.

Re: MK3S Upgrade kit is HERE!!!!

I finished installing the MK3s extruder upgrade on a MK3. I did the firmware update, ran all the calibration steps. And... it doesn't work. It seems to be caught in a loop where it thinks it needs to load filament, and just wants to unload and load over and over again.
Did anyone else see this?

Mine worked fine after the upgrade. Perhaps there is something wrong with the sensor. You can see the sensor value to verify that it's working. I believe it's in the menu at: LCD menu > Support > Sensor info > IR value. When the IR value is "1", it is detecting filament. If it's "0", it's not. I'm curious why it keeps trying to unload the filament.

I had problems when I did the MMU2S upgrade. The arm which triggers the sensor wasn't long enough and I had to modify and re-print one of the parts to bring the arm closer to the sensor. In my case, it would keep trying to push the filament into the extruder at full speed.

Re: MK3S Upgrade kit is HERE!!!!

During the assembly, there was a note to be careful about leaving the little lever loose so that it could move freely. I took a couple video shots of the assembly , and in the video it appears to be appreciably loose, but not sloppy loose.

Good luck on your assembly, I thought the kit was kind of fun. Watch when you assemble it on the horizontal bars, the lower linear bearing was a little tricky to get aligned right, the fit into the clamshell bracket was little tight.

From a post I read here or saw on Youtube the lever with the magnet can be very loose if it's put in backwards and the "poles of the magnet are repelling and not attracting".
I don't have my MK3S upgrade yet, just remember reading about it.

Re: MK3S Upgrade kit is HERE!!!!

During the assembly, there was a note to be careful about leaving the little lever loose so that it could move freely. I took a couple video shots of the assembly , and in the video it appears to be appreciably loose, but not sloppy loose.

Good luck on your assembly, I thought the kit was kind of fun. Watch when you assemble it on the horizontal bars, the lower linear bearing was a little tricky to get aligned right, the fit into the clamshell bracket was little tight.

From a post I read here or saw on Youtube the lever with the magnet can be very loose if it's put in backwards and the "poles of the magnet are repelling and not attracting".
I don't have my MK3S upgrade yet, just remember reading about it.

The magnets are ment to repel, not attract, if they attract then the printer will think that filament is loaded when it isn't.

Re: MK3S Upgrade kit is HERE!!!!

I had problems when I did the MMU2S upgrade.

Out of curiousity, when did your MMU2S upgrade arrive?

Re: MK3S Upgrade kit is HERE!!!!

During the assembly, there was a note to be careful about leaving the little lever loose so that it could move freely. I took a couple video shots of the assembly , and in the video it appears to be appreciably loose, but not sloppy loose.

Good luck on your assembly, I thought the kit was kind of fun. Watch when you assemble it on the horizontal bars, the lower linear bearing was a little tricky to get aligned right, the fit into the clamshell bracket was little tight.

From a post I read here or saw on Youtube the lever with the magnet can be very loose if it's put in backwards and the "poles of the magnet are repelling and not attracting".
I don't have my MK3S upgrade yet, just remember reading about it.

The magnets are ment to repel, not attract, if they attract then the printer will think that filament is loaded when it isn't.

I understand this, but I was trying to let Byron know to check to see if he put his on backwards. The magnets repelling might of been his issue, but I think he resolved it already.