Does the MK3S+ upgrade from stock MK3 lose the filament jam detection?
 
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Does the MK3S+ upgrade from stock MK3 lose the filament jam detection?  

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dimprov
(@dimprov)
Noble Member
Does the MK3S+ upgrade from stock MK3 lose the filament jam detection?

According to this article: https://hackaday.com/2020/10/08/the-prusa-i3-mk3s-and-a-tale-of-two-sensors/

the filament jam detection ability was lost when upgrading from stock MK3 to the MK3S version.  It says that MK3S is only able to recognize whether or not there exists filament in the hotend, not whether it is moving or not.  Does the MK3S+ upgrade restore that functionality, or does that functionality remain lost?

I'd like to either keep that functionality, or else find another way to add it back in.  Any ideas for how to do that?

Posted : 03/12/2020 7:18 am
cwbullet
(@cwbullet)
Member
RE: Does the MK3S+ upgrade from stock MK3 lose the filament jam detection?
Posted by: @dimprov

According to this article: https://hackaday.com/2020/10/08/the-prusa-i3-mk3s-and-a-tale-of-two-sensors/

the filament jam detection ability was lost when upgrading from stock MK3 to the MK3S version.  It says that MK3S is only able to recognize whether or not there exists filament in the hotend, not whether it is moving or not.  Does the MK3S+ upgrade restore that functionality, or does that functionality remain lost?

I'd like to either keep that functionality, or else find another way to add it back in.  Any ideas for how to do that?

I do not have a way to add it back, but you are spot on.  It do not think it exists in the standard MK3S.  

--------------------
Chuck H
3D Printer Review Blog

Posted : 03/12/2020 2:26 pm
dimprov
(@dimprov)
Noble Member
Topic starter answered:
RE: Does the MK3S+ upgrade from stock MK3 lose the filament jam detection?

I can think of two possible solutions:

1.  Modify the original MK3 optical sensor to use a "darkfield" mouse senosr.  Those are sensors that are used in mice that can work even on a glass tabletop.

or

2.  Find some way of detecting when the undriven extruder gear (whatever those toothy bearings are called that grab the filament and force it into the hotend) is moving round-and-round.

or

3.  As the hackaday article suggests, finding a way to track whether the roll of filament is moving.  This, while easier, isn't as good, as there might be some time lag, whereas the first two methods would presumably notice a jam much sooner.

Alas, this is what I paid Prusa to have figured out when I purchased the printer.  A couple years of R&D should have sorted it out.   I'm sorry to hear that instead  Prusa has (apparently)  removed the feature and given up on it.    To me that means the MK3S/+ "upgrades" are at least partially downgrades.

This post was modified 4 years ago 2 times by dimprov
Posted : 03/12/2020 8:11 pm
dimprov
(@dimprov)
Noble Member
Topic starter answered:
RE: Does the MK3S+ upgrade from stock MK3 lose the filament jam detection?

Anyway, perhaps the "spaghetti detective" would eventually notice that the hotend is printing air rather than filament?  Again, not ideal because of  the lag, but maybe better than no jam detection at all?

Posted : 03/12/2020 8:23 pm
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