Re: MK3S - New printer model
No worries. Happy to help.
Re: MK3S - New printer model
Is it turned off? False jam detection is commonplace. Not detecting jams is unusual (unless turned off).
My sensor is very much on. Like Nikolai said, i guess that precision is just too low to be sure what sensor really detects. So, if something is so unreliable (such as no jam detection, false jam detection, blindness for some colors...) is way better NOT to have it at all. In my case loading new filament usually needs to push filament two or three times before sensor "see it" and starts to load. Rather annoying.
But, it would be nice if someone from Prusa developers would write some words and explain why decision to remove jam detection was removed. They surely had a good reason to do it...
Re: MK3S - New printer model
We all recognise that the original Mk3 sensor setup wasn't very effective. The point I was making is that these problems you list have been solved, and that at some stage it's likely Prusa will have to reinvent the wheel and bring jam detection back.
I suspect the new sensor is a way to step back from complexity for a bit. It's a very simple item to troubleshoot (maybe. I'm not sure about the MMU door sensor). Might be a case of freeing up resources to focus on other, more pressing, matters.
Re: MK3S - New printer model
One way to have the new system detect filament movement woud be to use an encoder wheel with slits/spikes attached to a small bearing. As the fliament moves against the bearing the encoder wheel could turn and register a change in the new sensor, but it is more mechanically complicated to do this than to just have the original sensor detect a moving bearing as the mod does. Perhaps Prusa were worrind that a buid up of dust would interfer with the free movement of the bearing?
Re: MK3S - New printer model
Is there difference in printed parts beside the Extruder body, Y-Axis belt holder and tensioner. My Mk3 was shipped Jan 24, 2019.
If I had of known a new version was about to hatch 2 weeks later I would have waited and got the upgrade.
I looked over the full published printer parts for MK3S in github repo, and the only thing I see changed are the ones you mentioned, extruder is R4 now and stuff for the Y belt are R4. For other parts they seem the same. If you have another printer you can prepare the Y axis parts now. For the extruder it's not that easy - apart from the missing sensor, magnets and ball, it seems that the PTFE tube is shorter, so cutting that could be problematic. Other parts (plus the nots and bolts from the spare parts) could be enough to mount the new plastic parts.
Re: MK3S - New printer model
Perhaps Prusa were worrind that a buid up of dust would interfer with the free movement of the bearing?
I believe so too. Maybe that is also why they don’t use gears for a different extruder ratio like a 3:1 that the bondtech mk3 extruder uses.
A solution for both “problems” would take the mk3 to a new level.
Re: MK3S - New printer model
looking for the new-to-print parts but seem not able to find stl's somewhere.
Does anyone have or found more info on this?
https://www.prusa3d.com/prusa-i3-printable-parts/
https://github.com/prusa3d/Original-Prusa-i3/tree/MK3S/Printed-Parts
thx chap!
Re: MK3S - New printer model
Bear in mind that dust is also a problem for current laser sensor... Prusa even posted a video where clearly say that a user should check and be sure that sensor sufrace is clean, dust free and without any scratches.
Re: MK3S - New printer model
We all recognise that the original Mk3 sensor setup wasn't very effective. The point I was making is that these problems you list have been solved, and that at some stage it's likely Prusa will have to reinvent the wheel and bring jam detection back.
I suspect the new sensor is a way to step back from complexity for a bit. It's a very simple item to troubleshoot (maybe. I'm not sure about the MMU door sensor). Might be a case of freeing up resources to focus on other, more pressing, matters.
The interesting thing is that the revised sensor is actually more complicated, strictly speaking. What (should, we don't really have any reviews yet. Haven't assembled mine yet) makes it more reliable is essentially making it a closed system. The flaw in the optical sensor is the same as has been a problem with optical mice for their entire history... they are fairly easily flummoxed by unusual, particularly glossy, materials. The revised sensor uses IR not visible light, and by measuring against a piece of the mechanism rather than the filament directly, material shenanigans are theoretically eliminated (it does raise the question of how filament movement might be detected, however. We all assume the new sensor lacks that capability, but we'll know for certain when we start getting reports from people. As an engineer, I am for one very curious as to how they might have achieved it if the capability has somehow survived.
As for intent: Frankly, I think it's a simple pragmatic decision. Adding the mechanical element removes a degree of variability (the unknown characteristics of whatever filament is coming through), thus theoretically increasing reliability massively for a minor increase in complexity. Assuming the ability to detect filament movement has gone away, there are various mechanical options for potentially bringing it back. The most obvious being an optical encoder akin to ball mice (though their tendency to get dusty and such would be undesirable)
Re: MK3S - New printer model
The interesting thing is that the revised sensor is actually more complicated, strictly speaking...
Only mechanically. Electronically it's very simple. In the firmware it's also very easy to read AD pin and react to a threshold. You don't even need to debounce the value.
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Re: MK3S - New printer model
The interesting thing is that the revised sensor is actually more complicated, strictly speaking...
Only mechanically. Electronically it's very simple. In the firmware it's also very easy to read AD pin and react to a threshold. You don't even need to debounce the value.
Yes, of course you are right (unless they're doing something clever in there. I haven't looked at the code). I was only really thinking about the hardware.
Re: MK3S - New printer model
The interesting thing is that the revised sensor is actually more complicated, strictly speaking...
Only mechanically. Electronically it's very simple. In the firmware it's also very easy to read AD pin and react to a threshold. You don't even need to debounce the value.
and judging by some of this, it looks like it does have some electrical debouncing. thats good, you wont get loads of crazy readings, you will get "off" or "on".
https://github.com/prusa3d/MKxS-IR-sensor/blob/master/rev.01/ibom.htm l"> http://htmlpreview.github.io/?https://github.com/prusa3d/MKxS-IR-sensor/blob/master/rev.01/ibom.html
the sensor is all thats needed, and only has 2 states, that is all that should be there. i always felt the original one was overkill bordering on flawed, and well, i was right. it relied on too many variables being perfect. too many people expected it to work flawlessly with 5000+ different materials. this this approach is better, i would have prefered to see a bearing, but i expect this to be so much better, and ill be able to turn the sensor back on.
https://www.mouser.com/ds/2/307/EE-SX1103_1010-6312.pdf didn't go for cheap .05c ones either.
without having it in my hands, after looking over the redesign. i consider it all 95% improvement from a mechanical and electronic standpoint.
firmware concerns? i dont think they are going to wipe the original firmware out of existence. and i dont see it being difficult at all to add lines of code back in... who knows, they may have just commented the old code out if needed or left it in since it wants to know, object, or no object .
if i get time, ill look over the firmware code and see what has changed(for gits and shiggles)
and we’ll be saying a big hello to all intelligent life forms everywhere … and to everyone else out there, the secret is to bang the rocks together, guys.
Re: MK3S - New printer model
I took a quick look at the code, I didn't take enough time to really analyze it, but it looks like there is, in fact, no motion detection implemented with the IR sensor, and thus Jam detection capability does in fact appear to be lost (unless there's something I'm not seeing). This is what everyone suspected, but disappointing.
Re: MK3S - New printer model
Is there difference in printed parts beside the Extruder body, Y-Axis belt holder and tensioner. My Mk3 was shipped Jan 24, 2019.
If I had of known a new version was about to hatch 2 weeks later I would have waited and got the upgrade.
I looked over the full published printer parts for MK3S in github repo, and the only thing I see changed are the ones you mentioned, extruder is R4 now and stuff for the Y belt are R4. For other parts they seem the same. If you have another printer you can prepare the Y axis parts now. For the extruder it's not that easy - apart from the missing sensor, magnets and ball, it seems that the PTFE tube is shorter, so cutting that could be problematic. Other parts (plus the nots and bolts from the spare parts) could be enough to mount the new plastic parts.
Thanks for the check. I was printing the Y parts as I wrote the question. Currently the extruder parts are running. LOL fasteners are not a problem. My regular job is design, build, program industrial machines.
Since I am going to be taking things apart I am going to make some changes besides the Mk3S stuff. A pair of those is replacing the threaded screws through the idle pulleys to proper shoulder bolts. If I have to tweak parts no biggie.
I will order the upgrade sensor pack. I have had issues with the current filament sensor.
Re: MK3S - New printer model
You don't need to look into code to see that new sensor doesn't have jam functionality. Design alone tells that- it's just a simple IR switch. What is real question is does OLD system has this function or doesn't?
Re: MK3S - New printer model
Sorta off topic from the current discussion, but when do you expect PR will be releasing the MK3 to MK3S upgrade guide? (as well as the MMU2S guide)
Jonathan Kayne
Virginia Tech Class of 2021 - Electrical Engineering
Thingiverse Profile: https://www.thingiverse.com/jzkmath/about "I am always thinking about making. My future begins when I wake up and see the light." - Miles Davis
Re: MK3S - New printer model
I doubt it will be long now...
Re: MK3S - New printer model
You don't need to look into code to see that new sensor doesn't have jam functionality. Design alone tells that- it's just a simple IR switch. What is real question is does OLD system has this function or doesn't?
build guide is already available. see extruder section in new manual. been avail since the 13th.
and we’ll be saying a big hello to all intelligent life forms everywhere … and to everyone else out there, the secret is to bang the rocks together, guys.
Re: MK3S - New printer model
build guide is already available. see extruder section in new manual. been avail since the 13th.
It is not the same as an upgrade guide.
Re: MK3S - New printer model
I wonder how quick PR will get the upgrades out the door? Limiting factor is probably the IR sensor stocks, I guess.. other than that, it's the magnets, PTFE tube, any additional fixings and documentation. Plus it ships with 300g of black prusament ( which is supposedly sold out? )
If there are 10k (??) mmu2 units out there, that's a lot of prusament.