Questions about silent mode in MK3  

Re: Questions about silent mode in MK3

Hi Jaroslaw,

I believe that crash detection does not work in silent mode, because the way that the trinamic stepper drivers are driven prevents reliable collision sensing.

regards Joam

Re: Questions about silent mode in MK3

1) Is it possible to evaluate the percentage risk of printing failure, let's say in 10 cases? In other words, I would have print 10 models - would it be possible to determine that in the first of them (ie the risk of 10%), the layer will move - or is it rather so rare and random that it cannot be predicted / there is nothing to worry about?

it is random, out of hundreds of prints i had about 20 times that x or y had a collision

2) So, do I turn off the layer shift (that prints me suddenly, eg 1 cm to the right from the previous layers), or collision detection - that after shifting the extruder he will not return to his place, when I'm turning silent mode on? Or both? Because I thought it was the first thing only, could someone say how it is.

layer shift happens when the print head or bed is impeded in some way and it loses x,y zero points and does not accurately know where it is. in normal mode it will recover most of the time since the drivers providing current to the motors detect that the motors are requiring more current than they should. in silent mode current levels are reduced and therefore the feedback is not detectable by the drivers. this is why crash detection is not possible

3) If there is a print error in the silent mode, will the entire printout be discarded? So in short, when printing something large, it should only be done in normal mode?

well that depends on a few things
1) is the part still usable? you decide this
2) are you there when it happens? if so you simply turn it back to normal mode and cause it to rehome

4) Do you think that Prusa can handle this and there will be some update, or in the future they will reach the place where the silent mode will not have any negative impact on the print?

as noted this is expected of low current mode (ie silent mode)

5) Is this a problem only for this printer, are all printers equipped with this quiet mode of operation so have?
as noted this is expected. I am unsure if any other printer has this technology. most printers, when they crash, simply fail the print and do not recover.

6) What exactly is it that Prusa cannot keep this setting while working quietly? The printer is pretty quiet in normal mode. silent mode is literally that. so unless you have some reason for having the printer silent, leave it in normal.

Re: Questions about silent mode in MK3

Thank you for your detailed answer,
to make sure we are on the same page - does silent mode in prusa mk3 prevent from getting leyer shift BY ITSELF in effect of some error which I cannot imagine now, or it prevents from getting layer shift BY PUSHING EXTRUDER by applying force? Or both?
I am asking beause - if a printer is not pssible to be touched by anyone during printing - is it still possible to get layer shifts?

Does silent mode - prevents from layer shifts (which can happen by itself/which cannot happen by itself it needed to be triggered manually) or from collision detection (rolled filament etc.)?

2) are you there when it happens? if so you simply turn it back to normal mode and cause it to rehome

So if I understand correctly - when I would turn it back manually to normal mode - it would detect when the currect was bigger last time, and would print from that point?

Is it possible to write a script to switch to normal mode automatically when failure happens?

Re: Questions about silent mode in MK3

Thank you for your detailed answer,
to make sure we are on the same page - does silent mode in prusa mk3 prevent from getting leyer shift BY ITSELF in effect of some error which I cannot imagine now, or it prevents from getting layer shift BY PUSHING EXTRUDER by applying force? Or both?
I am asking beause - if a printer is not pssible to be touched by anyone during printing - is it still possible to get layer shifts?

lets divide this out, layer shifts are caused, as i mentioned before, by having either the x or y motion restricted. for instance, if the tip of the extruder hits a part of the print that has warped up it may not be able to go left or right, or front or back, in any case since the motion is stopped the layer will now be shifted in that direction.

What prusa does for layer shift recovery is, when the printer is in normal, detect excess current events. These indicate when the motor is stalled by a restriction to the motion. It then rehomes to recover the shift.

In "quiet" mode the current to the motors is reduced, This actually makes layer shifts more likely since the motors will not push as hard.
This also makes detecting current draw increases unreliable. this is why it cannot detect.

2) are you there when it happens? if so you simply turn it back to normal mode and cause it to rehome

So if I understand correctly - when I would turn it back manually to normal mode - it would detect when the currect was bigger last time, and would print from that point?

Is it possible to write a script to switch to normal mode automatically when failure happens?

you misunderstand, turning normal back on is step 1 crashing, on purpose is step 2 them it would rehome.
as far as a script, you could insert a rehome x,y command on every layer if you want. i dont see a point. crashes dont happen frequently enough to warrant doing that.

do you have an mk3?

Re: Questions about silent mode in MK3

OK thanks for explaining it for me.
Yes, I do have mk3