MMU V2 Stepper for Idler is warm
Hello out there,
my stepper for the idler (Not Selector and not the "Extrude") becomes warm after switching the printer on, which switches the MMU on, too.
It is fully functioning but it sounds like a slow running fan and the motor becomes warm, even if he is doing nothing. The "fan" sound is clearly
coming from the stepper itself.
Don't think, that this is normal.
Any ideas, what's wrong... Stepper defect???
Thanks in advance,
Dirk
Re: MMU V2 Stepper for Idler is warm
Good morning Dirk,
the stepper motors do not have any indication of their current position, at any time.
when the printer is turned on, the Z motors are energised and the MMUv2 motors are energised.
the MMU, Initialises, and moves the idler and selector to ensure that it knows where they are in relation to end-stops within the mechanism,
the motors remain energised to maintain the positional accuracy during the print session.
Prusa have found that the Z axis motors (being lead screw motors), don't normally need to be 'Reset' every time the printer is turned on, but they are at risk of getting out of 'synch', during maintenance procedures, so the power is maintained whilst the printer is turned on.
if the Z motor synchronisation is disturbed, it can be reset by raising the Z axis all the way to the top,until the X axis end pieces both rattle against the Z axis top brackets. which ever z motor arrives at the top first, loses steps until the other motor reaches the top, at which point, they are once again deemed to be synchronised.
the X and Y motors are un- powered whilst the printer is at rest, and the Gcode 'start code' initialises these motors at the beginning of every print. once initialised, the X and Y motors remain powered until the end of the print G code. when they are turned off by the'end Gcode'
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: MMU V2 Stepper for Idler is warm
Always powering the stepper motors seems is quite a waste of energy. The printer could go into a sleep mode an turn off all stepper motors. When waking up, a Z calibration an MMU reset should occur. That would really be very convienient, especially if the printer is connected to an Octopi.
Please, Josef Prusa, consider an energy-saving sleep mode.