strange behaviour of my vcore
Hi
I am having some strange behaviour from my vcore v3.1 ,I switched it on this morning to run a print and when it homed the axis it made a very loud resonating noise and ran slowly like as if the steppers were grinding .
Anyway after a while it sorted itself out and I managed to get a print off fine.
Now gone and started another print and it started to do the same.
Please see the poor video of it lol
I haven't changed anything and when moved hand the axis run fine.
What could it be please.
Thank you
9 Replies
run a resonance test...that at that particular speed is sounds like the carriage rattle on the linear rail
on second review.... wondering why it went to Xmax after homing Xmin Sound/looks like one of your steppers is misbehaving...as it takes BOTh AB steppers (rear corners) running at the same speed to run a striaght line in X or Y only. It's homing on X, then never really homes on Y (gos to X max then to Y max)
Agree with this... Not 100% sure what would cause this but given the noise and the intermittent behavior, I'd look to replace the stepper drivers for a & b and see if that helps
unless you're trying to do crazy speeds, you can also turn down your current just a tad. If in perf mode, just override it in printer.cfg and back it down to 1.5A (from the 1.68A by default) But if you have cooling on the drivers, they should not be your issue. Again, test the resonance as various speeds. Lower (~300mm/s at homing) makes those noises (vibrations) but at faster speeds it's not doing it. Thus my suggestion it's the carriage rattling on the linear rail (BTDT)
Def keep us posted... Haven't seen anything like this before so can prob learn something from it
..... funny....this same issue (noise at different speeds) is currently being discussed in the vzbot discord channel as well! same consensus.... different vibes at diff speeds.
stormy-gold•12mo ago
Thank you for all your inputs much appreciated.
I have been running this machine for over a year with no problems my homing speeds are usually 750mm/s and I am running 2209s cooled it's seems to start up like this and after a few homes goes away and then runs fine.
As you can see from the video the homing is all over the please and it even attempts to pickup the euclid in the middle of the bed so it was out of sync.
I have been running the steppers at 1.8 so maybe I have over done them but everything has been running fine but just lately the weather in the UK as been hotter than usual.
Thanks again
2209s are not really designed to run that high a current. The mosfets could be starting to go, and or motor winding insulation breaking down especially as temps rise.
stormy-gold•12mo ago
You could be right ,I shall lower them down to standard .
Unless you have rail binding, or are running crazy speeds, there is no real reason to run high currents. It's better to run high voltages.
In practical terms, your stepper motor windings are only a few ohms. EG: 24V / 2 ohms = 12A! Yet a spec sheet will say the windings can handle 1-6-2.5A (depending on stepper motor in question here) . The drivers 'pulse' power to the windings...even when not rotating (hold mode). The inductance of the windings controls how fast you can charge the coil to get full power to the motor. I digress.... easy to remember here... volts/amps/resistance/power voltage is the steepness of the hill, current is how many rocks you loaded into the wagon, resistance is brakes/no brakes, power is the resultant speed down the hill. So upping the voltage, while retaining the original rock load, the wagon goes down the hill faster.
Yeaha..childish example, but easy to understand the resulting actions. (ref... this is why you see 'VA' specs on stuff...'total work possible/probable' specifications) It Klipper...the current setting 'can' overload the wagon with rocks if you set it that way. Creates heat in wheel bearings, stess on the wagon etc. The stepper hill you just go faster. he he