Topics created by sga

@dc42 Thanks

I will report on that. It definetly doesn't like nozzle crashing into it.
I upped the temperature with edge filament to 240°C and I am doing a print tonight first layer adhesion is actually better ( I used too low temperatures due to some wrong indication on the e3d sticker spool box and also because I was lacking experience)
I still get a lot of goo around the nozzle which I need to babysit clean every 5-10 layer or so… I wonder what is wrong in my slicer settings. The ngen (colorfab) didn't do that.
problem with the goo is that it detaches and hardens always at the worst place and then you get a nozzle crash...

Where can I get those slim blower fans?

Thanks!
Ian

@peridot:

I'm still not clear about whether RepRapFirmware can turn the stepper motors off when they've been idle for long enough; in fact I'd prefer the firmware to automatically turn the ATX supply off and on when needed, but I realize that "when needed" is a little complicated given that steppers lose microsteps when powered down and hotends can jam if the heatsink is not cooled when it needs it. So for the moment I have G-code to cool the hot end and then shut down ATX power at the end of a successful print; cancelled prints require the user to shut down by hand.

By default, RRF reduces motor current to 30% of normal when all motors have been idle for 30 seconds. The percentage and the timeout can be adjusted using the M906 command.

You can write a macro file to cool the hot end down and then turn the ATX PSU off.

In a future version of RRF, I intend to add the facility to move all motors slightly to a position that corresponds to how they will power up again. That should reduce the risk of the motors jumping steps when you power off and on.

Thanks,
I read you all and this fully answer my question. I guess 25V shall be fine.
What is a typical pumping voltage when breaking up to 3-4 volts?
I guess it depends on how well the powersupply regulation electronics can sink reverse current and of the stepper inertia and inductance.
We had a problem like this on one of our electronics and we had to change the regulator to cope with it.

Good thing about the psu on!

@dc42:

As Tim says, the limitation is the stepper drivers, which are rated at 30V when the motors are powered, and motors pump energy into the supply rail when they are decelerating. The other components are rated at 35V or more. A future revision of the firmware will disable the drivers if the bus voltage exceeds about 29V.

Is there a reason why you want to use more than 25V?

The remote power on/off facility on the Meanwell PSUs appears to be compatible with the implementation on ATX PSUs, so it ought to be work with the Duet WiFi PS_ON output.