QU-BD dual extruders and some other OrdBot qeustions

[alpha]

I have both installed and it is kind of working OK (only did test with ABS), there is some oozing and sometimes there is not filament. The best thing I found so far is to have the skirt build around all layers, the catches the oozing and keeps the nozzle flowing (but only the first one) - but it is a expensive way of doing it. I'm using Slic3r 0.9.9-dev and I tied to turn the temperature down a little bit and added 4 mm retraction on tool change. I do use Marlin form Github with a RAMPS 1.4 and 12V 30 Watt power supply.

1. My heated bed (Ordbot -Lava) is only reaching 90 C, I did measure 12 V - is that normal?
2. How to PID AUTOTUNE two different extruders? Do I need to do T0 M303 and T1 M303 and build a average value? How did you do it, for some reason the the heaters behave different, the first is fast and hotter???
3. any other way to handle oozing, best settings, other slicer, etc?
4. any good way of purging the nozzle if not used for some time to prevent holes for the first couple of seconds? add a purge tower?

Thanks,
Markus

[bdring]

I had a very early version of the Lava and it had trouble getting hot.

You can Autotune two extruders it is something like M303 E0 S220 & M303 E1 S220. If your voltage is drooping significantly with current, you could have weird results and the Autotune may be off due to the mode of the other extruder. Use a strong power supply, short and heavy gauge power wires.

Try a fast retract of like 60mm/s

I have not used dual extruders yet.

[orcinus]

I had a very early version of the Lava and it had trouble getting hot.

Ah, so it's not just me.
Mine does get there eventually, but takes it's sweet time. A lot of it. A looooooot of it.

[bdring]

I switched from PC type power supplies to those cheap 30A 12V power supplies because you can adjust the voltage up a few volts. Just accounting drop voltage drop in the wiring can reduce the heat up time by 10%. I usually run about 12.7V at the controller under load. It really helps with heat up time. I also have end gcode set the bed temp to about 40 so it does not get too cold between prints. The extruders heat up really fast so that does not bother me.

The only thing I don't like is the noisy load based fan speed of those supplies. It is load and you can hear every change in the PID loop.

[orcinus]

I have one of those too.
Except on mine the fan is bang-bang, not PID, and temperature controlled.

Whenever it heats up, the fan turns on full blast for a while, then turns off, then it heats up again, full blast again etc.
Really annoying. I'd prefer a PID loop over that any day.

Funny thing, the fan fell apart weeks after i first bought that PSU.
The rotor just fell off the stator. Awesome craftsmanship.
It's been working fine since day one in all other aspects, though...

[bdring]

You might change your mind after you hear it. Sometimes it sounds like it is trying to sing a horrible song.

[Medel]

cut a hole in the case and put a 120mm 12V fan on it and pull the plug on the internal one?