Heating 2nd nozzle requires heating 1st nozzle?

[nathanstenzel]

I have been wanting to do dual extrusion for a while now and I actually have a 2nd extruder set up. Both hotends are using 12V 40W ceramic heater cartridges. It seems that I can't heat the 2nd hotend unless there is power being given at that precise moment to the 1st hotend to heat it. What's up with that? Is anyone else having that problem? I have different color filament in the two extruders and the hotends have different nozzle sizes. Sometimes, I want to print using the larger nozzle for speed and sometimes I want to print with the smaller nozzle for detail. I do not think it should even be a requirement to have the 1st hotend set to something else than 0C. Am I missing something?

[bubbasnow]

yea thats not right. your heat up codes should be using t1 and t0 to control each hot end individually.

[nathanstenzel]

The firmware does use T0 and T1 to heat them individually. I can set T0 to whatever temperature I want and T1 to whatever temperature I want, but if T0 is not below the desired temperature so that it is given power to heat up, T1 will not be given power.

[dpmacri]

Last time I looked at it, the SeeMeCNC firmware 0.91 used the "Heat 1" connector on the RAMBO board for the Hot-End cooling fan. In configuration.h, it's this line:

#define EXT0_EXTRUDER_COOLER_PIN 7

That "7" is for the HEAT1 according to the RAMBO documentation. For dual extruders, you'll need to change that. For my configuration, I changed it to 6 and have the Hot-end cooling fan (I only have one) hooked up to the Fan 1 connection on the RAMBO board. Further down in configuration.h, I changed

#define EXT1_HEATER_PIN HEATER_2_PIN

to

#define EXT1_HEATER_PIN HEATER_1_PIN

In pins.h, HEATER_2_PIN was set to -1 and HEATER_1_PIN is set to 7. There are other ways to arrange things, but this is how I did it. You'll also want to make sure your temperature sensor is hooked up correctly.

[Jimustanguitar]

That's right. The Heat 1 connector is setup for the PEEK fan. You'll have to change this if you're starting with the "factory fill" firmware.

[nathanstenzel]

Thanks much dpmacri and Jimustanguitar. I have made that adjustment (switched EXT0_EXTRUDER_COOLER_PIN from 7 to 6).

Looking at the schematics, the left 2 pins are ext0 heat, the next 2 pins are ext0 fan, the next 2 pins are ext1 heat, the next 2 pins are ext1 fan, and the final 2 pins are the heated bed. I have ext0 heat in the ext0 heat pins (the first 2) and I have the ext1 heat in the ext1 heat pins (the 5th and 6th from the left).

I will try to compile this firmware change, upload it and test the individual heating of ext0 and ext1.

[nathanstenzel]

That one change did the trick. Thanks much.

[nathanstenzel]

I have a 480W power supply. Do you think it could be that the one pin being set wrong could have caused it to shut down when trying to use both hotends and the heated bed or do you think that was the load balancing feature?

[nathanstenzel]

YES! It is a ways later than I had originally planned, but I am FINALLY dual-extruding! (does the happy dance)

[nathanstenzel]

My nozzle alignment is off and I seem to have a tad bit of dual extrusion boogers, but I hope to fix that sometime this week.

Thanks again for the help.

[nathanstenzel]

It looks like my 4th attempt will be a success. It seems that I needed to update my EPROM with my nozzle offsets. Changing the firmware was doing squat.