Fan Control

Hello everybody!

In my dual extruder configuration (direct drive) I activated the extruder cooler fan feature for each extruder:

Quote

#define EXT0_EXTRUDER_COOLER_PIN FAN_PIN

and

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#define EXT1_EXTRUDER_COOLER_PIN FAN2_PIN

After heating up the extruders in repetier host only the fan for extruder 2 starts automatically, while the corresponding for extruder 1 stays still. The fan 1 can only be controlled manually in repetier host and is not directly related to the extruder temperature.

How can a change this behavior so that both fans start if their corresponding extruder gets heated?

Regards

The problem is that FAN_PIN was not designed for extruder cooler but for cooling the PLA below the extruder. If you use that pin you have to disable the normal fan control, or the 2 overwrite their settings.

#define FEATURE_FAN_CONTROL false

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OK, I change that in he suggested way and it works now fine. Thanks repetier!

So, if I want the "automatic" fan control for both extruders AND the FEATURE_FAN_CONTROL I have to do the following:

- add a third fan for the nozzles on a separate pin.
- assigne this third pin to FAN_PIN and enable the FEATURE_FAN_CONTROL.
- assigne the former FAN_PIN (which was originally for extruder 1 in my setup) to a new FAN1_PIN.
- change the source code for extruder 1 at the same point, where extruder 2 starts its fan by use of FAN2_PIN.
- compile, upload, done :-)

Could that work in this way?

Regards

Yes, that should work. You can use any pin as output, but you need to amplif it for 12v. there is need to use names for the pins. Simply set the putput number.

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At the repetier host i can Set the fan on/off and set the fan speed and the fan reacts how it should be. But if i start a print the extruder heats up and the fan stands still....
Need help plaese

You can set fan control in slicer settings. Some fans need a minimum speed to work (some even 100%) so make sure your slicer settings enable fan and use it in an area where it works. Also depending on settings, fan gets enabled only for short layers.

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when does the fan starts cooling?
I dont want to test it because it is cooling my hot end so everytime when it doesnt sart cooling but the hotend heats up i have to stop the print.
I have set the configuration of Slic3r to: Keep fan always an. And minimum fan speed 100%, But nothing happens.

Thx for answer

If your extruder needs active cooler you are using thw wrong fan feature. Extruders have 2 fans. In configuration.h you can set a extruder cooling fan - this is for cooling the extruder itself for hotends needing this. It turns then on automatically if temperature goes above 50 or is set > 50. The one you control with host and slicer is for cooling the pla not the extruder itself.

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#define EXT0_EXTRUDER_COOLER_PIN -1
does i have to change this?

Yes, thats the one for cooling the extruder when hot.

Make sure not to use the same fan pin twice (e.g. also for M106 fan which uses FAN_PIN from pins.h) or nothing will happen.

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but the fan pin from pins.h is the right one for the hotend(9)...so do i have to change FAN_PIN to something else like 66666 and then change EXTRUDER_COOLER_PIN 9?

if it is the only one just set

#define FEATURE_FAN_CONTROL 0

to disable normal fan usage. Then the pin does not get used by fan control - in fact you have no fan control at all then. If you have a second fan for fan control ser
#define FAN_PIN x

in configuration.h to set the pin number for fan control (after including pins.h)

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Ohhhhhhh thaaaaaaanks <3
I love u it works...
are u the person who wrote the programm?

And thanks that u answered so fast

NOOOOOOOOOO :'(
Now the fan works and the print gets startet but the extruder doesnt work.....
im using RAMPS 1.4

i cannot use it with manual control of repetier....it doesnt starts at all

the motor itself works and the stepper driver too so it isnt a hardware problem

Edited 1 time(s). Last edit at 08/10/2015 03:08PM by thePrinta.

Motor and driver work but extruder not? What is then the part not working? Is it blocking or not hot enough or did you have dry run enabled? Check also log if firmware sees a problem and disables extrusion for some reason.

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the reason why i didnt wondered about the extruder before was that i thought"printer isnt ready so he sets to dry-rum-mode"....but now the printer IS ready there are no error notifactions but it still deosnt work

what does extruder offset x,offset y and temperatur offset means....they are all set to 0
and dry ru is disabled when the point next to it is blue filled isnt it?

Edited 1 time(s). Last edit at 08/11/2015 08:53AM by thePrinta.

if a stepper motor is powered but he doesnt get any signal (or gets the signal to stand still) then u cannot turn it because its power in there...
but u can turn my extruder so it doesnt get any power!
so i think there is something in the software wich disables the extruder motor

Edited 2 time(s). Last edit at 08/11/2015 09:13AM by thePrinta.

Ok, just had a similar problem. Reason was that autoretract was enabled which ignores pure e moves mostly. Sending M209 S0 solved it. But also check eeprom -> Enable retraction conversion which should be 0 so it also starts without autoretract.

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thx :*

OK, I have a MKS 1.5 board, which is supposed to be a combination Arduino/Ramps board on a delta printer. The board has a non-controllable, always on 24 volt outlet which is used by the cold end fan and a separate layer cooling fan which is attached to the fan terminals. This is a bowden setup, so there is no co-location of the fan wires and the extruder stepper wires once they leave the board area.

1. The board is power reset completely
2. The hot end is heated
3. Using the front panel, a little filament is extruded. No movement is seen in the cooling fan.
4. A small print is done.
5. Using the front panel, a little filament is extruded. This time, the layer cooling fan comes on whenever the extruder is run, and it stops when the extruder stops.

I am having extrusion problems. I thought, "maybe the extruder is having power robbed from it to run the fan".

So I reflashed the software, yesterday, using the stable version of repetier freshly downloaded. And just to be sure, since I thought I had a bad extruder motor, I swapped the extruder driver in the firmware to use the E1 controller rather than E0 and moved the plug. It still happens.

Is this intentional? A bug in the repetier firmware? Is there any case where extrusion could turn on the layer cooling fan? Or is this some sort of hardware issue on the board?

Maybe you have assigned 2 fans to the same pin. You can have a extruder cooling fan and a filament cooling fan. If both use the same pin this might happens since fan would only turn on when both are on otherwise one will toggle signal off while other toggles it on so not sure who wins here. So check the in config the cooler fan is not set to same fan pin.

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Thanks for replying. I used the online program to build my configuration.h. This is the relevant part from the json, I think. Sigh. I started in this business when state of the art was punch cards and terminals were usually reworked typewriters. Or teletypes. This jus seems excessive. As I get this, the fan pin is set to "ORIG_FAN_PIN" which matches what I see in the regular c preprocessor syntax stuff. But the thermostatically controlled fan is set to -1.

"featureFanControl": "1",
"fanPin": "ORIG_FAN_PIN",
"featureFan2Control": "0",
"fan2Pin": "ORIG_FAN2_PIN",
"fanThermoPin": -1,
"fanThermoMinPWM": 128,
"fanThermoMaxPWM": 255,
"fanThermoMinTemp": 45,
"fanThermoMaxTemp": 60,
"fanThermoThermistorPin": -1,
"fanThermoThermistorType": 1,

But maybe I was not clear. When I say that the fan came on while the extruder was running, I mean for the seconds that the extruder was actually pushing filament out of the heated hot-end. Then the fan turns off - it might not have gotten all the way to speed. At first I thought, "maybe the wires are crossed" and then I thought about it and realized that because of the bowden setup, the wires never run in the same channel. Then I thought that there was a problem in the circuitry so I reconfigured and told the extruder to use the extruder 1 motor driver but the rest of the extruder 0 stuff, like the heater and the thermistor.

Now, the pin names are indirected through pins.h, I guess and this MKS board is an atmega with the board number 33. So, as I read it, ORIG_FAN_PIN is 9. That overlaps with HEATER_2_PIN. So that might overlap with the second extruder heater, oddly, but I could see no reason why running the extruder would turn that on after a print but not immediately after a reset.

I have attached my configuration.h. See Configuration.h. This configuration.h was built with the online tool, as I mentioned and the firmware was freshly downloaded and the build was based on that. So no other mods were made to the firmware. Please note that this issue happened both before and after the change I made to use extruder 1's driver instead of extruder 0.

I think your analysis is correctl. You have no cooler fan set, so that is not the problem.

As I understand you fan is only working if a) Fan is switched on and b) you are extruding.

Firmware has no such condition and normally these are not dependent. So question is if your compilation leads to this strange problem or if you have a weired hardware problem by a shorted lane.

So I suggest writing a simple sketch that sets fan out high and sets the 3 motor control pins (step/dir/enable) off or on and see if the result depends on motor pins. It should not but I have seen errors no one thinks off so testing it is a good way.

You could also try upgrading arduino ide to latest version and firmware to dev version. Make sure you have 900 byte free ram as shown in ide or strange things will happen just from running out of ram.

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No, I guess I was not clear. The fan comes on when switched on. But after a print (not immediately after a reset), between prints when the cooling fan is normally off, I preheat the extruder, then extrude some filament from the front panel. For the short time that the extruder motor is running, the cooling fan comes on and then immediately goes off.

While I could write such a sketch with only minor confusion, I don't expect the above test to show anything because this does not happen immediately after a reset, before a print. I guess I will try loading the development version, I am at 1600 or so bytes now. Maybe I can save a little by turning off some features.

I am currently less concerned about this than I was. The problem I was having seems to have been a bad hobbed gear, which was not firmly gripping the filament. I will replace it, but for the shot term I am getting good prints from the printer by tightening the spring (with a spacer). I had been trying to diagnose it and thought that it might be a power diversion issue - then I realized that it didn't happen after a reset so it seems like a software thing, although I don't get how.

1600 byte free ram is more then enough.

Apart from this I'm also confused. Firmware does the same after reset as a while later. If something only happens after a while it is often thermal introduced hardware problems like hot drivers/FET, ....

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