Cooling Fan Connections

Hi all
Can someone tell me why with the Fisher Delta we cannot use the 'FAN0' connections then use macro's to control the output of the fan. Connecting the fan as per current instructions the fan continues to run even when the printing has stopped.
Does anyone know of any issues that could occur if I disconnect from the current location to FAN0?

Many thanks
Gary

If you have a single combined hot end and print cooling fan then you can do that. Use M106 to configure the fan as a thermostatic cooling fan in config.g so that it turns on automatically when the hot end is above about 45C.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

dc42,
Thanks for the quick response but please excuse my ignorance, When you talk about a single combined hot end and cooling fan I don't understand. If I just move the fan wires from there current position to FAN0 will this cause an issue or will it effectively become a combined set-up oir will nothing happen at all?

I have to say i'm not sure of the set-up of the PCB so I may be asking a stupid question!
Regards
Gary

Hi Gary,

I too am fairly new to 3D printing but have developed my printer on the lines you suggest.

I have the fan on my Fisher1 connected to FAN0 and I'm still experimenting with it. This mod should be used with caution as when the hot end is at a high temperature and the fan is not running, or stops prematurely, then the heat from the hot end could damage other effector parts.

That said, I changed the 3 pin molex connector to a 2 pin molex connector (using a pin in the slots on the 3 pin connector to carefully press and release the small metal tab that retains the connection socket pins).

The yellow wire should connect to FAN0+ the first pin from the edge of the Duet PCB connector and the white lead connects to FAN0- the second pin.

I then modified my config.g to include the following:between the Tool definitions and ;// Z probe and compensation definition


; Fan Control
;M106 S1.0 ; Turn Effector fan on 100% at startup
;M106 P0 T35 H1 ; Turn Effector fan on/off at 35 deg C for just the Effector temp
M106 P0 T35 H0:1 ; Turn Effector fan on/off at 35 deg C for both Effector and Heatbed temps


This gives you three options to play with by removing and replacing the ";" comment.

The first line gives you similar fan control to having the fan permanently connected, but you can change the S parameter from 0.0 to 1.0 to give you fixed control eg S0.8 will drive the fan at 80%
The second one is as DC42 suggests, links the control to the actual temperature of the effector heater, the fan being on when it remains above 35 degrees C (T35)
My preferred choice is for the third one where, as the second one, it is linked to effector temperature but also heatbed temperature so the fan remains on whilst either or both effector and heatbed are above 35 degrees C

You can also control the fan speed manually through the control panel, but again be cautious about keeping things cool by not having it too low or off!

I have included the the above on my Fisher1 with a view to reducing the fan speed for printing ABS, for example, which requires less cooling than PLA, rather than changing or modding the fan duct to achieve the same result.

DC42 may also wish to comment on my solution and offer further advice?

I hope this helps!

Ian

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SSMagic

Fisher Beta, upgraded to Fisher 1 with heatbed and full fan control

That sounds good advice to me, although personally I would use 40 or 45C rather than 35C. I didn't reply before because a reply from someone who owns and understands the Fisher is better.

Edited 1 time(s). Last edit at 11/19/2016 01:11PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks Ian
That's exactly what i'm looking for. I saw the mod for the redirecting the airflow but this meant dismantling and reassembling the print head which i'd rather not do.
\as i'm experimenting with ABS and PLA I wanted the option to adjust airflow via fan control which the FAN0 connections seemed to offer.
Your detailed explanation has encouraged me to go ahead and make the relevant changes.

Many thanks Ian and dc42 for your continued help.
Regards
Gary

Gary, I'd be interested in feedback from your experience when you get it up and running!

Ian

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SSMagic

Fisher Beta, upgraded to Fisher 1 with heatbed and full fan control