E3D fan wiring Mendel90

Hey guys,

Im almost finished my Mendel90, I am just unsure how to attach the E3D hot end fan (I also have the bed fan on the x- carriage ). I know the bed fan uses the +12V allocated for the heater can I also do that for this fan ? can I just run the black wire through the spare (wire no 5, pin 2) on the x-carriage ribbon cable ?

the E3D fan is meant to be attached directly to the power supply

Thanks so much

Jeremy

Hey Jeremy

As its meant to be attached to +12V and Gnd you can use those ports that exist on the ribbon cable breakout board.

This picture should help illustrate what I mean, just ignore the bits about a second extruder:
Lasercut_Mendel90_Dual_extruder_PCB_wiring.jpg
Its from this blog post which also has the wiring as a table (or use Nophead's Mendel 90 Manual)
dual-extruders-on-lasercut-mendel90

The one issue with wiring it this way is that the fan may make the thermistor reading a little noisy, I have not noticed an issue with this though. If that does turn out to be a problem then you can use the +12V from the hotend and connect another ground through the spare cable you mention.

Cheers

Tony

Edited 1 time(s). Last edit at 04/02/2014 12:11PM by T3P3.

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DuetWifi.: advanced 3d printing electronics

Cool thanks heaps Tony !

If I was to use the +12V from the heated bed, should I just tape the fan wires onto the ribbon cable (on the x axis) so I can attach them ?

- Also I didn't end up getting the break out board, I do regret it now, but at the time I was trying to save money - with shipping from the UK to Australia I thought I could do without it - what alternatives would you recommend ? (I have the d-sub plugs mounted and just a short section of ribbon cable coming from the IDC on the X carriage )


thanks heaps

Jeremy

Sorry for the typo above - I meant to type "hotend" (changed now) it should make more sense now.

The X carriage ribbon cable has the +12V and GND on it if you have connected it as per Nophead's design, without the breakout board though I am not sure how you have wired the hotend etc into the D connectors. If that is all soldered in and insulated so you can get to the 12V+ and GND at all then an really simple alternative is to run two wires for the fan along the same route that the ribbon cable takes, taped onto the side of the ribbon cable (but that can look rather "cheap 'n nasty").

Tony

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DuetWifi.: advanced 3d printing electronics

Yeah true Toney, I should have looked into it and bought the breakout board --- I probably will order it soon and change it over ,

Thanks heaps again

Jeremy

Hey Tony, just wondering if you could tell me where to attach the ground wire for the bed fan (that sits on the x- carriage) , it's connected to the +12V for the hot end heater but I am not sure where to attach the ground wire - I am using RAMPS

I am going to connect the ground for the E3D to a spare ground wire of the PSU


Thanks heaps

Jeremy

Hi Jeremy

Ground wire for the bed fan should be onto the FAN - (marked F- on the breakout board) which is on core 12 of the ribbon cable and goes to D09 - on the RAMPS look at the wiring for the second extruder. The table on page 63 of Nophead's Mendel 90 manual for the full pinout of the ribbon cable.

So in summary E3D hotend fan between always on 12V+ (eg the heater 12V+, Ribbon 6, 7, 8) and always on GND (eg the spare core number 5 on the ribbon cable, connected to the power supply ground)

The Bed fan is wired as described in Nophead's manual between always on 12V+ (eg the heater 12V+, Ribbon 6, 7, 8) and Ribbon 12.

Hope that helps!

Tony

Edited 1 time(s). Last edit at 04/07/2014 05:44PM by T3P3.

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DuetWifi.: advanced 3d printing electronics

Hi,

I'm having jams during printing and I think it's because of the fan.
I used your picture to connect the fan to the 12 V. I have a 2-wire fan.

When I switch on power the fan immediately starts spinning but when I heat the hotend the current is interrupted and the fan stops.
During the last jam I noticed the fan wasn't spinning either causing the heatsink to heat I suppose.

Does the fan have to spinning always or is this like it should be.
Does anybody know why the fan stops spinning when the hotend heats?

I'm using the PCB board from Nophead so I think all the wiring is correct.

Sounds like one of two things could be happening.

1) the hot end has a lower resistance than it should have (so when it gets switched on it pulls down the +12 rail at the x carage end more than it should) look for a partial short near the hotend)
2) there is more resistance on the 12V wire too the x-carage than there should be between the power supply and the x-carage... look for a duff connection.

If you have a multi meter try measuring the resistance across the hot end and between the x-carage end of the 12V line and the power supply.

If the fan stops when the heater is on the most likely thing is you have the heater wires swapped at the RAMPS end. The effect of that is the positive of the fan is connected to the negative of the heater, which is switched instead of the positive of the heater that is permanently connected to 12V.

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[www.hydraraptor.blogspot.com]

Hi nophead,

I tought of switching the wires but wanted to be sure.
The wires are now switched on the Melzi and the fan keeps spinning when the hotend is heating.

Thnx again for your help!