Hot end fan replacement

Dear All,
It has probably been covered many times here - but, it is worth posting it again! I accidentally broke one of the vanes on my hot end cooling fans yesterday (don't ask...). I went out to Maplins this morning and bought their 40mm (10mm thick - N48QT) low noise fan and fitted it. The fan is clearly pushing less air, but the temperature measurements of the heat sink are stable at 45 degrees (which I think it OK). The difference is that the Ormerod is now very quiet. It is a vast improvement! If you are suffering with a noisy fan there are solutions available.
Greetings,
Christof

Yes, I and many others have replaced the cooling fan with quieter ones.

Dave

... or with 4-pin PWM fans to adjust the speed on-the-fly It seems to be quite difficult to source them directly from the UK though.

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zombiepantslol
... or with 4-pin PWM fans to adjust the speed on-the-fly It seems to be quite difficult to source them directly from the UK though.

How do You use the pwm control? Is it included in the firmware of either you or dc42? I assume it Needs a dedicated pin. Same for the rpm feedback, supported?

Yes pantau, both dc42's and my firmware fork support PWM-controlled fans. You can connect the control line to the FAN0 output pin on the Duet (the left one IIRC) and the tacho line to pin 25 on the Duet, or to pin 10 on the Duex4 on the expansion header. It's a good idea to insert a diode between the tacho line and the RPM pin though, I believe dc42 even put up some schematics somewhere on this forum showing how it can be done. You can then control the fan speed from the web interface, both my new Duet Web Control and dc42's and my Ormerod Web Control forks provide sliders for this purpose. In addition, you can take advantage of the cooling options Slic3r and Simplify3D provide. This helps a lot with very low layer times.

Even RRP's official firmware supports M106/M107 to some extend, but AFAIR their PWM signal is driven at 10kHz, while dc42 changed it to be driven at 25kHz which is the recommended frequency for PWM fans. RRP haven't implemented support for the tacho line in their current firmware version, though.

The good thing about PWM fans is that they won't turn off entirely when you run M107 (turn off fan), so the printed hot end parts won't melt even if the nozzle is still hot. When I drive my PWM fan at minimum speed, it has roughly the same throughput as a small 40x40x10 fan.

Ok I already use this to control an additional fan, not the hotend fan. So am I correct only one fan is supported?

The hot end fan needs to run whenever the nozzle is hot, to prevent filament melting too far up the nozzle. On my differential IR sensor board for the Ormerod, I include thermostatic control of the hot end fan, so that it turns off when the hot end is below about 38C. This keeps the Due fan output free for a cooling fan.

I suspect that the latest RRP hot end design for the Ormerod 2, which uses a laser cut spacer and no ducting, is probably OK with a quiet 40mm x 10mm fan.

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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].

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ChristofSchwiening
Dear All,
It has probably been covered many times here - but, it is worth posting it again! I accidentally broke one of the vanes on my hot end cooling fans yesterday (don't ask...). I went out to Maplins this morning and bought their 40mm (10mm thick - N48QT) low noise fan and fitted it. The fan is clearly pushing less air, but the temperature measurements of the heat sink are stable at 45 degrees (which I think it OK). The difference is that the Ormerod is now very quiet. It is a vast improvement! If you are suffering with a noisy fan there are solutions available.
Greetings,
Christof

The original fan on our Ormerod 2 siezed up after only 2 or 3 months work. I replaced the fan with this: [uk.farnell.com] which might be similar to your Maplin part.