Geeetech

I have had my i3 Pro B set up for a few weeks (GT2560 board) now and have been trying to add a part cooling blower fan but have encountered a problem.

The fans which come with printer work exactly as expected on the PWM header, allowing for speed control on the fan, so no problem there.

I got a 50mm blower fan from RS Components, with the three pin cable and connected it up, but the fan will only run at 100%, any lower value and it stalls. I assumed a faulty fan so got a replacement and its exactly the same. (http://uk.rs-online.com/web/p/blowers/7878967/)

When the fan is set to 100% (In Repetier) they run fine, blasting out a huge amount of air. If you drop the fan speed, even to just 99%, the fan slows and stalls withing a few seconds (making a buzz/whine sound still), its like the board is not receiving the taco signal so keeps dropping then power?

I have not hooked the fan up on a PC yet to test, plan to do this tomorrow, but to have two faulty ones seems unlikely. Anyone else had this problem, or can suggest a fan which will work with the GT2560 board?

Hi,I think it's the firmware problem.Try to upgrade the latest one and see if it still the same.
Except for using Arduino,you also can upgrade the firmware with EasyPrint 3D.
Here is the download link:
http://www.geeetech.net/firmware/EasyPrint.msi.
And here is the instructional video you can refer to
:https://www.youtube.com/watch?v=U3ua4vM ... pqufTgHOgE.

Thanks, I have tried updating the firmware but it didn't help. However, I have also been able to test a couple of other fans, including a big 120mm and these are working fine so must be an issue with the blower design.

I also tested the blower on an Arduino (http://www.themakersworkbench.com/conte ... pm-arduino), and the signal wire seems to be working 100% ok! So I'v ordered another blower from China, as I cannot find any others in the UK with 3 pins. Once it arrives this will hopefully solve the problem

smith69085 wrote:Thanks, I have tried updating the firmware but it didn't help. However, I have also been able to test a couple of other fans, including a big 120mm and these are working fine so must be an issue with the blower design.

I also tested the blower on an Arduino (http://www.themakersworkbench.com/conte ... pm-arduino), and the signal wire seems to be working 100% ok! So I'v ordered another blower from China, as I cannot find any others in the UK with 3 pins. Once it arrives this will hopefully solve the problem

If you are using gt2560 I think the pwm output isn't even connected. There is a schematic on the forum somewhere in case you want to check it yourself. But there is an tiny smd transistor soldered on the gt2560 not too far away from the atmega2560 which controlls the fan. Maybe your fan isn't made to be controlled with voltage and instead for static rpm?
see: viewtopic.php?f=13&t=17443
schematic: http://www.geeetech.com/forum/download/file.php?id=532
Sometimes it's bad if the fan is to strong... You will cool down the heated bed and the nozzle if your fan is to strong. I'm personally using an super silent 40mm pc fan...

thanks for your information

Hi dear,
I have also encountered the same problem and replaced the mentioned blower fan with much effort to fix that. the seller got assurance to fix it however, I ordered another one from Enrgtech which is perfect. I recommend checking that would possibly help a lot.