Peek fan not spinning

[precision]

Hi, I just finished my V2 build and printed the peek shroud and installed it, however it isn't spinning. I tested the leads from HEAT 1 to the solder points for the fan and they are testing clean. I also tested the fan by applying some voltage to those wires to make sure there wasn't something blocking the fan from spinning. Is there something in the firmware I have to do to turn on the peek fan?

[teoman]

It should start when power is sent to hotend and stop once it drops below 40 degs.

Check the voltage at the rambo board. And at the end of the wires. Also see if fan still spins once in its holder.

You heve not confused the peek and layer right?

[precision]

I double checked the peek vs layer connectors and that isn't it. Once my current print finishes I'll hook a multimeter up to the HEAT1 lines on the rambo leads directly and see if I can see anything there.

[DanHall]

Sounds like you are on you first prints so I would check a couple of things. First, as said before, the fan should engage based on firmware settings during the heat up at 50C and stop when cooling when it reaches the same temperature. Disconnect both sets of fan wires from the mosfet and double check for continuity to make sure they are what you think they are and a wire did not get pinched or cut during assembly. If you used kapton tape at the joints for the fan wires it should be easy and only a little more work if you used shrink tube. You can also heat the hot end above 50C and check for voltage at the mosfet as well as engage the layer fan and check for voltage on those terminals. Being lazy and since everything is wired I would probably start with the second step and make sure you have voltage at the mosfet terminals. That way you will have a better idea of where to keep looking.

[precision]

That is basically what I did. I have the layer fan also wired up already and that I can turn off/on manually just fine. I did hook my multimeter to the screw terminals on HEAT1 and then to the solder points for the peak fan splice at the hot end (right before I wrapped them up in tape) I'll check for voltage directly at the mosfet later tonight.

My limited set of prints seem to be coming out decent enough, what's the downside of running w/o a peek fan? Reduced life the hot end?

[DanHall]

Without the fan you can reduce the hot end life but you can also get heat creep up the nozzle and lengthen the melt zone. On a long print it can stop extruding and then, when it cools, you will have a long plug that won't melt properly and you can't extrude. I don't know what failure mode you will see first. Probably distortion in the PEEK section.

I recently had a fan failure on a different hot end and melted filament up through the heat break and through the entire heat sink. It was an all metal (E3D V6) hot end so I did not have any damage I couldn't fix. This was a different printer and the problem turned out to be from the printer manfacturer and no fault of the hot end. They mixed up a 12V fan on a 24V system so it died in relatively short order. Lasted longer than I would have expected though... They owned up to it and got me a new fan in the mail quickly so all is good now. We did confirm that the heating element was correct - 24V.

[DanHall]

Good luck getting it fixed quickly. I think you will be a lot happier in the long run if you get it fixed now and don't run into problems later.

[precision]

I just hooked my multimeter up to HEAT1's screw terminals and I was reading around 100mV while the hot end was at about 60C. As soon as the hot end dropped below 50C that reading drop to about 20mV. Any ideas?

[DanHall]

Bad RAMBo or firmware are the first thoughts that come to mind but I'm not great on that end. In the interim you could run the fan directly to another 12V source so that it would run whenever the power supply is on. I would probably start by reflashing the firmware and seeing if that helps.

[teoman]

Yes. For now if you are not printing pla i would plug the peek fan to the layer socket and run it full time.

[DanHall]

Is there a reason not to run it directly to the power connector and just let it run when the printer is on? That way you don't have to remember to turn the layer fan on.