Solved Extruder fan cuts out at high temp

I installed an E3D v6 hot end this week. The cooling fan for this extruder is connected directly to the RAMPS 12v supply. It starts fine when the R1 is turned on. It will continue to run as long as the extruder isn't hot. Once the hot end gets to 235*C though, the fan will only run for only a few additional minutes before it shuts down. It will only turn back on if I power the R1 down and restart after everything cools down. Could the fan be getting to hot? I'm using the same fan and shroud that came with the v6.

I've only tried printing a calibration cube so far. I ran through the PLA that came with the R1. I switched to ABS at the same time I installed the v6, so I've been troubleshooting many different issues. I now have the correct settings for printing ABS with this machine, but I don't want to run any long prints without an extruder fan.

It sounds like its time for a new fan? Unfortunately, the only fans I have on hand are a 40mm fan (too large) and a 30 mm that is rated for 8.5v max.

 

Yeah. So I pulled the fan and shroud off of the heat sink and tied it off out of the way (above the extruder steeper) where it couldn't get any heat. It still shut off during the first few layers of the print. I noticed that the fan tried to start a few times - it made a few revolutions - but ultimately never restarted and was still smoking hot.

I plugged in the 40 mm spare fan I've got. If it shut off too I'd know it was the wiring. It never did shut off. The fan they sent with the v6 was junk. I've attached the big fan to the v6 fan shroud with 1 screw so I can get some cooling going. I'm half way through printing a 40 mm fan adapter for the v6 that I found on Thingiverse.

The print is looking good and the fan is holding!

 

I think the instructions say to change the fan wiring location. There are two options.
The small fan with the V6 is the same fan as came with the R1.

 

Yup. They do, Franklin. But the stock fan that was on the R1 when I got it was already wired back to the power supply (just as it was suggested in Mike Kelly's 2nd photo, if you're familiar with that post over in the Mods and Updates forum). I used that same wiring, with a little solder and heat shrink to attach v6's fan. I'm now using that same wiring for the large fan I had lying around, and its running great (knock on .... uh ... ABS?)

 

Hay Waldo, I just pulled out the V6 kit and the Hex kit and measured the fans. I got to admit that my micrometer eyeball that just cost me $3K is a bit off. You are correct on the fan sizes. Frank.