Hot End Jamming!

[Batteau62]

I would spring for the multimeter w/ temp probe and verify your temp. Especially with PLA. And I would hardwire the PEEK fan to run 100% all the time. Don't forget to PID autotune if you do. Is it a stock hotend? If so maybe upgrade to the new nozzle. I think I read on here that it doesn't temp creep as much?

[Polygonhell]

I have found however that through manual control the fan will not run at 15%. once you turn it to 30-35% the fan starts moving!

That's normal for fans, they aren't designed to be controlled by PWM signals, I've seen fans that will run at 20% but not start without going to 80%.
Either way for PLA run it at 100% all the time, there really is no such thing as too much cooling with PLA as long as the hot-end can maintain temperature.

[geneb]

If you followed the docs, the PEEK fan should be running at 100% for the length of the print run. 15% won't cut it.

If M42 P6 S255 doesn't turn the PEEK fan on, you've got it connected to the wrong output.

g.

[jonyzdude]

I found out through trial and error that the photo shown in the instruction document was incorrect. The peak fan should have been plugged into Fan 0 on the RAMBO not Fan 1.

[geneb]

Well considering I wrote the documentation, I know exactly what I specified and why. You're perfectly welcome to assemble it however you like, but don't come crying to me when it doesn't work.

FAN 0 is for the layer fan, FAN 1 is for the PEEK fan.
g.