Hot End Jamming!

[jonyzdude]

My hot end seems to be clogging up and jamming causing the extruder to skip. When this happens the quick disconnect at the top of the hot end gets jammed as well making it impossible to pull the filament out of causing me to have to buy another quick disconnect. This has happened twice now and there is a reason for it. I have followed the directions to a T and so this shouldn't be happening. If you have had this problem or can help me I would greatly appreciate it. Thanks

[bubbasnow]

do you have a PEEK fan?

how far are your retractions?

[jonyzdude]

I do have a peek fan and it works. the minimum travel after retraction is 3mm and the box is checked for retract on layer change.

[jonyzdude]

under Retraction these are the following

length-5mm
lift z-.2
speed-60
extra length-0
Min travel after retraction-3mm
Retract on layer change- checked
wipe before retract- not checked

[bubbasnow]

thats abs?

what is your temps?

what speed is the PEEK fan running at?

[Batteau62]

What material are you printing? ABS or PLA? What extrude temp? Have you verified temp at the hotend with multimeter temp probe?

[jonyzdude]

Im running 1.75 PLA. the extruder temp is 185-190. I have not checked the hot end with a temp probe as i don't have one.

[jonyzdude]

I was told from a guy at SEEMECNC that my peek fan should be on the whole time, is this correct?

[jonyzdude]

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!

[bubbasnow]

mine runs about 80%

i do pla at about 215c.

[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.