My way of solving PLA jams with E3D hotend. Please knowtice the oval hole in the fan mount for cooling PLA. This is redirecting some of the air to the SS barel of the E3D and breaking heat convection from the heater to cold end. Sorry for rendered image, but you should get the idea what is all about.
Looks nice. Will you share your stl or other source file?
Sure, you can find everything here: https://drive.google.com/folderview?id=0B73C_MyFsgfxTW53Nm9ST1l4cG8&usp=sharing
I’m curious. Is this a common problem? I have printed many KG’s of PLA through multiple E3D hotends/printers using only the default fan mount without any problems.
@David_Gray It seems to be a problem associated with printing PLA at lower flow rates. Heat migrates up the barrel and softens material above the melt chamber which deforms around the incoming filament and cools causing a jam.
Nophead added insulating tape around the hot-end and directed some of the fan airflow onto the hot-end in recent modifications to the Mendel90.
I don’t leave my extruder heated with no material movement (I just pre-heat in the starting GCode and go straight into the print) and try not to print at very low flow rates. So far I have not experienced any jams under these conditions.
This is my much more simple design http://shapedo.com/guin/fan_duct_for_delta_tower
I have issues with jammed filament when I heat up everything and don’t print for a while. But I can avoid this.
With good cooling around the noozle I have much better prints.
@David_Gray generally dont have any issueses, but jaming (blocking would be more appropriate term) occours when a lot of retcations happen in small period of time. And more, I think this is only problem with bowden setups becaose bowdens need much more retraction distance. This setup gets rid of 99% of the problems. It basically does the same as @nophead setup.
@Marcus_Guin_Klutmann depends from the poit of view. Yours just could not work with my setup.
Now to calibrate my printer enough to print it so the fan fits. (There’s something off in my Z height, I may have to compensate for it in the slicer.)
I definitely have pla jamming issues with mine (3mm direct); looking forward to trying this out.
If PLA is jamming perhaps the heat break tube [the stainless steel] is not properly contacting the heat sink. I’ve run all kinds of filament without issue at temps 200 + including PLA
I find that it depends on the color of PLA I’m using. Some additives may make the filament more prone to stick or expand than others.
@William_Frick how would the heat break not contact the heat sink, isn’t it screwed directly into it?
@Eric_Moy If not tight enough the heat xfer would be significantly impaired. I remember assembling mine with a little trouble keeping things tight until the first heat cycle.
I did a very compact E3D fan that splits the airflow of a bigger 40mm fan between the E3D (2/3 of airflow) and the print (1/3 of airflow). While it’s not controllable, it has worked well enough with slight extruder temp changes that I haven’t yet felt the need to redesign after printing >300 cameras (2700+ hours of printing) for my Pinhole Printed Kickstarter project. If you need a compact design, this might be of interest to you. https://www.thingiverse.com/thing:152853
@William_Frick , ah, good to know
My plugging problem was discovered to be too aggressive retraction numbers. Changing KISSlicer from 1.25 to .25 greatly improved performance.