My first blowout :( Help diagnosing the cause please?

[Wolfie]

I was printing a tray out of black PLA. It has a lower section and a handle. The attached image are the supports that it was building to make the handle, obviously the handle didn't happen either. All supports and piece parts all disintegrated at about the same altitude off the build plate. Any thoughts on why or what I did wrong?


0.3mm layers
5 Solid top and bottom
4 Perimeter
.35mm nozzle on a hex hot end (Taz5)
Extrusion width .42mm
Support with 25% infill and inflation of .5mm
Extrusion at 215c
Bed 60c
Cooling at layer 5+ 100%

[soofle616]

The print looks to be getting more and more sparse as z increases so I would be looking for a clogged nozzle, a hobbed wheel that is all clogged up with fines, a tangle in your filament spool, or some other source of insufficient feeding of material.

[Wolfie]

I took the PLA out and switched back to ABS. Printed fine. Guessing something to do with settings I am not getting right. Not sure what. Redesigning the print from the ground up. Won't need to be printed vertical and won't need hardly any support. Less waste and probably less print time. Live and learn

[3dkarma]

If ABS is OK then you've got heat creep up the barrel into the cold end eventually causing the PLA to expand, friction to increase and extrusion to slow and eventually stop. If you don't have a fan directed at the cold end, install one and you should be able to print PLA ok.

[Wolfie]

This is what I got....



Its got a fan for the extrusion. Its got a little fan blowing on the heat sink of the hot end. No other fan that I know of. Not sure where I would put one.

I do have a piece of piece of fleece that I am covering the taz with (but leave the electronics box uncovered). Maybe that was my fault on the PLA? Does it need a warm enclosure?

[3dkarma]

PLA needs cool, not warm. Remove the fleece and make sure you have a fan blowing on the heat sink above the hot end.

[Wolfie]

PLA needs cool, not warm. Remove the fleece and make sure you have a fan blowing on the heat sink above the hot end.

The tiny fan I do not believe can be turned off. It comes on the moment the printer is powered up and doesn't shut off. The larger one that has the duct that blows on the extruded plastic is controlled by gcode or on the control panel. Is there an established fan use for PLA? On at what layer? On how much, I mean at what %?

For ABS I set it to off until layer 5 then 30%. This has worked well for me. Not sure if its right.

[3dkarma]

Your printing problem is caused by heat creeping up through the cold end, which is where the heat sink on the hot end is. The first fan you describe is supposed to be on all the time to prevent this happening. If this is obstructed or if you do something like wrapping fleece around the hot end, you'll get a problem with heat creep. Once your hot end is at the correct temperature, you should be able to touch the cold end / heat sink comfortably. The cold end on my E3D V6 remains cool to the touch while printing

The larger fan with the duct helps you with overhangs and bridging. Keeping it off until layer 5 is a good idea for PLA to help prevent warping. The level (30%) is specific to your printer and the plastic you're using - things like distance from the hot end, shape of the duct can affect its efficiency tremendously. If it works for you then it's a good setting.

[grezmel]

Did you get this resolved ?

I have the same extruder and found that the small fan wasn't up to the job so designed and printed off a fan duct to take a 40mm fan. i also had to reduce retract settings as this was also causing issues with this extruder.

[richardphat]

I see big problems here, the material sticking bed, active cooling with no brim.

Active cooling with no brim is instant guarenteed to warp, PLA or ABS.