Help with extrusion issues

[alberto 0]

Hello,

I am having issues in getting a regular flow of PLA from the extrusor.

I tried to regulate the adjusting screw on the material feed to not compress too much the PLA (the plastic is pushed in the bowden tube with minimum marks from the drive bolt).

At 230° the extrusor doesn't flow any molten PLA. To get some flow I have to raise the temperature to 260 - 265 and the flow is not always regular: sometimes the filament comes out curling.

I am using the standard purple PLA supplied with the machine package.

[ian 32]

have you checked the diameter of the PLA ? does it change a lot ?

Also have you checked that the small screw holding your heating sensor on the alumium block is good and tight ?

movement from the heating sensor would cause mixed signals.

Ian

[alberto 0]

I checked according to your suggestions:

a) The filament diameter is between 2.8 and 2.9 mm.

b) The small screw holding the heating sensor is firmly in place, it cannot move.

I warmed the hotend (which is a V.2) at 180°, opened the material feed and pulled back the filament by hand.

At the end of it, i noticed a small burned part that i cut away.

I pushed the filament back in the bowden tube and I saw the filament flow through the hotend.

So I think that the temperature and the thermocouple is working correctly.

I made another print test at 225° and the PLA extrudes from the hotend now. Unfortunately, it didn't stick to the build area as the hotend appears to be to high. The extruded PLA was quite thin so it didn't fall down but it curled around the hotend nozzle.

I think that this issue can be closed. This evening I will calibrate again the Z axis following the wiki and the suggestions I saw in other posts in this forums.

I case of other issues I will ask again some suggestions. Thank you for your answers.

PS: I measured again the extrusion length. Following a command to extrude 100mm, I measured an effective feed of around 105mm in the Bowden tube. Is it worth to calibrate this? Where I have I to do it? (I am using Netfabb and Ulticontroller).

[Daid 306]

If your start Z is too high, you can simply turn the big screw by hand during the printing of the first layer. The machine can withstand this. Sometimes this is easier then calibrating the Z bed again.