Extrusion question

My son was gifted a ender 3. We finally got x y and z running smooth.

The extender and hot end are directly connected.

Now when we use pronterface and hit extrude it runs smooth.

When we try and run a test print it spits out an initial line/glob then stops extruding and when we take it apart we find a knot or kink that looks warmed up at the top of the ptfe tube.

Thanks in advance


Yours might be the same but on mine when you put the tube on you are supposed to leave the fitting loose about 1 turn, press the tube in so the lock ring has a good hold then tighten the fitting. this will make sure the tube is tight against the hot part with no space for the melted plastic top ooze out


sometimes replacing the Bowden tube can help as well or trimming a little bit off the end with the razor blade or PTFE cutter. Also Glens advice was exactly correct if you leave the push fitting a quarter to loose as you push the bowden tube back to the nozzle while it’s hot make sure it pushes right down to the nozzle then put the push fitting clip back in then you give that extra quarter turn tighten down on the push fitting, and it seats the Bowden tube to the nozzle. overtime the tube will eventually lift again away from the nozzle causing jams this is typical of all Bowden tube machines to avoid these problems micro Swiss all-metal hot ends are a great solution as well they make a direct drive kit which is also amazing and makes it easy for removing jams if or when they do happen, because of the all-metal hot end you no longer have Bowden tube touching the nozzle it’s metal to metal and you heat tighten them