Hi All,
I am using a Taz6 with a v3 dual extruder running firmware 1.1.9.34.
Recently my prints stopped extruding. Running through the process I found the hotend isn’t coming to temp. The LCD reports the target temp I set, 100 to 240 C, but an infrared thermometer shows that both extruders are way under tamp… for example, extruder 1 should be 240 C and it gets to 109 C. Not hot enough to melt PLA. The second extruder temp maxes out at 77 C. When I remove the filament, it still has the angles end I cut to load the filament and it is cool to the touch.
I step up the the temp by 10 C increments and the average reported change was +4 C per increment. It seems to be getting worse.
There is some PLA remnant in it, but I don’t think it’s actually clogged, it just won’t melt to clear.
I can’t find anything online why the Taz thinks it is one temp and isn’t heating properly. Wiring looks OK and is set properly. I don’t know if I need the heat creep mod or something else is bad on this device.
Any guidance or troubleshooting ideas are appreciated.
It’s unclear, is the reported temp never reaching target, or does it say it’s reached the 200 C target and it’s your infrared thermometer that says it’s not hot enough?
Those infrared thermometers are junk at measuring something as small as the hot end. The laser point on them is a rough estimate, and it’s measuring the average of a cone that grows the further you get from the surface, so unless you’re measuring accurately from a couple centimeters away, they’re going to be measuring the cold end, fans, and walls behind the thing. So I would just discount that thermometer for measuring a hot end.
What happens if you set the temp to 220 and touch some filament to the exterior of the nozzle? does it start to melt instantly, after several seconds, soften, or stay completely solid?
Something broken off in the heatbreak is probably most likely, where it’s not getting hot enough to melt.
You may be able to clear the clog by removing the nozzle and forcing the clog through with a hex key (which will also let you inspect the nozzle)
Yes, I set the temperature on the printer using the knob and the printer reports the desired temperature has been reached. Then the IR thermometer shows the temperature is not hot enough to melt. When I used the thermometer, I took the measure at a right angle to each end at an equal distance (The thermometer pressed against the face of the tool head under the fans… maybe 2 cm with the laser center and dots being entirely on the metal by the nozzle). I’ve adjusted the emissivity and know there will be some inaccuracy, but the ~130 C difference seemed like a lot.
I will do the test touching the filament directly to the hotend when I get in to work. Thanks for that tip! I have reviousl;y set the temp to 240 C and left the filament in. When I removed it (after about 10 minutes), nothing was coming from the nozzle and the filament still had the pointed cut I made on the tip to feed it in. It wasn’t even hot.
I’ll have to find some instructions for removing the nozzle. It’s a work machine, so breaking more is not optimal.
Removing the nozzle is pretty easy, heat up to about 200C, then power down the machine.
I think the 3.1 dual extruder still uses 18mm hexagon hot ends, so you’ll need an 18mm wrench (or adjustable wrench) to hold the heater block while you use a small socket to remove the nozzle. You want it hot while you do this, but you don’t want power to it while you do it, in case you accidentally touch the wires.
Installing the nozzle back afterwards is mostly the opposite - screw it in while cold, but don’t force it tight. Then heat back up to 220C or so, switch off, and tighten the nozzle while holding the heater block. Turn on again, heat back to 230C, switch off and tighten the nozzle again, while holding the heater block.
The 100k Semitec GT-2 Thermistor failure can result in a HUGE variety of problems/effects…I’ve even seen mine result in a loud “Pop!” and shut down, and start over and do it again. It would be unusual for two to fail at once, but I’ve seen unlikely failures occur on my Taz 6. Try to measure the 100k ohm resistance while it has not been moved or tampered with…while still attached to the block. Check to see if it has come dislodged or loose in the block, before extracting it for visual inspection. Always keep one Thermistor in stock ready to install.
The Heater Cartridges are probably not your problem, but they fail in multiple ways with a few different results. I’ve forgotton how many ohms to read on this item.
The Thermister and Heater are both located in the block where you should be measuring your temperatures…besides at the nozzle.
Check your Printer Head Assembly for sturdy tightness. Some prints jiggle and jerk a lot, and this can rattle your Hexagon Metal Hot End to be loosely mounted and isolating heat without distribution. Resulting in intermittent clogs because the wheel slips and chews through the filament and hot filament doesn’t heat the nozzle…just stays hot in the block around the heater …Or maybe another thing happens, but if the assembly is loose, then you have problems.
I’ve never used my Dual Extruder, so I’m not too familiar with trouble shooting yours.