1.75mm clogging - TAZ Pro modified to 1.75mm Titan Aero

I recently purchased a TAZ Pro that came set up with 2.5mm Titan Aero print heads. I replaced the heat sink, heat break, and nozzle tip to the 1.75mm version for each print head. I have everything up and running and started to printed the Vernier calibration sample print to see how close the automatic nozzle offset calibration was.

The problem that I’m running into is that the filament (3DXTech PLA) for extruder 2 is clogging while it waits for extruder 1 to finish printing a layer. I have attached a picture of the filament after I pause the print, pull out the filament and reload to resume printing. I have changed the print settings to 1.75mm diameter, retraction speed to 3.0mm/s, print speed to 30mm/s, and travel speed to 120mm/s. Is there any other parameters that I’m missing that need to be changed or is this type of clog something that needs to be adjusted mechanically? I have attached a picture of the filament

Is that PLA with Carbon Fiber? I had a hard time printing that on my Taz 6 v3 Dual Extruder. Seems softer, more affected by heat then regular PLA. I was using PLA with Carbon fiber from Matter Hackers. I would suggest lowering the temperature as much as you can get a way with and print on the lower side of the suggested printing range. If that easy fix doesn’t work you may need to do some minor Gcode manipulation in the Start Gcode section.
Preferences > Configure cura… > Printers > Machine Settings > Printer tab > Start Gcode

Watch the screen during the startup sequence? Do both extruders heat up to the wiping temperature then the probing temperature then the printing temperature and then the 2nd extruder drop down to the standby temperature? What is the standby temperature? It should be about 175 or less. The point here is there’s no need for the 2nd extruder to heat up to its printing temperature if its not going to start printing right away. So comment that line out, should look like something like this:

M109 R{material_print_temperature_layer_0} ; wait for extruder to reach printing temp
or this
M104 S{material_print_temperature_layer_0_1} T1; set extruder temp

Make sure you’re commenting out the one for the second extruder E0 or T1 or maybe something different?

By commenting that out the 2nd extruder will only go to its probing temperature while the first extruder heats up to its printing temperature, then when it begins to print the 2nd extruder will heat up to its standby temperature.

To me that filament looks like a victim of the heat creep problem all too common with PLA. I was hopeful that problem was fixed on the new series of printers. Also, be sure to slow your print speed down when printing with Carbon Fiber infused PLA. I see that you have done that so you’re good there. Good Luck let us know if any of these things helped!

The PLA pictured is Premium PLA Biopolymer so there is no fiber. I have the same thing happening with the other spool of PLA (Black PLA from HatchBox). I was printing at either 205 or 210 so I will try printing at a lower temperature to see if that solves the issue. The more that I search, it seems that heat creep is the issue. Hopefully I’ll be able to report more success later today. Thanks @JoeBowler300