Print Discoloration/ Burn Marks

I recently got a new Taz6 for my office (architecture field) and have been trying to put it through the ringer and learning the ins/outs before opening it up to project teams. I’m currently using nGen Colorfab PLA and have only been using white filament after the initial green rocktopus. I’m honestly not sure what would be causing ‘burn marks’ or discoloration in the print. So far I’m mostly seeing it happen in the Top and Bottom layers.

My assumption is that there is some filament that is getting stuck and frying inside the print head that is coming dislodged as the print progresses. But we all know what happens when you assume…

Any help/advise would be greatly appreciated!

That is a blob of filament, likely from the startup sequence, that has been roasting on the hotend until it catches on something and comes off.

That may be true for what happened on the interior wall, but in the other image, there is discoloration in multiple places on the flat surface within the top 2 layers.

What temperature are you printing your PLA at?

Hi Jim,
I’ve been printing from 220-230.

You will want to print Color Fabb PLA at 205C for better results.

Thanks David, I’ll make that change today. Is that number based on manufacturer recommendations for their material or more on your experience with it?

That temperature recommendation will be from testing on the printers for our established profiles.
Here is a link that may help with some of the recommendations:

I hope that helps.