red blade - what does it take?

Hi there,
What does it take to make the robo master tell you that the red blade is needed? Even when I have it set to max thickness mine ALWAYS tells me to have the yellow blade on. Just wondering if anyone's ever been told to use the red one.
TIA
Sam

I added a setting to mine for cardstock and now it tells me to use red when I'm on that. Not sure how I did it, though!

I don't think it ever tells you to use the red. Either remember to put your red one in (it won't make any difference to the software settings) or put your own setting in.
Click on Add Media, enter the details of your card/paper, the speed, thickness and blade colour. Click OK and that's it. Next time you get to that window, click on your own setting and it will all be there for you.