I created this to work in the new SYS3 attic lids. The SYS3 version is different from the previous TLOC attic insert in several dimensions so I designed this from scratch to fit. I decided to put the dovetails in the side rails of the bit insert to lock into the sides/dividers. I am realizing it was probably not necessary, however it definitely improves the "snug-ness" and I don't foresee it ever falling out.
I printed mine at 0.2mm and infill at 15% since its pretty thin, and it's working well. I drilled out the 5mm holes after the print and you may need to file the "pins" on the bit holder part to make them rotate easier in the hinge holes.
File is in mm so scale by 2540% if you import in inches. I printed with supports on both parts (fairly minimal needed) and printed the bit holder with the hex holes facing down.
Feel free to comment any suggestions or changes you see necessary. I have made this to fit the left/right/center slots in the attic lid so it can be placed in any position, or 3 can be used as well. There are 4 spots for bit holders, and if all 4 are used you can only insert 1in bit tips, however you can omit bit holders if you plan to use longer bits or drill bits.
I have made an 8 hole version which is best suited for small bits/drills and a 6 hole version that is for larger countersinks/self centering bits etc.
I also added a small partition divider which allows you to subdivide a thin section as shown in my pics.
I recently purchased GratKit Light Gray PLA+ on Amazon and the color is a very close match for the Festool gray RAL7035.
UPDATE:
I got a new Bambu P1S and noticed I had fitment issues with the bits as my old printer wasn't as well calibrated as the Bambu.
I have uploaded new bit holders as I found that centrotec bits and regular 1/4" hex bits fit a lot differently. I found inserts worked well for one or the other when there is no magnet. Eventually I plan to redesign the holders to incorporate little magnets but for now I just made updated versions that fit either with a pretty nice friction fit hold.