While I was building my AM8 and almost finished it, I realised that I miss 4 sliding blocks. So I quickly made a design that fits snuggy into the 2020 profiles.
Just put a M3 (metric) screw nut into the hexagonal hole and throw that thing into the profile.
Yes, you've read that correctly - It's made for M3 screw nuts - So use M3 screws (M3x10) and washers, if the screw is to small for the hole in your part. It was pain in the coconut to grind the edges of usual M5 nuts off and M4 would have been too big for the design.
I wouldn't recommend to use this design for higher loads (Motor mount or stuff like the PSU mount), but it's fine for the LCD for example.
Be sure that your printer is well calibrated, otherwise the block could get too big and won't fit into the profile. When this happens resize it to 96%-98% before printing, heat up the screw nut a bit and push it slightly in - But be careful or you will end with an unrecognizable heap of plastic and a brand mark in your hand. The screw itself will find her right way afterwards.
Edit: The round hole should be at the bottom while printing - I forgot to rotate it! I think it was -90 on the Y-Axis.
Last but not least: Remove the support properly!
Thank you for reading the safety instructions carefully.
Have fun with your brand new sliding blocks! (After 6 minutes per block or 16 minutes for four!)