I've received the JK 563 couple of days ago but I did not have any pulley removal tools so it took a day to get the right jaw puller... Anyway I've tried my 3d printed pulley today which unfortunately was very tight on installation and cracked.... so tomorrow another print. Thanks Jimi for the stl, but I will try the one I made in Fusion 360 first. I can share my Cura settings for support if you have problems with support being difficult to remove after print.
I've also received a standard straight bore 15mm pulley as Constabulary suggested just to see how easy is to modify it for the JK. Installing 1mm sleeve sounds like a good idea but whats about the bigger 5mm key hole in the standard pulley instead of 4mm on JK ?
Matt, it took an hour to have one half printed. It would be much quicker in PLA but making it in PETG and 0.1mm layer height took longer..
I've got Anycubic i3 Mega S which I modified a lot.... Its relatively good and not expensive starting platform but has few issues in my opinion so has to be modified sooner or later otherwise results are inconsistent. If you need something good from the box then Pusa i3 mk3 would be your choice.