Hello, the idea is to buy a Gotek drive complete with case. This way you have all the screws needed to bolt it down on the 3D printed bracket.
I believe the Gotek drives are only sold complete with case.
The AmigaKit version is already programmed, which makes it easy to install it directly on this 3D base.
Or you can program the drive yourself following these instructions:https://cortexamigafloppydrive.wordpress.com/
You have to buy a Gotek floppy drive from places like Ebay for around 17 euro's. USB programmer for around 3 euro.
I'm using Gotek drives for several years now and they are working great. Sometimes when writing data to the disk it doesnt't work properly.
Another possibility is to program the Gotek drive with the HxC firmware which fully supports reading and writing. (I haven't experimented with it yet)
Note: for the A500 the diskdrive cables can be a bit short. It works but it might be necessary to get longer cables (internally)