I made one of those dongles years ago and used 2x DB23 connectors & some telephone wire, once I got the wiring right it worked a dream.
I remember copying F29 Retaliator & had no problem with making the copy, it took about 35 minutes to copy one disk, thought the drive had given up as it was so slow.
PS - make sure you get the wires on the right connectors and the soldered joint is secure as my first attempt when moving the Amiga 500 with the dongle plugged in a wire came loose & shorted, hence no expansion memory and the disk drive chip got frazzled.
Got the Amiga repaired and it worked fine.