While experimenting with the 40 Years old Sewing Machine of my mother..... I made a few modifications to it. One of them is a new Spool Holder that can be swapped out for the old on. Now it is possible to use up to 4 Threads at once. Why would I want to do that? I just like to experiment with different Colors of Thread. They make Nice Color effects in different kind of Light. In my Experiments it worked up to 7 Threads at once. 4 trough the Needle and 3 wound up on the Coil below the Needle.
Note: I had to remake 2 Gears because the Teeth where broken (please ask if you want to know more about these gears :-) ). PET-G does the job apparently Because they are still going. So be careful with using more than 2 Threads ;-)
Maybe someone somewhere on the Internet can also use the Spool Holder :-)
If You have any questions, feel free to ask :-)