I've recently got into wiring some coils for metal detectors and the likes. Some of the coils don't require any thing special while others can be vexingly complex.Suffice to say working direcly off the spool just wasn't working for me. There were a bunch of old pens laying around and 20 min later one of them had been repurposed!The stl has support material built into it to help with the end being tapered. I currently have two spools of magnet wire the one pictured is rather stout the other is much longer. Both were taken into account in the design so there is a decent bit of flex.Short spool ~50mm,~40mm Tall spool ~45mm,~60mm1) Print Pen Wire guide 2) Cut away support material 3) Find a pen and remove the cap, ink and attatch guide 4) string the wire through the guide and through the pen 5) once the wire has made it through the pen place the spool onto the spool holder 6) wire some coils!Optional: cut a piece of fine sponge to fit inside the pen and a channel half way through that for the wire. It's a bit more work initially loading the wire but it adds just a bit of friction to the equation.