I stand the drill up and built a wooden jig I clamp onto the table with a hook to hold the swivels parallel with the drill. I made some DIY bobbin threaders (search YouTube) and also have a couple store bought ones from a fishing store. I saw a video that someone used a empty protank head as a guide, it works quite well. The pressure on the spool by the bobbin threader holds the wire tight and it fits inside the chimney of the protank head thus holding it steady against the core wire. Once you get the wraps started I don't have to hold the spool, it just dangles under the wire and maintains consistent pressure on the wraps and the PT head guides it down the core wire. The only issue I've come across is that if the core wire isn't perfectly balanced, it begins to wobble then throw the wraps out of sync. I kinda solved that since your only using 1 hand to trigger the drill, the spool is dangling so no need to touch it until your done, the other hand I push down on the core wire so it doesn't wobble as its spinning. I only make a foot of clapton at a time and make nice tight claptons that the wraps don't space when your building the coil.
Home made bobbin threader made with some coat hanger, a couple wooden mushroom caps, heat shrink and a generic qtip shaft that has a hollow center. I had to put a hex wrench into the qtip shaft cause when heating the heat shrink it heated the plastic qtip shaft enough to collapse under the pressure of the heat shrink shrinking.
A pic of the Lego stand holding the spools and that works like a hot damn to store spools. Spool on the far right is the store bought threader and the other 4 threaders I made in about 15 minutes.
