Hello I used a homemade drill rig for many years and mine worked quite well
I took a cheap second hand plug in style hand drill from a pawn shop 7$ . A broken fiberglass rod butt from the 80's that I got for a few dollars about 30 years ago. I think this was maybe only a $1?
I purchased some long thin bolts and few nuts and made a pile of host spools so I had a round part to chuck onto the drill $2 O ya and a few U bolts to hold the stuff together.
The backing holding spools where free recycled plastic spinning line hubs A friend said he found at local tackle shop and where in the recycle bin. $0
For returning the backing onto the fly reel spools drill a hole to a board and add the nut with a small chunk of rubber on either end for a bearing and a spring to adjust the drag with a wing nut to stop the backlash , then add the fly reel spool to the drill with a bolt "IF YOU CAN" maybe some will not fit like this? not sure I really only have one style spool to worry about.
Bolt all this junk together in a line ,, and on a free board from trash day and
Now I upgraded the pre made system. A good friends mother gave me an old plastic one like the above, 10 bucks at a garbage sale, and it has a fun foot controller.......
Just yesterday a found a big old powerpro spool just tossed on the river bank by some joker that used my river for his trash can. I picked this up and used it for a long belly spey line holder.