I've needed a bunch of springs lately for projects.  The spring assortment I bought has all the wrong sizes.  The local hardware store has all the wrong sizes for obscene prices.  The winders I found on YouTube all used drill presses or motors and seemed overly complex, flaky or dangerous.  Thus, this winder came to be.  I can have any size  I want in a few minutes and I don't have to design around stock spring sizes now.  I've wound springs on 1/16" mandrels with .008" wire up to .062" wire on 1/2" mandrels and it works well with them all.  Mandrels can be anything round.   Steel rods, screwdrivers,  whatever.   (Maybe hardwood? Haven't tried)
 

The winder part is fairly self-explanatory.  It just cranks.  The handle/tensioner has a hole through it that guides the music wire through to the two plastic clamping discs that supply the tension and provides control.  Feed the wire through the handle and discs and clamp the tension screw (wing nut) down tight.  Then bend the first 3/4" of the wire to 90 degrees+/- .   Insert the bent end into the chuck with the mandrel and tighten it down so it grabs the wire. Heavier wire requires a small hole in the mandrel to anchor it as the chuck can't grab hold of it.  Position the tensioner with the notch riding on the mandrel.  The notch on the end of the tensioner rides on the mandrel as you crank and provides easy control over the feed.  
 

The finished spring will spring back when done and be larger in diameter than the mandrel.  Springback amount varies.  Seems to be greater with larger diameter wire.  Higher tension seems to reduce springback but its trial and error if you need greater precision.   The crank handle can spring back with a LOT of force, so be careful. (Ouch!)

I get larger diameter music wire in 3' lengths from my local hardware store.  For small stuff I use guitar strings.  I get them from:  [https://juststrings.com/search.php?page=2&section=product&search_query=bulk+plain+steel](https://juststrings.com/search.php?page=2&section=product&search_query=bulk+plain+steel)
Hope you found this of use. Thanks for looking.

Final note: Don't try to cut music wire with your flush cutter. DAMHIKT

Hardware required:
 

Handle/tensioner:
1  1 1/2" - 2"  1/4-20 carriage bolt
1  1/4-20 wing nut
2   1/4' X 1 1/4" fender washers 9 (hole filed square to fit bolt)
1  1/4"washer

Winder:
1  chuck (this is the one I used: [https://www.amazon.com/dp/B0BFB2JGJT?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1](https://www.amazon.com/dp/B0BFB2JGJT?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1)
1  5"  1/2-20 bolt (to fit chuck)
1  1/2-20 nut (to fit above)
1  4 1/2" carriage bolt
1  1 1/4: hex bolt
3  1/4-20 hex nuts