Engine Baffle Fastener Springs

 To wind the springs I'm using a Porter Spring Winder which I borrowed from Rich Wilbur for our WACO NINE projects.  I measured the wire on a spring on the Fly Baby baffles and found it was .040" so I ordered some .041" music wire from McMaster-Carr.  After a little experimenting I decided to make springs with a 1" free length, 4 pounds of force when compressed to 5/8", 2 closed turns at each end, 10 open turns, and the ends ground flat.  I wound them using the 1/4" dia. mandrel.

The first step is to bend the end of the wire and lock it into the handle.

For the first 2 turns the Pitch Gauge is moved clear of the coil so the winds will be tight to each other.

 After winding the closed turns the Pitch Gauge is moved to use the smallest pitch. The farther you turn the handle the wider gap it forces between coils.  Ten turns are wound at this setting.

Then the Pitch Gauge is moved clear and 2 more closed turns are wound.

 The mandrel is about a foot long so more than one coil can be wound.

To make it easier to cut the springs apart I put a couple open turns, then started with 2 more closed turns, etc.

 I needed 8 springs and 4 fit well on the mandrel.

The wire was cut off as close to the closed coils as possible.

To hold the spring while grinding each of the ends I slipped it over a 19/64" drill, keeping the end of the drill clear of the belt sander.  The end was then ground square and flat on the belt sander.  I found it worked better if the cut off end of the wire were at the top where you can see it. Then you just grind with a light touch until the cut end is just blended smooth.

They make a spring force tester but I don't have one.  To check the force I set my vernier to extend the depth gauge 5/8" and locked it.  Then I just used the vernier to push the spring down until the end of the depth gauge just touched the table on the scale. It's not quite touching in this picture.  You can see we're right around 4 pounds with the spring compressed.  I figured out a way to use my magneto timer, buzz box, to determine when the vernier just touches the table.  You need an insulator between the top of the spring and the vernier.

All the wires and springs are made.  The 2 original wires are at the top, hooked together.

The original wires were very rusty so I decided to paint the springs and wires.

We now have all the fasteners ready to install the baffles.