The standard method of adjusting the Model T coil current (amps) is to change the vibrator spring tension. The more tension - the more current and the less tension - the lower the current. The recommended current is 1.3 Amps.
The recommended method to increase the tension is to hammer on the outer end of the vibrator spring support. This will rotate the support a little away from the points and increase the spring tension.
The recommended method to decrease the tension is to pry up on the end of the vibrator spring support. This will rotate the support a little toward the points and decrease the spring tension.
I made a tool that can be used to adjust the coil current and it seems to have the following advantages over the recommended procedure.
1. No hammering is required on a possibly fragile old wood coil box.
2. Rotating (bending) the vibrator spring without prying against the wood box causes less stress on the wood. (See "Prying to decrease tension" photo)
3. Solves the problem of the spring support bending and not rotating the spring. (See "Bent Support" photo)
4. Solves the problem of a short tail on the spring support. (See "Short Tail" photo)
5. Solves the problem of not being able to grab and bend the vibrator support with a needle nosed pliers. (See "Needle Nosed Pliers" photo)
This crude tool was made from a 3/8” diameter rod with a stiff wire hook brazed on one end and a clip welded on the other end. One end is used to increase the tension/current and the other end is used to decrease the tension/current. The hooked end is used for increasing the spring tension. To do this, one hook is hooked under the right or left side of the vibrator spring support and the handle is pushed down. The hooked end has a two hooks and can be hooked on one side and bent a little then hooked on the opposite side and bent a little more just to keep things uniform. Or, if the points are not aligned correctly, maybe bending on one side would help.
The opposite end of the tool has a little projection that will fit under the end on the vibrator spring support to decreasing the spring tension.
No, I don't sell the tool but anyone that is handy in a workshop should be able to make one. You are welcome to share the photos/details with whoever could make one for you.
Thanks, Jim
Paul Carns
16-Oct-2015 01:34
Would you sell these? I could use one, but do not have the equipment to make it. Nice idea.