Hi Dave,
The capacitor on the motor I'm working on had the wires soldered to the terminals. This might be the case with yours as well. If you really need to remove it, get a soldering iron, heat the solder and pull the wire out. Then use solder wick to clean the old solder off. I do recommend wearing safety glasses when desoldering loose wires. Sometimes loose wires like that have a tendency to spring out once they break loose, at which point the liquid solder that is still on them goes flying off into your face. It's happened to me, I've seen it happen to others.
Since you have 4 wires coming out of the motor, then this schematic that was posted on Paula's thread will probably match your motor.
So forget the drum switch at this point. First step is to figure out which wire is which. Your terminal wires were labled T1, T2, T3, T4. Forget those names for the moment. I've labeled the wires on the schematic R1, R2, S1, S2, as it will be simpler to explain things using those labels.
R1 and R2 are the wires connected to the Run winding.
S1 and S2 are the wires connected to the Start winding.
A single phase motor only needs 1 winding to truly run.
In this image, there is only the run winding that is connected to the power line. If it was a 230V motor, then the power Line is labled L1 and L2. If you are using 110V, than the designations are Hot and Neutral. The Hot wire is the black one, and Neutral is the white one. So R1 is connected to L1/Hot and R2 is connected to L2/Neutral. This could be reversed (L1=R2, L2=R1), and it won't make one bit of difference because the power line supplies alternating current. The problem with this setup is that the motor will not self start. That is to say, it will not turn on it's own and and will just sit there humming. One way to start it would be to hook it up like that, and then once the motor is just sitting there humming, put a hand crank on the rotor shaft, and crank it in whatever directions you want the motor to turn. Kind of like they used to start old car engines. If you spin it real fast by hand, and then release the hand crank, the motor will then continue running on its own, due to the momentum of the rotor.
But you don't want to do that each time you want to start your lathe.
So, this is where the start winding comes in.
In this image the start winding is connected in parallel with the run winding. L1=R1=S1 and L2=R2=S2. There is a centrifugal switch that is in series
with the start winding. When the motor is not spinning, this switch is closed. When you apply power to this motor in this setup, the start winding, and
the run winding will both have current running through them. As the motor accelerates and reaches about 75% of it's top speed, the centrifugal switch will open, and the start winding will be disconnected from L1. At this point, the start winding will no longer have any current going through it, and only the run winding will continue to spin the rotor, just as if the start winding wasn't even there. The problem with this setup however, is that you are only using single phase power. That is, the current going through the start winding, and run winding will be exactly the same, and both coils are in phase. This is not sufficient to start the motor from a full stop. In order for the start winding to start turning the rotor, it needs to be out of phase with the run winding, that is to say, there must be a delay between the currents in both windings. There are 3 ways to achieve this.
1. Use multiphase power from the power company, which you don't have.
2. Make the start and run windings different. This is done in
split phase motors. They use a smaller diameter wire for the start winding, which increases its resistance. This difference in resistance of the start and run windings puts them out of phase.
3. Keep the windings the same, but add a capacitor in series with the start winding. This capacitor will cause the current through the start winding to be out of phase with the current through the run winding. This is shown in the image below, and this is called a
capacitor start motor.
This will run exactly the same way as the
split phase motor without the capacitor. Only difference is that the windings are the same, which produces higher starting torque, and that is a plus in certain applications. The extra capacitor also increase the price of the motor.
As with the polarity of the run winding relative to the power line, the polarity of the start winding is not important to get the motor started. However, the polarity of the start winding relative to the run winding will decide on which direction the motor spins: clockwise or counterclockwise. To figure this out, you do it by trial and error. Simply hook it up as in the above figure, run it, and note the direction of rotation. Then you reverse the polarity of the start winding as shown below.
Now:
S1 is connected to L2,R2
S2 is connected to L1,R1
This will reverse the direction of the motor.
----
The last piece of the puzzle is the relay you have. Many motors don't have that. From what people said on Paula's thread, this relay allows the motor to be
instantly reversed. You did that already by throwing the motor from forward straight to reverse, and you said it worked. Well, there you go. I'm not sure what would happen if you did that to a motor without the relay, but I'm guessing the motor would simply not reverse and continue running in the same direction, simply because the starting coil would still be disconnected by the centrifugal switch. Anyways, I don't think you have to worry much about the relay, other than maybe take it off the motor, and clean any oxides of the relay contacts. Relays and switches tend to arc and bounce when they are closed, and over time some oxidation/carbon will develop on the surface. Cleaning with electrical contact cleaner, or alcohol, or just very light sanding should do the trick and clean up the contacts if they look really bad.
So to figure out which of the 4 wires is which you will need an Ohm meter to measure resistance. You said the terminals you had were labeled T1, T2, T3, T4. So you need to measure the resistance between all possible pairs of the 4 wires you got:
T1-T2 = __ Ohms?
T1-T3 = __ Ohms?
T1-T4 = __ Ohms?
T2-T3 = __ Ohms?
T2-T4 = __ Ohms?
T3-T4 = __ Ohms?
That is 6 possible pair combinations, and
only 2 of the 6 should give you a small resistance reading, while 4 of the pairs should read open circuit. At this point you will have identified 2 pairs of wires, and one pair will be for the run winding, and the other pair will be for the start winding. The pair with the smaller resistance is probably the run winding.
However, If you only get a resistance reading for 1 pair of the 6, than that pair is probably the run winding. In this case you are not getting a resistance reading for the start winding because the relay is broken or disconnected from the motor. This would also be the case for motors without a relay in it. To get around that problem, you can temporarily short across the 2 terminals of the capacitor with a small jumper wire, and then see if that other pair gives you a resistance reading. If it still doesn't, then there could be a problem with the centrifugal switch, as in, it's open for some reason. But this is only important if you really want to know the resistance of the start winding. Which is not really important.
But to be 100%, mark the pair of wires that gave you the lowest resistance reading, and move them aside. Next, check the two wires you have left and see if one of them is connected to the capacitor or the relay. If that is the case, than that pair is definitely for the start winding.
So now that you have identified the pair for the run winding, and the pair for the start winding, mark the wires with lables. You can use the labels R1, R2, S1, S2 as shown in the pictures above. At this point, you should test this
without using a drum switch:
Step 01: Tie R1 and S1 together
Step 02: Tie R2 and S2 together
Step 03: Get a power cord
Step 04: Connect black wire from power cord to R1/S1
Step 05: Connect white wire from the power cord to R2/S2
Step 06: Use electrical tape to insulate the temporary connections you have made
Step 07: Bolt down or clamp down the motor to the bench. If you don't, it might jump or fall of the bench as it spins up
Step 08: Put on safety glasses
Step 09: Step back
Step 10: Plug it in
Step 11: Note the direction the rotor is spinning
Step 12: Unplug it
Step 13: Remove the electrical tape
Step 14: Disconnect all the connections you have made
Step 15: Now you will try to run it in the reverse direction
Step 16: Tie R1 and S2 together
Step 17: Tie R2 and S1 together
Step 18: Connect black wire from power cord to R1/S2
Step 19: Connect white wire from the power cord to R2/S1
Step 20: Use electrical tape to insulate the temporary connections you have made
Step 21: Step back
Step 22: Plug it in
Step 23: Note the direction the rotor is spinning. It should be the
opposite direction than before.
Step 24: Unplug it.
Step 25: Remove electrical tape:
Step 26: Disconnect all the connections you have made
Step 27: Drink a beer
At this point, set the motor aside, and focus on the drum switch. To start, take the cover off the drum switch, and take pictures of it for all 3 positions: forward, off, reverse. Post the pictures here and once we know the internal connections of your drum switch, we can figure out which way to connect the motor.
Cheers