Many thanks to those who responded to my question about wiring a 614 switcher correctly. I DO have the Lionel repair manual, but for this particular engine, the schematic doesn't mention anything about making sure that the solder lug on the brushplate has to be isolated from ground. A couple of the responses were right on the money. I just connected the one winding wire and the lead wire from the e-unit together and put a piece of electrical tape over the joint, until I can get a shoulder-washer and wire it up like the original. I still can't figure why Lionel wired the engine this way. Why not do it the way I ended up doing it, and just use fibre tubing (like they used to use) or a heat-shrink joint.
initagain Many thanks to those who responded to my question about wiring a 614 switcher correctly. I DO have the Lionel repair manual, but for this particular engine, the schematic doesn't mention anything about making sure that the solder lug on the brushplate has to be isolated from ground. A couple of the responses were right on the money. I just connected the one winding wire and the lead wire from the e-unit together and put a piece of electrical tape over the joint, until I can get a shoulder-washer and wire it up like the original. I still can't figure why Lionel wired the engine this way. Why not do it the way I ended up doing it, and just use fibre tubing (like they used to use) or a heat-shrink joint.
They probably just found it handy to use the existing screw-and-solder lug set from other locos to connect the ends of the wires from the two windings. All they had to do was add the now-infamous nylon washer. Easy to manufacture; easy to repair. Also easy to confuse the public because that same solder lug had been used elsewhere, without the nylon washer, to serve as a ground-post.
initagain just connected the one winding wire and the lead wire from the e-unit together and put a piece of electrical tape over the joint, until I can get a shoulder-washer and wire it up like the original. I still can't figure why Lionel wired the engine this way. Why not do it the way I ended up doing it, and just use fibre tubing (like they used to use) or a heat-shrink joint.
Your solution places the wire lead coming from the field in jeopardy. Constant flexing of the magnet wire could cause it to break. When it is anchored to a solder lug it will not flex, and there is no chance of it breaking. If the wire lead is from the outside of the field winding, you could fix a broekn wire by just unwrapping one turn. If the wire lead is from the inside (center) of the field winding, and the wire broke off close to the coil, then you would need to rewind the field.
cwburfleYour solution places the wire lead coming from the field in jeopardy. Constant flexing of the magnet wire could cause it to break. When it is anchored to a solder lug it will not flex, and there is no chance of it breaking. If the wire lead is from the outside of the field winding, you could fix a broekn wire by just unwrapping one turn. If the wire lead is from the inside (center) of the field winding, and the wire broke off close to the coil, then you would need to rewind the field.
Good point! I guess Lionel knew what they were doing, after all, and I also guess I would probably never get a job assembling engines at their plant! I DO plan to replace the solder lug and wire the motor as originally done, but I just wanted the temporary satisfaction of knowing that the engine will run in forward and reverse.
If you are a true collector, obsessed with authenticity, you won't want to read this; but if you are an operator it might interest you.
You can easily replace the two-position reversing unit (E-unit) with a three-position one, either electro-mechanical or one of the newer electronic types.
The two-position units are quite reliable, but the first time some kid or adult clown hits the direction button with a train running at speed, one might well wish for a three-position E-unit with the intermediate neutral position.
Imagine that you're out on a highway running 65 mph, and you decide to go backward without slowing doen so you slam the car into reverse. A two-position E-unit will do just that to your locomotive. Just one more thing to consider....
Another consideration: If you rewire with a 3-position e-unit, you will have the option of using the entire field winding instead of just half of it. This will give you a slower, stronger-pulling motor.
Bob Nelson
lionelsoni Another consideration: If you rewire with a 3-position e-unit, you will have the option of using the entire field winding instead of just half of it. This will give you a slower, stronger-pulling motor.
Please explain how to do that. I've only seen instructions for disconnecting and taping-off either the red or green coil, a solution that keeps things pretty much as they were operationally. Your method seems to have great advantages.
It's pretty simple. Instead of using just the green or just the red winding, you use the loose ends of each one, with the connection between them maintained but not connected to anything else.
lionelsoni It's pretty simple. Instead of using just the green or just the red winding, you use the loose ends of each one, with the connection between them maintained but not connected to anything else.
Thanks, Bob.
That seems simple enough. Somehow I felt that if you did that the rotor would just sit there while the windings overheated. I'm going to try it.
Have you converted many engines using this technique? The Lionel service manual recommends making the conversion by choosing one of the two sets of windings, and disconnecting the other. Aren't the motors designed to use only one field winding at a time, with the armature and field coil impedance matching? If you double the windings on the field, I beleive it's impediance will be higher.
I have converted the only double-winding locomotive that I have, a General. It works fine. The Lionel recommendation of course results in exactly the same motor performance as before, which is presumably the performance that they thought it should have. Those who want no change should follow their recommendation. Imagine that they had recommended using both windings, "to make the locomotive will run slower and pull better." Your immediate reaction would be to wonder why they didn't design it to run slower and pull better in the first place!
There is no requirement or advantage that I know of in having the armature and field impedances the same. An ideal motor would have them both zero and would have no electrical losses as a result. The motor avoids being a dead short on your transformer by generating back-EMF as it turns, not by virtue of the unavoidable impedance of its windings.
Diesel-electric locomotives with series-wound motors have shunts around their field windings. The shunts are open for starting and then connected to reduce the field current for higher speeds. This technique, along with rewiring the multiple motors in series and parallel combinations, is how those locomotives "shift gears". Using more or less of the Lionel motor's field coil accomplishes the same thing. Doubling the field winding in use doubles the field flux, so that the armature generates the same back-EMF at half the speed. If your train runs faster than you like, especially if it is a switcher, you may like the result of shifting to a "lower gear" in this way.
As for the idea that using both windings together will cancel the field completely and turn the motor into a buzzer, 'tain't so. They would cancel if you simply connected the loose ends together and used the windings that way, in parallel. But when you use the loose ends with the existing middle connection intact but not connected to anything else, you create a series circuit and incidentally reverse the polarity of each winding relative to the other, so that their effects add rather than cancel.
Let's call the loose green end G, the loose red end R, and the point where they are connected together C. Now let's say that a current flowing from C to G produces positive flux in the field and that a current flowing from C to R produces negative flux. So, if we connect R and G together and run current from C to R-G, we get currents in both windings, producing fluxes that cancel. But now run the current from R (past C) to G. The current from C to G produces positive flux as before; but the current from R to C, being now in the opposite direction from before, also produces positive flux, not negative flux as before. So we get twice the flux, which is what we want.
By the way, even if we reversed one of the windings and then connected them in parallel, so that their fluxes added rather than cancelling, the motor would run but just as fast as before we modified it, because any current running through the second parallel winding would be current that didn't flow through the first winding; so there would be no greater flux than if we had left the windings alone!
lionelsoniI have converted the only double-winding locomotive that I have, a General. It works fine.
Thank you for writing the above explanation. I am always looking to learn something new about toy trains, and their components. I have a couple of spare double wound alco motor trucks. I think I will try wiring one up as you suggest, and see how that works for me.
Let us know how it goes!
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