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Old 07-08-2019, 01:24 PM   #11
AmFlyer
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Adding a 977 caboose to a two motor PA set should not visibly slow down a train running on a 15B.
Gilbert steam engines with smoke are about 2.5A max (at stall) maybe 1A to 1.5A normal running. The dual motor PA is about 4A max, half that normal running.
For Gilbert transformers if you use VA there is about 20% loss from input to output, say 90VA output. Since our trains are inductive motors the current lags the voltage. Some of the load like lights are resistive so we can use 75% including the losses to convert the transformer output capacity to real (less reactive) AC power. Then 110W input times .75 divide by 15V equals 5.5A continuous output. The 15B will output more for short periods assuming the breaker does not trip.
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Old 07-09-2019, 12:46 AM   #12
shaker281
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Great explanation. Thanks. Guessing you are an EE. I'm self-taught in electronics, so conversations like this are great learning experiences for me.

I am believing now that any issues I might have are more likely weight, overall conductivity or my engine is not running at full efficiency. I get consistent voltage readings all around the track (don't have an AC ammeter that will measure above 200 mA) , but will focus on cleaning a bit more, conductive oil and temper my expectations on pulling power.
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Old 07-09-2019, 11:18 AM   #13
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A long time ago I earned a degree in EE however my professional career was not in the EE field so I have forgotten much of it. I still know Ohm's law. Six years ago I guest lectured in a 300 series EE class back at the university, that was truly scary.
If you try to measure voltage on your track the meter will show the transformer output voltage everywhere on the track regardless if the connections are good or bad. The reason is the meter has an input impedance in the megohm range so it draws almost no current to make the measurement. No current means no voltage drop per Ohms law. A load is needed in parallel with the meter to get an actual voltage reading. At 15V a 3 Ohm resistor to draw 5A needs to be connected at the same spot the meter is connected to get an accurate voltage reading. Unfortunately the resistor would have to be 75W rated, good luck finding one. Some people use an old automotive incandescent headlight for the load, others just mount an easy to see digital volt meter on a flatcar coupled to an engine. Others, like me who have been doing this for half a century trust our experience and techniques to get the track right.
I do get surprise voltage drops on layouts. With good trackwork they are always at the lockon power connection or oxidation of the internal contacts in the turnouts.
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Old 07-09-2019, 11:33 AM   #14
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Concerning your PA powered A unit. You have cleaned and lubed the engine but it seems to be down on pulling power. These engines are notorious for wearing the axle holes in the chassis. Once these holes enlarge the engine will run poorly. If this engine has a lot of run time that is likely. The repair involves disassembly, drilling out the chassis and installing new brass bearings. One done it is a lifetime fix. Some have done this at home but it requires the right tools. I would send it to one of the pro's who offer this service.
Flyernut, if you are reading this what do you think?
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Old 07-09-2019, 12:29 PM   #15
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Concerning your PA powered A unit. You have cleaned and lubed the engine but it seems to be down on pulling power. These engines are notorious for wearing the axle holes in the chassis. Once these holes enlarge the engine will run poorly. If this engine has a lot of run time that is likely. The repair involves disassembly, drilling out the chassis and installing new brass bearings. One done it is a lifetime fix. Some have done this at home but it requires the right tools. I would send it to one of the pro's who offer this service.
Flyernut, if you are reading this what do you think?
Yes Tom, send it to a pro, but that's not me,lol.. Everything you said I agree with. I've had basket case PA's that I've manage to resuscitate, but I don't like working on them, especially the 2 motor type. I've never done the bushing repair if that's what needed; I would send it to Doug peck at PortLines for the repair, again, if needed.
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Old 07-12-2019, 01:04 AM   #16
shaker281
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Thanks guys, been busy getting the old 312 to run (see other thread) and other incidentals.

I would say the engine has average run time. And seems to be doing good at pulling 6-7 ordinary cars. I really only notice a slowdown when I add the bay window caboose with brakeman or the non-functional diesel-roar unit. Even the dummy A unit seems to be OK. I will disconnect all electronics in the B unit and lubricate well as a next step. And lube up the 979 caboose. The thing buzzes continuously, due to the brakeman solenoid. Not sure if that is normal or a cleaning issue or something else. My problem could just be friction and weight related with an added dose of current draw, I suppose.

A few questions:

1. How would one determine if the axle holes are problematic? Excess play? I did not notice any when I had the trucks apart for rebuild and lube. They actually rolled pretty good.
2. How would one know if the field is properly centered? I centered mine by eye and have not tweaked on it since.
3. What is a good locally available conductive grease? I did purchase some CRC 2-26 from Home Depot in spray can.

I have measured up to 16.5v at the variable output of the transformer, about 16v at the track near the terminals and find ~13v on track with train running full speed. So, I think the transformer is doing OK, despite not having a suitable ammeter to test with.

I have been fine tuning the track layout and think things are improving as I clean and apply CRC 2-26 lightly at points of contact/friction.

Last edited by shaker281; 07-12-2019 at 01:56 AM..
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Old 07-12-2019, 01:42 AM   #17
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Hi, I haven't been around the forum for a while. I've had a similar problem with one of my Standard Gauge trains before, have you checked to make sure the commutator on the motor and the brushes are clean? My Standard Gauge loco was having trouble pulling cars, but when I replaced the brushes and cleaned the commutator it ran a lot better. Also you mentioned your 21165 has a reverse unit, was that something they only included on some of their 4-4-0's? I have a Casey Jones Game Train that looks very similar, but it only goes forward.
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Old 07-12-2019, 01:48 AM   #18
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Hi, I haven't been around the forum for a while. I've had a similar problem with one of my Standard Gauge trains before, have you checked to make sure the commutator on the motor and the brushes are clean? My Standard Gauge loco was having trouble pulling cars, but when I replaced the brushes and cleaned the commutator it ran a lot better. Also you mentioned your 21165 has a reverse unit, was that something they only included on some of their 4-4-0's? I have a Casey Jones Game Train that looks very similar, but it only goes forward.
Hi, Blue Comet. I did clean the commutator, but while repairing the wire to one of the brushes, the brush got a slight bit out of alignment. It seemed to sit against the commutator well, but I may check and tweak it a bit. This unit had a complete clean and rebuild. Along with wiring repair. Thanks for the suggestion.

On the rear of the Casey Jones there should be a small black and white reverse unit. If so, there is a silver colored tab at the bottom that can be pulled down and pushed up. In the up position, the reverse unit is locked. In the down position, it is free to cycle from forward to reverse. If the internal contacts are not clean, or moving freely, it can cause the motor to receive no power or stick in one position (forward or reverse). I had one where the solenoid was completely locked up too. It would not move at all, almost like it was internally fused.
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Old 07-12-2019, 12:47 PM   #19
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Shaker, I will try to answer some of your questions. First the conductive grease. A spray lube is not what you want for the track pins. I use a product by GB called OX-Gard, #OX-100. It is made for joining aluminum to copper wires and terminations. It is a grease that improves conductivity and prevents oxidation.
I am wondering about the voltage drop you are getting on the layout. I just did a quick check on my layout. The voltage measured on the transformer terminals was 14.1, the voltage on the track near the engine wheels was 13.7. These two points are about 25' apart. I recommend you first check the unloaded voltage at the transformer terminals. I think you did this a saw 16.5V. Measure it again with the train running at a fast speed and see what it is. This will show the transformer voltage sag under load. Assuming the two motor diesel is drawing two to three amps at speed the output voltage sag under this half load should be very small, around .1V or .2V. All the other drop is connections, wire and track resistance.
Your post says there is a .5V drop between the transformer and the track at the track terminal. This is likely the track terminal connection to the rails, The track flanges need to be cleaned, the track clip cleaned and tightened and conductive grease used on the track flanges. Properly cleaned there should be no more than a .1V drop at this point (assuming you are using at least 16gauge wire.)
In order to drop 3.5V with the engine drawing 3A there is 1.13 Ohm of resistance in the wiring and connections. That 1.13 Ohms is dissipating 10Watts of energy as heat. Making tight, clean connections will eliminate most of the resistance. It is a pain but the trains do run better. Also if you have any turnouts they need to taken apart and all the internal contacts cleaned and tightened. This is really easy on Gilbert turnouts and can make a big difference.
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Old 07-12-2019, 01:16 PM   #20
flyguy55
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If you do consider re-busing your power trucks you may want to consider the cost.Two trucks with shipping back and return will surely be over a hundred bucks.You may consider looking for a donor two motor PA.It may be cosmetcally bad with good running chassis.Although that opens another can of worms as the donor may have same chassis issues.If that is the case you have another project.....
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