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Discussion Starter · #1 ·
Hello folks. I'm relatively new to the hobby and I have a question.

I have a Bachmann Spectrum 2-6-0 Mogul that appears (to me) to be low on speed and power. The locomotive is from Bachmann's newer run and I have owned it for just over a year. I don't have much run time on it, maybe 10 minutes.

The facts. I have a temporary setup in my house with about 50 feet of LGB track. The curves are 8ft diameter. I'm running track power with an MRC Train Power 6200.

The Mogul runs slow as compared to my other locomotives on the same set up. I hooked a string of 4 USA Overton Passenger Cars to it and the locomotive just crawls, almost stalling out when it gets into the turns. I realize the Overtons have a ton of drag. They are not easy cars to pull and I could make they better with a little more grease. However, for reference, my "Annie" pulling the exact same cars on the exact same set up runs just fine. In fact, the Annie pulling the cars runs down the Mogul without a train when I put them both on for one of the runs. I have also run recently a USA GP9 pulling a string of mixed freight (maybe 10 cars) with no problems on this set up.

I have applied lube to all of the areas the Bachmann directions have indicated. While I can work to make the Overtons more locomotive friendly, I really want to know if there is something wrong with this Mogul or is there something else I should do? Any tips or ideas?

Much Appreciated
-Kris
 

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Sounds like the loco itself.. Go out to that corner where it almost stalls, and measure the voltage on the rails AS the loco passes by, i.e. moving, pulling the load.

Then, at the same transformer setting measure the voltage on the rails at the same spot with nothing on the track.

Greg
 

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You don't mention which generation of mogul this is, so I'm going to presume it's the latest version with the electronics in the tender and brass gears, since the original version has been out of production for quite a while. You can easily tell by looking at the wires going between the loco and tender. If its only 6 wires (one set of two wires and one set of four) then it's the original version. If there are two sets of 8 or so wires, then it's the new version. I have one of the new versions. (And one of the old ones, too.) At 13 volts going to the motor, the loco will run at roughly a scale 20 miles per hour, which translates to roughly 18" in one second. I've not run my new one with my old one to see if there's any significant difference, but I believe the gearing is very similar.

If it's the older version, I might be led to suspect the main drive gear, which was known to crack and slip on the axle. If the crack does not go all the way to the edge of the gear, it will slip a bit when under a heavy load, but then pull better when the load is reduced, such as on curves, etc. (The new version has brass gears, so slipping isn't likely going to be the issue.)

Later,

K
 

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Discussion Starter · #4 ·
Thanks for the responses guys. The loco is from Bachmann's latest run. I tested at two points.

Test Location A: About 3 feet from the power supply leads, straight and level. This is were I did my timing.

Test 1
Loco unloaded
13V measured at the rail (about 65% throttle)

Result: Takes between 1.1 to 1.2 seconds to traverse 18 inches. Given the fact that the timing method (tape measure, stop watch) is not too precise, I believe its in the ballpark of EBT's loco.

Test 2:
Loco Loaded with the 4 Overton cars
Same Throttle Setting as in Test 1 (65%)

Result: Takes 1.8 Seconds to traverse 18 inches. Voltage dropped to 12V

Side Note: Annie with same load and throttle position traverses 18 inches in .8 seconds. Noticeably different, hence my original concern.

Test Location B: Curve where the loco appears to struggle the most, about 15 feet from power supply

Test 3:
Loco Unloaded
Throttle 65%

Result: Voltage at rail under loco while it was passing is 12.1V

Test 4:
Loco Loaded with the 4 overton cars
Throttle 65%

Result: Voltage at rail under loco while it was passing is 10.1V. (it crawled and eventually stalled)

My Thoughts: That is a significant voltage drop from Location A to B while under load (2 Volts). The setup is not a good one and this loco (as compared to the rest of the roster) appears to be the most sensitive. Even with the setup issues, I'm not convinced I have a good loco. I am going to bring out my Aristo C-16 which is a much smaller unit and compare. If this unit out pulls the Mogul with this same setup, I'm not going to be happy.

-Kris
 

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Yes, 2 volts might not seem a lot, but it's about 17%. That's a significant drop.

The other thing is that motor speed is not a linear relationship, but from my experience, at higher voltages/speeds a few volts makes a big difference in speed.

So, you can probably improve the track connections, and there may not be anything wrong with the loco.

This is why I started with just verifying the power before taking off on the loco mechanicals.

It could just be the differences in motors and gearing.

Greg
 

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Discussion Starter · #6 ·
Thanks Greg my thoughts too, however, I just tested with the C-16. Similar to the Annie, I can't really get good voltage readings while its running. While pulling the cars, it traverses 18 inches in about 1 second and comes no where close to stalling at the problematic corner. In fact, it too runs down the Mogul (unloaded) while pulling the string of overtons.

The setup is definitely an issue (no question there), but it is shocking to me that my newest most expensive loco (albiet nicest looking) on my roster is also the poorest performer by a long shot.
 

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Kris:

Have you checked the gauge of the wheels on the engine? There is more friction on curves and if they are not within specifications that could be a contributing factor.
 

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Discussion Starter · #9 ·
Thanks for the replies HH and Pete. I am currently running on 8ft diameter curves with no turnouts. I don't have a way to precisely measure the gauge but I parked the loco in the turn and looked at the play. It appears I have sufficient play between the flanges and the rail. I can "wiggle" the axles around a bit. I don't perceive there to be any binding. I checked the tender too. The curve is naturally where the performance is worst and served as a good talking point for this post. The loco is a slug everywhere (straights and curves) compared to the others.
 

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Pete, the latest version of the mogul eliminated the pins behind the center drivers. Instead, they're blocked by the suspension from being able to drop below the railhead.

Kris, that your available voltage drops to 10 volts under load in the corner makes me wonder if your power supply may be struggling a bit. Four-foot radius curves and passenger cars with significant drag will tax the locomotive. Only about half of the total power available on the MRC 6200 goes to the variable track output. Can you measure the current draw as the loco enters the curve with and without the cars in tow?

Later,

K
 

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I have found that the MRC 6200 outputs pulse power all the time and some loco control boards do not like it. I fixede one by inserting the Aristo pwc filter and got great results from the 6200.
 

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Discussion Starter · #13 ·
Great suggestions gents. I switched the power supplies. I have two others; an MRC tech II and an old cheepo LifeLike that came with an HO starter set. They are packs meant for smaller scales and only put out 18V max but even still, the Mogul lags behind the other two in speed and grunt when using both supplies. It didn't seen to make a difference. I measured the current draw from the 6200 from all 3 locos at both locations
Location A: 3 foot from power supply on a straight section
Location B: about 15 feet from power supply on the dreaded curve

Unloaded (loco only)
Location A
Mogul: .5 Amps
Annie: .33 Amps
C-16: .67 Amps

Location B
Mogul: .73 Amps
Annie: .43 Amps
C-16: .78 Amps

Under Load (4 Overton Cars)
Location A
Mogul: .96 Amps
Annie: .66 Amps
C-16: .93 Amps

Location B
Mogul: 1.4 Amps
Annie: .89 Amps
C-16: 1.1 Amps

Doesn't appear to be to far out of bed in terms of power draw when compared to the other two. It just does the least amount of mechanical work with it. Side Note: I am renaming the Annie to the Al Gore Locomotive. :)
It pulls the hardest and does with the least amount of power consumption. That thing is a tank!

I don't know guys. I'm going to reach out to Bachmann and see what they say. The weekend is nearing the end and it's about time to put all the toys away. Thanks for all of the suggestions.

-Kris
 
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