Does anyone know how the new MTH stuff(2Rail) performs on straight DC power?

I own several of the scale-wheeled (#-2)locos by M.T.H.
All of them run flawlessly on my 2 rail layout under straight DC current. All of them pull 40 freight cars or 7 heavyweight passenger cars with no problem on the level. And they will operate at very SLOW realistic speeds.

Although, I prefer to run them under DCS control so that I have all of the loco sounds and system features. Under straight DC you still have the loco synchonized chuff sounds, and smoke, if you prefer. You currently need a Commander box to access the whistle and bell. According to sources at M.T.H. new improved models (some of which will be released later this year) will have many enhanced features and will be compatible with AC, DC and DCC and will give operators lots of power/control options.

jeb

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Does anyone know how the new MTH stuff(2Rail) performs on straight DC power?

Jim,

My 2 rail MTH models run great right out of the box. All ya do is install some kadee couples on the existing mounting plates (already pre-drilled for mounting screws) and away ya go. How do they run? Lately, I have been running them a whole lot more than the brass that I own. They pull well and actually run at very slow speed without tweeking! I can't say that about some of my brass models.

I ran my MTH 2 rail scale wheeled locomotives on straight DC down at my club. They ran and sounded great with one exception. For some unknown reason to me the speed control did not work. The locomotive would unrealisticly speed up and slown down on grades. The only theory I could come up with is maybe there wasn't enough reserve power to allow the speed control system to function properly.

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Originally posted by Hudson J1e:
The locomotive would unrealistically speed up and slown down on grades.

Haha, Wouldn't that be REALISTICALLY speed up and slow down on grades?
{ assuming it's slowing on the uphills and speeding on the downs?}...dave

No Dave. In some situations when the prototype is going down a hill it doesn't jump from 15MPH to 35MPH in a heartbeat. In fact the engineer must be vigilant to NOT allow the train to gain too much speed.

In short the reason I used the word unrealistically is because, yes it true that real trains pick up some speed downhill and slow down uphill, the jump from such high speeds to low speeds IMHO looks very unrealistic. Please correct me if I am wrong but real trains don't slow down or speed up all that fast.

Phil,

That phenomenon also happens at NYSME. Its not the PS2.0 systems fault. It has to do with the nature of DC power. There are areas that have power sag and DC is much more prone to sag than AC. PS2.0 locomotives use the input voltage sampled from the track to set the speed, when there is a voltage sag the speed also goes down, when there is a boost like from a track feed it will gain speed. You can test this by looking at where all the power feeds are and how far each block goes then run through that block. Do you also solder all the track joints together? We do but in some areas, the sag is just enough to slow it down. Regular DC motors aren't as sensitive to voltage changes since going from 12.5 volts to 13 volts makes hardly a change to the wheels RPMs. When running on constant voltage, 24VDC and DCS the set speed is the set speed no matter what.

Hold on Mike, I never said it was the fault of PS 2.0. My guess was it was something to do with the DC and judging from what you wrote I am not too far off. We don't solder rail joints at the club but we do have feeders every 3-4 feet. I don't think the problem is the wiring. If it was the locomotive would have other problems on other parts of the layout. I think it has something to do with that fact it is a large layout and it's running on straight DC. Sort of like there isn't enough reserve energy (in conventional mode) for the speed control circuit to work properly.

PS2.0 is a bit stingy when it comes to getting power to the motors. A better operating range would be from 6-16 instead of the normal 3-12 where most motors run. There is a 5 volt overhead is required for the speed control to work so I can understand the reserve energy problem you talk about. If it were on DCS I'm sure it will not race down the hill. Getting back to the previous behavior, it could also be differences in voltage between blocks.

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Originally posted by Hudson J1e:
Hold on Mike, I never said it was the fault of PS 2.0. My guess was it was something to do with the DC and judging from what you wrote I am not too far off. We don't solder rail joints at the club but we do have feeders every 3-4 feet. I don't think the problem is the wiring. If it was the locomotive would have other problems on other parts of the layout. I think it has something to do with that fact it is a large layout and it's running on straight DC. Sort of like there isn't enough reserve energy (in conventional mode) for the speed control circuit to work properly.

Thanks Mike. At least now I understand the problem. HHmmm, I doubt my club would want to put a DCS/DC line in where the DC line is now. As you said that would solve this problem. Most of the guys are either very pro-DCC or very pro-DC so I don't think it will happen.

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Originally posted by Hudson J1e:
Most of the guys are either very pro-DCC or very pro-DC so I don't think it will happen.

Just have the DCC guy offer to put free decoders in the DC guy's locos. If they try it they will never go back....dave

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Originally posted by Hudson J1e:
Please correct me if I am wrong but real trains don't slow down or speed up all that fast.

No but this is modeling where everything is compressed, if we din't speed up the process a bit they'd be at the end of the layout before the grade had any effect on them :>) . Any change of speed is better than a cruise control where the train never changes speed no matter what the grade or the load, speed change gives a reason to have a throttle knob and an operator ........dave

Dave, it is a personal preference. I agree a slight change in speed would look realistic but I personally prefer no change in speed to an extreme change in speed.

You guys have really peaked my interest. Now, who has an easy way tp pull six or seven hundred dollars out of the air?

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Originally posted by R.R.:
You guys have really peaked my interest. Now, who has an easy way tp pull six or seven hundred dollars out of the air?

That's usually takes somewhere between 6 to 7 Wa-wa's and a fast car,

Michael,
So what you are saying is in the straight DC units they got rid of the flywheel strip? Did they also do this for the 3 - 2 units?

Gene Anstine

Flywheel strip for the closed loop is there, its just not as effective as running constant voltage command. All of my units run very well.

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Originally posted by grfd59:
Michael,
So what you are saying is in the straight DC units they got rid of the flywheel strip? Did they also do this for the 3 - 2 units?

Gene Anstine