Pecos River Brass N 4-6-4 ATSF 3450 Class

[Mark.S+10]

I purchased my first brass locomotive last week, a Pecos River 4-6-4.  It was very dirty and had old grease, hair, and some sort of fiber inside.  I have cleaned it and it now runs very well.  Smooth and quite with a nice very slow speed creep.  However, it takes more track voltage then my plastic locomotives.  It doesn't start moving until 4 volts track voltage and really doesn't get going until about 7 volts.  At 7 volts it is moving at about 30 scale mph.  The top speed is well above scale speed.  What I'm wondering from those of you who have one of these, is this normal?  The motor is a 5 pole, but only has two small magnets, one on the top and one on the bottom.  The magnets are much smaller than say the ones on a Kato/Con-Cor Hudson.  Further, the magnets are flat and not curved.  This may account for the greater voltage required.  I'd appreciate some information from anyone that has one of these.  Thanks, Mark.

[UP4-8-8-4]

     CONGRATS Mark, you got a good one !
Mine runs like a swiss watch, you'll love it -------------------- 

As far as the running, mines the same.



Ernie

[sizemore]

While the previous post says its normal, makes me wonder what the AMP output is of your power pack? Conversely have you measured/compared the AMP draw? In HO-land old box frame Mantua's were notorious for needing power packs that needed a little more "chutzpah" in amperage to operate at what the modeller considered normal compared to an Athearn Blue Box diesel.

If you really want to get scientific we can compare motor design, windings, air molecules, elevation, planetary alignment.

Just some food for thought,
The S.

[Cajonpassfan]

Mine's a smooth runner too, but I've converted it to DCC with a Lenz silver mini and that took care of the high staring voltage and high top speed. Now if I could only figure out how to synch the sound properly on this engine...
Otto K.

[Mark.S+10]

Thanks all for the replies.  Thanks Ernie, nice to know that the higher than plastic voltage is normal.  It is beautiful and it runs very nice.  I don't know how to measure the Amp draw, I'm running an old MRC Tech II model 2500 power pack.  The power pack is capable of putting out 2 amps but no Amp or Volt measurement, I just hooked up a voltmeter to the track to measure voltage.  Has anyone changed the motor magnets to either curved or rare earth magnets?  Thanks to all, Mark.

[robert3985]

I'm in the process of changing a motor on an old brass Key GS-3, along with super detailing it and painting it up for a friend of mine.  Brass engines are pretty simple, and I'd venture a guess that your PRB 4-6-4's motor would be fairly easy to replace if you were so inclined.  I'm sure a more modern "can" motor would improve its performance, but I'd be aware of a "coreless" motor if you ever want to run it on a DCC layout at address "0", which will smoke a coreless motor.

The biggest problem is cutting the shaft, which is always steel.  Cut it with a Dremel cut-off disk a little longer than you think you need.  You can always shave a bit off, but it's difficult to make it longer.  Make sure you chamfer the cut end, so the U-joint (which is a press-fit) will more easily slide on.

The shavings can get into the motor because of the magnets and they're difficult to get out once they're stuck inside.  Sooo....before you cut the shaft, wrap your motor very well with part of a plastic food storage bag and tape, so there are no holes that aren't taped.  You'll see the steel filings sticking to the outside of the bag, attracted to the magnets of the motor.  Luckily, they aren't inside the motor!

However, if you plan on DCC-izing your engine (and your layout) the higher voltage and amperage across the tracks that DCC provides will allow you to regulate it to run with the rest of your motive power without replacing the motor.  That's one of the nice things about DCC!

I find that my old brass engines that haven't been run in a while are "stiff", and if I run them again for a while, both backwards and forwards then pulling a train around the layout, in an hour or so, they'll be running at a higher speed on the same voltage as they "loosen" up.  Keep track of it by feeling the engine body for excessive heat.  You might want to give this a try if you've got a circle of track, or a loop on your layout before you seriously consider replacing the motor.

Cheers!
Bob Gilmore

[sizemore]

Thanks all for the replies.  Thanks Ernie, nice to know that the higher than plastic voltage is normal.  It is beautiful and it runs very nice.  I don't know how to measure the Amp draw, I'm running an old MRC Tech II model 2500 power pack.  The power pack is capable of putting out 2 amps but no Amp or Volt measurement, I just hooked up a voltmeter to the track to measure voltage.  Has anyone changed the motor magnets to either curved or rare earth magnets?  Thanks to all, Mark.

You're better off replacing the motor with a Mashima or NWSL standard 5 pole motor.

The S.

[Mark.S+10]

Thanks to all.  Motor replacement is more than I currently wish to do.  I'm sure a modern motor would make it run much better.  I was looking for simple improvements and those two small magnets sook very easy to replace in this motor.  Have fun, Mark.

[mmagliaro]

...
 I'm sure a more modern "can" motor would improve its performance, but I'd be aware of a "coreless" motor if you ever want to run it on a DCC layout at address "0", which will smoke a coreless motor.


...

Cheers!
Bob Gilmore

Bob... I hate to divert this thread, so I'll open a separate one on this and we'll take it over there. 
Please have a look and we'll discuss there.
Are you sure about this issue of running DCC on "0" killing coreless motors?   Have you actually seen this happen, and was it to the "serious" corelss motors like Maxon or Faulhaber?