Model Railroading > Repowering Brass Steamers and DCC

There have been some good deals lately on a certain auction site for used/likenew Brass Steam locomotives. I'm an old school DC guy moving into the DCC/Sound world. How hard is it to DCC/repower a brass import that otherwise runs well on DC? Do they all need repowering, what criteria applies? I understand about isolating motors etc but what about open frame/can motors? Would a can motor possibly negate the need to repower?

Lots of questions here, so I hope this will be one of those posts that help a large number of members. Thanks for you time and info. Bob

CFWRRCEO Wrote:
-------------------------------------------------------
> There have been some good deals lately on a
> certain auction site for used/likenew Brass Steam
> locomotives. I'm an old school DC guy moving into
> the DCC/Sound world. How hard is it to
> DCC/repower a brass import that otherwise runs
> well on DC? Do they all need repowering, what
> criteria applies? I understand about isolating
> motors etc but what about open frame/can motors?
> Would a can motor possibly negate the need to
> repower?

Bob - I'm in a similar situation in that I just picked up 2 PFM GN 4-8-4s very reasonably. One had a can motor, one an open frame. The open frame is running fine for now. Neither has been DCC'd yet. I also picked up a PFM NP/GN/SP&S Z-6 with open frame. That ran well for about an hour and then died. So I had it remotored with flywheels.

The crucial point as you recognize is to isolate the motor. You are going to have to open the units up anyway - can or not - bec. both feeds to the motor have to come off the decoder rather than as wired for DC. Given that, I'd remotor with a can if it has an open frame motor. Go with a suitable A-line motor/flywheel (s) - the "DS" motors listed are Mashima or Canon. Those have much lower current draws than open frame and the addition of a flywheel(s)makes a big difference in smooth running.

I also add wipers to the "ground" side drivers to augment the tender pickup through the throwbar. Just a short piece of PC tie material and phosphor bronze wipers, double-sided foam taped to the underframe.

My 2 cents.

Walt in Sausalito

One way to isolate the motor is to use GE silicone sealer. Use double sided sticky tape to position the motor using it to keep the motor from touching anything metal and put the silicone around the tape and bottom of the motor.

Current draw is one criteria by which you'd decide to remove an older open-frame motor and replace it with a can motor. Pound for pound, a can motor almost always draws a fraction of the current used by an open frame. This may be especially true with a large, heavy, mainline-type steam engine with a big original motor. If you choose a DCC decoder with a 1-amp rating and your loco draws, say, 1.4 amps at full slip/full power, you could be in a risky zone. Granted, most adults don't operate their scale brass at full power or full wheel slip, but it's good to have your entire electrical system operational under even a worst-case scenario. The can motor is a solution to the current draw.

If the loco has a smooth-running open frame motor, its current draw is well within your chosen decoder's limit, and you can fully isolate the motor frame from the chassis, as the previous poster suggested, stick with the original motor.

I agree, adding the extra pickup wipers is a huge help. I always add wipers to the right side (insulated) wheels on a brass engine's tender trucks, and as mentioned, to some of the left-side (insulated) loco drivers. My equipment may have other maladies, but stalling due to poor electrical pickup isn't usually one of them. The attached images show wipers added to a Rivarossi 2-8-8-2 (the ideas and process are similar from brass locos). The tender trucks were all insulated with no pickups from the factory so I made wipers from .003" phosphor bronze, screwed to the frames. The engine wipers are on PC ties, same phosphor bronze material, screwed to holes drilled and tapped in the loco frames. This engine has a truly bogus spring-loaded-pin pickup system for some right-side drivers, so I added wipers to that side, as well; that's why you see wipers on both sides in the photos. This engine has its own quirks, but it keeps going.

Jeff Johnston
www.trainvideosandparts.com

---

---

---

First, I apologize for the poor image quality. These are scans of slides from very darn early in my understanding of scanning and the like.

This is slightly off topic from the original question but since electrical wipers were brought up ... the tender trucks are from an an Athearn USRA Mikado. Nice frames, beautiful wheelsets, no electrical pickups, so I added wipers to both sides.

The loco frame is an MDC 2-8-0, with wipers attached to fiber tie strips screwed to the frame. I generally use 1./4mm screws for this, available from NWSL, along with suitable drill sizes, taps and such.

The third shot is a side view showing how the wiper attachment mounted to the frame and was bent at 90 degrees to place the wipers parallel to the wheel faces.

Jeff Johnston
www.trainvideosandparts.com

---

---

---

I have been building engines for years, but had no layout. I graduated from DC to DCC prior to starting my layout and started putting Tsunamis in most of my engines (all brass steam) that have been sitting in boxes for many years. I have finally gotten to the point of disassembling the running gear, cleaning the frame jaws and bearing sides to bright metal and hard wiring or using plugs everywhere along with wipers. Almost all of my engines were painted, so I had to be careful not to screw that up. They are 99% dependable now, but I had to learn the hard way.

Some good points here especially adding wipers on the tender trucks. Another thing is some of the older brass had a rubber hose to connect the gear tower to the motor. Bad news. They can dry up and break or just come off. Replace it with something more reliable.

The PFMs are great but with much of the older brass you'll be disapointed with the amount of cars they can pull up a grade.

Great responses so far and a bunch of good info. I've heard about the lousy pulling capabilities of some brass locos. I have a Westside Models UP FEF-3 and that thing pulls like there ain't no tomorrow. I had it more than 20 years before I ran it on a layout for the 1st time. It ran for almost 8 hours at the local club open house without a hiccup. It is a candidate for the DCC/sound conversion. Keep the good info coming, it helps. Bob

I am wondering...

There used to be an argument that the only way that you can get true Synchronization of steam exhuast is to use a cam rather than just a decoder.

What do you all say?



Edited 2 time(s). Last edit at 10/20/10 06:36 by wabash2800.

CFWRRCEO Wrote:
-------------------------------------------------------
> .... I have a Westside Models UP
> FEF-3 and that thing pulls like there ain't no
> tomorrow.

Same with the 3 PFMs I mentioned above - plenty of weight on them drivers !

Walt in Sausalito

My Balboa SP GS-4 was upgraded in the 1990s with a can motor, etc. For the last year it has been with a DCC specialist in Calgary who is having a helluva time trying to fit a Tsunami sound module. I am told the sound was truly startling for about ten minutes but then failed The unit is still in the shop and no-one seems to know what the problem is. I am posting this not to find a solution to this problem but to warn others that the upgrading of a brass steamer may not be straight forward as some will claim.

There seem to be always a learning curve, but in the end conversion to DCC/Sound is very rewarding. As mentioned above, a mechanically sound engine is a must. The first engine I converted (a smooth runner on DC) drove me up a wall. It stopped at a certain position of the drivers at irregular intervals. Even after elimination all probable causes, still the same thing. I finally tested the engine in the dark to detect any sparks from a short, and sure enough there was a short across a single spot in the ring insulation of one of the drivers, every time that spot was close to the rail, a short occur ed, enough to trip the decoder, but not strong enough to trip the command station. Closer inspection of that wheel set revealed a spot there the insulation was corroded and the resulting air gap was insufficient to provide insulation. Filling the gap with nail polish (now a routine preventive procedure) restored insulation and the engine runs flawlessly.

Some decoders allow the adjustment of the chuff rate through varying the wheel diameter and trim to achieve a more precise synchronization. This usually only works for a part of the speed range. Typically synchronization (or lack thereof) is only noticeable at low speed range. I have a pair of engines, one runs the chuff off a factory installed cham, the other from the decoder, I actually prefer the sound off the decoder, it results in a much sharper exhaust at low speed (where the engines usually are run at full cut-off).

ThomasE