On the agenda for today was to clean and paint my new PFM WP 2-8-2 and reassemble the drive chassis for my friends N&W Y6b that underwent a motor transplant yesterday. In the first picture we can see the reassembled power chassis for the Mikado. It was totaly stipped bare, washed, prime, painted and then baked for 1 hour at 180’. Reassembly took some time, those little springs for the drive boxes are a pain in the arse at times! Its actualy running in the picture. I hand painted the valve gear hanger after the pic was taken and the chassis was running smooth. I have the motor isolated for DCC and it runs so well, its as quiet as a Kato or Proto diesel when running with low amp draw, that I am hesitant to replace it with a can motor. Dont fix whats not broke I guess. The boiler is air drying due to a Seuthe smoke generator I installed, so it cant be baked. In the second picture we see the Mikado’s painted tender, just needs the mounting plate for the WP decal to go on and jewels in the maker lights. Rear headlight MV lense and raised knuckle Kaydee coupler are already installed. In the last picture we see the previously mentioned Y6b with the new NWSL Mashima can motor installed in place of the original PIttman that was suffering a weak magnet and running hot. I had to make a custom cradle to support the front of the motor so it wouldnt bear down on the gear box assembly. There is still the normal PFM transfer gear noise, but she does run smooth with low amp draw. Enjoy the pics!! Mike
The open frame motor in the PFM WP 2-8-2 is a darned good one–smooth and powerful, so you’re probably just fine with not replacing it with a can. I was at the point where I needed to replace the motors on my two PFM L-131 Rio Grande 2-8-8-2’s, when a friend of mine suggested substituting rare earth magnets for the old, weakened magnets in the open frame motors. I did one loco as an experiment, and it turned out remarkable. Low speed torque was vastly improved, amperage dropped and believe it or not, the gear noise was almost halved. Those two articulateds are smooth, powerful crawlers and darned near quiet as mice, lol!
I highly recommend the rare earth magnets to replace failing magnets in open-frame motors.
I have done that when I have a smooth running but weak open frame motor. My WP Mikado is a late run, 1978 production and benefits from being a bit newer with a healthy motor magnet. It loves to suck up tools and screws while on the bench! The Y6B is a 1959 production and the Pittman was noisy, has a vibration to it when it runs out of the model. So it got consigned to the spare parts bin. I have another motor like it that runs ok but he wanted a can with flywheels so thats what I installed. I used a delrin shouldered washer to isolate the motor. This style with the motor brushes up against the magnet are impossible to isolate the ground brush. The motor already had a rubber shim under the motor to absorb sound. I tried it with a sound decoder temporarly installed and it ran good. That decoder is adjusted for a can motor, so it made the open frame run a bit slower, but thats just CV adjustments, and I was running on analog DC. The gearing in most brass steamers is so steep in ratio, that the normal benefits of a skewed armature are mostly lost. Its those old magnets that are failing that cause the poor running. They used to advertise remagnitizing in the old MRR magazines from the 50’s and 60’s. Pittman even had an exchange program for fast turn around for ailing motors. If someone would make a direct drop in, one piece magnet for the popular PIttman motors, many in the brass world would rejoice. The little rare earth magnets do the job, but leave the motor looking a bit odd sometimes. Mike
The only concern with the motor would be the amp draw, especially if you plan sound. But if it’s running that nice, it could already be well within specs of most decoders. Wouldn’t hurt to check it just for peace of mind, otherwise I’d say it sounds like it’s running well, which is always 90% of the battle with brass.
I havent done a full stall yet since its in pieces still, but running without its boiler pulling a small train, its around 1/4 amp if that. Most sound decoders are 1 or 1.5amp so I think it will be safe. Usualy if an open frame is drawing large amps, the magnet is weak. Replacing said magnet will get the amp draw down to where a new motor isnt needed. And that is much cheaper than a new motor for those of us on tight budgets. I only afforded this engine thru my repair work I have had for a few months. I have a MRC steam decoder, one that has worked flawlessly thru several engines I have used it in, but it lacks the turbo generator sound so I am planning to pick up a Tsunami for this engine eventualy. I will put the MRC in for now till funds allow me to upgrade it. The speaker will work with either decoder. The sound I am shooting for is similar to what the CB&Q Mike’s sounded like. I have a recording of one made decades ago that i got at a library book/record sale. Basicaly follows the same Mikado around while she switches, runs transfer jobs. Has a nice bark to the stack and a chime whistle. I am thinking a heavy steam decoder will fit the bill. Mike
