I feel like I hijacked another thread so I will start this one.
I picked up from Ebay a 1957 import of a PRR F3c 2-6-0 made by MB Austin. It looks as if it has been sitting in its box all these years. There is still paint on the wheel treads and over spray on the worm gear. I did not pay much for it. I tested on the DC test track and needless to say it did not run very good. It started moving at 6 volts and drew almost 2 amps slipping. I disassembled the loco and thought about a re-power with a can motor. Someone on another forum suggested a new magnet for the motor. I ordered some new NEO magnets and installed them. I tested the chassis alone on the test track and WOW what an improvement. It started moving at .26 volt and stalled armature was .987 amp. Slow speed is incredible and top end is just right.
I will warn you right now. The Rare earth magnets are very powerful and will attract everything iron bearing around them. Do not let them slam together as they will shatter. Set up a video camera during the changeover. It will be very comical. Even though the screws are brass the screw driver is not. Anyone who has messed with these will get what I mean.
I ordered my rare earths from Micromark, they come 20 to a pack, they’re 1/8th" thick, 1/4" wide and 1/2" long. 5 of them will stack and fill the magnet cavity of just about any open-frame motor. So far, I’ve installed them on 4 locos, 2 PFM Rio Grande 2-8-8-2’s, one Akane 2-8-8-4 and one Max Gray AC-8 cab forward 4-8-8-2. The difference is AMAZING, especially since the oldest of these locomotives date from about 1964. I’ve got several older brass locos that I’ve yet to convert, but since Micromark accidentally filled the second pack with 25 magnets instead of 20, that means 5 more locos I can work on. (and yes, I notified MicroMark, just in case they want to charge me for the extras, LOL!)
Slow speed control is incredible, top speed is WAY below the usual ‘race-horse’ open frame capacity, and for some strange reason, noise reduction has been almost 50%. The pulling power of these locos has been increased by about 50%–at least that’s what I figure, since my PFM’s used to have a problem with anything more than 20 cars up a 2.2% grade, and now they waltz up the grade as if it weren’t even there. Haven’t tried more than 35 cars yet because of a ‘stringling’ fear (I’ve got 34" minimum radius on these grades).
But I can’t recommend these magnets highly enough, especially for modelers who are hesitant to replace a good-running open frame motor with a can in their older lokies. It’s like a second life.
And yes, I DEFINITELY recommend that one is very careful installing them–they will ‘slam’ into the motor (and anything else metal) like a head-on collision, LOL! But once mounted and running, the difference is absolutely incredible.
Now all it needs is a decoder. This coming payday is when I will order it. I think a Loksound version 4 with a medium oval will work just fine. I would hate to lose the weight in the tender but I can compromise.
I was going with a Loksound version 4 with PRR steam sounds but life and unexpected expenses took all my hobby $ away. So for now it has a TCS T1 decoder in the tender with the 9 pin JST plug. The old open frame motor gave me some fits. I had thought the bigger and more powerful magnets would be better but it turned out not to be the case. I ended up using four N42 1/8 inch thick 1/4x1/2 inch. The N54 5/16 x 5/8 doubled was too much. Now that it is altogether it draws .045 amp at full speed and .001 amp on speed step one. I wired the headlight with a 1.5 volt grain of wheat with a 480 ohm resistor. The drivers were checked for quarter and the loco has a good lube and cleaning. It is surprisingly quiet for an open worm drive. I could not ask for a better running loco such as this one. When some extra cash comes my way the sound decoder will be an easy instal.
It was driving me crazy. It ran fine without the boiler. As soon as the boiler was covering the motor the amp draw was all over the place and it ran very sporadic and jerky. I ohm ed out the grey and orange wires to see if it was shorting and got nothing. I removed the boiler and it ran great. Just setting the boiler over the motor caused erratic running and too much amp draw. I was about to pull the motor and order a can motor when I ran into an electrical engineer. I talked with him about what was happening and he asked what the boiler was made from. As soon as I said brass he said you have an issue with Lenz Law. Even though the brass is non magnetic it still reacts to strong magnetic fields. The N52 rare earth magnets acting with the iron core motor armature trying to turn caused eddy currents to counteract the iron core armatures motion. I took one magnet out and used a steel spacer and it cured it but the magnet still stuck out the sides of the steel case. The new magnets are completely covered by the steel motor plates and not as strong and the N52 magnets. http://en.wikipedia.org/wiki/Lenz's_law