Field wound K&D open frame motors

[SWrailroader]

I would be interested in hearing about people’s experience with field wound open frame motors often found on the older steam from Lobaugh, Scale Craft, Hines, etc. Usually I swap them out for a Pittman, but occasionally I like to keep it stock. Yes, I know they are current hungry like 2 amps and they produce ozone. Most that I have encountered seem pretty robust except one recently in Scalecraft SP 4-8-2 was pretty weak despite looking in good shape.

[bob turner]

Check the rectifier. Wire for forward only and note the performance. No magnet to get weak, so these things go until the bearings or brushes die.

[up148]

No help from my end. All my old models have been converted to can motors.

[bob turner]

We had a 4-4-0 at the museum - scratchbuilt. An interesting model,but the gears gave out. Back then, NWSL had only the small Mod 0.5 box, so I put that in (long story short, once I put ball bearings on the worm shaft the thing did literally years of nonstop daily operation).

But the story here is while the gearbox lasted seemingly forever, we went through DC-91 Pittman about once every six months.

I finally went to a K&D (we simply ran out of the DC motors). That went for years, until the bearings got so much slop the armature started hitting the stator. Of course we had truckloads of the series-wound motors laying around.