BN #2076 gets a new primemover

Discussion in 'N / Z Scale Model Trains' started by Ray Marinaccio, Aug 23, 2003.

  1. Ray Marinaccio

    Ray Marinaccio Active Member

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    BN #2076 (a Model Power RSD-12) is in the shop for a primemover (motor) upgrade.
    I came across this unfinished project at the bottom of a box of junk.

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  2. Ray Marinaccio

    Ray Marinaccio Active Member

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    After repairing the motor I removed enough of the frame to accommidate the motor, plus .030" for the mount.

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  3. Ray Marinaccio

    Ray Marinaccio Active Member

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    Silicone gasket sealer was applied to the motor and frame and held in alignment with small peices of a Q-tip on the shafts. A peice of cardstock was used as a shim and the body installed to insure proper positioning of the motor. It was then set aside to dry overnight.

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  4. Ray Marinaccio

    Ray Marinaccio Active Member

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    The next day I removed the body, cut the Q-tips and removed the worm assemblies.

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  5. Ray Marinaccio

    Ray Marinaccio Active Member

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    I then fabricated flexible couplings from an old spring and a Q-tip. The springs were cut to size and the ends bent inward. The peices of Q-tip have a small hole drilled for the ends of the springs to seat in.
    Lube the worm bearings and install the worm assemblies and couplings.
    The chassis is now ready for a set of trucks.

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  6. Ray Marinaccio

    Ray Marinaccio Active Member

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    I borrowed a set of trucks from my Rock Island Unit and dissassembled them for cleaning.

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  7. Ray Marinaccio

    Ray Marinaccio Active Member

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    The inboard axle bearings are oval shaped so that the weight is transfered to the geared axles. The spring applies LIGHT downward preasure to improve electrical pickup.

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  8. Ray Marinaccio

    Ray Marinaccio Active Member

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    The total axle to bearing clearence was .012" , Which seamed a little to sloppy to me. Sleeves were installed to bring this down to .004" total clearence.

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  9. Ray Marinaccio

    Ray Marinaccio Active Member

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    The traction tires were replaced, resized and trued on the lathe.
    The trucks were then lubed and reassembled.
    Note that the wheels with the tires are on the center axle.

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  10. Ray Marinaccio

    Ray Marinaccio Active Member

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    I placed the trucks on a peice of track snd pushed them back and forth with the 0-5-0 to seat the bearings.
    Lube the worm and reduction gear and install the trucks.

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  11. Ray Marinaccio

    Ray Marinaccio Active Member

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    Wire the motor (I also installed diodes for directional lighting). Then install the weights.

    The bottom weight had to be glued in (due to the removal of it's mount during the milling of the frame).

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  12. Ray Marinaccio

    Ray Marinaccio Active Member

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    I installed th body and took it out for a test run.
    It was a little tight at first but loosened up after a few minutes of running.
    I'm pretty impressed with it concidering it doesn't have flywheels and has the stock weights

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  13. garyn

    garyn Member

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    Good job Ray

    Another option for shaft coupling is the flexible fuel hose for R/C gas models. I used that for a couple remotor jobs.
  14. Matthyro

    Matthyro Will always be re-membered

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    Thanks for this interesting "how to" Ray . Nicely done.
  15. SD90

    SD90 Active Member

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    There sure is lots of small parts that go into a locomotive!
  16. sumpter250

    sumpter250 multiscale modelbuilder

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    Ray,
    Nice rebuild ! I'll bet that loco runs much better now!
    Pete
  17. Ray Marinaccio

    Ray Marinaccio Active Member

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    Yes, SD90, lots of little tiny parts to chase all over the floor, for a while there I thought I would be better of working on the floor.
    Thanks Pete. It is quite an improvment over the RI unit I partsed out. It runs better every time I run it. Those bearings must be breaking in.
    I had it MUed with my son's L/L GP38-2 with no problems.
    Now all I need is a cab roof and hornsand the parts to rebuild the RI unit. I'd like to find a hi hood version to rebuild and paint for the PC. May need to bash one.