A division of ROUNDBELL HOBBY PRODUCTS and available at better dealers.


       Many older locomotives are great mechanisms just waiting for a great motor and fltwheel to make them run to their full potential.
        Since many of the conversions we have proven for our ProvenConversions page use the same basic parts in standard combinations we decided to put all the parts together in several standard kits and offer them pre-assembled in one pack. In most all cases these will consist of a Mashima motor with a Roundbell flywheel mounted on the non-brush end of the motor (this arrangement allows for a shorter length of the motor/flywheel combination which makes installation easier). In most cases we even dish the flywheel and remove unnecessary material from the motor case to further shorten the total lenght . The kits also come with our Universal Drive Shaft (UDS) to couple the motor shaft to the wormshaft of the gearbox and a stabalizing arm. This positions the gearbox but allows it to float vertically while removing lengthwise pressure between the worm shaft and motor shaft.

        Glue the motor to the frame of the locomotive (in the place of the old motor) with some silicone seal (bathtub caulk, auto seal, fish tank seal) in line with the worm shaft. If the model has a low mounted worm it may be necessary to replace the original gearbox with an idler gearbox that puts the worm higher for easy alignment. We don't normally use a motor mounting bracket because each has to be custom made, takes time and is not necessary. The silicone is much easier, faster and dampens any minor motor vibration.When dry and free turning (you didn't glue the flywheel did you?) cut the Universal Drive Shaft to length and install, then press fit the stabalizer arm to the motor and glue it to the top of the gearbox.

        This is a very easy conversion to install and finished engines run with the quietness, smoothness and flywheel action "purr" similar to a modern Kato or Atlas diesel. You will not believe how great a 30 year old Westside or PFM steam engine can run. The flywheel is the difference, even the new $1500 locomotives of today will not run as well as a 1978 Westside Daylight of FEF-3 (and many similar locomotives) with our GLIDE DRIVE installed. If you are scared, start with a large engine with a big firebox where the motor fits easily. When you see how easy the conversion is you will continue with other engines where the fit is more dificult because you know how great the operation is improved.


G-DRIVE A25     Our FM-1833 motor with FW-251020  This is pretty much for articulateds
      with big fireboxes.
G-DRIVE A22     Our FM-!833 motor with FW-221020. This is standard for 4-8-4, 2-8-4s
      and some 4-8-2s.
G-DRIVE A19     Our FM-1833 motor with FW-190820.
G-DRIVE B22     Our FM-1824 motor with FW-221020. This usually fits in most 2-8-2s
      and 4-6-2s. Some locos may need the motor slot in the ashpan detail widened especially
     for the flywheel but nobody can see it and the improvements are worth it.
G-DRIVE B19     Our FM-1824 motor and FW-190820.
G-DRIVE C19     Our FM-1430 motor and FW-190820  Will fit in Westside K-36 and
    K-37 2-8-2s.and PFM SF 2-8-0s
G-DRIVE C16     Our RM-1630 motor and FW-160820

         Complete steam loco upgrade kits with general instructions and hints are priced at $69.95.

PART # A25 A22 A19 B22 B19 C19 C16
MOTOR # 1833 1833 1833 1824 1824 1630 1630
M.WIDTH .73" .73" .73" .73" .73" .635" .635"
T.LENGTH 1.56" 1.56" 1.50" 1.23" 1.17" 1.52" 1.52"
FW.DIAM. .995" .87" .74" .87" .74" .74" .62"


These are complete kits with the flywheels mounted on the motor and with the flywheels dynamically ballanced. They also include low mass constant velocity universals and drive shafts (our UDS) that don't cause vibration like the Athearn universal parts do and electrical leads soldered to the motor. Following the instructions sillicone glue the motor into the frame in allignment with the worm shafts and set aside for 24 hours. Cut the UDS main shaft just shorter than the space between the flywheels and worm shafts, slide the couplings on the flywheel shafts and press the outer UDS flexible couplings on the worm shafts. Wire the motor to the electrical pickup from the wheels.


K-100 FOR ATHEARN SW-7 using FM-1824 motor and 181320 flywheels (one tapered to fit the body)
K-102 FOR ATHEARN SW-1000/1500 with FM-1824 MOTOR AND 181320 flywheels
K-110 FOR ATHEARN GP-38-2,GP40/50 etc. FM-1833 motor and 181820 flywheels
K-120 FOR ATHEARN SD 40-2, SD 40T-2 etc. FM-1833 motor and 181920 flywheels

          Complete diesel locomotive upgrade kits with general instructions and hints are priced at $74.95.
NWSL UPGRADE WHEELS We also highly recommend NWSL "blackened" machined nickel silver wheels to replace the sintered iron wheels that used to come on Athearn Locomotives. The new wheels improve the electrical pickup and reduce the noise of the wheels rolling on the track.

Bearing type outside-old inside-newer outside-old inside-newer
Wheel Contour RP-25 RP-25 .88 semi scale .88 semi scale
Wheel Diam.
36" 37138-4 37143-4
40" 37139-4 37141-4 37239-4 27241-4
42" 37140-4 37142-4 37240-4 37242-4
45" 37144-4 37244-4

Each of these wheel sets is 12 wheels with half axles that press into the Athearn axle gears. Priced $9.95


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