RSD-15 ATSF Class 800 (4 versions ) + SP/SSW version, RSD-7 Class 602

RSD-15 Class 800    4 versions                                                             

numbers 800-823 1959-1964 + 1964-1975, renumbered 1969 9800-9823 numbers 824-849 1960-1964 + 1964-1975, renumbered 1969 9824-9849

RSD-7 Class 602 numbers 602-611

RSD-15 SP/SSW version              scroll down and click on pictures to enlarge

RSD-15 (roadnumbers 800-823, 1959-1964)              RIGHT SIDE                RSD-7 (roadnumbers 602-611)                                         RIGHT SIDE

RSD-15  (roadnumbers 800-823, 1959-1964)               LEFT SIDE                RSD-7 (roadnumbers 602-611)                                          LEFT SIDE                                       

RSD-15                                                                                                                 ETCHING               RSD-7                                                                                                                   ETCHING

RSD-15                                    FRONT                 RSD-15                                      REAR                RSD-7                                      FRONT                  RSD-7                                        REAR

RSD-15 (roadnumbers 824-849, 1960-1964)         RSD-15 (roadnumbers 800-823, 1964-1975)        RSD-15 (roadnumbers 824-849, 1964-1975)

3D printed shell only, on modified chassis               3D printed shell only, on modified chassis             3D printed shell only, on modified chassis

KIT NUMBER/NAME and CONTENTS (see PRICELIST for prices). Atlas motorized chassis (C-628 or C-630) not included.

301 RSD-15, 800-823 1959-1964 era. 3D FXD printed shell, brass etching (less couplers, decals), alignment tool, brake wheel, horn

302 RSD-15, 800-823 (numbered 9800-9823 in 1969) 1964-1975 era. 3D FXD printed shell, brass etching (less couplers, decals), alignment tool, brake wheel, horn

303 RSD-15, 824-849 1959-1964 era. 3D FXD printed shell, brass etching (less couplers, decals), alingment tool, brake wheel, horn

304 RSD-15, 824-849 (numbered 9824-9849 in 1969) 1964-1975 era. 3D FXD printed shell, brass etching (less couplers, decals), alignment tool, brake wheel, horn

305 RSD-15. brass etchings and alignment tool, brake wheel, horn

306 RSD-15. dummy chassis and 3D FXD printed trucks, wheels

311 RSD-7. 602-611 3D FXD printed shell, brass etching (less couplers, decals), alignment tool, brake wheel, horns

312 RSD-7. brass etchings, alignment tool, brake wheel, horns

313 RSD-7. dummy chassis and 3D FXD printed trucks, wheels

307 RSD-15, Southern Pacific / Cotton Belt version. 3D FXD printed shell, brass etching (less couplers, decals), alignment tool, brake wheel, horn



RSD-7 numbers 602-611.

These units were acquired by the Santa Fe in 1955 and were retired between 1965 and 1969. They arrived in zebra stripe paint scheme and had an Alco 244H prime mover.

RSD-15 numbers 800-849.

Units 800-823 were acquired in 1959, units 824-849 in 1960 . The first batch had both air reservors on the right, the second had 1 air reservior on both sides and a slightly different diesel fuel tank. The last one was retired in 1975.

Numbers 800-823 arrived in the black and silver zebra stripe paint scheme, the others arrived in blue and yellow. The all had a Alco 251B prime mover.

In 1964 the dynamic braking system was modified: extra air intake high on the side in the center of the long hood and a raised outlet on the roof. In 1969 a renumbering took place to roadnumbers 9800-9849. The zebra striped first batch was also repainted into the yellow pin stripe scheme.

Additional information can be found in "The Santa Fe Diesel, Volume, published by Paired Railroad Publications, "Santa Fe's Diesel Fleet" by Joe McMillan and "Iron Horses of the Santa Fe Trail" by E.D. Worley. Also the internet is a great source for pictures and info.

Southern Pacific/Cotton Belt version.

SP acquired 3 units in 1959, numbered 4816-4818. They went to T&NO in 1960, numbered 250-252. Renumbered in 1965 to 5160-5162 and rebuilt/renumbered in 1973 to 3100-3102.

SSW acquired 10 units in 1960, numbered 850-859. Renumbered in 1965 to 5150-5159 these lasted till 1972.

For number specific lights please check pictures......... the configuration changed quite a bit in their lifetime.


SHORTENED CHASSIS                                                 WIRES/PICKUP               DUMMY CHASSIS AND TRUCKS



                                                               INSERTS AND TAPE PROTECTION

Building instructions RSD-15.

(The building of a RSD-7 is the same except for 2 little changes: 2 horns (supplied) and the MU receptacle on both end handrailings. On the 3D printed shell there are 4 little MU receptacles on the inside of the front and back stairwells. 2 of these should be glued (tiny bit of ACC) into the dimple on the outside of the end railing etching; the other 2 are spares.) 

The building of this model is divided into two parts: the chassis and the shell.

The chassis is a shortened frame of the Atlas C628/630 locomotive. This is a very good running engine with the right trucks. It is only a little too long...... 4,5 mm between trucks to be exact. You might be able to pick up a used good running unit second hand (eBay, local hobby shop, swap meet) at a nice price; roadname is not critical. Disassemble the chassis completely. For rebuilding purposes you might want to  take some pictures with your mobile during the process. Loosen the 2 screws near the and of the chassis and gently pry the 2 halves apart. It helps to push the four black plastic motor supports a little inward. Be careful to store all loose parts (trucks, gears, bushings, motor, circuit board, contact strips, screws + insulation) in a little box.

The two chassis halves have to be shortened. Right in the middle between the rear gear tower and the rear flywheel a 4,5 mm piece of chassis must be removed (see picture above). If you remove a litlle bit more than 4,5 mm that is no problem, but certainly not less. The cut should be as square as possible but it is not very critical as the alignment tool will hold the parts straight and square while the outside reinforcement plates are glued on when all the cutting/grinding is done. Make the cut using your motortool with a grinding disk. Mark the area to be removed with a scribed line on both chassis halves. Cut one chassis half at a time.


The most important issue is to keep the temperature of the chassis down. The friction of the grinding disk generates a lot of heat which can weaken the chassis. Keep a cup of water with ice cubes nearby on your workbench. While grinding, support the chassis as close to the cut with bare fingers as possible for two reasons: avoid stress on the thinner parts/connections of the chassis and feel the temperature of the chassis. When it gets hot to the touch stop grinding and cool the chassis in the ice water. The cold water has another advantage: keeping dust down and acting like a lubricant.

Shorten both ends of both chassis halves for about 2 mm exactly to the nut/screw cavity.This is done for two reasons. First you have to shorten the ends for about 1 mm anyway because the trucks are closer to the footboards, second the extra 1mm creates room for wires to go from one engine to the next (see additional info below).     

Because the rear truck comes forward 4,5 mm you have to remove the same amount of the back of the fuel tank. The chassis under the flywheel is quite thin so grind a little at a time avoiding pressure or heat; use the icewater trick frequently.

The next grinding job is on top of the short nose where the front headlight used to be. You only have to do this in case you want to put a sugarcube speaker in the cab. Remove some material (about 2 mm square seen from the side). Again be careful, a little at a time, no pressure, no heat, because the conncetion between the front part of the chassis and the bridge over the motor will get quite thin.

Also remove the 4 little lugs on both sides of the chassis halves. These are not needed anymore and in the way of the new shell.

Finally, but only for the 1964 versions, you have to remove about half the thickness of the bridge above to motor (red painted area) to accept the air intake openings. On the motorized version you will be able to see the chassis through this opening if you look closely (leave bare metal or paint chassis in a light color of you liking); in a dummy unit this is a see-through.   

With all the grinding done clean the 4 chassis parts thoroughly using an old toothbrush; there will be dust all over.

Place all 4 halves around the alignment tool (length 90 mm exactly) and check if everything fits. When everything is straight and square you can glue the outside reinforcement plates on the chasis halves using just enough ACC. Avoid gluing the alignment tool as well. When the glue has set you can insert the inside reinforcement plates and glue in place using ACC. This time a liitle more glue to also fill the gap between the chassis parts. Be careful to leave about 1mm between the inside reinforcement plate end the inside bearing of the worm gear. If you fail to do this the black plastic bearing will not seat properly. Also remove all excess glue from that little slot (see pictures above).     

One of the drive shafts  has to be shortened using the included insulation bushing as a connection between the 2 halves.

The shaft between the end cups is 8,0 mm long. This must be rduced to 3,5 mm, leaving 1,75 mm on both end cups. Use flush cutters and your grinding disk/motor tool to do this. The bushing is 3,5 mm long and using some ACC you can reconnect all three parts.

If you are going to use DCC solder 2 short very thin flexible wires to the motorleads and isolate the motor/leads from the chassis using Kapton tape. Lead the wires upwards.

Personally I am no fan of the long contact strips under the running boards; they tend to loose contact with the truck contact strip and hamper the pivoting of the truck . My solution is as follows:cut the strips just as long as the fuel tank, using the ends only as a soldering point. Remove the truck sideframe and contact strips. Now is a good time to clean the gears (often old thick grease) using an old toothbrush and to check the wheelgauge (often narrow). Also clean the backside of the contact strips (often paint and dirt). Solder a thin very flexible black wire to the top of the truck contact strip (minimal solder, wire horizontally towards the fuel tank). Solder this wire to the end of the chassis contact strip. There is enough room above the truck for a little slack in the wire and it will be conceiled at the same time. This connection is much more secure and if you need to disconnect the trucks you can simple desolder the wires from the strip.

Now you can reassemble the chassis. One suggestion: using ACC glue some small 0,7 mm styrene strips to the inside of one chassis half at different locations: you cannot squeeze the chassis halfs together anymore, avoiding damage to the undeniably weaker (but still strong enough)  chassis (see picture above).

Check if the shortened driveshaft has enough play. When you move the worm gear lengthwise (there should be some play between the two square black plastic bearings) using tweezers the armature itself should not move to and fro. If it does, shorten the small end cup a little bit. It can be shortened till 3 mm length and the slot can also be lengthened slightly lengthwise using a 1,2 mm thich flat file. Remove all burrs. You may also shorten the large end cup by max 0,5 mm to create some extra lateral play for the drive shaft assembly. There should be no bind whatsoever. Be sure there is not old grease or dirt on all parts, especially the bearings! Using thk DC leads check if the motor runs just as freely now as it did before: it should!   

The lowest point of the chassis (beneath the gear towers) should be level with the underside of the sidewalks of the shell. Some styrene strips or lead strips can be glued inside the shell to achieve this. Depending on how much you cut away from the nose part of the chassis: there is a chance the chassis will hit the slanted sandboxes at the top of the nose inside the shell. If so, grind a little off the chassis at a 45 degree angle just above the screw/nut cavity

EXTRA point of attention: the small black universal inside the flywheels has a tendency to split or slip. You can check this by running the engine and pressing down gently on the chassis. If the motor decelerates its OK but if the motor keeps running full speed while the wheels are almost stopped the small universal is most likely the culprit. I solved this by installinf 4 small brass tabs into the flywheel as follows. Wrap the whole motor/armature in tape. This way no metal particles from grinding/drilling can attach to the magnets (see picture). It also helps to keep the flywheels locked for the time being. Grind 2 small spots halfway down the flywheel (lengthwise) 180 degrees opposite each other. Drill two 0,5 mm holes in these spots towards the metal motor shaft. Insert Tichy Train Group brass wire .020 inch (#1103) dipped in some ACC into these holes touching the motor shaft. 

Perfect allignment of the brass inserts is not critical because the slot in the black drive shaft is about 1,2 mm wide and the brass inserts are only 0,5 mm. This should give a friction and trouble free connection. I have not experienced any extra motor/shaft vibrations duet o this procedure.

If you run on DC you can use the old circuit board.

If you use DCC you can employ a sound decoder..

The shell has been designed to accommodate  an ESU Loksound Select Micro decoder in the back. ESU has great sound versions of both the 244 en 251 Alco engine.The speaker is a sugarcube in the cab. SMD leds for front and rear lights.

Happily the RSD-7 has a high nose with lots of room. Even for some extra lead weight.

With all the electrical connections and 2 resistors it will be a tight fit in the RSD-15.

There is an alternative: put the decoder and speaker in a dummy engine: the RSD-15's usually ran in sets of 3 or 4 anyway.

Currently I am running a set of three with two motorized units (front and back) and a dummy in the middle.

The six wires (2 x pickup, 2 x motor lead, 2 x front/rear light) run through the coupler hole in the pilot. There is even room now for some extra lead weight over the motor and back gear tower (use Kapton tape to insulate the lead strips).

Use the brass coupler bars (included in the fret) and two leftover MTL coupler screws to permanently couple the engines.

Use the 1.1 Amp ESU Loksound Select decoder which has enough power to drive both motors.

This setup pulls 70 cars up 0,5% grade around my layout with ease.

The appropriate dummy trucks are available from James Train Parts through Shapeways (truckpins included) or directly from this site. Put some Kadee Greas-em or graphite lubricating powder into the axle holes. The FXD material is not as slick as regular trucks. Burnishing with a very pointed dril will also help to minimize drag.The wheels are Fox Valley Models number 3611 (not included).

The dummy chassis can be ordered through this site but is also easily made from 1 mm sheet styrene (see picture above).

The length of the dummy chassis is 108 mm, width 10,2 mm. Height at the nose 6,5 mm and at the rear of the hood 13,5 mm. The length of the low side is 33 mm. The underside of the dummy chassis should now be flush with the underside of the walkways. The 3 small stiffener plates (between the vertical sides of the frame) do not go all the way down to the floor to allow passage of electrical wires.

Glue a 1 mm thick styrene plate (10 mm x 10 mm)to the underside  to bring the dummy trucks to the correct height.The center of fthis plate should be 13 mm from the ends of the frame. Test fit inside the shell requently. When ready/satisfied, mark the hole for the truck king pin while holding the truck exactly in the middle between the fueltank and the stairwell/footboard. Use a 2 mm drill and carefully clean out the hole for a nice press fit of the pin. 

Using sheet styrene fabricate 2 fuel tank ends and the bottom of the fuel tank flush with the shell. I filled the empty space inside with sheet lead to give the model some extra weight. If you intend to use the extra electrical wheel pick up on the dummy trucks drill out an extra hole for the red/black wire (see picture above). The fret has 2 pickup strips (one side pickup only per truck). One of the middle contact strips has to be bent straight up through the hole in the truck and a hole in the styrene chassis and the other contact middle contact strip can be bent over backwards to reach the middle truck axle. Be sure to bend all contact strips enough to barely touch the axles, otherwise excessive drag will occur.

The dummy chassis has enough room to hold the larger decoder (use the 1,1 amp Select version because of the two motors), a bigger speaker and all the wires (with some slack) from both the front and rear units.

The advantage (in my opinion) of this setup is: you can have a 3 or4 unit engine at reasonable cost (2 Atlas donor units, 3 or 4 shells, 1 decoder, 1 speaker, 2 or 4 dummy trucks, 6 or 12 FVM wheels) with all wheel pickup and great sound and no issues with consisting, The only disadvantage is handling and storing the set due to the permanent coupling.

Adapting the shell is a much shorter story. When you receive the shell it is still a bit sticky from the support material used in the 3D building process.

Soak the shell for 24 hours in GooGone or Bestine. Wash/rinse in soapy water afterwards and let dry completely.

Use a toothbrush and small needle to remove the last traces of support material from hard to reach places (the stairs for examaple) but be gentle and do not scratch the shell.

Small irregularities on top of the flat nose and cab roof can removed with a flat jewelers file and very fine sandpaper. 

Carefully remove the 2 printing supports between the fuel tank.

Be sure to airbrush a primer paint on both the shell and etching before applying the paint of choice. Mr Primer Surfacer 1000 has given me very good results. This (diluted) primer can be airbrushed and helps creating a smooth surface.

Drill out the holes for the handgrips on the nose, rear and sides with a 0,4 mm drill. Be aware that the most left and most right holes of the ladder handgrips on the back of the hood are printed at an angle (see the handgrips on the etching). These handgrips also are curved a little (curve following the curve of the hood).

Insert the handgrips and apply a little ACC with a toothpick/steel pin from the INSIDE. The only critical position at that moment is the distance to the shell; using the point of small knife you can move the handgrips around a bit for a short time. The horizontal plane can be corrected later gripping the handgrips lengthwise with long tweezers and gently bending them. After the glue has set grind off the protruding pieces flush inside the shell (mainly of the ladder handgrips close to the cab) otherwise these will interfere with the frame.   

If you intend to apply the zebra stripe paint scheme (Microscale Decal 60-247 and /or 60-248), apply the nose front and back zebra stripes first before installing the handgrips and/or the front and back handrailings. Also apply the zebra striping on the front and back handrailings/footboards before installing these on the shell and before installing the couplerpin lift bar and footboard handrailing.

Using pictures prepare how to cut the V shaped decals on Microscale Decal 71154. Apply rectangular pieces on the nose (8 mm high, 14 mm wide), rear (13 mm high, 14 mm wide) and footboards (6,3 mm high, 16 mm wide). After the decals have dried completely cut off the free standing excess pieces on the nose and rear in front of the sandboxes. Turn the brass foot boards over and cut the decals to fit. Use a fresh/sharp scalpel. You will be surprised how easy this works. Bend the couplerbox contour frame 180 degrees and secure with a tiny drop of ACC.

Use a steel sewing needle to pinpoint all holes covered by the decals. Check if the holes in the footboard (brass/shell) are in perfect alignment. If not use a 0,4 mm drill to clear the hole, taking care not to scratch the decal.

If you intend to apply the yellow/blue pinstripe paint scheme I suggest you paint the yellow first, before applying the handgrips on the nose and rear end. This makes masking the yellow areas (nose, rear end and number board over cab window) much easier. Apply the handgrips directly in front of and behind the cab before painting the shell blue. Mask the whole upper shell before airbrushing the walkways, fuel tank and footboards black. Paint the raised walkways (over the battery/tool boxes) black by hand afterwards. 

The handgrips and handrails should be airbrushed (primed and painted) while still in the fret. For the black version that is pretty straightfoward, for the yellow/blue pinstripe version some masking has to be done before airbrushing the yellow parts. Paint the vertical stanchions of the handrails blue by hand/brush afterwards. Gripping the end of the MU connections bend these in a nice curve a little over 90 degrees and glue into the provided slot.The cab side window inserts should be painted aluminum before gluing them inside the cab. Extra parts are included in the fret just in case. 

Bend the ends of the side handrails about 20 degrees inward right after the last stanchion before painting and/or gluing to the shell. Also bend the little gluing tabs at the bottom of these handrails inward for about 110 degrees. Using a tiny amount of ACC these will be glued to the  stairwell. Touch up paint afterwards. Please check the fit of both side handrails before gluing them to the shell. There should be a perfect fit between the 2 ridges at the end of the sidesills. If not, remove a little material from these ridges with a small fill and/or grind the last 0,5 mm of the brass sidesill (temporarily bend the stairwell stanchion out of the way). Apply the footboard handrail first (bend the center locating pin a liitle more than 90 degrees) and then the coupler lift bar (bend the end handgrips  80 degrees downwards).

For windows there are 2 options: clear plastic or Microscale Krystal Klear.   

The window frames (facing forward and backward) and the head- and rearlight openings can be painted by hand with a small brush or with 0,8 mm silver paint marker (for example an Edding 780). If you use the brush simply insert the brush carefully through the window opening (almost perpendicular to the wall) and very carefully paint the inside of the window frame. This way you will also cover the outside ridge/frame around the window. I use Tamiya flat aluminum straight from the bottle.

Glue the included Leslie Supertyfoon S-3L-R horn on top of the shell.

The coupler housing is designed for Micro Trains Line 1015 couplers and should be at the correct level. Remove the trip pin and insert from the back. Use a short MTL screw to secure the coupler. Replace the trip pin.

This may seem a long story but I just wanted to describe the conversion as elaborate/clear as possible/necessary.

Just  some time and patience will do the job: enjoy your RSD-15 afterwards! 

ATSF N Scale Models                           Dirk Jan Blikkendaal                                            © 2017