Amos/Andy, nose end, cleaned 3D print

Amos/Andy, side view, cleaned 3D print

Amos/Andy, rear end, cleaned 3D print

Amos/Andy shell with all handgrips/handrails.

Atlas frame cut down on both sides of motor to accommodate decoder and speaker. Lengthened and reinforced with brass strips.

Lengthened Atlas RS-1 frame with friction bearing trucks without cutouts for decoder and speaker.

Trucks and motor hardwired (easy DC or DCC).

Amos and Andy in original paint with truck skirting.

Models are not yet fully finished: no nose decal and nose striping, no window glass, no couplers, no aluminum window framing.

Truck upside down with skirt added.

Styrene strips added to the sides and roof to hold and keep the frame in place.

Topside view of adapted Atlas frame. Lengthened drive shaft on left side, truckframes cut down to equaliser level with 3D printed skirts attached.

Topside view of adapted/lengthened Atlas frame. Lengthened driveshaft on left side.

Trucks and motor hardwired (easy DC or DCC).

Amos and Andy in aluminum paint for the first streamlined 1937 Super Chief.

Truck skirting and 3 nose skirtings have been removed.

Models are not yet fully finished: no nose decal and nose striping, no window glass, no couplers.



440 EMC Amos/Andy, one 3D printed engine shell, cleaned, aluminum grit blasted, primed.......SMOOTH FINE DETAIL PLASTIC

450 EMC Amos/Andy, one 3D printed engine shell, cleaned, aluminum grit blasted, primedSMOOTHEST FINE DETAIL PLASTIC

447 Waterslide DECAL SET for the original 1936 and/or first lightweight Super Chief (1 engine)........................COMING SOON

       EMC Amos/Andy also available through my Shapeways shop (ATSF Amos/Andy) in Smooth Fine Detail Plastic

       EMC Amos/Andy, also available through my Shapeways shop (ATSF Amos/Andy) in Smoothest Fine Detail Plastic


In 1934 the Santa Fe ordered their first two passenger diesels from Electro Motive Corporation: the Twin Spots or Amos and Andy, powered by two 900 HP Winton 201A engines each. They were delivered in August 1935 and were intended for the then heavywheight Super Chief.

There were numerous (smaller) changes to the looks during the first years, skirting partially removed, extra cooling equipment on the roof, different paint schemes.

In 1937 the engines pulled the then new lightwheight Super Chief and the paint scheme was adjusted to aluminum, dark blue with red striping.

In 1938 the were rebuilt into the 1 Spot and 10 Spot, with 1 raised - bulldog nose - cab each, better cooling systems and painted in warbonnet style. Also the lead truck was changed to 6-wheel, with the lead axle unpowered.

The units were now used primarely on Eastern Lines passenger trains. Very shortly afterwards the rear trucks were also changed to 6-wheel, with again the lead axle unpowered.

In 1941 the 10 Spot was converted to booster 1A by removing the raised bulldog nose cab.

In 1948 this 1A booster was converted to transfer/road switcher 2611, riding on 2 EMD FT trucks. It was first used in the Los Angeles area but later transferred to the Eastern Lines.

Both units were returned to EMD in 1953. They were rebuilt into two EMD E8m engines, numbers 83A and 84A.

Al lot of useful information can be found in THE ONE SPOT TWINS by Larry E. Brasher, published by the Santa Fe Railway Historical and Modeling Society. Also IRON HORSES by E.D. Worley (the motive power handbook) and SANTA FE's EARLY DIESEL DAZE by John B. McCall and searching the internet provides much information.



There are different possibilities for the drive train. The only real necessity in choosing a donor drive is the truck: an AAR type B truck. These trucks are found on Atlas or Kato narrow hood switchers or road units. If you model the original skirted truck version you can use both roller bearing and friction bearing trucks. If you model the later unskirted trucks you have to take the friction bearing trucks. These are found - for example - on the Altas RS-1 or the Kato RS-2.

The main modification is adjusting the chassis length. The distance between truck centers must be altered to 75 mm.

That means cutting both chassis halves on one side between the gear tower and the motor with a Dremel tool (grinding disk).

Before ypu make those cuts flatten the outside of the chassis halves by removing the latching nobs and leveling all other protrusions, using a metal file and/or the Dremel with a grinding disk.

When grinding or cutting avoid excessive heat by cooling frequently. Dip the chassis in a cup filled with water and ice cubes.

Clean the 4 chassis parts thoroughly afterwards.

Cut scrap strips of brass/ phosphor bronze/stainless steel cut to length and shape (see pictures) to glue the chassis parts together at the correct 75 mm truck center distance. Glue the 2 parts of 1 chassis side first on one of these strips using the underside to level both parts, using CA glue (my favourite is Zap A Gap Medium).

When you are satisfied that this side is straight/level (if not, pry the part loose that is not OK, remove all glue residu and try/glue again) and at 75 mm truck center distance, attach the other 2 chassis halves in place with the appropiate screws and bolts but without the insulation washer. This way these parts are flat/level with the other chasis halve and glueing the second metal strip is easy.

In my first conversions is used 2 metal strips on each side. The inner most strip has spaces/areas cut out where the flywheels are to avoid possible contact between flywheel and strip. On my second conversions I changed the inner strip to 0,5 mm styrene: much easier to cut/shape to the chassis parts.

In case you want sound (larger decoder, speaker) you have to remove some extra material form the chassis halves and the reinforcement strips (see pictures above).

Next is lengthening the steel drive shaft. Use some 1,6 mm inside brass tubing as a sleeve and some 1,5 mm steel rod to lengthen 1 drive shaft. ACC glue the sleeve and extension. Make sure you cab move the shaft to and fro a little after re-assembly to avoid binding in the mechanism. In case the shaft is not (almost) completely in alignment you can gently bend the sleeve/extension a bit.

Personally I do not like the brass contact strips along both sides of the chassis. I prefer to discard them and solder some thin wire to the inside bottom strip of the truck/wheel/cone contact strips (ample clearance). Remove these contact strips from the trucks before you solder the new leads. I also soldered new leads to the motor contacts, insulating them from the frame halves with Kapton tape.

This way the model is easily set up for DC and/or DCC.

There is ample room to attach extra wheight/lead inside the shell. Your new drive is only about 11 mm wide and the inside shell width is 15,5 mm (top halve) and 17 mm (bottom half). 

To center the new drive inside the shell, glue some equally thick styrene strips inside the shell just behind the side doors (see picture above). The ends of the underside of the metal chassis should be flush with the underside of the 3D printed shell. This way the coupler pockets are at exacly the right height (check with coupler Kadee/MTLgauge). With some trial and error you can make the chassis fit snugly inside the shell.....it will remain in place when you lift the engine by hand.

Last conversion job is to adapt the trucks if you want to model the original skirted truck version. The inside width between the skirts on the 3D print is 16 mm. The outside width of the large outside equalizer hangers on the Atlas and Kato trucks I measured is also 16 mm. This means you have to grind/file all other extensions (brake cylinders, eleptical center springs, axle/wheel bearing caps) flush with these hangers creating a flat surface to ACC glue the 3D printed skirts on. The underside of the 3D prints should be about 0,5 mm above the underside of the Atlas/Kato trucks and the ends of the brake rigging on these trucks should be cut off. To position these truck shields correctly I suggest to put the shell on the chassis and then the engine on a short piece of track (handheld). Put some ACC Zap A Gap medium on the flattened truck side and holding the shield with tweezers (the truck shield openings are perfect for this) apply the shield. There is some time to shift the shield to the correct level/height and to the center of the shell side truck frame opening. If the glue sets too soon and you are not satisfied with the shield position gently pry/cut the shield loose with a sharp hoby knife or scalpel, file/remove all glue remnants and start over again. This way the truck shields should be exactly centered inside the frame clearing for the trucks and they also should be able to swivel freely.



If you buy the shell from Shapeways you have to clean/de-grease it first and my favourite second treatment is aluminum grit blasting with an Air Eraser.

These methods have been described and discussed in THE RAILWIRE forum many times (and many other places on the internet).

If you buy the shell from me you will get it treated like described above and also primed with diluted MR. SURFACER PRIMER 1000.

Check all holes for handrails/grips/steps with a 0,5 mm drill (nose and rear end, sides and undersides).

Shape all handrails and handgrips using  pliers and 0,35 mm brass wire. My preferred way is to have a small cup with a small puddle of ACC glue ready. Holding them in tweezers dip the ends of the preformed and tested handgrips/ladders into that puddle.

Insert into the appropiate holes and, using an old toothbrush, swipe away all excess glue. Rising or lowering to a good square position is done with pliers and/or a small sharp screwdriver, rather quickly after application of the hand grip and before the glue sets. The side ladders are a different matter. I found some spare ladders in my scrapbox that fit the job perfectly. The ladders under the side doors have an outward angle. Check prototype pictures for the ladders and their shape.

Be careful with the cab sunshades and lifting lugs (and horns) on the roof. They are fragile..... In case these parts get damaged replace the lifting lugs with spare brass etched antenna or handrail holders. If a cab sunshade gets chipped remove the whole sunshade and ACC glue a short strip of  0,4 x 1,0 mm Evergreen stryrene strip in place.

At this point I also added extra wheight: several layers of 1 mm lead sheet cut to fit the room above the chassis (decoder and speaker/baffle).

If you want to model the 1937 first streamlined Super Chief with aluminum painted engines you have to remove the lower part of the nose skirting/pilot in. Only the front of the first engine retains the full nose pilot. Using the grinding disk in a Dremel motor tool you can remove these parts. Only the coupler box/mounting should be left in place.

Clean/degrease the model before painting. I suggest to first airbrush the model again with a primer - mainly the brass details - and next with a paint of your choice.

Paint is an issue with these models. I have communicated with quite a few knowledgeble ATSF modelers and institutions but there are no true colour pictures of these engines and even the old file paint numbers do not give the slightest hint of the real colors.

Combining all info, I came up with the following paint formulas using Vallejo Paint thinned 15% with Vallejo Airbrush Thinner 71.261.

The original 1936-1937 colors are: roof = 1 part UK Azure 71.108 + 1 part Signal Blue 71.091, upper body = 2 parts Medium Yellow 71.002 + 1 part US Interior Yellow 71.207 + 1 part Duck Egg Green 71.009, lower body = Signal Blue 71.091.

The first lightweight Super Chief 1937-1938 colors are: roof and upper body = Aluminum 71.061, lower body = Signal Blue 71.091.

The color separations are done with Tamiya masking tape. Use prototype pictures to locate the exact color separations.

The black and red striping is done using 0,5 mm and 0,75 red decal stripes. The Indian head Herald is borrowed form Microscale Decals.

I am trying to create a decal set with all necessary decals: the appropiate nose herald, the red whisker striping on the "eyebrows", all other striping in red and black, plus the Indian Head Herald. This set will be on sale lateron (simple letter envelop by regular or airmail).

Microscale Krystal Klear is the best solution ot create the windows in my opinion.

A light coating with Dullcote (and maybe wheathering) is the last step.

Enjoy your model!


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