With the introduction of the Atlas SD35's in beautifully applied Southern paint I purchased one of these units. Looking over the model carefully I discovered there are several features that don't match the Southern units. The Southern SD35's rode on the newly introduced three motor Flexicoil trucks with two low mounted brake cylinders. The Atlas model only comes with the older three motor flexicoil and three high mounted brake cylinders. This type truck was used on the SD7, SD9 and SD24 on the Southern. I started looking around for a swap of trucks. The only flexicoil that matched the Southerns is the type on the Kato SD40/45 models. The Kato truck has a higher mounting bolster than the Atlas so cannot be swapped straight away. The sideframes are the only thing that can be used. The Atlas trucks will not accept the Kato sideframes without major modifications. More investigation revealed that the P2K SD7 & 9 trucks will accept the Kato side frames. Next question was the P2K and Atlas trucks interchangeable. Not straight away, some small modifications are required. Here is what I came up with: Parts needed-Sideframes and metal strips from the Kato SD40/45 units. A complete set of trucks and drive shafts for or from a P2K SD7/9 . Obviously you need an Atlas SD35 in Southern Tuxedo paint! Atlas SD35 mods: Step 1-Remove body from Atlas SD35, then remove the metal weights at each end. There is a Phillips head screw holding these. Step 2-Remove the wiring to the trucks from the printed circuit board. Step 3-Remove the trucks, front and rear, remove the drive shafts and keep with the trucks. Remove the wire from the trucks this will be used later. The trucks and drive shafts will become surplus. Step 4-Tap the hole above each truck with a 2-56 tap. Install a 2-56 by 1/4" machine screw in each hole. Just snug up but don't strip the threads you have made. The trucks on the Atlas unit have a plastic pin that goes thru the hole and the P2k trucks have a hole in top of trucks with a cast metal pin on the chassis. The 2-56 by 1/4" machine screw will clear the internal gears in the P2K trucks. Step 5-ACC a #6 brass washer to the frame bolster so the machine screw passes thru it. This will allow the P2k truck to swivel a bit further and allow operation on 18" curves. This completes the mods to the Atlas unit for now. P2K truck modifications: Step 1-Disassemble the trucks completely. Set aside the sideframes and pickup strips. These will become surplus. Step 2-solder the wires you removed from the Atlas trucks to the Kato pickup strips. Step 3-Install the Kato sideframes and strips to the P2K trucks. They fit like they were made for each other! Reinstall the bottom retainer making sure the pins line up with the holes on the Kato tabs. Step 4-Paint the truck sideframes black. This completes the P2K truck mods. They now have correct sideframes for the Southern SD35's. Reassembly of the Atlas frame and P2K trucks etc: Step 1-Using the drive shafts and trucks from the P2K install these on the screw, slip the top retainer on and reconnect the wires to the circuit board. Step 2-Reinstall the weights at front and rear. Place the wires in the channels provided in the weights. Step 3-Reinstall the body. Put on track and admire the transformation. Here are some PICTURES of the model with the Kato sideframes in place unpainted and painted and the NW SD35 as released by ATlas.
© S.A. McCall