Heads Up on MT SP SW1500s

[TinyTrains]

Hi all,

New to the board here, but I had something I felt needed sharing. My apologies if it has been discussed before.

I just received both of the new SP SW 1500s from different retailers. Both had the same problem. The white wire to the motor was shorted to the right side frame with the light board removed. While this is harmless in DC, it can kill a DCC decoder instantly. I had to remove the motor from the frames and grind out a bit more metal on the right side (the factory ground some). Then add Kapton tape to the right side of the motor to cover the hole in the black tape. The both run fine now, but this is way beyond plugging in a decoder. Getting the motor out is a bugger because the frame is riveted together.

The bottom line is check the motor wires for shorts to the frame before you install the decoder.

Scott

[railnerd]

The frame is actually screwed together— those frustrating looking blind ends are actually screw covers.  Threw me for a loop until I popped them off.

-Dave

[rrjim1]

I purchased two Reading locos, and installed Digitrax DCC decoder.
I removed the tape and cut the motor contacts so they were as short as possible. I then solder regular DCC decoder wires on the contacts close to the brush holders. This eliminated the need for the thick sticky black tape around the motor. 

[peteski]

Welcome to the forum Scott and thanks for the heads-up.  As you suspected, this has been already discussed in couple of existing threads. The latest one is https://www.therailwire.net/forum/index.php?topic=36093.0

The riveted chassis halves are a news to me though. That will make it difficult to fully service the model.    The original Life-Like SW1200 chassis (which is what this loco is based on) had screws holding the chassis together.

[victor miranda]

Lifelike used black plastic caps over the screw heads.

is MT?

victor

[TinyTrains]

I did not expect caps on the screws. Maybe that is "try" and keep the body clips from catching in the holes. Thank you. I have never seen that before.

The other thing I noticed is the wheels are way too tight on gauge. They would not go through an Atlas c55 switch without adjusting.

Scott

[sp org div]

Hey Scott, and welcome to the group.
What's up with that big-ol motor feeder wire? 
I got analog shut off on the layout so went straight to the install before any testing... 
Not sure if this is from us all struggling to remove the shell, or if they are shipped factory with the short.
Got mine back together and running again, but have to revisit someday to add sound and the rear light....
Jeff
http://espeeoregondivision.blogspot.com/

[TinyTrains]

Hey Jeff, funny meeting you here!

I am sure the big wires are to fit in the terminals on the light board. LL/MT did not clear out enough frame material for the solder connections, especially with the jumbo wire. Plus the black  tape is soft and a sharp point can poke through it. I got both of mind running fine, but with a list price of $140, you should not have to disassemble and rebuild them.

Scott
Torrance

[TinyTrains]

Oh, and I found this when I put it on the track and got a short too. Amazingly, the decoder survived. This is normally instant death to a decoder. I wonder if TCS found a way to protect the motor transistors on the new decoders.

Scott