Have you ever heard of the RX500? It's a novel and modern industrial switching locomotive, made by Republic over the past twenty years. Railroad Picture Archives has a large collection of RX500 photos from various locations. From the moment I saw the little locomotive, I knew I wanted a model of it for my layout. Of course, the RX500 has hardly been modeled in ANY scale, much less three-rail O. But when I turned up a scale diagram of the RX500, and started staring at the RMT Beep that's been sitting in my parts bin for a year, the plan began to form!
I started by making a CAD model in Fusion. After carefully measuring the Beep's chassis and making a "digital twin" of it, I fitted a new body and frame around it. Here is a screencap of the finished design. I wanted to add lots of handrails, but I didn't want to make them too fragile. I designed a handrail stanchion that could be used with metal wire for a realistic but sturdy look.
After a day or two of nonstop printing, I had all the parts made up in sturdy ABS plastic. The first order of business was putting together the handrails. The 3D printed stanchions worked quite well with the 0.050" wire I use for pretty much everything.
After carefully cutting and gluing everything together, I had the frame fully assembled. I somehow missed photographing the process of painting and striping the frame, but you will see the results further down.
With the frame all set, it was time to work on the body. I hand-bent the grabirons for the front hood and back of the cab. I stuck them all into a piece of styrofoam and painted them all white.
I had some leftover Boston and Maine decals from another project and a famous fondness for the color blue, so selecting the color scheme was pretty easy. The B&M was resigned to the history books long before the RX500 entered the locomotive market, but I like to think of this as a "what if" livery.
Once the grabirons were dry enough to handle, I was able to finish assembling the body. Over the course of several days, I clearcoated the body and frame with Rustoleum Matte Clear and added window glass to the locomotive cab for a proper sharp look.
This left the business of wiring the locomotive. I run mostly command control on my layout, so a TMCC conversion was in order. I had a ERR Mini Commander II board left over from another project and it seemed to fit quite well. I replaced the Beep's original tiny incandescent bulbs with LEDs. I also changed the wiring of the motors from parallel to series, which made the locomotive prototypically slow-- the real RX500 is governed to a max speed of 10MPH.
Once everything was packed inside and lined up, I very carefully eased the body into place and bolted it down. There are 2 screws in the front and one in the back. I did have to drill a few mounting holes through the Beep's plastic chassis, but otherwise the new frame snaps in place.
Finally, the RX500 is ready for the track!
Here's a view of the rear. Painting the white stripes was a huge pain but the results were worth it. It's nice to have another B&M diesel to help my Legacy SW8 peruse my sidings.
Check out the victory lap on the mainline of my layout!
