Locomotive Gondola Spoltlight Crane Caboose
Locomotive Gondola Spotlight Crane Caboose

MOW Kitbashed Spotlight Car

Made from Plastic Marx and an LED Flashlight

A Kit Bashing Project

These pictures and descriptions show a kit bashing project combining a plastic Marx flatcar with an LED flashlight to make a spotlight car for my MOW train. I really thought that this project would be simple and quick. I had no such luck.

Marx 4587 Work Caboose Marx 4587 Work Caboose
This Marx 4587 Work Caboose served as my inspiration for a kitbash of a plastic Marx, 4-wheel car.
Flashlight and Flatcar
The basic components are a flatcar body and a small, LED flashlight. It seemed to me that once I had these two pieces, the rest of the project would be very simple and very fast.
Center Rail Pickup
This center-rail pickup is supplied by Robert Grossman.
Axle Pickup in Jig
Oh Gosh, now I need to pick up power from the outside rails. This gadget is a soldering jig used to hold a piece of brass tubing while I solder a solid copper wire to it.
Axle Pickup Complete
Here is 1 completed wheel pickup assembly.
All 4 Pickups
And here are all four of them. The project has already taken more time than I had expected. The plastic car body is a good insulator.
Axle Pickup Installed
The original axle holes were worn and elongated. By installing the pickup assemblies, I repaired that damage as well as making contact with the outer rails. The only lubrication for these is graphite powder. Oil would insulate. Drilled a hole for the tubing and a hole for the wire. Secured with ACC super glue.
Connections on Bottom
Here are the solid wires that collect the connections to the outside rails into a single point.
Spotlight Mounting Parts
I used angle aluminum to make the yoke that holds the business end of the flashlight. Lots of sawing, filing, drilling and tapping.
Spotlight Installed
This photo shows the light bezel mounted and the connections to center rail and outside rails routed up to power the light.
Circuit Reference Book
Its another hitch. For normal LED power we just need a resistor to limit the current. But, this flashlight uses 3 AAA cells for power and no outside resistors. I don't have a reliable way to measure current, so, I decided I needed to build a regulated power supply that would accept track power and provide something very close to what the 3 AAA's would do. Time to hit the books.
Power Supply Circuit
A simple circuit to produce a regulated power supply. I used a 7805 to give me 5 volts and then put a couple of silicon diodes in series to drop the voltage to about 4.6. That is what the batteries produced, together.
Voltage Regulator Circuit
This is the second try. The VR I got from Radio Shack was a bad part and fried the first LED flashlight. Its a good thing I had two of them. I bought better regulators from Jameco and they work just fine.
Diode Bridge
Here is the diode bridge on the input side of the first try.
Circuit Ready To Mount
This is the second try with the better parts. The aluminum chunk is a heat sink for the regulator. The capacitors keep the power smooth.
Circuit Cover
The circuit will produce heat, so, I need a cover that permits some ventilation. I used perfboard and reinforced the corners with some wood strips.
Circuit In Place
More wood strips keep the circuit board aligned.
Connections To LEDs
These are the connections to the backside of the LED portion of the flashlight.
Front View
Here is the front view at the same stage in the process.
Final Configuration
The circuit cover fits into the stake holes on the side of the flatcar.
Almost Ready
Another view ready for wheels and a test.
Still Needs Wheels
Here is the spotlight looking up at its big brother.
Assembled, decorated, tested and fully functional. I expected the project to take a couple of evenings. In real time, it was more like 4 months. I can't say I recommend it, but, it is done and it was fun. The voltage regulator protects the LEDs from excess voltage, provides a constant intensity and flicker-free operation.

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