It’s been several weeks since I’ve updated the Matson’s Landing in L-Gauge series. In all openness, there hasn’t been a lot of progress. I find that, from time to time, I need to take a break from a project and come back to it with fresh eyes at a later time. I was running into some design issues with the Matson’s Landing locomotive, so I moved on to other projects. This week I returned to this locomotive, and find myself energized to work on it again.

In my last article on the design, I promised to document the main drive system for the Climax logging locomotive that I’m building. First, though, for the beginners, a quick run-down of the LEGO Power Functions technology that I’m using.

The Power Functions (PF) system was released back in 2007, at about the same time that the LEGO 9v and RC train systems were discontinued. Power Functions elements were designed to be used cross-theme, with elements showing up in both Technic and Train sets. The first official Power Functions compatible train was the Emerald Night (10194), released in 2009.

At its most basic, a PF system consists of a battery box connected to a motor. The battery box has an on/off switch, which sends or cuts power to the motor. There are a few different types of battery boxes available. For our purposes, we’ll use the box with a 4 x 8 stud footprint.

The next step up from the basic box/motor setup is the Rechargeable Battery Box (8878) (http://brickset.com/sets/8878-1/Rechargeable-Battery-Box), connected to a motor. The rechargeable box, in addition to the lithium polymer battery, has a small speed-control dial built into the top of the box. With this, you can set or change the speed of the motor. This is good for models that stay in one place, but difficult to use for models that will vary their speed and direction often.

To gain more control over a model, an Infrared Receiver (8884) (http://brickset.com/sets/8884-1/IR-Receiver) and Remote Control (8885) (http://brickset.com/sets/8885-1/IR-Remote-Control) can be added. The receiver will pick up signals from the controller, then send the information along to one or more motors. The IR Receiver can pick up signals over 4 channels on two ports, allowing up to 8 motors or other outputs to be controlled. The basic controller allows for forward/stop/reverse movement, which must be monitored by the user.

Another step up, and what most brick train builders use, is to swap out the IR Remote Control for the IR Speed Remote Control (8879) (http://brickset.com/sets/8879-1/IR-Speed-Remote-Control). The Speed Control remote allows for all the basic functions of the IR Remote, but also adds speed dials to the mix. Each speed dial can be increased or decreased in steps, allowing for smooth control of locomotives and other models. Each speed dial also has a red kill switch, which will immediately send a signal to the IR Receiver to set the power on that port to zero, effectively stopping the motor.

For the Matson’s Landing Climax, I’m using a very simple application of the last PF setup. The battery, IR Receiver, and a Medium Motor (8883) (http://brickset.com/sets/8883-1/M-Motor), will ride on the base of the locomotive. An small 8-tooth gear is attached to the output of the motor. This gear meshes with a second 8-tooth gear to transfer power to a larger 24 tooth gear that rides just below the base of the locomotive. The large gear drives the axles that are connected to the universal joints of each truck, thereby driving the locomotive’s wheels. The small to large ratio of the main drive system gears the power down, decreasing the overall speed of the locomotive, but increasing the power. While it doesn’t look as flashy as a speeding locomotive, it is more typical of a logging locomotive on a mountain line.

In the next installment, I’ll talk about track testing, and how the results will drive the design of the Matson’s Landing track plan.