Brick Model Railroader has been going far and fast since our launch. We’ve been really happy with how far we’ve come and grateful for all the support from the LEGO train community. But, as with our models, we are always looking for the next step to take.
As an electrical engineer, I have always found lithium batteries to be…. amusing. They’re extremely volatile; if overcharged, they explode. If over-discharged, they explode. If charged too quickly, they explode. If discharged too quickly, they explode. If punctured, they explode. If they get too hot, they explode. If they get too cold, they simply don’t work. Think back to the recent debacle of the Samsung Galaxy Note 7 battery woes. But yet, these are the best batteries that are currently mass produced. Almost everyone carries one in their pocket and frequently holds it close to their face. For applications where the energy density (energy stored per volume) or the total energy stored (in Watt-hours) isn’t important, there is an alternative storage media that might be of interest to my fellow model train fans. Enter supercapacitors.
What follows isn’t for the electronically faint of heart. Accidentally short circuiting an alkaline battery or similar for a few seconds isn’t going to cause much harm. Short circuiting a bank of supercapacitors will melt wires and turn your supercapacitors into charcoal in no time. Be smart.
A supercapacitor is different than a battery in several important but sometimes subtle ways. For a model train, some of these differences are to our advantage, others are not. First off, when a battery is discharged from 100% to 0%, the voltage is fairly consistent. The difference between the full and empty voltages and the rate at which it falls depends on the type of battery. For example, a NiMh battery is about 1.45V full, and 1.2V empty. A capacitor is different; when empty, it is 0V. The “full” voltage is whatever you charge it to. Different capacitors have different maximum voltage ratings. When discharged, the voltage falls from the charge voltage to 0V. Most supercapacitors are rated for either 2.5V or 2.7V. Similar to batteries, putting multiple capacitors in series is how you get the desired voltage capacity. For example, a 9V system would need 4 2.5V/2.7V supercapacitors in series. When the system is charged up to 9V, the voltage will be split evenly with 2.25V each on the 4 capacitors.
The second major difference between the two technologies is the speed at which they can be charged. NiMh and LiPo batteries are usually limited to some fraction of their amp-hour capacity for their charge rate. Meaning, a 2000mAh NiMh battery can be safely charged at 1-2A. Of course, this varies based on manufacturer specs, and charging them faster will degrade their capacity faster, but that is neither here nor there. A supercapacitor has a much higher safe charge/discharge rate. The small ones I like to use in my locomotives are safe up to 3.3A! Much higher rated ones exist too, I built an experimental system that used 100F supercaps rated up to 35A. Additionally, a rechargeable battery typically is only rated for a few thousand charge cycles. A supercap can be charged several hundred thousand times.
The major downside to supercapacitors is energy density, or how much power you can store per volume. My choice supercaps are 4mWh/cm^3 whereas a 2000mAh NiMh battery is about 350mWh/cm^3. So they’re less dense by about a factor of 100, useless, right? No! If all we need to do is get over an unpowered track section, for example an unpowered ME Models R104 180 degree curve, we only need about 10 seconds of run time. So if we have an equal volume of supercaps to AA batteries, our run length will be 1/100th: an AA battery set lasts several hours, call it 2h on the conservative side. That means an equally sized supercap bank will run for 1.2 minutes, plenty of time for zipping through a short unpowered track section!
Some of the difficulty in implementing a supercap bank is limiting the charge current. From the perspective of your power supply, capacitors are more or less a 0 ohm short circuit which means the theoretical charge current will be infinite. You can limit this with a resistor, but realistically this is unfeasible. A resistor spec’ed correctly would have to be very physically large to allow for high heat dissipation. It’d get hot enough to melt LEGO (ask me how I know)! Additionally, as the capacitors charge, the charge rate slows down exponentially. Luckily, there are other methods available to limit the current. I found a cheap, small product on eBay that fits the bill perfectly: a CC/CV regulator. Not only can this thing limit the voltage to the bank, but it can also limit the current.
With a CC/CV regulator set to never charge past the supercap’s rated voltage and current, the next step is regulating the output of the supercaps. Because we don’t want our train to slow down as the supercap bank discharges, we need a DC/DC regulator. There are some nice cheap ones on eBay for about $1.50 that just so happen to be exactly 3 studs wide.
I’ve also made a system with 10x 100F supercaps. The added capacity doesn’t really add any utility over 10F-20F supercaps, so all of my recent systems are 15F. One of the downsides to charging the supercaps as quickly as possible is the sizing of the power supply required to handle the peak current, especially when you have multiple locomotives on the same circuit. Luckily for me, my work has stacks of 24V 6.5A power supplies lying around. Unfortunately for you, they are not cheap new. A used PC power supply can be rigged up to perform similarly, but as always, the exercise is left to the reader…
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.
A few days ago, The LEGO Group announced a contest with a pretty amazing prize package. Since model railroads are as much about scenery as they are about trains, I think many of our readers will be interested in this one.
From the announcement:
Today we’ve launched a new contest on LEGO Rebrick, one we’re only sharing with RLUG/RLFM members. To mark 10 years of Modular Buildings, we invite you to build a mini modular for a chance to win the grand prize of all modular buildings as well as the Mini Modulars! This includes:
• 10230 LEGO Mini Modulars
• 10182 LEGO Café Corner
• 10190 LEGO Market Street
• 10185 LEGO Green Grocer
• 101097 LEGO Fire Brigade
• 10211 LEGO Grand Emporium
• 10218 LEGO Pet Shop
• 10224 LEGO Town Hall
• 10232 Palace Cinema
• 10251 Brick Bank
• 10246 Detective’s Office
• 10243 Parisian Restaurant
• 10255 Assembly SquareWe will also have two runner-ups in this contest, who will win the 10255 Assembly Square.
For more information on how to enter. Including rules and size requirements, please visit:
The contest closes May 12th at 10:00 a.m. EST. Don’t forget to share this contest with your fellow RLUG/RLFM readers/subscribers/readers/subscribers!
Most exciting about this prize package, other than the sheer size of it, is the chance to win some pretty incredible retired sets.
– Brick Model Railroader is a Recognized LEGO Fan Media (RLFM) outlet.
The Union Pacific 4-8-8-4 “Big Boy” is one of the most recognizable locomotives in the world, and one of the most often built n LEGO. In spite of this, skilled builders are still finding ways to make a better version of this iconic engine. Nate Flood is one such builder.
His Big Boy, his second version of it, as he states, is wonderfully detailed. I am especially taken by the work he did on the pony truck and tender trucks.
This picture also shows one of my other favorite details; the use of chain links for the tender side ladders. Making ladders and steps for locomotives is really difficult in LEGO. The real things were usually much narrower and made of thinner pieces than most LEGO ladder options.
Following up on my previous article introducing LEGO’s 9V system and their Power Functions (PF) system, I’m going to go a little more in depth about building hybrid systems that utilize both PF battery packs and 9V train track. I’ve developed and iterated through several different systems that combine the best of both and have come up with several easy to implement systems. Anyone with a few dollars, a volt meter and a soldering iron can hack together one of these hybrids in a matter of hours. Continue reading Hybrid PF/9V Systems
This is the third installment of a continuing series detailing my progress on modelling the Union Pacific’s 9000 class locomotive in LEGO.
In this installment, we will discuss the scale my model will use, and why I use it, as well as custom and aftermarket steam locomotive parts.
First, the issue of scale. Model train hobbyists tend to consider scale before anything else because, in general, scale is rigidly established for most model railroads. Most people are familiar with the common model railroad scales, such as HO, O or N. There are countless others, but they generally have one thing in common – their scale is fixed based upon the track gauge. That is, the distance between the inside edges of the top of the rails. In the LEGO train world, that scale is not so rigidly fixed. LEGO never intended their trains to be part of a model railroad system, so they did not design their track and trains to be in the same scale. The first LEGO train system (not considering earlier wooden and plastic trains without a track system or power) was introduced in 1966. The rails were blue, and the ties white, but the gauge has remained the same in all subsequent LEGO train systems, roughly 38mm. between the inside of the rails. The locomotives and rolling stock were 6 studs wide, roughly 6 feet wide if we considered the rails to be standard gauge. That is obviously not a realistic scale for width but that does not make it somehow ‘wrong’ of course. Many locomotives in the real world are more like 11 feet in width, about 11 studs in LEGO in a strict track gauge equation. There are many excellent models out there in this scale, but it is not typical for a LEGO train layout, and it is not the scale we use in my club.
Central Railroad of New Jersey 1940’s Commuter Train in LEGO
This is my LEGO model of a 1940’s Central Railroad of New Jersey commuter train. This train is typical of those that made up the CNJ’s short haul commuter service in the first half of the 20th century. You may have already seen the locomotive in my recent article on Vinyl Decals, or on a recent youtube livestream. Now that the locomotive is properly decaled, I finally took some time to photograph the whole train and write this article.
The seeds for building this train were planted several years ago while on a trip to visit Steamtown National Historic Site. While there one of the locomotives that caught my attention was an odd little Canadian National engine, no. 47. Canadian National no. 47 is what is referred to as a “Suburban” locomotive. These locomotives were built for short haul service on commuter lines. The Suburban type had its tender, carrying coal and water, integrated with the main frame of the locomotive, rather than having a separate “tender” car semi-permanently coupled to the locomotive. This gave the locomotive excellent dual directional capability, handy for when there were no provisions for turn the engine around at the end of it’s run. It was not uncommon to see these engines running backwards pulling their train on a return trip.
Before I begin, I should briefly touch on some of the standards for LEGO track configurations. More information can be found on Michael Gale’s L-Gauge.org. Standard spacing practices for most layouts (including my own PennLUG) use a 16-stud spacing between the centerlines of two parallel tracks. There are two main reasons for this standard. One, it was set by LEGO, when they produced the 9-volt switch tracks. Using a turnout, a return curve, and an extra length of straight track, you get two even and parallel tracks. Two, this yields a convenient way to build track: two lines evenly spaced on one baseplate.
In my first article in my series on decals for LEGO® trains, I covered some popular model RR manufacturer’s who make decals suitable for use with LEGO trains. This time I want to highlight one of the options for making your own custom decals for LEGO trains, vinyl decals. This is a newer option that I’ve come across but it offers some great possibilities.
The story of how Maci’s Monograms got side tracked into LEGO decals.
This all started some time ago when I came across a post on Facebook about some decals that LOLUG – Lincoln/Omaha LEGO User Group had made using cut vinyl. My friend and fellow train builder Nate Flood is a member of LOLUG and he quickly brought me up to speed on them. As it turns out, Nate’s daughter Maci is the one who produced the decals, and she has started her own business for the purpose.