Ring Engineering LM-3S-G

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LM-3S-G 'G' Scale Locomotive Module with Sound

The LM-3S-G is a module that you can install into a model train locomotive so the locomotive can be controlled and setup by a Ring Engineering RailPro Controller, such as the HC-2 Handheld Controller with a Color Touch Screen! After the LM-3S-G is installed in a locomotive, you will be able to control the locomotive speed, direction, up to 6 light outputs and sounds! The LM-3S-G has “Direct Radio” (RF transceiver) built inside. The built in RF module allows commands and data to be sent and received to and from the module. You can load a picture of your choice into the LM-3S-G module.  Then you will be able to touch the screen of the HC-2 to take control of your locomotive! You can even download new sounds and light effects using the built in Direct Radio!

The LM-3S-G is equipped with Direct Radio! This allows Ring Engineering Controlling Devices such as the HC-2, Handheld Controller with Color Touch screen, to control and configure your locomotive by sending and receiving data directly to the LM-3S-G through the air by use of RF transmission! The Direct Radio is very fast giving your locomotive quick response to your controls. Further, a controlling device can detect your LM-3S-G with just a few touches on the screen. Because of Direct Radio, you can load a picture of your locomotive to the LM-3S-G! You can also load Sounds, Light Effects and much more!

Your LM-3S-G is equipped with Rail Sonic HD Sound System!  This is Ring Engineering's technology that allows your LM-3S-G to produce realistic locomotive sounds!

Radio Load Sharing is a truly an innovative invention from Ring Engineering.   It allows your locomotives that are linked together (sometimes called Consisted or MU'ed) to actually share pulling power.  Only RailPro equipped locomotives use Direct Radio to talk to each other to be sure each locomotive pulls its share of the load! Even more amazingly, Ring Engineering's patent pending process only takes seconds to setup!

Six  light outputs.  Can be configured for multiple light effects on a single output including On/Off, Dim, Ditch, Mars, Strobe, and more!  Additional light effects can be loaded using DirectRadio!

Built in protection with fault reporting by Direct Radio!

Tiny size 3.35 x 1.32 x 0.57 Inches for easy fit.


Price $179.99

You will need a RailPro controller such as a HC-2 (Handheld Controller with Color Touch Screen - Not Included) to control, setup and monitor a LM-3S-G. Actual HC-2 screen shots are shown below!

Important:  If you are running your trains outside be sure to buy the model HC-2-SUN handheld controller instead of the standard model HC-2. The HC-2-SUN is easily readable in sunlight.  The HC-2 screen was designed for indoor use and looks real good inside.  Outside the standard HC-2 screen can look washed out when the sun shines on it.

Pages to Select and Control Locomotives


Pages to Setup Locomotives



Page to Monitor Locomotive


Package Contents:
LM-3S-G Locomotive Module
WH-9 9 Pin Wiring Harness
Instruction Sheet

US Patent 8,807,487 and 10,780,362
Made In USA
Not recommended for persons under the age of 14

LM-3S-G Frequently Asked Questions

If I link different types of locomotives will they run well together?    (This is often referred to as Consisting or MU'ed)

YES.  In fact you will only need to set one adjustment to get locomotives with even different motors and gear ratios to work very well together. The one adjustment that needs to be set has an auto set feature.  You can actually setup different locomotives to run well together in under a minute.  All you need to do is run the auto set feature for the Motor Full Load Current adjustment on each locomotive. 


The way RailPro links locomotives together is patented technology and unlike any DCC system.  Direct Radio allows RailPro locomotives to communicate together almost instantly to be sure that each locomotive pulls its portion of the load and runs smoothly together.  Any DCC system that we are aware of, only allows communication to locomotives and the locomotives cannot talk to each other.  Ring Engineering's Direct Radio allows all RailPro products to communicate in both directions at full speed!  Two way, full speed communication is key to many of RailPro's easy to use and unique features including the way linked locomotives run together. 

Can RailPro locomotive modules be battery powered

YES.  There are customers that are running RailPro locomotives that are battery powered now.  However, we do not believe that battery power is the best choice for the majority of users. We believe that a wall powered layout is a better solution. Click here for the long answer.


If my club is DCC can I run RailPro on the club layout?
YES.  You can take your RailPro equipped locomotives and Handheld controllers to a club that has a DCC layout and run it on their layout.  You can run your RailPro locomotives on the same tracks and at the same time while other club members are controlling their DCC locomotives.  However, you will only be able to select and control RailPro equipped locomotives and you will not be able to control DCC locomotives.  DCC cabs can control your RailPro locomotive because RailPro locomotive modules respond to DCC and Direct Radio commands from RailPro controllers such as the HC-2 handheld controller.

If my locomotive has a RailPro module installed can I run it with typical DCC systems?
YES.  A Locomotive with a RailPro module installed is dual mode!  You can control the locomotive with Radio control and or DCC control!

How far does the Direct Radio signal reach?

You can control locomotives on huge HO scale layouts with outstanding control using Direct Radio.  The Direct Radio signal can reach over 100ft in an open environment (outside).  When properly setup, you can achieve fast and dependable control that has the feel of being directly wired to your locomotives. 

If you want to control your trains from the far side of your layout, we recommend a repeater every 15 ft for areas divided into small rooms.  Our power supply has Direct Radio built in and can be used as a repeater.  With one PWR-56 in the middle of the layout, you can expect outstanding coverage for a 30 ft x 30 ft layout while transmitting through multiple walls. If the room is open, it may work well for 50 ft x 50 ft or even larger areas with only one repeater.  The current program in the handheld controller lets you use up to 4 repeaters for outstanding coverage on huge layouts.

You can run RailPro without a repeater.  For example using only a handheld and locomotive equipped with a RailPro module.  If you follow your trains (staying within 15-20 feet) you will not need a repeater and you can expect fast and dependable control.  However, if transmitting through multiple walls, you might find that at some angles you will loose communication at 40 feet away.  By adding repeaters as necessary, you can get fast and dependable control from over 40 feet away through multiple walls.


Since RailPro is all wireless and can transmit over 100 feet, can anyone control my train set?

No.  RailPro has a simple solution for stopping unintentional or unauthorized users from controlling your equipment.  You can set a password in each piece of RailPro equipment.  For example, when you set a password in a locomotive module, then only the people that you share the password with will be able to control your locomotive.  This is a great feature in a club or model train show environment because you can have complete control over who can control or adjust your RailPro products.


Is the response time good?

YES.  The response time is so good that you feel like you are connected to the locomotive.  As soon as you change speed, the locomotive instantly responds.  The touchscreen is so fast that you feel that there is no detectable delay from pressing the screen to seeing the action on a locomotive such as the lights turning on or off.  The exceptionally smooth speed control knob gives you the feel of using an analog controller!

If I install a RailPro locomotive module in a locomotive that I already own, what do I need to do so the handheld controller will display a picture of my locomotive?

Since Ring Engineering does not know what locomotive you are going to install a locomotive module into, our locomotive modules are preloaded with a generic locomotive picture. You can change the picture on your locomotive module to match your locomotive. You can load pictures from Ring Engineering’s Internet site or use our RailPro Assistant software to convert your own pictures to RailPro format and load them to your handheld controller and locomotive modules. If you find a picture of your locomotive on our Internet site, you can load it to your locomotive module for no charge.  If you cannot find a picture of your locomotive, then you can take a picture of your locomotive with a digital camera and email your locomotive picture to Ring Engineering or use our RailPro assistant software to convert it to RailPro format. See RailPro Assistant Program for complete details.

Is it difficult to get files like pictures, sounds, and light effects from Ring Engineering's Internet site?

NO.  Basically you use our RailPro Assistant software to select from lists of pictures, sounds, light effects, and programs available from Ring Engineering's Internet site to download.  Connect your handheld controller with a USB cable and press the download button on the handheld controller. The handheld controller will copy whatever files you selected from Ring Engineering's Internet site onto your handheld controller.  To send a file to a locomotive, you select Copy File, choose the picture of the locomotive you want the file to go to, and then choose the file to copy. Then you go to the adjustments and setup the locomotive to use the new file.

Can you install RailPro locomotive modules in older non-DCC ready locomotives?

YES.  You can wire in a DCC 9 pin plug on most locomotives (even ones that were originally not DCC ready) and connect a locomotive module.  Basically, any information you can find which shows how to wire the locomotive for DCC can be use to wire the locomotive for RailPro operation because the RailPro locomotive module wiring is compatible with DCC wiring.  You will want to be sure the final wiring is proper according to the directions provided with the RailPro locomotive module.  Many non-DCC locomotives will require isolating the motor and the lights.  One possible problem you may run into with older locomotives is that some of the very old locomotives may draw too much power for the RailPro locomotive module.  In that case the RailPro locomotive module may turn off and report to the handheld controller an over temperature fault.  Some people use very old locomotives with the RailPro locomotive module by replacing the motor with a newer more efficient motor that needs less power.  If you are interested we can recommend shops that specialize in this type of installation work.

What about RF interference?
Our RailPro system uses advanced technology like cell phones where many can be in use at the same time in the same area.  Our products are not like the easily disturbed RF products found in many toys.  This makes it unlikely that you will experience any interference.  Our products have worked successfully around wireless computer networks cell phones etc.  Any RF product may have, or cause, some type of interference but because of the technology that we use it is very unlikely.  At the time of this writing we have really  had no users complain about not being able to dependable control their trains with RailPro.

Can the locomotive module fit into all HO scale locomotives?
We believe that our locomotive modules are small enough that they can be fit into almost any normal locomotive (typical switch engines and larger).  There are shops that do locomotive module installation work. We would be happy to recommend a shop for you if you would prefer someone else do the installation work.

Will RailPro work in brass shell locomotives?
We have not done much testing with RailPro in metal or brass locomotives but several of our customers have said that they work well in brass and full metal locomotives. The Model RR News installed one in a full die cast locomotive and told us that it worked well. RailPro locomotive modules might not have as much range in metal body (brass) locomotives because the RF signal may get attenuated.  We have been told that the range is typically about 2/3 of its normal range. 

** RailPro system uses fixed voltage DC power. So, yes, it could be powered by a battery. The minimum voltage would be about 12 volts.

Of course we only recommend using RailPro components provided by Ring Engineering for safety and so you can be completely confident about the products working together.

If you are considering using battery power because of dirty track issues or because you think wiring is difficult, we think you may want to consider the following:
- Because RailPro is a fixed voltage DC system we are confident that you will not need to clean your RailPro track nearly as often as you clean a track powered by DCC.***
- The cost involved for the high power batteries required would be expensive.
- Your run time would limited
- We sell a RailPro auto reverse module that only has 4 wires and will require no adjustments. So reverse loops can easily be handled. It retails for only $39.99!

- Because RailPro is equipped with Direct Radio you do not need any network wiring like required for some popular DCC systems. You only need to wire the track for power.
- Wiring the track for RailPro is easy because there is no signal put on the track. Therefore you can not run into problems of corrupting the signal on the track with bad wiring like is possible with DCC. 

However, we do think that battery power for outdoor G scale is a more reasonable idea. Keeping outdoor track clean is a real problem. Also the larger G scale locos have more room for batteries.


***  When we were developing our End of Train Device products, we accumulated a lot of testing hours running on analog and DCC power sources because it was important to know that our products would work well with both power sources. What we discovered was that we had to clean the DCC track far more often to keep it running. We cleaned the DCC test track multiple times more often than the analog track. The theory we came up with as to why the DCC track needed cleaned more often is because on a DCC system track power is a high frequency square wave that causes the current to pulses into the locomotive module (through the wheels) at higher peaks than with an analog system. We know that if we put no current through the wheels, then no arcing between the wheel and the track would happen. We also know that if we put hundreds of amps through the wheels, then the wheel to track contact point would arc and leave black burnt carbon deposits on the track. Therefore we are confident that higher currents cause more arcing and deposit more black carbon residue. The reason why DCC current pulses at higher peak currents than analog is because the DCC signal constantly changes polarity. All locomotives modules have front end capacitance (parasitic or intentional - most likely both). Because the DCC signal is square wave in shape, the signal has very fast rising and falling voltages. When a fast rising or falling voltage is applied to a capacitor, the capacitor looks like a short circuit. This temporary short circuit is one cause of higher peak currents through the locomotive wheels on a DCC system. A second cause of higher peak currents through the locomotive wheels on a DCC system comes from the fact that there is a time that the DCC voltage goes to zero. If a DCC signal changes polarity, than it must go to zero volts before it can change polarity. When the DCC signal is at zero volts, the motor, lights, and sounds of the DCC locomotive module are still using power. This power is supplied by an on-board capacitor (a capacitor stores electrical energy). During the time the voltage is at zero, the on-board capacitor discharges and when the DCC voltage returns, the capacitor charges quickly causing higher peak currents through the locomotive wheels on a DCC system. And since RailPro uses fixed DC, (no high frequency switching on the track) it does not have higher peak currents through the locomotive wheels like a DCC system does. In fact, it is expected that RailPro runs even cleaner than analog! Even though analog does not go to zero volts, many analog supplies increases and decreases voltage at 120 cycles per second (rectified 60 Hz from a wall outlet) where in comparison RailPro's DC power is steady. We ran a small RailPro test track for about a year and never needed to clean it! We finally cleaned the track just to see if the RailPro system was going to run any differently, and it did not. We are confident that we would have needed to clean the track several times if it were powered by DCC because previously the same test track was powered by DCC and needed cleaned often.


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