# Making my LGB go slower



## AppleYak (Dec 3, 2014)

Probably a weird question but here it goes...

I purchased a LGB kit (engine, cars, track, transformer). I would like the train to go slow since I feel that it better represents the scale of the train. I spoke with my local hobby shop and they said that it wasn't good to run the train at a slow speed with the standard transformer (especially with LGB) and that it would destroy the motor of the train. They recommended a larger transformer (over $250 worth of larger) in order to get more voltage to the train and to handle going slowly.

So my question is, how do you make a train go slower without ruining anything? Is this something with LGB in general? Do I need a larger transformer and if so, any recommendations? The train is basically on a large oval (6' x 6" area)

Thanks !!


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## riderdan (Jan 2, 2014)

I think you need to describe your problem in a little more detail, but my first impression is that your local hobby shop is blowing smoke--in hopes of selling you $250 worth of stuff. The idea that you need "more voltage" to run slower is completely... wrong. 

It sounds like you bought a starter set. I have one for the kids and it runs fine at low speeds--and that's with the little starter-set transformer. It will creep along pretty slow, though I get better low speed performance on my outside layout where DCC can really make them crawl. There's no harm in running them at low speed... I've left the little Stainz running all afternoon as slow as it would go and it was fine. 

Is your problem that it won't go slow enough for you, that it stops and starts, or something else? There are lots of very knowledgable folks on here who can help you, but more info is needed.


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## Greg Elmassian (Jan 3, 2008)

Running at a slower speed will be LESS load on the transformer.

Better get your advice here ha ha!

Greg


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## Pete Thornton (Jan 2, 2008)

I agree with RiderDan. The advice is rubbish - more voltage means more speed. The kit you have will be fine at slow speed.


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## chuck n (Jan 2, 2008)

I'm with the others. That is why there is a dial on the power supply. LGB does seem to require more voltage that some other engines, but if it moves it will be OK.

At a show yesterday I ran a 35 year old LGB stainz. It has been run at slow speed all it's life. 

Chuck


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## ntpntpntp (Jan 14, 2008)

As we would say in the UK, that dealer is talking absolute b*ll*cks. The LGB starter set power pack is fine for running the loco at slow speed, you won't ruin a motor with under-voltage.

Way back in the 60s and 70s we had power packs that would use "half-wave rectification" in order to make old style open frame motors run slow in small scale locos (old Hornby OO/HO stuff etc.). A bit like a very very crude form of pulse power. This can cause some modern coreless motors to run hot and fail in small Z & N scale locos - but not the larger can motors in our G scale trains.


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## DennisB (Jan 2, 2008)

When I started in the hobby I purchased a 1 (one) amp LGB transformer. It ran an LGB Southern w/sound and pulled 4 LGB D&RGW cars on 200 feet of track. It ran fast enough. It's a train, not a race car set. The dealer is really messing with you. Regards, Dennis.


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## toddalin (Jan 4, 2008)

Are you sure that everyone knew what was being asked/stated?

When you want to run a train slow _from a dead stop_, a pulse width system can let the train start sooner and there after run slower.

Basically, the system uses higher voltage to give the engine a "series of stronger kicks" that get it moving, as oppose to a "smaller continual shove" that must reach some friction threshold before the train moves.

With a linear system, the train may wait until a certain voltage is reached, then "jack rabbit" to a start, by-passing that initial slow speed that may be attained with pusle width control.

Maybe his other system included PWC and this is what he was alluding too?


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## Totalwrecker (Feb 26, 2009)

Time for a new hobby shop.
I had a buddy like that; for a long time I thought he'd cover my back. In time I realized he was coveting my wallet!
Run them as slow as you like, but slow them by power, not by too many cars. That could hurt the power train, at any speed.
PS, the folks here like first names...
John


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## stevedenver (Jan 6, 2008)

i agree with the others, your starter power pack will do fine, without harm to your loco. I have no idea why someone would tell you this, other than selfish interest.

im my experience, LGB requires less juice than many other g scale motors. typically, a single large motor requires 1/2 amp. YOur starter power supply should be at least this, and if newer, the type with separate throttle and power block , 1 amp.

BTW

LGB strongly warns against using any type of pulse DC with its motors. Pulse will cause unnecessary heat with motors, unless used in a limited and short period application, or, the power pack has a variable pulse built in, ie the more voltage, the less pulse applied. I have this in a Model Power Tech III, which I use with my n gauge trains, and it works really nicely and I don't have to switch it on and off manually. FWIW I do not use pulse with my LGB locos. 

LGB motors , in my experience, are robust, but do not have super fine , slow acceleration from a rest, _in some locos._ I have once long ago tried pulse and it can smooth acceleration, brightens lights, makes smoke at 'lower' voltage, etc, but, it also heats up the motor, substantially. 

You will not harm either your loco or power pack by running very slowly.

Wwhat I will offer, however, is that as you add load, motors, coach lights, drag, (such as from a 3019 postal car with plunger electrical picks up against the wheel backs), grade, yard lights, powered switches, etc., you will likely need a larger power pack. 

But this is unrelated to your present situation. 

As your power pack works, it may/will heat up. If it heats up too much, it will automatically shut off, until it cools down. Again no harm whatsoever, simply an inconvenience. In my early days, I had a MRC 6000, which was about 3 amps. When I ran three motors and 30 axel long slow trains, after about half an hour, it would shut down. This prompted me to buy a much larger Bridgewerks 15 amp power supply. It is delightful, fan cooled, and I have never overtaxed it. 

You should be just fine. And, you may find your starter power supply is perfect for your needs. If not, then you can address the situation.


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## Sampug394 (Dec 30, 2010)

In general slower speed implies less friction and wear on every single moving part, whether it be a model locomotive, or your car. I'm not sure why anybody would try to convince anyone that something slow wears out quicker than something fast, other than the previously mentioned claims that the fusspot at the hobby shop was flapping his gums... 

Most smaller G scale locomotives are narrow gauge, and as a reflection of real life prototype, none were ever meant to go fast. Maybe a Mogul or 4-6-0 could hit 30mph with a light train on good track, but a little kettle like an 0-4-0 wouldn't be pushing too far past 15-20mph.

Having run both my LGB Stainz and LGB Porter yesterday, they operated just fine at a nice slow rate, and can easily puff around with a train of 2 axle Hartland or LGB stock. The Stainz was brought down to a literal crawl around a 4ft diameter curve with four metal-wheeled european cars, and kept on going like a champ without a stall anywhere.

Trains going slow allow you to study them as they roll by, seeing the rods rocking and spokes spinning is the real treat. Don't let anybody tell you that high speed blurs screaming by are more fun.


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## Totalwrecker (Feb 26, 2009)

I've got a feeling the HS was suggesting a better power pack that has more steps, ie; a better wound rheostat in the old days. So it could separate the divisions better. Aren't starter packs kind of coarse?
The OP mentioned an LGB Kit(starter set)...
Just a thought.
John


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## Dan Pierce (Jan 2, 2008)

My older self contained 1/2 amp and 1 amp LGB power packs from sets do run engines very slow. I have not tried the newer separate transformer/speed control units by LGB.


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## AppleYak (Dec 3, 2014)

Thanks everyone for all your responses !! Sorry to take so long to reply. I thought I had subscribed to my original message but never received any notifications when folks started responding. Took a look and noticed a lot of great feedback - and some quite funny.

A little more detail. Its a LGB 72302. When I first received the train, I set it to run slow. The problem was that after an hour or so, the train would just stop. I would go in and adjust it to a higher speed and then back down to slow and it would work for a while again. I tried cleaning the track, etc but it would never stay consistently slow. That's when I went back to the train store and they mentioned a larger transformer - more voltage.

I'm planning to set it back up tonight, clean the track and see how it goes again. Will report back. May also try to pickup a second cheap power pack and see if that helps.

I think someone mentioned more steps on a better power pack and maybe that's hat the issue is - maybe I really want somewhere in between what I currently have. 

Oh and I love this quote from Sampug394 - Its precisely why I like slow trains. 
"Trains going slow allow you to study them as they roll by, seeing the rods rocking and spokes spinning is the real treat. Don't let anybody tell you that high speed blurs screaming by are more fun."


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## Michael Glavin (Jan 2, 2009)

I believe we can all agree that our DC electric motors are designed to run at specific voltages carrying specified loads at given RPM’s. An electric motor has an efficiency curve which simply put is best served by its nominal motor voltage specification. Whereas running said motor at its lower voltage/RPM extremes works there are cons associated with same. Specifically higher current demands which inevitably creates elevated operating temperatures assumably within design parameters.

In the circumstance herein; LGB Stainz starter set #72302 with 1 amp transformer the locomotive is governed by the potential provided by the transformer, i.e., 1 Amp @ its rated voltage range. Every motor requires a known value of potential to operate efficiently. Matters not how it’s provided i.e., higher voltage lower current and or lower voltage higher current it’s all the same to the motor providing the potential is within the input specifications of said motor. A 500 Watt motor will consume 500W under normal operating parameters. 

The voltage across a DC motor, minus IR losses, is proportional to the speed or RPM of the motor. Accordingly current through the motor is proportional to the torque produced by the motor. Typically back EMF created by the speed of the rotor opposes the voltage being applied and limits the amount of current the motor draws. Providing a lower voltage to the motor will cause the motor to turn slower reducing back EMF allowing more current to flow.

A transformer is also an impedance converter. The impedance of source or load goes up or down across a transformer in the same direction as the voltage goes up or down, but the impedance ratio is squared while the voltage and current ratios are "straight", compared to the turns ratio. Plug this into Ohm's Law to see that it exactly makes up for the voltage changing in one direction and the current changing in the opposite direction to keep the power equal.

I’d suggest the original OP’s train shutting down is a result of the operator setting the transformer to the lowest possible setting that moves said train. Eventually heat builds up, impedance changes and engine stops. Increasing the transformers power setting provides more potential to offset increased impedance and all is well again. Perhaps voltage and current readings would confirm my thoughts.

Michael


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## AppleYak (Dec 3, 2014)

Thanks Michael

Total beginner question but how would I check the voltage and current settings? I have a meter, just not quite sure exactly what to test for. 

Also, for a better power supply, anything you recommend - within reason cost wise?

Thanks !!


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## Dan Pierce (Jan 2, 2008)

For slow speed operation nothing beats a good DCC decoder. My engines will 'crawl' very slow and you can just barely see them moving.
Of course there are settings that allow the 128 speed steps to be set to act on half voltage which at low speed is an effective 256 speed steps. This is 12 volts divided by 128 giving voltage steps at approx .1 (100millivolts) volts.


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