What's so good about 9v?

[Legoist]

I'm curious. Besides expense (and now availability), what do you see as the bugs of the 9v system?

You can't control different trains on the same track layout indipendently.

[Eilif]

You can't control different trains on the same track layout indipendently.

That is a bug. I think the only way around that is to insulate multiple loops and run them similtaneously. Not a huge deal (just a piece of electrical tape at a switch) but it would be easier with PF.

[Brickthus]

Thanks Mark,

There's some really good information in your post. Clearly PF blows RC away. The dual engine capability, and power of the new PF motors does sound like a good thing. Your IR repeater is a great innovation, but I'm of the opinion that we shouldn't have to wire custom devices to get full functionality out of our train sets. However, any new startup clubs or new train fans, will probably find your innovations invaluable. Overall though, I see PF as a good deal for LEGO, but not an upgrade for 9V AFOL's.

You mention the cost of transfering from 9v to Power functions at 1500. Does that including selling off your 9V system? I wonder if selling off 9v systems to acquire PF systems would be a loss, break-even, or come-out-ahead proposition. If I was looking at a 1500 upgrade for a system that isn't really an upgrade, I'd definitely stick with 9V.

Selling LEGO? That's an alien concept to me as I don't have a Bricklink store!

£1500 would be 18 sets of [a LiPo battery and 2 IR receivers per train], a charger or two, a handset and 32 packs of 8867 flexi-track pieces to replace the 104M radius curves on my layout.

Having said that, it would be best to wait to get most of the LiPo batteries only for exhibitions where their 500 cycles will be used within the 3-year shelf life (google LiPo battery life). Better still to design the layout so that the whole battery can be removed, charged and sent out in another train = less capital cost of batteries.

Mark

[Eilif]

Selling LEGO? That's an alien concept to me as I don't have a Bricklink store!

Right there with you, I do a tiny bit of trading, but when it comes to LEGO, I definately "Aquire".

£1500 would be 18 sets of [a LiPo battery and 2 IR receivers per train], a charger or two, a handset and 32 packs of 8867 flexi-track pieces to replace the 104M radius curves on my layout.

Having said that, it would be best to wait to get most of the LiPo batteries only for exhibitions where their 500 cycles will be used within the 3-year shelf life (google LiPo battery life). Better still to design the layout so that the whole battery can be removed, charged and sent out in another train = less capital cost of batteries.

Definately better to design the batteries to be removed, because I'm afraid you do some damage to the case for PF right here. Based on your original calculains, In USD, you are looking at spending $900 for the battery boxes alone that are only going to last for 3 years. In the club, we have folks who have run whole collections of 9V motors for a decade, and have only ever burned out a couple of $25 motors.

Even if a small-timer like me only purchased just 3 battery boxes (one to run, one to charge, one to back up) I'm out 150 bucks for a product that is only going to last 3 years. It just doesn't make sense.

[Legoist]

That is a bug. I think the only way around that is to insulate multiple loops and run them similtaneously. Not a huge deal (just a piece of electrical tape at a switch) but it would be easier with PF.

Yes, but creating multiple loops is not exactly a solution but rather a trick to make it look like they are on the same track layout, when instead you have separated them.

Also, with 12v and 9v you cannot run trains on a dead-end track, for example if you want to create a train station of the type like Milan's central station (all tracks arriving "perpendicularly" to the station and stopping there instead of "passing by" parallel to it), an engines' sheds roundabout or any other terminal piece of layout. This because 12v and 9v tracks need to be closed to deliver the electric power.

A by-product of this is the fact that you must avoid closing loops with wrong polarities (creating a circling loop with one only entrance track to it for example), but this is usually less likely.

The problem of controlling trains indipendently was typical in old non-Lego model trains too. Usually fans had a great challenge (but then also great fun) in designing huge layouts where all trains were running automatically thanks to a series of semaphores and automated switches. But controlling trains individually would be much more fun for kids, since designing such automated layout is a huge task even for adults. I remember that some model trains companies of the 80s like Arnold and Fleischmann solved the problems by creating individually-controlled engines with a remote digital control system. However this made each single engine cost something between 100-300$, and in the 90s the hobby had become pretty much an upper-class adult hobby only. The majority of those train models companies are nowadays bankrupted and defunct

For these reasons, and for the facts that there are less cable around and no electric parts exposed (safety!), I would certainly prefer a battery-based system rather than a wired one.

But clearly the battery-based systems so far have too little power, take up more space inside the engines, and need to be recharged too often. The fact that they can't power other electrical devices such as lights, switches, semaphores etc is another shortcoming of the RC and PF, however you can imagine to have battery-powered trains together with a wired system that controls only "everything else" (and you can actually use the old 12v system for that, if you just don't plug it into the train track itself).

I think the "perfect system" can be achieved only the day that technology gives us miniaturized batteries that can deliver more power than today and still last a few days before recharging. Or even better... when technology manages to deliver a reliable WIRELESS system for transferring power, which you may have heard it's one big topic in electric engineering research activity nowadays, but still many years before it becomes commercially viable.

Edited April 3, 2009 by Legoist

[pe668]

Yes, but creating multiple loops is not exactly a solution but rather a trick to make it look like they are on the same track layout, when instead you have separated them.

Have the main lines with long loops and you run mulitple trains on the same line. Use switch points to bring trains on and off the main lines. I have my switches powered with 9volt technics motor driven by a mindstorm rcx. The rcx is controled from an I/R remote control. This gives me remote control of as many trains as I have sidings. Then there's always DCC which 9volt is the champion for Lego. 9volt rules if you want micro processor controlled trains.

[Brickthus]

Also, with 12v and 9v you cannot run trains on a dead-end track, for example if you want to create a train station of the type like Milan's central station (all tracks arriving "perpendicularly" to the station and stopping there instead of "passing by" parallel to it), an engines' sheds roundabout or any other terminal piece of layout. This because 12v and 9v tracks need to be closed to deliver the electric power.

A by-product of this is the fact that you must avoid closing loops with wrong polarities (creating a circling loop with one only entrance track to it for example), but this is usually less likely.

12V and 9V LEGO railways can be run just like any standard 2-rail model railway.

Layouts with two terminii might need more feed wires to reduce voltage drop along the distance of the layout, but in any model railway the power is ideally fed directly from the control panel to each isolated track section. They do not need to be closed if the power is fed correctly. BTW last chance to get 9V feed wires from LS@H!

To operate a layout with two terminii you need 3 engines because the engine is changed at each end, just as it would be with loco-hauled operation on the real railway. DMUs, EMUs and Driving Van Trailers have reduced the changing of locos on trains nowadays. For LEGO trans, a DMU or EMU should have either a motor in the middle of a 2-3 car train, or a motor at each end of a longer train (to avoid pushing too many vehicles).

The engine shed or turntable is only required if that fits with your layout design - tender steam engines on the main line need a turntable because they cannot run fast tender-first. This is not the case on a British preserved railway at 25mph maximum speed. One railway that does use a turntable is the Romney, Hythe and Dymchurch railway in Kent, England. These are 1/3 scale steam engines and presumably they cannot safely run tender-first at 25mph!

Reversing loops and triangles are possible with the correct isolation. A reversing loop is good for a layout with 1 terminus, making it is easier for one person to operate the layout. Cyril Freezer's book "The PSL Book of Model Railway Wiring" gives 20 model railway wiring rules and shows how each track formation may be successfully wired and operated.

Mark