The main LEGO train systems are all roughly compatible. They all use a 6 stud gauge, so with a bit of fiddling, you can use all of the systems together. If you want to be most compatible with the current track offerings, you're better off with 9V and RC/PF track. This question discusses the specific compatibility issues in more detail.
There are several ...
The larger hole is present in older 9V track as well:
I've never actually done this, but I've always assumed that the hole is there so that the track can be screwed or nailed down if desired to create a semi-permanent layout. This is common practice with traditional model railroad track:
There is now official documentation for the Bluetooth protocol used by the Powered Up product line:
The community has created some tools to interact directly with Powered Up and Boost hubs. Here is one example:
That tool supports basically every ...
For this experiment we're using the wheeled Duplo push and go motor block and red cabin from Set #10874.
The wheel width of the motor is the same width as a non motor base.
So, for this train to stay on the six stud track, the wheels need to sit either on the inside of the tracks or the outside of the tracks.
As the last picture shows, the wheels ...
Each train needs the following two components:
I'll assume you purchased a second set of these to convert your 9V train with, since you're asking how to control both trains using the same remote.
The LEGO Powered Up team has provided an FAQ for Powered Up which contains instructions for how to pair multiple Powered Up Smarthubs with one ...
You can do most things that you can do with traditional model railroads using LEGO trains. This includes cross track, bridges, switches, and inclines.
As far as I know, this was never released for either RC or PF trains. As you noted, there was a cross track part for the 9V trains. If you aren't aware, 9V, RC, and PF track is ...
You can absolutely run RC and PF trains on 12V track. You can leave out the center conducting rail since it won't be delivering any power to the train, unless you are planning to run both 12V and remote trains.
The main LEGO train sets have all used the same rail gauge, which is the main thing that matters.
If you'd like to use both your 12V track and the ...
The red car that you mentioned is Mail Van (7820).
There are a number of other trains in the picture including:
7730 - Goods train (the locomotive doesn't seem to be visible)
7710 - Push-Along Passenger Steam Train (just the cars)
7750 - Steam Engine with Tender (pulling the cars from 7710)
7814 - Crane Wagon
7760 - Diesel Shunter Locomotive
7720 - ...
LEGO tracks are 12mm high, train wheels go below the true height of the track and so in reality only add 7mm of height.
The structure gauge (also known as clearance) tolerance will obviously be a lot lower than real life. You could perhaps get away with 1/3 a brick clearance but having at least one or two bricks height clearance at minimum is best.
Here are ...
I would recommend BlueBrick, which is a versatile LEGO layout editor by Alban Nanty.
Apperently it has Duplo parts too, so I believe it should meet your needs. It can actually do much more for your layout planning needs (including modular tables if your club has some, for example), so maybe you'll consider it overkill as well, but since it's specifically ...
Mathematically, the largest driver wheel you can buy for LEGO is Big Ben's XL driver, with a diameter of 36.8mm. To reach 10 mph, that wheel will have to spin:
36.8 mm diameter -> 115.6 mm circumference -> 7.2 x 10^-5 mi/revolution -> 2320 RPM (!!)
This means that you have to gear up a motor to run at 2320 RPM. An XL PF motor with no load spins at about ...
With a bit of trigonometry and some observation we can estimate a theoretical limit to the maximum length.
I assume you are looking for the maximum length that would run on the sharpest possible curve, which appears to be one made with flexible track. By observing this photo of 52 flex track pieces arranged in a circle, we can estimate that each piece can ...
If you want to “turn on and forget” you might want to look into obtaining a circle of old 9V track (metal rails produced by LEGO until 2007) and a power supply, plus a 9V train motor. It will not be cheap (the track pieces, especially curves, won’t be too expensive but a working 9V train motor is a $50-$75 purchase) however it will allow you to turn the ...
The best way to solve this type of problem is to break it down and isolate the fault.
You might find that it is easier to remove the Power Functions components from the model for some of the following:
Check all connections. Disconnect each cable and re-connect everything. Ensure that the plugs are the right way around (they don't sit right if not) and ...
I'm not aware of any sites that are dedicated to DUPLO train layouts, but there are certainly interesting layout ideas out there. For example, this was included in set 2932:
There are also loads of great creations in this Pinterest category:
The LEGO Power Functions connectors have 4 standard designations regardless of the usage:
C1 "control 1"
C2 "control 2"
It seems for motors that the 9V and Ground are unused. The C1 and C2 are used in combination to pick the motor direction. If C1 is providing power and C2 is providing ground then the motor goes forward. If C2 is ...
Based on the layouts from this answer, a half-bridge seems to be 2 straight tracks + 1 quarter-circle (split mid-track at the end, because the middle of the bridge is centered with the crossing track below it).
From this guy's measurements, a quarter-circle of the newer DUPLO tracks is about 18x18 studs. Straights are 8 studs long.
So, a half-bridge should ...
It's an interactive piece that makes the train perform a cool(ish) function when it rolls over it.
The train has a sensor on the bottom that reads the piece and does the deed.
When the train reads this red one... it stops moving, which is sorta coolish for a jealous older sibling maybe ;).
Watch 3 videos explaining all the cool possibilities. (1), (2), (...
Those are the two City-themed trains that are currently available. LEGO is currently transitioning to a new electrical system for trains, so that may explain the relatively low number of trains available. There are a couple of other trains available if you are interested in something outside of the City theme.
There's Winter Holiday Train (10254):
And also ...
As jncraton noted LEGO is going through a transitional time now. Sadly trains are not a huge portion of their sales so it tends to ebb and flow through time anyway. So if you want a train definitely grab it while it is for sale widely. If you wait a year or two it could be gone or harder to find.
There are other options however...
Buy new trains on the ...
I think you want to consider using the 4-stud-wide "rollercoaster" tracks, part numbers 25059, 25061 and 26022.
Here's how those to parts look like in set 60228:
The straight track are 8 or 16 studs long, and the 90° curved track has a radius of 12 studs (counted from the track centerline). These dimensions allow for a few track pieces to be ...
I just built the bridge yesterday. I didn't have all the parts so had to be creative at some points.
I'll improve some joints once I picked up more of my Lego at my dads' place.
Very funny project!
The main benefit is consistent performance. The rechargeable battery puts out almost the same voltage until it's almost flat, and whatever current is required with little voltage drop. Disposable batteries have more voltage, but cheap ones can't supply much current. Expensive ones can supply the current, but cost more. You'd be lucky to get 5 sets of those ...
All LEGO train tracks have had the same gauge, so newer trains will fit old tracks, including 12V/4.5V. Since the wheels themselves are not exactly the same, you may run into some small issues at points, but it should be OK most of the time - and using RC track wouldn't fully prevent the issue anyway. (If anything, I suspect trains woudl actually derail more ...
Each piece of flex track is equivalent to 1/4 piece of regular track. The standard train curves are 1/16th of a circle and thus an oval shape is not possible, however, with 64 pieces of flex track you could make an oval by squashing the circle a bit. 7499 comes with 16 flexible tracks, so you'll need 4 of them to make a regular train circle.
The flex track ...
The compression member in your design looks thin to me, and the tension member oversize (assuming they are the top and bottom respectively). I would use string for tension and the technic beams for compression as the first step.
The low-part-count solution that occurs to me is going to kill the clearance under your bridge, but if that's acceptable a single ...
Warning: LEGO pieces were harmed for this answer
How the switch works
So, how does it work then? Well, let's open it up!
The back plate is held into place by 14 pins. We'll carefully pry it open with a knife. Alternatively, we could use a drill bit to slowly scrape off the pinheads.
Both methods are destructive. The back plate needs to be glued back on ...