legoman666

http://alpha.bricklink.com/pages/clone/catalogitem.page?P=4081b Let's you reverse stud direction in a very small space.

Some trickery behind the glass. That's a headlight brick holding the windshield together and is centered on a 1x2 technic brick /w 2 holes above it.

I won't take it apart but I have a couple photos on flickr. The front window is 7 1/5 studs, not 7.

I just ran a test with fully charged caps, it ran for 1:55 at half throttle before stopping. It has 4L motors. I have to use 10 caps because I run my rails at 24V, each cap is rated for 2.7V, and the voltage gets split more or less evenly across all of the caps so they're ~2.4V when full. So, for my setup, no. But if you ran your track at a lower voltage, then yes. Capacitors fill as fast as they can. If you hooked one up to a theoretically unlimited power source, it would draw an infinite current. But since we don't live in such an ideal world, the resistance in the circuit limits the current (or if you have a fancy power supply that can limit current). You wires have resistance, your connectors have resistance, your caps have resistance and your power supply cannot supply an infinite current. My power supply is rated for 2.2A @ 24V. My wires and connectors perhaps have a resistance of 1ohm. Without additional resistance, the caps wold pull 24A (24V / 1ohm) when charging. This would kill my power supply. So I added 13.5ohms which yields about 1.7A (24V / 14.5ohms = 1.7A). Power lost in the resistors is I^2 x R = 39W. Of course, as the caps charge, the current decreases and the power loss goes down to a more reasonable level. During operation it seems to level out at about .8A which means only 9W is wasted. My DC/DC regulators are pretty efficient, around 90% according to their spec. Without the regulators, the train would slow down as the caps got lower. For a prototype, it works fairly well. I may add super cap banks to my freight train next.

I have my caps wired up in such a way that reverse polarizing them is basically impossible :) My locomotives do not back feed on to the track; there is a bridge rectifier between the rails and the electronics on the locomotive. 60A is definitely enough to weld metal, although my 24awg wires would probably fail before than happened. Correct, it's only designed to get the loco over unpowered curves or bridges. Locomotive can probably run for 2-3 minutes on fully charged caps. I'll test tonight. Higher capacity caps do exist but this seemed like a good place to start. Capacitors in series add together like resistors do in parallel, so this array is actually 10F @ 24V even though each individual cap is 100F @ 2.7V.

What happens when you throw both levers :)

5.3A continuous, 58.7A max. I am charging them at ~1.7A max and discharging them at .4 - 2A depending on their charge level. The potato comment is a joke that I think is from reddit.

Since ME Models is only making R56 in metal (assuming they ever come out), the wider radii will never see electrification. All of my locomotives except one have battery backups, but swapping batteries during a long show sucks. A friend clued me in to super caps. For the uninitiated, a typical capacitor you see on your motherboard is something like 50uF and good up to 25V or so. The super caps I bought are 100F, which is 200000x the capacity of your typical 50uF cap, although they are only good up to 2.7V. Caps higher than 100F exist too! There are some benefits to using caps and some trade offs compared to batteries. Benefits include up to 500,000 charge/discharge cycles. No charger required. Apply 24V to the circuit and the caps charge up to 24V and stop. Massive maximum charge/discharge current allowed. The main con is that they are not as energy dense as lipos or ni-mhs. But since I'm stuffing mine into an empty coach, it is not an issue. Another concern is that as they are discharged, they decrease in voltage. A DC/DC regulator is required to maintain a constant voltage to the motor controller otherwise the train would slow down as the caps decreased in voltage. My locomotives already all have DC/DC regulators. Anyway, to the pics! I did lower the 25ohm resistor to about 13.5ohms. The resistors limit the charge current through the circuit so I don't melt my power supply, track or wires. The diode bypasses the resistor during discharge. I also added a thermostat to only turn on the fans when the resistors hit 50C. Since not all caps are created equal, each has a 200ohm resistor across its terminals to balance them. Lower capacitance caps increase in voltage faster, higher voltage = more current flowing through 200ohm resistor and thus lowers it quicker. Higher voltage caps will also charge adjacent caps. The shiny bit is a bimetal thermostat. Closes a circuit at 50C to turn on 2 fans and opens at 35C to turn them off. Track is electrified to 24V. Notice how the ammeter reads 0A when the tender passes onto plastic curves then jumps up to about 1A when on 9V straights. Excuse the potato quality.

Make the trailing pair of wheels able to pivot?

there's good instructions for a middle sliding axle on a geared 3 axle truck in railbricks issue 6.

At our LUG setups and shows, we don't allow interactivity for our train exhibits, regardless of the amount of supervising adults. I only let 2 other people even control my trains, much less every lug member. We normally have a bins of Duplo out for kids who need to get their hands on something.

I'd like to show you folks a system of lights our LUG came up with that I was tasked with soldering :(. 470Ω + 1kΩ, 9V - 24V = ~6mA to 16mA. Life Lites hollow lamp posts Much soldering. Modular system, can add as many as you want and no voltage drop since they're all in parallel. Someone else gets to put these together. I'm only 1/10th done soldering and I'm already tired of it. A very pleasant 2800K warm white LED, not that 7000K crap blue.

I'll buy 3d prints of anything interesting you release the files for. I can paint them or order them in dark grey from shapeways. I don't need 9v power, so that simplifies things quite a bit.

Why should we do Lego's job for them?

I just use 3-in-1.

The NS diesel is boring and the box car roof likes to dismantle itself if you look at it askance.

Instead of trying to upload the photo to the forum, you might try using an external image host, like imgur or flickr.

A good start. Might consider using droid arms for the handrails. The lighting makes the details on the trucks impossible to see. I think you could fit more cab windows in if you did some more tinkering.

Looks great! At first I thought 8W meant 8-wide. I was looking at the hood thinking to myself, that isnt 8. then I realized it meant 8 wheels. I'm going to finish my coffee before I try thinking any more today.

Did you people even look at the photos? The gauge is like 2.5'.

Honestly it took a lot of work to get it to run well. The transmission is not very well designed.

I did a narrow gauge 5w mining train a while back that had problems with traction. I never really solved it completely, but I ended up adding several ounces of solder as ballast. Not a pure solution, but it certainly helped. I also replaced the stock Lego rubber bands with some that were more tacky.

Thanks! The locos are all here: https://www.flickr.com/photos/77871011@N08/albums Mostly they're astounded by the mess. The yellow train is a Union Pacific GE EMD, a UP Big Boy, 2 baggage cars, and 4 coaches. All told about 14' long. The Big Boy and coaches I found instructions for online, the EMD is my own design. First person view from the Amtrak locomotive. Birds eye view from security camera.

Redid the truck details and increased the wheel spacing. Both are now more prototypical.

I'll have to give them a look, I don't have any on hand in black. I may have some red ones though. Thanks for the suggestion! Do either of you have photos of yours so I can look at them and shamelessly steal your ideas?