Decoupler

[Ballast]

The Mk III looks nice! So simple and yet so clever. It's not even 'jumping in the eye' the way it looks on the track

[zephyr1934]

Mk III is fantastic. I still think that there has got to be a way to eliminate the need for two plates underneath the track. I'll let you know if I get any ideas (for 9v perhaps the antenna for a radio, 3962, through the hole that is used to run wires under the track).

[doug72]

re use only one plate under track.

There is a way if you have a firm baseboard then only one plate is required to lift track by allowing the slider to run on the board surface.

Using the system as described as a starting point I have evolved an un-coupler that is SNOT using some Technic parts for the hinge part using two plain tiles 1 x 6 side by side. Two longer plain tiles 1 X 8 each side give the un-coupler the appearance of a level crossing.

Hinge consist of two 1 x 2 technic bricks with axle hole / 1 x 4L axle / 2 x 2 plate with double axle hole.

1 x 6 tiles attached to the 2 x 2 plate.

Photos of my un-coupler design using 1 plate under track :-

Top left: un-coupling ramp in raised position

Middle right: ramp removed showing pivot axle

Bottom: componant parts

Sorry system won't let me load image greater than 100K

Edited March 17, 2013 by Doug72

[HenrikLego]

I have made my own version of your uncoupler, but I have found a problem. When you have long trains with heavy wagons, my train can't reach the necessary speed to detach from the wagons behind the uncoupler. Any solutions to this would be great.

[CamelBoy68]

Hi HenrikLego,

Yes I think that is going to be a problem. In the three vids, I tried various lengths/weights of wagon to test this out and I found I needed to reverse slightly and then floor it for some of the wagons.... It also seemed to work best when there was a nice firm connection between the magnets.

When I was trying the earlier versions, it worked well on the long wheel-base wagons, as the plates would be pushing against the underneath, rather than attacking the magnet part of the bogie. Which was fine except it only worked in one direction and failed miserably with the smaller wagons...

Hi Doug72,

Nice job ! The only reason it needed to be raised by two plates, was if you already had track on a baseplate. One plate was note enough to get the tile under it, so two plates made it work. The non baseplate version was only one plate extra, as its assumed you are already on a flat surface (even carpet/ hardwood floor or table).

cheers

CB68

[JopieK]

Here is an automated version:

Lowered:

And raised:

A demo:

It uses a simple Arduino program at this point (serial control, if you press 'l' it will lower, if you press 'r' it will raise) but hope I will incorporate it in an automated PF setting later on (maybe even this week).

Arduino Sketch / Instructions

[JopieK]

very innovative. I still miss the 12v system a lot.

So do I but one thing I did not get when I was a child: the decoupler. When I finally got one as an adult, I was very disappointed by the result tough.

[Capparezza]

Sorry to bring back an old post from the crypt... but I was pondering if a solution with an electro-magnet to negate the magnetic field of the coupling might work?

That way you can decouple anywhere on the layout if you mount it near your locos coupler (or even use additional battery boxes and put it on your trailers) and it would only need a power supply, no additional LEGO parts. It could even be used stationary for those who prefer a solution like the "camel hump" above. Would this be interesting enough to give it a try?

[ColletArrow]

@Capparezza I can't tell what you're suggesting. Are you suggesting that introducing a third magnet (electromagnet) would somehow interfere with and destroy the magnetic field between the coupled magnets? I don't think that is possible.
Or are you saying we should replace the coupling magnets on our locos with electromagnets? That may work, hold on and I'll give it a go.

EDIT: OK, it doesn't. I used a small 2-coil electromagnet, and even when switched off it stuck to the coupling like glue. When energized, there was a mild repulsion if the coupling was lined up between the two (parallel) coils, but most of the time it made no difference.
(Watch out, physics-y bit coming ) I suspect the strength and internal orientation of the LEGO coupling magnets is what causes them to stick to any metal capable of transferring flux ('magnetic current'). This means any electromagnet will always stick, whether on or off, as they all have iron cores. The LEGO magnet will stick to any metal by passing flux out of its north pole, through the metal and back into its south pole.
(Physics A-level actually comes in useful in real life! I need to know this for my exams next week...)

I guess you could make this work if EVERY coupling was an electromagnet, but that would have too many problems of its own to even start to consider.

Edited June 8, 2017 by ColletArrow
Experiment results and interpretation

[Capparezza]

Hm, well that's not exactly what I was thinking about. However, nice to read about your view of the problem

Maybe the description behind this link explains it a bit better: http://www.wattnotions.com/low-power-magnetic-hold-and-release-mechanism/.

In short: Yeah, I am indeed suggesting that introducing a third (electro-)magnet, which induces another magnetic field when under power, might be able to break the existing magnetic field of the LEGO couplers. This was just something popping into my mind while on a five minute break at work, maybe this is not feasable at all...

[ColletArrow]

@Capparezza That link if I have understood it correctly, is simply using an electromagnet 'the wrong way round', i.e. applying power interrupts the field caused by the magnet. Whilst cool, it is not useful for our situation, as he has an 'air gap' between the magnet and the LED he's holding up. We don't know if it would work for two magnets touching eachother.
Also, my guess is it works by 'pulling' the magnetic field towards and through the inductor rather than below the magnet to the object. Therefore, you would need one on both the loco and the wagon, as both magnetic fields from both magnets would need to be deflected to decouple them. At that point things have got too complicated with around 4 magnetic fields interacting, and who knows what would happen! 

[Capparezza]

22 minutes ago, ColletArrow said:

At that point things have got too complicated with around 4 magnetic fields interacting, and who knows what would happen! 

Global Peace? Aliens taking over Earth? I am motivated to give it a try, but currently I'm in preperations of moving to a new home... might be finished in August.

[Jasseji]

On 4/27/2013 at 10:30 PM, JopieK said:

Here is an automated version:

Lowered:

And raised:

A demo:

 

 

It uses a simple Arduino program at this point (serial control, if you press 'l' it will lower, if you press 'r' it will raise) but hope I will incorporate it in an automated PF setting later on (maybe even this week).

Arduino Sketch / Instructions

Hi, does anyone still have those instructions ? The website doesnt seem to work

[JopieK]

I can have a look for you, but I think you forgot about the rules (the topic is from 2013). So a PM would have been a better alternative.