crossings

I don't think there's anything ready-made for swing gates. On a single- width crossing, each gate would have to swing independently.

You might be able to rig something with memory wire. See:

Or google for "memory wire" +"model railway"

Also known as Nitinol wire or muscle wire, commonly used in robotics. It contracts when a current is applied.

There was a recent discussion on one of the Yahoo groups (small layout design ?) of using a servo to open and close enginehouse doors. The same idea might work for crossing gates.

It's not as simple as it seems at first sight, because it is made of soft plastic.

You could probably cheat and fix the gates permanently to the posts, but these would need to have a metal "axle" going up into them, rotating in bearing bushes.

If the road crosses the track at an angle the gates don't need to operate independently. But this kind of crossing would most likely have been manually operated by a crossing keeper (or station porter) opening and closing them himself.

I once worked out a scheme using a pair of Hankscraft geared slow motion motors the Americans sometimes use for turnouts, and limit switches, but it was fairly complicated. In O-gauge, using a Springside white metal kit. In the end I didn't build it but I've still got all the bits. One of these days...

That's probably a good solution. It could be programmed to stop at the right point without limit switches, and also to start and stop smoothly. But you would still need to operate each gate separately.

Come to think of it, I prefer that to the setup I played around with but didn't build because it was too complicated, using Hankscraft motors and limit switches.

I will try the Servos, I am going to have to lift the whole crossing slightly, The gates swing is too low and catches on the rail head, the planks in the 4 foot look like they are slightly out too, but that could make things easyer if its left as it is for the time being. thanks for the advice Simon G

It would be extreamly helpfull if you could Regards Simon G

I don't know of any commercial mechanisims specifically for level crossings. However, there are various brands (Tortoise for example) of slow motion motors which could be used. Some brands give lineal motion while Tortoise goes round (the shaft, not the motor) One motor per gate under the baseboard would be quite simple to make but pricy. One motoe with linkages to each gate gets more complicated but would be cheaper. String operation would be cheapest :-)

From my experience of making similar things, a slip joint of some sort will make set-up easier and save damage from "finger-pokers". I've used a loose arm on the operating shaft with nuts/washers and a ball-point pen spring for tension. Adjust the tension with the nuts (lock nut over the adjuster nut)

Greg.P.

Occasionally another hobby has something useful or some components that can be used with a little adaptation In this case I would look at what is available to Radio control aircraft builders for raising and lowering landing gear or in the model boat world the mechanisms for steering or the sail winches. There are many parts available such as retract servos and linkages.

G.Harman

Anyone remember the old tri-ang crossing that used exactly that method?

Jeff

Thats a good idea, After the crossing i may try that on my peco shed, regards Simon G