Jump to content

Hinged lifting sections


Recommended Posts

On 29/07/2020 at 00:51, simmo009 said:

The current bridge was designed with O gauge in mind, and OO has recently been added.  Our builder really did a fantastic job on them, especially when you consider they had to be repaired twice due to incorrect operation (the mind boggles).

 

 

 

Something like this ?

 

 

 

Link to post
Share on other sites
36 minutes ago, Michael Hodgson said:

Yes, good way of doing it.  If it's not all on one common return, use the bolt to operate a relay, and use as many sets of contacts as necessary, wiring it via Normally Open contacts for fail-safe.

 

I didn't express myself too well, did I?

 

There will be no inter-board wiring, so that all boards except the lifting section can be hinged to the wall.

 

There will be two 20v AC bus pairs to feed plug-in controllers; plus two 12v DC feed buses (from two controllers), and one 0v common return bus. These busses will run along the walls the entire length of the continuous run layout, except across the doorway / lifting section.

 

In order to avoid trains approaching the raised lifting section, the board to the left of the lifting section will have its connection to the 0v common return bus taken via one of the brass draw bolts to the bus termination to the right of the door, and the board to the right of the lifting section will have its connection to the 0v common return bus taken via the other brass draw bolt to the bus termination to the left of the door.

 

Crikey - that sounds even more complicated, but it's really quite simple.

 

John Isherwood.

Link to post
Share on other sites
22 hours ago, cctransuk said:

This pre-supposes that the sections of track either side of the lifting section will be isolated from the common return elsewhere on the layout.

 

John Isherwood.

Thinking about this, my brain is beginning to hurt!

The least number of wires crossing the opening, that I can come up, with is three. Two are the positive and negative for the main line. One is a feed to one of the rails in the section before the hinges. If the lifting section interrupts power to the section beyond the gap, there should be no need to have a separate isolating section there. 

However I plan it, I can't manage with one, or even two bolts. Plan B therefore sounds like a bolt triggered relay that breaks more circuits. Plan C is a series of simple contact strips that are similarly broken when the lifting section is raised.

Or am I making things unduly difficult?

Best wishes 

Eric   

PS The original exam question was to find a way to wire the lifting section so that I do not have to remember to unplug a connector separately from raising the lifting section.  Sooner or later, I won't!

Link to post
Share on other sites
1 hour ago, burgundy said:

Thinking about this, my brain is beginning to hurt!

The least number of wires crossing the opening, that I can come up, with is three. Two are the positive and negative for the main line. One is a feed to one of the rails in the section before the hinges. If the lifting section interrupts power to the section beyond the gap, there should be no need to have a separate isolating section there. 

However I plan it, I can't manage with one, or even two bolts. Plan B therefore sounds like a bolt triggered relay that breaks more circuits. Plan C is a series of simple contact strips that are similarly broken when the lifting section is raised.

Or am I making things unduly difficult?

Best wishes 

Eric   

PS The original exam question was to find a way to wire the lifting section so that I do not have to remember to unplug a connector separately from raising the lifting section.  Sooner or later, I won't!

 

The first thing to remember is that all of my ten boards will be electrically independent - no interboard wiring except the safety wiring for the lifting board. This is specifically to allow each board to be hinged to the wall; (except for the lifting access board); for ease of wiring and maintenance.

 

Secondly, and as a consequence of the lack of interboard wiring, each board will have three DC feed wires from the power buses; two +12v wires from two controllers and one 0v common return wire. This, of course, applies to the lifting section.

 

So, the wiring to the lifting access board will comprise two +12v wires from two controllers, and one 0v common return wire. In addition, the 0v common return wire from the board to the left of the access lifting board will be taken across the lifting section to the board to the right via one of the two brass draw bolts, and the 0v common return wire from the board to the right of the access lifting board will be taken across the lifting section to the board to the left via the other brass draw bolt.

 

Bear in mind that, as a consequence of my 'no interboard wiring' edict, all section switches are mounted on the boards to which they apply; not grouped together at a control panel. Doing this greatly simplifies the electrics, at the expense of more moving around to control the layout.

 

John Isherwood.

Link to post
Share on other sites
  • RMweb Gold

Simple suggestion with diagrams:

 

Imagine the two rails crossing the lifting section are fed by red and green power wires. They could be feeding either DC or DCC to locos on the track.

 

The green rail is simple. You just connect green wires permanently to the rail either side of the bridge and use a flexible loop at the hinge end to feed the rail on the bridge itself:

1560168365_bridgewire1.png.e0e807c3c582d6aebc7f962af8cabd08.png

 

 

The red rail has insulating joints either side of the bridge. The power is fed to the bridge by a springy brass contact or by one of the locating slide bolts. Thus the bridge only has power when it is down.

At the hinge end a flexible loop feeds the isolated section of rail from the bridge so that it too only has power when the  bridge is down.

At the other end a second spring contact or sliding bolt takes the power from the red rail on the bridge back to the isolated section of track at that end so it only has power when the bridge is down.

666971806_bridgewire2.png.394ae48f453179fc09e9551501c420c9.png

(I have drawn the spring contacts one above the other for clarity but they would really be beside each other.)

 

 

When the bridge is open the power feed to the red rail on the bridge is disconnected and the isolated sections of rail either side are also disconnected because they take their power from the bridge:

1326501264_bridgewire3.png.6e0f70d52c61ab3980bafa7cb4ae0a27.png

 

 

Edited by Harlequin
  • Like 2
  • Thanks 2
Link to post
Share on other sites

It all sounds horribly complicated.

I would use a microswitch, or two, that is a switch which has a very abrupt over centre action and can snap over abruptly near the centre of its travel, not necessarily a small switch. For DCC 5 amp should be good.

Wire board A through microswitch A so there is no feed down one of the two Bus wires when the flap is up and there is feed with it down and do the same with board B and switch B. All the electrics remain on the relevant boards .   Springy strips and bolts are fine for exhibitions but get tired far more quickly than decent microswitches

For the lift out run the feed wire from the wall along the hinge line so the wires twist lengthwise and move through a very small angle compared to the loop which hangs down when the flap is down and goes tight when its raised as shown further up the page. 

Wiring.png

  • Thanks 1
Link to post
Share on other sites
  • RMweb Gold

Complicated? Really?

As discussed on many previous occasions the axis of the hinges has to be above the rails and so the flexible wiring under the boards at that point will have to have a fair amount of slack to allow the bridge to open. They won't simply be able to twist.

 

Edited by Harlequin
  • Agree 2
  • Informative/Useful 1
Link to post
Share on other sites

They're both pretty simple designs. Harlequin is basically using the hinged section as the switch blade, or you can buy a proprietary microswitch. You say potato...

 

If you want complex then you could go to town with all kinds of sensors and create a working signalling system which will have dead track where the relevant signal is not cleared, and interlock it with the position of the bridge. Would be even more complex if it were a single line, as the train would also have to be carrying the token...

  • Like 4
Link to post
Share on other sites
  • RMweb Gold
2 hours ago, Harlequin said:

Complicated? Really?

As discussed on many previous occasions the axis of the hinges have to be above the rails and so the flexible wiring under the boards at that point will have to have a fair amount of slack to allow the bridge to open. They won't simply be able to twist.

 

You could of course be very clever - if you have the carpentry skills - and use bar counter hinges which can sit flush (just like they do on lifting flaps on bar counters.  Next question - I wonder how many places sell really good bar counter hinges nowadays?  (There's plenty of not very good ones on the 'net)

Link to post
Share on other sites

Would bar counter hinges put the pivot point high enough above the rails though ? 

 

I have 8 lifting flaps superimposed on each other (layout design by Topsy !), currently under construction, at the moment the 'failsafe' consists of remembering not to drive off the end but the wiring is only jury-rigged at present. I like John's idea of routing all the common returns through the brass bolts. 

 

Here's 6 of them, only the right hand 3 are normally required, the left hand 3 are only needed to get into the cupboard behind them to get at the stepladder and tools stored in it. The top two (scenic level) boards are not fitted in this shot.

20200819_220722.jpg.01de46f3a71ce9bff34f790b7f756609.jpg

 

20200819_234337.jpg.ee07b8882b14d8c5926102310db93fe6.jpg

  • Like 3
Link to post
Share on other sites
1 hour ago, The Stationmaster said:

You could of course be very clever - if you have the carpentry skills - and use bar counter hinges which can sit flush (just like they do on lifting flaps on bar counters.  Next question - I wonder how many places sell really good bar counter hinges nowadays?  (There's plenty of not very good ones on the 'net)

A cunning plan, but, if you have scenery in the way, you would  have to make sure that items interlocked with each other when the board was raised. An interesting challenge!

Best wishes 

Eric  

  • Like 1
Link to post
Share on other sites
On 28/10/2020 at 07:56, Harlequin said:

Complicated? Really?

As discussed on many previous occasions the axis of the hinges has to be above the rails and so the flexible wiring under the boards at that point will have to have a fair amount of slack to allow the bridge to open. They won't simply be able to twist.

 

 

DSCN2429.JPG

DSCN2435.JPG

DSCN2437.JPG

  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.