Interested in a signal building group?

[Eddyg]

Jonny,

Thanks for the signals diagrams. Unfortunately the resolution isn't too good so it's difficult to see some of the detail, so can you confirm the following:

Access to Shildon yard is controlled only by the subsidiary signal S3 and and the stop and distant signals on the approach are fixed.

Signal M1 on the Middleton Junction diagram is the same post as signal N2 on the Noble Sidings diagram. I assume M1 is the distant and N2 the stop signal.

Signals S3, M3, M7, M1/N2, all have a symbol fixed to the post. Is this the "B" sign indicating "signal released by the block at line clear". If this protocol is built in to the control/interlocking systems do we still need the single line token?

On another tack the bracket signal N1/N3/N6 in Noble Sidings looks a bit awkward to me placed on the wrong side and covering the egress from both reception and departure sidings. I understand the need to place the signals such that access for the over sized yardmaster is not compromised, but I think it might be better to put a bracket on the correct side of the departure road with N3 and N6 and a separate post for N1 on the right hand side of the reception siding closer to switch N4A. This would make the reception road block just a little bit longer so the pilot can get in behind the signal when drawing off the brake van, and there is still plenty of space between the roads for the yardmaster's size 12s.

The fixed signals will be different from the others, presumably just requiring a post, signal arm, lamp and ladder. Our build list doesn't identify the fixed signals, but we should do this to save unnecessary work in making the operating gear, and signal and balance weight bearings, etc..

Regards

Eddie

[Jonny Ward]

Jonny,

Thanks for the signals diagrams. Unfortunately the resolution isn't too good so it's difficult to see some of the detail, so can you confirm the following:

Access to Shildon yard is controlled only by the subsidiary signal S3 and and the stop and distant signals on the approach are fixed.

Signal M1 on the Middleton Junction diagram is the same post as signal N2 on the Noble Sidings diagram. I assume M1 is the distant and N2 the stop signal.

Signals S3, M3, M7, M1/N2, all have a symbol fixed to the post. Is this the "B" sign indicating "signal released by the block at line clear". If this protocol is built in to the control/interlocking systems do we still need the single line token?

Yes to all the above Eddy. I have built a pair of Tokenless Block instruments and proven the circuitry (They look a bit 'Western', but I'm hopping no one will notice...), which I think would be useful between Noble Sidings and Middleton with it being a short section. I suppose S3 and M3 really ought to have a 'T' for 'released by Token', but in a fit off 'not thinking about it too carefully', I've put 'B's on them.

On another tack the bracket signal N1/N3/N6 in Noble Sidings looks a bit awkward to me placed on the wrong side and covering the egress from both reception and departure sidings. I understand the need to place the signals such that access for the over sized yardmaster is not compromised, but I think it might be better to put a bracket on the correct side of the departure road with N3 and N6 and a separate post for N1 on the right hand side of the reception siding closer to switch N4A. This would make the reception road block just a little bit longer so the pilot can get in behind the signal when drawing off the brake van, and there is still plenty of space between the roads for the yardmaster's size 12s.

We talked about this at the meeting. Originally, I've marked two individual post. However, we concluded that by making it a bracket on the fence side, there would be less chance of it being walked on. It will just require any drivers in the loop to look across at the signal (The cantilever wont actually be going over the track).

The fixed signals will be different from the others, presumably just requiring a post, signal arm, lamp and ladder. Our build list doesn't identify the fixed signals, but we should do this to save unnecessary work in making the operating gear, and signal and balance weight bearings, etc..

Regards

Eddie

This is true, but in the interest of using as few standard parts as possible, I'd be inclined to keep all the signals to the same pattern. It will also allow us to use them in other positions/layouts in the future.

[Eddyg]

Hi Johny,

All points answered, thanks. Only actual operations will show if the position of N1/N3 will restrict the shunting at Noble Sidings, although I'm sure our people will work their way around any difficulties. Over length trains could be challenging.

Eddie

[Eddyg]

Hi Dave,

This forum has been quiet for quite a few days. Any chance of a progress report?

Eddie

[Dave Noble]

Hi Eddy and all,

Yes it's been quiet, sorry but had work to do, though I believe that's a thing of the past to some. Haha. I'm looking forward to that.

Anyway, I've ordered laser cut parts for the ladders, stays, safety loops, cranks and balance levers. Also a couple of servo bases. I've ordered two Hitec HS-55 servos, they have a good name and are easily available and cheap. I've slightly modified the base design and sent a drawing to Ben, he will make a new one in PVC. I've asked Chris to laser cut a new bottom cover from acrylic for it. I've tapped my posts 1/4 BSP at the bottom to take a hollow bolt (heck, that stainless is tough) and used a shortened double ended 1/4 BSP adapter for the bolt. I've decided to try this in the hope that it will nip the PVC and steel plates together and help stiffen things up a bit, I got the impression folks weren't too happy with the idea of silver soldering the post to the steel base.. Hopefully we can match this lot together at Morley, and there'll be an armful of ladder stiles and welding rod for you Eddy. I've received the stainless signal wire, but not tried forming loops yet. Just about to make a new pattern for the cap. Lastly for now, I've made some more posts. Eddy, have you some spares, I have a feeling you have bottoms only, if so, would you like me to bring some 1/2" material to Morley?

I think Graham is looking into getting spectacle glasses, must send him a drawing.

[Eddyg]

Dave,

Having considered the amount of domestic work I'm now involved with, garden walls , decorating kitchen refurb and so on, I think I'd rather be at work! I called in to see my old colleagues the other week and they looked just a bit busy. I was very tempted to offer my services, although I don't think they'd want to pay my rates.

I was on holiday last week and stayed in a cottage that had historic railway connections. See the photograph of the BR distant adorning the front wall.

WP_20150719_006[1].jpg (166 KiB) Viewed 26809 times

It looks like you have been pretty productive despite having to do some work, so I'm looking forward to getting to grips with the ladders. I do have two post bottoms spare so if you bring some top tubes I can join them up.

See you Sunday

Eddie

[Dave Noble]

Some laser cut parts have arrived, ladder seems to go together OK.

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P1030230.jpg (84.37 KiB) Viewed 26760 times

[Richard Phillips]

Looks good Dave, wouldn't mind having a go at one of these myself if we're doing a kit-of-parts (Royal "we" there ), does it need a jog to assemble?

You mentioned the servo choice. I guess it's the logical option as it is what is used at Ryedale. Their posts produce quite a quite snap on/off. You can ask the servo to move by degree, but it does tend to produce a jittery movement - I wondered if a motor might be a better option winding a spool, but then there are the issues of how to stop - a servo won't go beyond it's stops (180 degrees usually if I recall). You could use a motor with an arm/disc so you wouldn't go beyond the disc size in terms of movement (and lost motion as you go round), but you'd loose the advantage of smoothness over a longer distance pull on a small spool if you get my meaning. I think the cost of a cheap small motor and the cost of a cheap small servo is negligible now.

Anyway, the distance for the arm to be moved owing to the scale is so small I think it would be difficult to get any kind of replica movement, although I did like Jonny's description of the action of damped motorised semaphores.

[Dave Noble]

Richard,

Eddy has offered to do the soldering, but I can keep a couple of ladders back for you to do. Yes, there are a couple of soldering fixtures.

Servos/motors were discussed earlier, and I raised the question of jittery servos, but most folks seemed prepared to accept them because of their simplicity, unfortunately it's difficult to use much more than about 45 degrees of their movement without complications, and this exacerbates the jitters. I did rather fancy a motor, and thought a winch with a return spring for positive movement, and limit switches would work, it's getting more complicated, but I'd be prepared to try one. MFAComo drills 941D1041 might be a good start, at £19 each.

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Latest servo base.

[Scrat]

How much travel do you need?

I would suggest to do it like I did with my point motors.
One geared motor, running in one direction only (to simplify the circuit).
An eccentric to move the rods and two limit switches to stop it twice per revolution. (top and bottom position)
Wirks fine on my garden railway since 5 years (always outside, even in the snow).

[Dave Noble]

Hi Scrat,

The problem is not lack of movement, there is plenty with the servo, it is that we can either use a small angular movement (see the two cranks in the picture above) or a large one. Small angular movement makes the movement jittery, a large movement is smoother but makes the operating rod waggle from side to side which makes it more obvious and therefore unrealistic, and also makes the speed of the arm alter significantly as it moves.

I used the same method as you to operate my point motor, but using a scotch crank, unfortunately we don't really have room for that on the signals.

[Ben Lyons]

Hi all

Picture of PVC base will show Dave at Derby Tomorrow

[Ben Lyons]

Given the above this comes to mind has any one any thoughts the text comes straight from there web site.

Mega points controllers---

MegaPoints Controller £50.00
12 points/turnouts/semaphore signals, gates, barriers or doors from a single board.
MegaPoints Controller top viewNow includes semaphore bounce program!

This board can control up to 12 R/C servos to operate points, gates, barriers, doors, crossings or semaphore signals in fast or slow smooth operation. Includes the following features: Multiple memories, network interface, master/slave paring, adjustable speed, direction and movement range for fine point adjustment and tuning over each channel individually.

Ben

[Itchy]

Got the jitters? Going back a few years we did fit a small unit between the rc receiver and the servos on some of our production models at work. This was done to try and smooth out the survo movement coursed by interference. Maybe a survo smoother might help, most model shops should be able to get them if still available.

[Richard Phillips]

Got the jitters? Going back a few years we did fit a small unit between the rc receiver and the servos on some of our production models at work. This was done to try and smooth out the survo movement coursed by interference. Maybe a survo smoother might help, most model shops should be able to get them if still available.

It's not interference, but more the way the PWM instructs the servo, by telling it to move to the final position the movement is smooth, by trying to slow it down by saying "move by 1 degree, wait, move by 1 degree" you get this stepped movement, which is amplified the longer the arm, but movement is limited the shorter the arm.

I wonder if it can't be damped out a bit by using some sort of spring/elastic bridal, but I think it's just something we have to put up with with no speed control on the servo. It might be possible to program some careful timings, it something I'd need to experiment with.

[Scrat]

How about replacing the Servo lever by an eccentic disc? The operating rod then runs on the surface of the disc. This will cancel out "sideways" movement of the operating rod. The jitters would also have less effect with this configuration.

[Eddyg]

I did earlier suggest putting a tension spring between the servo and the signal arm to damp out the 'jitters'. It will just act much like a wire operated signal which has a delay between the lever in the box and the signal as the stretch in the wire is taken up and the inertia of the balance weight and arm is overcome, at which point the signal arm flies to the off position. Might take a bit of experimenting to get the right spring. It's a simple solution that requires very little alteration to the kit you have.

Eddie

[Eddyg]

I would think that everyone is probably back from holiday by now, and as the operating season is drawing to a lesser state of frenzy, work on the signalling will be ramping up. Any chance of a report on progress and future activity now?

Eddie

[Scrat]

A list of open issues would also be useful.

[alan w]

While on holiday in August in Skegness I noticed at the terminal station there is still semaphores in use at the station hope this may be of use to our Lincolnshire Lasses & lads.