Interested in a signal building group?

[Alan Wood]

I spotted something whilst going. Through the photos , In the pictures of the real life signal , the back blinder is facing the signal arm but in the line drawing and the pics of people's signals they face away from the signal arm , I thought that the back blinder exposed the back of the lamp so the signalman could see if it was lit and what position the signal was in , can anyone shed any light on this please .

[Eddyg]

Alan,
Dave and me have already discussed this - see page 12, about half way down

Eddie

[Richard Phillips]

Like your video Richard, but I'm bemused at the spectacle glass colours - Red on and yellow off?

Eddie

Looking good Eddie - yes I didn't pay much attention did I? I just fitted the pre-cut lenses - So this must be the first stop/caution distant..!

Ben has got the bases now, I think he intends to send yours on. If you power the signal with 9 or 12 volts with the servo connected it will drive to 0 degrees (ie "on"). If using the supplied horn you'll need to chop one side off and the last hole off the other end. This is (based on testing two servos which seem identical) really only necessary for anti-clockwise travelling servos as the splines didn't line up well, which is not the case for single arm posts, so fit in the position closest to the post. It would be perhaps wise to check the servo travel and horn position before fitting the servo to the mounting.

You can get the servo to drive to Off/Clear by bringing the manual control line to ground (DO NOT apply 12 volts to the manual control lines). You'll find out which one it is as you can pull each one to ground in turn. The modbus lines shouldn't be affected by pulling those to ground, but they are the next pins to the power pins, which should be fairly obvious as they are on top when the base is upside down - red for 12v and black for ground as per the normal conventions! If you don't have a DIN plug, the dark green wire is the manual control line for servo 1 - not to be confused with the lighter green wire that goes to the modbus board with yellow and white - the one next to blue/purple which are the other manual lines. A careful use of a jumper wire would bring the servo to Off/Clear.


There is only limited movement, this is in part because I go to this stage a bit close to the deadline - was more insurance than anything else - as a consequence you may need to use the outer of the 2 holes in the horn to get the movement required. It was the best I could do at short notice. What is really required is a small pot to control the angle, or an ability to set the angle from the signalbox - but obviously everyone won't have their own signalbox so I had to program something as a drive angle, and 55 degrees was the best compromise at the time.

[Ben Lyons]

Hi Eddie/ graham

Fitted out bases on way Via TNT, I have added 2 sets of 4 rubber feet which can be fitted vai the outer most M3 screw that fix the cover plate.
I will hopefull fit the cables but intend NOT to power up bases until Shildon as not sure what all the talk means.

See you soon Ben

[Richard Phillips]

Hi Eddie/ graham

Fitted out bases on way Via TNT, I have added 2 sets of 4 rubber feet which can be fitted vai the outer most M3 screw that fix the cover plate.
I will hopefull fit the cables but intend NOT to power up bases until Shildon as not sure what all the talk means.

See you soon Ben

I'd encourage you to get the servo horns in the right place before Shildon (I actually have done this for your base Ben) as the pull wires can be made up. It doesn't take too long to make the last pull wire to the servo so could be done at Shildon as long as you've done the wires to the balance arm and crank previously.

Just get a 9 volt battery and apply the correct polarity to the red and black spade clips - the servo will drive to ON/Danger (edit: I did previously write "Off", this is incorrect) as part of the power on routine. Fit the horn as close as possible to the base top, then make off the pull wires. The board is not like PC you have to power down properly so it's "safe" to remove power. Fitting the rod to the servo horn does tend to move the servo slightly so keep checking by applying power to see where things start. If you see the video for mine I've had to use the extreme holes to get the amount of movement required.

I did forget to mention the ribbon cable connector housing is too wide once the servo mounting base is fitted, you'll need to shave off one side (use the edge of the 6 pin plug as a guide - I'll get a photo to show what I mean, although my base with a mounting plate is now with Ben. Alternatively notch the servo mounting plate for a positive location.

plugreduce.jpg (19.89 KiB) Viewed 31360 times

[Dave Noble]

Eddie,

"I'm surprised at just how bright the lamps are when viewed through the lens."

To try and get the best effect, Rob one of my sons, and I, did a little experimenting to measure the focal length of the lens. So, I have placed the bulb at the focal point, and by sheer coincidence, this happens to be the middle of the lamp body!

You should have your replacement servo by now Eddie, and Ben should have his looms and other bits.

[Eddyg]

Dave,

Time was I could have calculated the focal length of a lens, but fourth form physics is too far away now and I don't know the refractive index for acrylic!

I received the servo, thanks, but its travel is much greater than the ones you sent first. Do I need to change the gearing or will the electronics take care of that ?

I also got the signal bases from Ben (thanks Ben) and spent about two and a half hours fitting them with the signals. It would have been much easier with another pair of hands, the signal posts are seriously uncooperative when trying to put the screws in or when threading wires through small holes. Anyway they got done without being damaged, but there were some heart stopping moments as I wrestled with them on the bench.
One thing for those assembling at Shidon is they will need an M3 tap for the signal baseplates. I found the holes were a bit small as well and opened them out to 2.5mm to make life easier for my borrowed tap (I don't do metric), which looked like a second rather than a taper.

Some questions for Richard. I take it that the seven pin DIN plugs are wired to take the 12V power on pins 1 and 7 and so long as the polarity is right any of then can be used to link to the power?

I will have to go out and get a 7 pin plug so I can test the servos. I searched the workshop today and found I only have five pin DINs which are of course missing the pins I need.

I've tested the servos using the servo tester recommended by Dave and have set the horns in the 'On' position with the tester. Do you think that will be OK?

I noticed the ribbon cable connector was a tad to wide for the space, but the bottom cover just deflects a little to accommodate it and that fixes it in place. Ill trim it a bit tomorrow if I have time.

Where should the lamp be connected? I've plugged it into the pair of pins on the ribbon connector next to the servo connection. I have used the pins nearest the input cable for the servo connection.

Does it matter which base is connected to which signal? I couldn't see any identifiers on the bases.

An finally I should manage to get to Shildon around midday, if the kitchen supplier delivers on time.

Eddie.

[Dave Noble]

Eddie,

Different servo travel? That shouldn't be. Please check that I've sent you an HS-55. You can't alter the gearing, and I don't know what Richard's electronics are capable of. Hopefully we can come up with a solution on Thursday.

[Eddyg]

Dave,

It's labelled HS-55 and looks identical to the others. The travel is 180 degrees or more.

Eddie

[Dave Noble]

That's a lot of travel without some sort of assistance. If using the same driver, all servos of the same type should have the same movement. Perhaps it's a dud. I'll have spares with me at Shildon.

[Ben Lyons]

Promised pictures of working but not finished.

[Dave Noble]

Nice work Ben, I wish mine looked that good.

[Richard Phillips]

I received the servo, thanks, but its travel is much greater than the ones you sent first. Do I need to change the gearing or will the electronics take care of that ?

Mine were 180 degrees travel and I wouldn't recommend adjusting with the gearbox.

..the signal posts are seriously uncooperative when trying to put the screws in or when threading wires through small holes.

Yes, unfortunately I couldn't get the sweep of a bent Allen key either in stiff M3 holes, but oddly I didn't make the trek to the garage to get my Allen key bits for my screwdriver! I know what you mean though, trying to gently place the signal somewhere as you do up the various screws without damaging the paint.

I take it that the seven pin DIN plugs are wired to take the 12V power on pins 1 and 7 and so long as the polarity is right any of then can be used to link to the power?

Correct.

I've tested the servos using the servo tester recommended by Dave and have set the horns in the 'On' position with the tester. Do you think that will be OK?

Possibly/probably not. I tested three types of servos and they all displayed different ranges of movement. The HS55s were consistent, and as you mention did display the full 180 degree sweep - although Dave did mention to me in an email that a HS55 he had did not, so some inconsistency between even the same servo type.

I encourage you to power up the signal with the servo connected, this will drive them to what the base thinks is 0 degrees - about a PWM pulse length of 650-700 uS if I recall. For the three hole arms I'd trim the last hole off and as mentioned previously a conservative sweep of 55 degrees was used. What is really required is a trimmer pot and setting switch so the bases can be programmed for individual servos.... something for the MKII program. I did start doing this on the signalbox code but got a strange error only to later realise I'd made an error in the arm assignments in the code - at this point I decided not to press ahead because time was short and I wanted to send out the bases with a known working code.

With a jumper wire or if you manage to get a DIN plug pull the manual line 1 to ground - this is the dark green wire in the group of 9 - not the light green wire next to yellow in the group of 2 - this will send the servo to it's Off/Clear position - and this is as far as the servo will move. It should fit in the space limits of the base with the shortened horn.

I noticed the ribbon cable connector was a tad to wide for the space, but the bottom cover just deflects a little to accommodate it and that fixes it in place. Ill trim it a bit tomorrow if I have time.

I trimmed mine to make the cover sit down properly with razor saw and also a sharp stanley blade. It might not matter if you're using mounting feet if the cover deflects a little. Just one thing I noticed when it was all fitted up, before I had the mounting base made up I assumed it would all fit - I don't think matters all that much but is my suggested remedy.

Where should the lamp be connected? I've plugged it into the pair of pins on the ribbon connector next to the servo connection. I have used the pins nearest the input cable for the servo connection.

Either of the 2 pin grouping will be fine, the ground and 5v lines are common for each servo position and the bulbs aren't polarised. Not the pin on it's own in the group of 3 is the PWM pulse and represents/aligns with the yellow wire for the servo.

Does it matter which base is connected to which signal? I couldn't see any identifiers on the bases.

[/quote]

No, the address is controlled by the DIP switch. I think your M3 and M9 so you need to set the switches in the following positions: M3

DIP switch 3

DipSw3.png (1.88 KiB) Viewed 31326 times

(1 and 2 ON) and M9

DIP switch 9

DipSw9.png (1.87 KiB) Viewed 31326 times

(1 and 4 ON)

[Dave Noble]

There seems to be some inconsistency around DIN plug pin numbers. The official numbers seem fairly random, but even so, it would seem sensible to use the same convention.

DIN socket wiring.jpg (44.88 KiB) Viewed 31322 times

If you look very closely at the plugs and sockets, you will see that they are numbered the same. Ignore the colours, they just happen to be what I used, and will be different from Richard's.

[Richard Phillips]

As Dave found DIN plug numbering seems to be a mixed bag. I think there's some rationale between the 3, 5,7 and 9 pin variants and spacing, but since I couldn't immediately put my mouse over the standard I can't give the "official" numbering. Since I was wiring "upside down" in relation to the diagram I did the mental rotation - although the power plugs are on spade connectors and if I've got that wrong could be swapped over.

So both Dave's wiring for PWM and mine for modbus are the same with regards to power. The basic conversion (using the numbers above) and internal wire colours is as follows

Pin 6, 12 volts, red
Pin 7, 0 volts, black
Pin 3, Modbus "A" Orange with White stripe
Pin 1, Modbus "B" Orange solid colour
Pin 4, Manual line 1, Grey ribbon cable/Dark green
Pin 2, Manual line 2, Grey ribbon cable/Blue
Pin 5, Manual line 3, Grey ribbon cable/Purple

I hope I've remembered which was manual line 1 and 3 - but they were consistent when I did it. There's a little pin connector so you can "patch" which lines to send on to the next board which would give some flexibility if operating 3 signals/arms manually at home. Otherwise the current trick is all modbus signals will pull off arm 1 when manual line 1 in brought to ground/0v as they are patched straight through.

In both wiring schemes I think the interconnect cables are wired straight through with no crossover, so the wire colour is largely irrelevant, as long as it's the same each end - although colour conventions certainly help - putting 12 volts on the manual control lines will be... not good. I think sending 5 volts to modbus by accident might be okay as they're opto-isolators and the Arduinos might bear a PWM pulse on the manual lines without releasing the white smoke - but there's no reason to interface unless there's a mis-connection at M1/N2 mechanically slotted signal, which I don't think has been completed in time for Shildon.

[Ben Lyons]

Hello all,

Hopefully you have all recovered from the weekend and are now settled back in to work or grass cutting.

As to signals I guess we can say WE ALMOST DID IT, some of you managed to get your signals finished and some not, for myself building the brackets was almost to much, only 4 days off work got them as far as they were. However with Dave's help fitting looms and Eddie trimming the servo,s
we did get some arms moving, I still have handrails to do, and I set the balance arms in the upper spindle hole and they should have been in the bottom so a job there plus I need to add weights. Eddie did you have any spare?
Jonny, Keith and Richard worked almost all week end getting the main and middle yard fired up, but not sure how they faired (Jonny maybe an update please)

So now it down to tiding up the ends and awaiting--- WHAT,S NEXT!-- maybe given the very narrow site at Noble yard 3 arms on a single post, would you get two starter and a shunt on one post, one above the other (ADVISE PLEASE)

Ben

[Eddyg]

Hi all,

Recovery in process amongst other things, although not too much grass cutting - yet. When we got back on Sunday evening and unloaded the car, I found there was no room for the signals in the workshop if I was actually going to do anything, so they've been shunted into the loft until needed for mods if and when required.

After cleaning the loco firebox and ashpan I set about finding out what was causing it to derail so easily and I found I need to increase the space between the bogie and the main frame because the compensation beams were fouling the main frames. This means I will have to make further modifications to the running gear as weight will be taken off the driving wheels making it slip even more. Might take a few days to get a workable solution.

Ben, I made my balance weights as a one off whilst waiting for the bases to arrive. They are made from a bit of scrap brass plate in two halves soft soldered together. I had intended to cast them in white metal, but found I had no RTV to make the molds and no time to get some. Dave has said he will make some when time permits. I could do them but I need to concentrate on loco building ahead of the Doncaster exhibition, so it won't be possible in the short term, but I will get round to doing your extra ladder in the next week or two.

Whilst we didn't get the signals fully commissioned at Shildon, we were close. Perhaps we could get together at one of the events we all attend, say the GL5 rally at Gilling and finish the job so we have working signals, to go with the block bells and token apparatus, at Shidon 2017.

Eddie

[Ben Lyons]

Hi Eddie

Sounds like a good plan we will need Jonny and Richard as well to make up the team plus all the other signals. Regarding ladders can you do two more long lengths I can then cut them up as required to fit the upper posts.

Ben

[Eddyg]

Ben,

Two ladders it is.

Eddie

[Alan Wood]

hi eddy , seeing Ben asking about ladders i seem to be missing 2 short bottom ladders i think they may have been lost ( perhaps by a certain 5 year old ) so i am slightly embarrassed to ask but i need them to finish my signals off , i will have a final check around tomorrow , if not found then perhaps you can help out ,many thanks Alan.