stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Oct 18, 2018 9:37:44 GMT
Don,
This is an interesting little project, and something different to our normal build threads of locomotives. (Not that there is anything wrong with that).
It's been fascinating watching your progress, and the signal is looking really good. I hope you can post a video when it is finished, showing the 'bounce'.
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Post by GWR 101 on Oct 18, 2018 14:35:11 GMT
Don, that's some fine work on a wonderful project, I am trying to convince the club I belong to that our 7 1/4" ground level track would benefit from a semaphore signal at the exit from the station possibly alongside a water tower.
On a different theme is your Miller a Nareok, no great detective work as I have one that looks identical. Purchased a couple of years ago off a poster on here, which I have found to be a sturdy and useful piece of kit. Regards Paul
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Oct 24, 2018 21:06:11 GMT
Hi again, firstly apologies to juliet2 for the late reply....yes it is a Naerok 350 miller, bought at one of Midlands Exhibitions years ago when the venue was Birmingham University. After all that time it was only last Sunday that I realised Naerok was “Korean” backwards! Anyway on with the signal. When originally thinking about building this, I didn’t plan to include the Weight Bar arrangement near the base of the main post but as its progressed, I have changed my mind. On the full size example I am copying, there are two different sized cast brackets that carry the Weight Bars....small bracket and one bar for the miniature arm, large bracket and three bars for the Stop & Distant arms. For anyone interested, when a Distant signal is mounted below a Stop signal, the Distant is usually associated with the next Signalbox along the line and is controlled by that signalbox, not the one that controls the Stop signal. There has to be a system of mechanical interlocking provided to ensure that the Distant can only be cleared providing that the Stop signal above it is also cleared and that if the Stop signal returns to Danger, the Distant returns to “Caution” automatically. This interlocking is handled by the Weight Bars and is known as “Slotting”. The arrangement of Weight Bars also keep the operating wires from the signalboxes in tension and help make sure the arms return to Danger/Caution if one of these wires break. Loads of info on-line if anyone wants to know more! This diagram shows the “Slotting” of a typical installation, although unfortunately some of the detail is not shown. I’m not modelling the electrical contact boxes that “prove” operation of the Weight Bars:- I chose to machine/fabricate the brackets and here a chunk of brass is being milled to make one part of the larger bracket, the LH end went a bit wrong so I started again:- I didn’t take a photo of the second part of this bracket, but it was silver soldered to the first part and after a bit of fettling, here is the finished item:- Drilling 0.9mm holes with a pcb drill for the split pins that retain the shafts:- The smaller bracket is a single piece as there is no closed space like on the larger one:- The two brackets fit on either side of the post and share the same two long bolts and sit on curved saddles:- The Weight Bars are 3/16 x 1/16 steel with little brass bearings silver soldered each side. A blackened 6ba screw and nut locate them for soldering:- And finally for tonight, a photo of all the the bits I’ve made that I wasn’t going to fit! I’m waiting for the cast weights to be delivered from Steam Workshop and when I’ve got them and it’s all assembled, I’ll take more photos.... Cheers Don
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Post by Roger on Oct 24, 2018 21:22:03 GMT
Stunning work Don, that looks superb.
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Post by Deleted on Oct 24, 2018 21:26:23 GMT
I agree with Roger...great work Don
Pete
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Oct 24, 2018 21:46:30 GMT
Hi Roger & Pete, thanks for that....all through making the brackets I kept thinking how you would do them Roger with your cnc skills. I drew out the tool paths I needed and did it manually by dials and numbers....going wrong a time or two but got there in the end! The weights are 3 different sizes and shapes and are available as Doug Hewson castings, so they should come soon.
Cheers Don
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Post by Rob on Oct 25, 2018 20:36:34 GMT
Don, this is fantastic. I love the attention to detail.
How did you draw your tool paths? I'm considering trying a similar Manual NC approach myself but haven't got as far as generating actual paths.
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Oct 26, 2018 16:55:01 GMT
Hi Rob, thanks for the interest....all I meant regarding tool paths was that with the brackets, after sketching the required shape etc. I zeroed the x and y axes over the lowermost hole, chose a cutter with an appropriate diameter to produce the curved portions I wanted, then simply “stepped over” to machine the outside shape of the bracket. Then indexed the vice round to machine the angled parts, that limit the travel of the Weight Bars (or “Balance Levers” as I’ve seen them called on some drawings).
Some of the machining was done by eye, noting the readings of one side so I could repeat the same shape on the other side....nothing clever at all!
In the past on occasions, I’ve needed to mill say a radius on something that couldn’t be done on a rotary table (expansion links could be an example) and used Excel to produce a table of all the offsets required for adjustment of one axis, for every increment of the other axis. The radius is then produced as a large number of small “steps”. It’s using mathematics in a similar way to how a proper cnc machine must do it.
Cheers Don
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Oct 26, 2018 20:30:13 GMT
Lamps....D Hewson castings are available for “square lamps” with tops! I don’t know what the proper name is for this type of signal lamp but I think they are correct for this LMS type signal. I know that they have been available for many years and were obviously produced with the intention of using an MES bulb and holder. The castings were open at the bottom with this in mind but I intended using LEDs, so firstly I filled the holes in the three lamp bodies with square pieces of 1/8 brass. This would also take some tapped holes so the lamps could easily be mounted on their brackets, which were posted about earlier. I tried some 5mm “warm white” LEDs which are ok, but don’t really look like a paraffin lamp! Anyway they are better than white ones so I devised a method of aralditing them inside the lamp, with the cathode tail fastened to the lamp body and the anode insulated for later connection to its feed wire/resistor etc. I forgot about photos until after this by which time they also had a coat of grey primer:- One of the “tops” hadn’t been cast properly but the supplier replaced it no problem. DH had intended these tops or lids to hinge open but I found it would have needed a lot more work for this to happen and didn’t bother....mine are tack glued on in such a way I could prise them off again if that’s ever needed:- I obtained some 10mm round clear perspex to have a go at making the lamp lenses. I had no idea if it would work or not but just picked an arbitrary radius for the first lens and made a complete pig’s ear of it. Undaunted, tried again and this time got a passable looking lens and although it didn’t polish very well, it certainly showed promise! Encouraged by this result, I reground the form tool with a smaller radius to get more of a “bulls eye” type of lens and made three more, managing to get a better finish using up to 2000 grade wet & dry:- ”Bugger” they didn’t magnify at all well and were worse than my earlier attempt. Further regrinding, another one turned from my dwindling length of perspex, polished up and it was the best yet! Made two more and settled for that.....would have had to order more material for any further attempts. Painted the lamps black then pressed the lenses fully home into the cast-in recess and here is the result:- Finally here is a photo of the current signal, that the new one is to replace:- Next update will be about the actual semaphore arms and spectacles.... Cheers Don
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barlowworks
Statesman
Now finished my other projects, Britannia here I come
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Post by barlowworks on Oct 26, 2018 22:42:30 GMT
Hi Don
Just a thought, our local pound land, in the toy section, does a stained glass window kit. It's like a small plastic window with an embossed pattern that you paint with a veriety of tinted varnishes. I'm sure one is yellow which you could use on your LED to give a more yellow look. You could try different layers to get the right tint.
Mike
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Post by Roger on Oct 27, 2018 7:49:22 GMT
Hi Don Just a thought, our local pound land, in the toy section, does a stained glass window kit. It's like a small plastic window with an embossed pattern that you paint with a veriety of tinted varnishes. I'm sure one is yellow which you could use on your LED to give a more yellow look. You could try different layers to get the right tint. Mike Alternatively, you can get RGB LEDs so you can create any colour you like if you want to get involved in a little electronics project. I did this to create a Purple LED years ago.
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Oct 27, 2018 19:30:27 GMT
Hi Mike & Roger, thanks for the suggestions. I already had the 5mm warm white LEDs and the lamps have actually been finished for a few weeks now (the updates in this thread are not always in “real time”). Before fixing the lids etc. I tried them behind the coloured film I am using in the spectacle plates and they look ok to me. The signal is unlikely to ever be used in the dark, unless there’s a solar eclipse one running day, so the illuminations are not that important!
As may be known, when lit by paraffin lamps, the “Green” spectacle glass is actually “Blue”. Its obviously the combination of the Yellowish light and the Blue glass that gives the Green light. The supplier of my coloured film (intended for model railway signals) acknowledges that some people would use white lights and supplies Green as well as Blue film in the pack.
There are “Gaslight” LEDs available from one supplier I know of (learned courtesy of some O & OO gauge signal building contributors to the rmweb forum) but only in 3mm dia. and I never got round to ordering any.
Roger it would be interesting to experiment with the RGB type, as one day I intend revamping my set of scale loco lamps for the 9F. They have wires coming out of them that used to connect to a 5v battery carried in the cab but it would be good to devise some “wireless” arrangement....maybe like electric toothbrushes that charge without any actual electrical contact to the charging stand 🤪
Hopefully more on the signal soon
Cheers Don
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Post by Roger on Oct 27, 2018 22:13:17 GMT
On the subject of coloured LEDs, I recently became acquainted with the rather ingenious PL9823 'intelligent LED' for a project I was involved in. (Just google PL9823 for the datasheet) This is a four wire LED where there's a + and - for the supply and a serial data in and serial data out pin. The idea is that you can cascade as many as you like in a daisy chain and control the brightness and colour of all of them.
The project I was involved in used over a hundred of them with fibre optics from each one to a spot on a naval chart. The idea was to have an antique naval chart for a clubhouse wall or Superyacht where the chart not only had all of the lighthouses and navigation lights showing, but also flashing the correct colours and sequences!
Frivolous, but interesting... oh, and it helped pay my bills.
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Post by David on Oct 29, 2018 7:44:53 GMT
Beautiful work, and I love the signal box too!
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Oct 29, 2018 20:29:43 GMT
Thanks David, the signalbox is named in association with “Britain Colliery” that once existed on the site of the railway.
Cheers Don
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Nov 1, 2018 20:50:57 GMT
Hi, the weights arrived so here are a few more photos to show them painted and mounted to their levers. There is plenty of photographic evidence that these balance levers, their brackets and the section of post they were mounted on, were painted in numerous different ways, so I have just followed a particular photo in my book on LMS Signals. The weights are of three different sizes, cast in white metal (although available in brass as well) and they came with the rectangular section holes already formed, but needed a small amount of fettling to take the 3/16” x 1/16” levers, plus a small piece of the same material to form the “nut” for the 10ba clamping screw. Here they’re fitted to their brackets and hopefully you can see how the slotting of the levers in the larger bracket works....? The smaller bracket is for the subsidiary, or miniature arm Next time it should be about semaphore arms and spectacles! Cheers Don
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JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,909
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Post by JonL on Nov 1, 2018 20:59:55 GMT
Fantastic work! Well done Don, looking grand.
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stevep
Elder Statesman
Posts: 1,070
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Post by stevep on Nov 2, 2018 9:30:48 GMT
Looking superb Don.
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Nov 2, 2018 23:08:04 GMT
Hi and thanks for the comments.
Hopefully it won’t be long now before I can assemble it all but I need to work on the base, so it will stand up properly without wanting to fall over! The last remaining material arrived today for the final part to be made....the ladder! Not looking forward to that bit but it’s got to be done.
Cheers Don
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 960
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Post by don9f on Nov 6, 2018 20:50:56 GMT
Ok, onto the arms and spectacle plates....there was a photo back on page 1 of this thread that showed one of the bare spectacle plates when I was making the spindles and bearings for them etc. These are Doug Hewson castings and I'm not sure exactly which type they are, as there are various designs in use full size and the ones for the main arms don't seem to have quite the correct "crank" for operating them, but they may have been made this way by Doug for some specific reason? Anyway apart from that minor detail, they really look the part for my LMS type signal and I certainly didn't want to make my own! The bolt holes for the actual arm were already cast in and when drilling/cleaning them out I realised that there was another small problem in that two of these holes were a bit too close to the opening for the red/yellow spectacle glass. This only applied to the larger arms but rather than mess about filling them in and "moving" them, you'll see what I did in the following photos....not quite prototypical but it doesn't really matter. Because I had some phos. bronze sheet material of a suitable thickness to hand, I used it to make the arms. I machined two bits of steel bar to the appropriate widths so I could use them as formers to fold the different size arms. The "returns" were folded a bit oversize, then trimmed back afterwards, also tapering them, as per full size. Obviously the Distant arm has a fishtailed end.... The arms were a good fit over the castings and the holes were spotted through for drilling. You can see the areas I filed a bit to clear the bezel around the glass opening, as otherwise the bolt holes nearest these bezels would have just about broken through! I didn't realise until afterwards that the miniature arm should only have four bolts, not five....since rectified! You may know that semaphore signals like these, display a white light to the rear, when the arms are correctly in the "On".....ie Danger or Caution position. Providing the rear of such signals are visible from the signalbox, in darkness the white light indicates to the signalman that the signal has returned to Danger or Caution properly when it is meant to do so and of course confirms that the lamp is lit. Signals out of sight or in advance of the box have some sort of detection arrangement with indications provided to the signalman. Contact boxes are used for this purpose where required....but I'm not fitting any on my signal! Paraffin lamps may still be used on some preserved lines(?), in which case a Pyrometer detects whether the lamp is lit or not. I would assume that all semaphores still in use on Network Rail are electrically lit with lamp proving circuits and so on. When the arm moves away from its Danger or Caution position, a "Backlight Blinder" obscures this white light. It is secured to the other end of the arm spindle and simply covers up the aperture in the back of the signal lamp. I chose to make my own Backlight Blinders, scaled from drawings, so they may not be totally accurate in size or profile but look ok to me. I sandwiched three pieces of material together and used a rotary table to mill the curved sections and added the "crank arms" on afterwards....photos often show the "Contact Box" referred to earlier connected to this crank arm. Although the lamp castings did have apertures for the "Back Light", I'm afraid they're now blocked up with araldite as they form part of the fixing arrangement of the LEDs! Next time it will be painting the arms etc. and fixing the spectacle glasses.... Cheers Don
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