sbduck Posted June 9, 2015 Share Posted June 9, 2015 Here's board 3 again. This board is the most complex in terms of track and wiring. I've just laid the two DCC traction buses in (the two lots of heavy red and black wires at the bottom and towards the top of the board), all the traction droppers are in place (the 12 bundles of wire - bundled together to keep them out of the way whilst I progress the wiring) and now I need to group wiring together to create the two DCC districts (split UP and DOWN) and the various subdistricts (protected by lightbulb overload devices All being well, I'll post an update in a few days to show progress with wiring - exciting eh? Link to post Share on other sites More sharing options...
RMweb Gold Budgie Posted June 10, 2015 RMweb Gold Share Posted June 10, 2015 (edited) (protected by lightbulb overload devices Why are you using light bulbs to protect your circuits from overloads/short circuits? I ask, because they do not remove the overload/short circuit; they just limit the current in the circuit. However, that current could well be the full amount that your DCC system puts out, i.e. 5 amps, which can do a lot of harm to your layout or the stock on it. You might like to look at http://www.mrol.com.au/Articles/DCC/LightBulbs.aspx and http://www.wiringfordcc.com/track.htm#5-4%20Bulb Edited June 10, 2015 by Budgie Link to post Share on other sites More sharing options...
Nergle Posted June 17, 2015 Share Posted June 17, 2015 Why are you using light bulbs to protect your circuits from overloads/short circuits? I ask, because they do not remove the overload/short circuit; they just limit the current in the circuit. However, that current could well be the full amount that your DCC system puts out, i.e. 5 amps, which can do a lot of harm to your layout or the stock on it. You might like to look at http://www.mrol.com.au/Articles/DCC/LightBulbs.aspx and http://www.wiringfordcc.com/track.htm#5-4%20Bulb Hi Budgie Your two attached articles answer why we're using lightbulb overload devices. They were recommended by a friend who is installing them on his large DCC layout (he uses ZTC/Taunton Controls kit) Remember that this is an exhibition layout; that means that I want minimum disruption to operation, hence the up/down DCC supply split. The theory is that we could experience a minor and brief short which, with the lightbulbs, will result in the bulb glowing/lighting momentarily (electrically absorbing the short) but preventing the Command Station/Booster from tripping (stopping everything in that direction). Obviously if we get a dead short, then the bulb will light and the DCC kit will overload. The bulbs are intended to create smoother and more reliable operation. If you look at your attached articles, one of them recommends Digitrax PM42 units (we did consider these) - these are in effect the same as the bulb, but in the form of a breaker - i.e on or off and you are simply subdividing your layout as you would your house. What the bulb does is to smooth current peaks because of the time taken to heat the filament. All electrical systems have a degree of tolerance; because our electrical load (the train) is moving, shorts can occur very briefly and sometimes having an overload system that is too sensitive (too quick) to shut down is a blessed nuisance as the wiring/motor etc can cope with the small spike in current. Where a short is more serious, both the bulb and the system overload, saving the chip and other delicate electronickary Just in case you were wondering, the bulb holders are car light bulb holders with 21W low voltage bulbs - if you want to know a more technical description and source, I'll post that if it'd be helpful? So that's the theory; the proof will be in the pudding! And if you have checked messrs Bachmann and Hornby back-to-back tolerances recently, you'll know that they are erratic; that's where I expect to get our problems/shorts from! All the best Link to post Share on other sites More sharing options...
sbduck Posted June 18, 2015 Share Posted June 18, 2015 Here's the Albany again! This time it's self-supporting - i.e glued together (super glue) and also has all sides, ends and some floors - note also the pediment which the pub no longer has in real life. Twickenham Junction is set in 1961 (or 1955-1965) and at that time the pub had the pediment on it proudly bearing the brewery name... Terry's trialing laser etched acrylic for the window frames and the windows - more on that for a future edition - and the next stage is to create some window frames (as in decorative external plasterwork) in MDF. Watch this space! 1 Link to post Share on other sites More sharing options...
sbduck Posted June 23, 2015 Share Posted June 23, 2015 Hurrah! Board 3 traction wiring conquered - complete with a celebratory cup of tea :-) Sorry to labour the point: this is DCC and this is the base level of wiring. Point motor power, point crossing-vee feeds, MERG data, and Digitrax data wiring still has to go on all four baseboards. Less than for sectional-control analogue wiring, but only just! I chose to sleeve all wiring to make labelling and routeing clearer to understand. A bit overkill, but does make it easier to see what's going on. Point motor wiring will have blue sleeving to differentiate. I won't bore you with update photos of the next wiring phase. I'll post a pic when board 3 is finished - won't be for a while! The heavy black sleeving covers the UP and DOWN traction buses; yellow sleeving covers the droppers going to the rails (one dropper to each separate piece of track), to each point motor for switching the crossing vee and also the point motor looms are sleeved in yellow. As before there are lightbulb overload devices protecting sub-buses and also each point motor feed (highest likelihood of shorts is at a turnout of course...) Any questions - please do come back to me! Link to post Share on other sites More sharing options...
RMweb Gold Budgie Posted June 23, 2015 RMweb Gold Share Posted June 23, 2015 And if you have checked messrs Bachmann and Hornby back-to-back tolerances recently, you'll know that they are erratic; that's where I expect to get our problems/shorts from! Aha! I think I now see your problem. The back-to-back measurement of a wheelset should have nothing to do with whether you get short circuits or not, because no wheel should be touching rails of both polarities at the same time; and if coupled wheels are electrically connected then the whole side of coupled wheels should be in contact with just a single polarity at the rails. Link to post Share on other sites More sharing options...
sbduck Posted August 30, 2015 Share Posted August 30, 2015 A behind-the-scenes breakthrough! Okay, this is the Common Fiddle Yard - so called as it's designed to be able to accept any project on the front. It'll be Twickenham Junction to begin with, and here is a standard class 3 tank trundling along road 7 (as proved by the green LED on the gantry) - this is on DCC in a member's garage with all route setting working. He deserves that big grin - he's been beavering away this summer as these photos prove... Lastly, to show the extent of the work - happy bunnies watching 3 archetypal Southern locomotives trundling around the crossover board - spot the route selection gantry - control is temporary to prove that it all works. Very smooth it was too 2 Link to post Share on other sites More sharing options...
sbduck Posted September 2, 2015 Share Posted September 2, 2015 Clive's been beavering away with the original water tank at Twickenham - here it is largely complete with a copy for his own layout. The structure likely formed the front entrance to the two-road loco shed at Twickenham (itself second hand from Richmond in 1850). Kingston had a similar if larger arrangement. When Twickenham's shed was demolished in the 1890s, the tank was left to serve the three water cranes around the station site. It still needs a roof and painting, but is largely there... Link to post Share on other sites More sharing options...
jonhall Posted October 31, 2015 Share Posted October 31, 2015 (edited) We have finally had some more laser time at www.richmondmakerlabs.uk and here is the first result ~2mm acrylic cut windows, the frame is laser engraved but leaving the protective coating supplied by the acrylic manufacturer in place, l then peeled the protection off the frames, leaving the windows masked, then sprayed with Halfords white primer, and once dry peeled off that coating as well - gives us rather flush glazed windows. Jon Edited November 20, 2015 by jonhall 4 Link to post Share on other sites More sharing options...
sbduck Posted November 13, 2015 Share Posted November 13, 2015 A test shot of the Albany’s windows. These are laser cut/etched acrylic with a self-adhesive protective coating. The whole window is painted in white primer and then etched so that what is peeled off is the clear ‘glass’ section, leaving behind the window bars and frames We’ve had major problems with the laser cutting machine (It’s been replaced!), hence the slow progress. Hopefully we can move ahead on this now… In the meantime, I’m still doing electrics and some track repairs on the TJ boards… Link to post Share on other sites More sharing options...
sbduck Posted November 19, 2015 Share Posted November 19, 2015 (edited) You may well ask! At the club’s recent Saturday workday, I spent the day repairing track – 5 defects needed sorting. If you look at the inner two rails in this picture, they’re sporting brown plastic rail joiners near the crossing vee of the point and metal (soldered) rail joiners 7 sleepers to the right…somehow some previous track-laying had left a 6mm gap by the crossing vee on both rails; they needed an insulated gap, but not that insulated! So I spliced in new (longer) sections of rail fed through the sleeper chairs and mechanically linked with the insulated rail joiners and soldered the metal joiner to the existing rail. Not pretty, but it works, has solved the problem and by the time it’s painted, no one will ever know! Edited November 19, 2015 by sbduck Link to post Share on other sites More sharing options...
RAY NORWOOD Posted December 20, 2015 Share Posted December 20, 2015 I hope that they have remembered to incorporate the disused tram tracks in the roadway over the over bridge at the end of the station. They outlasted the trolleybuses so were definitely still there in 1961 even though the old station had, of course, gone in reality. I remember the tram lines over the bridge in the early 60's. Link to post Share on other sites More sharing options...
jonhall Posted January 6, 2016 Share Posted January 6, 2016 Progress with the Albany over the last few weeks has involved cutting a lot of the window surrounds from cereal packet using the laser, and adding some raised mouldings from Evergreen strip. Jon 2 Link to post Share on other sites More sharing options...
RAY NORWOOD Posted January 6, 2016 Share Posted January 6, 2016 That's going to look fantastic John. Link to post Share on other sites More sharing options...
jonhall Posted January 9, 2016 Share Posted January 9, 2016 Its going to be right at the back of a 4ft wide board, so the public aren't going to be up close and personal to it - so that allows us to take a few liberties with it.. I say us, but actually I'm not actually a Twickenham member, just helping out with the CAD and laser! jon 2 Link to post Share on other sites More sharing options...
sbduck Posted January 29, 2016 Share Posted January 29, 2016 TJ is going to need a fair few EMUs… In the bad old days before messrs Hornby and Bachmann got their act together, sourcing EMUs for TJ was going to be tricky. I developed a tic about this and figured that if I grafted a Tri-ang EMU cab front and roof onto a Bachmann EPB, you’d get something half respectable looking and which ran like liquid silk – here’s the end product about three years later. It’s 2-NOB 1862. I’ve done two of these to run as a 4-car train. (If you are wondering, as the Southern had a toilet obsession, NOB stands for No-Bog!) 5 Link to post Share on other sites More sharing options...
Nergle Posted January 29, 2016 Share Posted January 29, 2016 Its going to be right at the back of a 4ft wide board, so the public aren't going to be up close and personal to it - so that allows us to take a few liberties with it.. I say us, but actually I'm not actually a Twickenham member, just helping out with the CAD and laser! jon You may not be an actual member of TDMRC, but honorary by association and hard graft I feel Jon! Thanks for everything, as the Albany and a couple of future builds have moved ahead far faster with your kind assistance 1 Link to post Share on other sites More sharing options...
sbduck Posted January 31, 2016 Share Posted January 31, 2016 The January workday in a lovely warm Kerswell Hall – here we’re testing the strength of a Bulleid Q1 on the gradient that Down Kingston trains will face climbing towards the flyover on TJ. Climbing at 1:33, the Q1 coped with 12 on – about the limit for the pick-up goods – but wouldn’t have managed another wagon. She was slipping a little, but was able to restart on the grade… 1 Link to post Share on other sites More sharing options...
sbduck Posted February 3, 2016 Share Posted February 3, 2016 (edited) Perhaps not the most exciting pic, but this was momentous! This 2-BIL motor coach was testing the three main running lines on TJ under power (DC only) for the full length of the layout – all passed with flying colours to my immense relief. Twickenham runs… We’re planning an Open Day this summer (details to follow). Come and see how we’re getting on! Edited February 3, 2016 by sbduck 4 Link to post Share on other sites More sharing options...
jonhall Posted February 25, 2016 Share Posted February 25, 2016 The Albany has had a quick coat of primer to unify everything, and we started trial fitting windows tonight Jon 2 Link to post Share on other sites More sharing options...
Kelly Posted February 27, 2016 Share Posted February 27, 2016 Great work on the pub looking forward to seeing future updates. 1 Link to post Share on other sites More sharing options...
RAY NORWOOD Posted February 28, 2016 Share Posted February 28, 2016 looking fantastic Jon Link to post Share on other sites More sharing options...
sbduck Posted April 12, 2016 Share Posted April 12, 2016 So here’s board three again as promised at the end of last summer – all the wiring is in place on this complex board – the three grey plastic baskets help to protect the MERG panels sitting underneath them – all I have left to do is to hook up the point motors to the MERG panels and test the whole thing. Joy! Link to post Share on other sites More sharing options...
sbduck Posted April 12, 2016 Share Posted April 12, 2016 (edited) Here’s a similar underboard view under one end of Twickenham’s fiddleyard – the wiring is easier as everything is in straightlines and if you are wondering, the point motors (PECO) are all surface mounted… Edited April 17, 2016 by sbduck 1 Link to post Share on other sites More sharing options...
sbduck Posted April 15, 2016 Share Posted April 15, 2016 What is this picture of you ask? It’s a transition board – it is a linking board between the fiddleyard and Twickenham. This is the St Margaret’s /London end, hence the three tracks. It is much simpler than the Country end which will hopefully appear in a month or two – all in good time for our Open Day on July 23rd – come and see us! Link to post Share on other sites More sharing options...
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