HAB

Quick snap of the session from last week. Rare to see the station this empty!

I think that might be because the panel has a Perspex over-lay and all the buttons protrude through holes cut into this (The Laird's laser at work again!) whilst the LED indications are mounted behind the Perspex.

Hi Ric, There are million or two to look through at RS Online. I think these are the actual ones we used:- https://uk.rs-online.com/web/p/push-button-switches/8207527 ... and you will also find various colour/voltage/rating options. Best Wishes, Howard

Even the S&T team found COVID lockdowns a hindrance, but we never ground completely to a halt, and the latest development is the installation of an "eNtry eXit"-style panel at Leeds West, controlling the hidden sidings representing Leeds City South and also Canal Junction between the Routes from Farnley Junction and Leeds City Junction boxes. We did consider using digital technology for this (given it was always going to be complex) but in the end opted for our existing and well-proven Relay Logic approach. From the operators veiwpoint it looks simple enough:- .. but its innards (seen here part complete) tell a different tale! We used our own design of PCB for the each of the modularised relay controllers for each point/route - 23 of them in total - as well as for the diode array boards which contain the logic for the route selection, interlocking and display controls. All that involved no small learning curve in designing PCBs as well as having them made to order on the other side of the planet (and delivered within a week!) There is an additional panel of 30-odd relays which provides the interlocking and block controls for the Track-Circuit-Block Section to Leeds City Junction. All that amounts to almost 190 relays and a couple of hundred Diodes. Perhaps for the next one, the decision regarding a Digital Solution might need to be re-examined ...! Hope that is of interest, Howard (edited for gramatical and arithmetic errors!)

Years ago "MEK" was Methyl Ethyl Ketone. This is the same chemical as Butanone and as dasatcopthorne correctly says, this is the only thing which will do the job. Plastic Weld is dichloromethane. The stuff sold as MEK these days is not Methyl Ethyl Ketone - I believe it too might be dichloromethane. Neither of these will work - though they may give the impression that they do - temporarily. How do I know? I built much of my plastic / ply track using Plastic Weld and all worked well, until in the middle of an exhibition there was a very embarassing plain track derailment... One of the team had to be dispatched to buy a bottle of butanone sharpish ... Best Wisjes, Howard

I discovered an important error in the Schematic Diagram ... Best Wishes, Howard

One thing is for sure - it will never be that clean again! Great modelling John - thanks for the continuing updates. Cheers, Howard

... sorry - meant to include this https://www.scalefour.org/forum/viewtopic.php?f=4&t=6692 which is a link to the scalefour forum where one chap shares his experience of building a locked frame. It includes some input from myself, but might still be worth reading for all that! Best Wishes, Howard

Good luck with the MSE kit! You need to be aware that it has a fundamental flaw - the radius of the quadrants is much larger that the radius struck by the catches so it can never work properly as supplied. Just ask anyone who has built onebut be prepared for a lot of vituperative invective in response ... I discovered that fault about 30 years ago and the design has never been changed. I am tempted to go into a rage ... As I am sure you will know from your researches that an alternative is the scalefour society's frame which is much better, the MkII version also has a kit for the locking. But then I would say it is better as I designed it(!) and I have built almost 200 levers worth of frames with the locking kits. The MkII version is only available from exhibitions or to members though given the current crisis, relaxations might be possible on that. for example this 50-lever frame:- You can see plenty of examples of conditional locks. If you look elsewhere in that thread, you will also find a 70-lever frame and you will also find how we implemented the electrical locking:- (edited to correct the link) Hope that helps Good luck, Howard

... which is where the design came from - I have a view that when designing anything for a model railway, the best place to start is with the real thing! In fact, the first time I rode on a paternoster was not far from the location of The Laird's layout! The problem with all devices like this is that they have to be VERY well engineered to work at all - let alone reliably - the tolerances on individual components have to be extremely tight as errors are cumulative - as is wear. And that problem gets worse as storage space increases. Bear in mind that the storage roads have to be about 3.3m long to accomodate the longest trains - so no easy answers here!

Funny you should say that ... The non-engineers amongst us remain unconvinced of reliability. Come to think of it, the engineers are not so sure either ... Best Wishes, Howard

If you lose the injector or or suffer any other low-water situation from whatever cause - and there are many - and drop a plug, you need the rake and the clinker shovel, you need them fast and you don't bvgg@er about making use of them! If you hang about scratching your head and fail to get the fire out in time, the dropped crown which is likely to result will kill you, your driver and possibly many others. THAT is the reason such things are always carried!! Trick question - how many "Ducheses" suffered a dropped firebox crown? Answer - there were three incidents of a dropped corwns on Duchesses. BUT two of them were the same loco (Princess Alexandra), and occured within a mile of each other 8 years apart. These three incidents were one third of the 9 low-water explosions to UK railway locos in the 20th century. And in case anyone thinks it "hardly ever" happened or is a thing of the past, the last fatal steam loco accident in Europe was a dropped crown in November 1977 at Bitterfeld in East Germany. The loco was a replacement after the crew droppped the plug on their previous mount (yes really!) Nine dead and 50 injured. Perhaps some idiot had left the clinker shovel behind Great modelling - very well done and many thanks for the thread.

Interesting development! Could you put a vernier on the gauge and tell us what it measures please? I would be interested to know the shrinkage allowance needed. Based on this piece, how long do you reckon it would take to print (say) a metre's worth of chairs and sleepers? Good luck! Best Wishes, Howard

"A pictorial Record of Southern Signals" by the late George Pryer, (OPC) has scale drawings of Drayton on page 116 and Bedhampton (strictly a "Brighton" design) on page 115. As far as I am aware, the kit you refer to was based on the former. The drawings were done by my good friend Graham Bowring from on-site measurements. Although long out of print, copies are often available on-line. Hope that helps, Howard.

Absolutely nothing to do with DCC, nor the train detection, nor anything else to do with the layout itself - it is purely the control logic for the Electric Locks on the lever frame. There have been earlier posts explaining how the DCC is set-up and wired. the 25-way connectors illustrated are the means of interfacing the various elements together using 25-way cables (lots of them!). this enables them to be built tested and mantained on the bench. Cheers.