RMweb Gold Metr0Land Posted May 21, 2015 RMweb Gold Share Posted May 21, 2015 My new layout has 3 electrofrog crossovers and I’m having trouble with (most) Lima mechanisms. On the pic, all my Lima items (Class 37, Deltic, Class 20/101/121) will traverse quite happily AB and CD. However if I want them to traverse say CB they die part way (except the Class 20 which is fine). See below, the dmu ‘dies’ when it gets here: It springs back into life after the power bogie has crossed the insulating joiners here: My old layout only had an electrofrog facing an insulfrog in this kind of crossover so the problem never showed itself. Needless to say I want to keep with all electrofrog. I’m assuming/hoping this is something to do with Lima pickups and wiring (or lack of it). I don’t want to go down the route of frog juicers as I prefer the KISS principle and I now have 3 crossovers laid which I don’t want to rip up. In any case it’s only the Class 101/121 that would be likely to use the crossovers in normal ops. I’ve run lots of new Hornby and Bachmann items across all 3 crossovers and they all work. I’ve tried a sample of old Mainline, Airfix and Joueff items and they are all fine, except one (but not both) old Airfix Class 31 surges a bit as it crosses the insulating joiners. I can’t find any of my items with Tenshodo bogies but have tested an Endo bogie which is similar. It’s only Lima that gives me grief. Is it just a case of adding extra pickups to eg the non-power bogies on all Lima items and joining them to the power bogie? Link to post Share on other sites More sharing options...
Titan Posted May 21, 2015 Share Posted May 21, 2015 I am guessing that you are using two seperate controllers for each circuit, and trying to drive across by operating them in unison? If so, with pickups at diagonally opposite corners what is happening is that when the loco crosses the insulated joiners, it is attempting to take current from the controller on one side of the insulated joints and return it to the controller on the other. As this is not a complete circuit current can't flow and the train stops. The Lima class 20 has all its pickups on one bogie so does not suffer this problem. I think the others that are OK also pick up from both sides of the same bogie. I bet if you tried an old Hornby Ringfield diesel it would behave the same as the Lima. In this case the easy solution is just to remove both insulated joiners on track CB only. This will also have the advantage that you will be able to drive through CB on the one controller. If you use the final destination controller then you can switch the crossovers straight when the train has passed and it can continue on its way without stopping. You will have to make sure that both ends of the crossover are operated simultaneously, as a short may result if one throws before the other. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted May 21, 2015 Author RMweb Gold Share Posted May 21, 2015 Yes I'm using one controller for each track. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted May 21, 2015 Author RMweb Gold Share Posted May 21, 2015 I couldn't find my Hornby Dublo Class 20 so can't test it, but I did find a 1970's Hornby King with tender-drive and that's so far the only other loco that's given me the same problem as Lima. Fortunately it will normally be diagrammed on the Main so not a problem! Link to post Share on other sites More sharing options...
Titan Posted May 21, 2015 Share Posted May 21, 2015 Makes sense, I think the Hornby tender drives picked up on one side on the tender and the other side on the loco, which would create the same effect. Link to post Share on other sites More sharing options...
RMweb Premium Chimer Posted May 21, 2015 RMweb Premium Share Posted May 21, 2015 I would suggest you leave the insulating joiners where they are (taking them out will cause different problems I believe) and use a couple of DPDT centre-off switches so that you can switch both circuits to the same controller (and the other controller off) when you want to drive over the crossovers. I can draw you a diagram if that would help .... All the best. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted May 22, 2015 Author RMweb Gold Share Posted May 22, 2015 I would suggest you leave the insulating joiners where they are (taking them out will cause different problems I believe) and use a couple of DPDT centre-off switches so that you can switch both circuits to the same controller (and the other controller off) when you want to drive over the crossovers. I can draw you a diagram if that would help .... All the best. Yes that would be a great help as I'm hopeless with electrics, and although Titan's reply was helpful it did leave me a bit anxious about poss short circuits. Although I have 3 crossovers at the mo' there will be 2 more in the storage/fiddle areas so if it's poss for something to go wrong with me, it will go wrong, trying to keep an eye on 5 crossovers! Link to post Share on other sites More sharing options...
RMweb Premium Neil Posted May 22, 2015 RMweb Premium Share Posted May 22, 2015 There are several ways to wire the crossover up so that a train can be driven over using one (or the other) controller. The simplest is to place a double pole on/off switch into the layout wiring as shown in the diagram below. You should keep the insulating joiners in place, the extra wiring just being added to what you already have in place. Throwing the switch to 'on' will electrically connect both lines at either side of the crossover and will allow either controller to drive the train across as long as the other controller is set to off. You will have to remember to throw the switch to 'off' when you want to use each circuit independently. Link to post Share on other sites More sharing options...
RMweb Premium Chimer Posted May 22, 2015 RMweb Premium Share Posted May 22, 2015 Alternatively, this is what I had in mind - very basic cab control, which can be extended so more track sections can be switched to one or other controller. Link to post Share on other sites More sharing options...
Grovenor Posted May 22, 2015 Share Posted May 22, 2015 Both Titan and Neil have proposed solutions that set up short circuits when mistakes are made in the operation. What you should do is follow the diagram given by Chimer which follows good DC wiring practice and can be extended as the layout grows. Regards Keith (I've been wiring layouts for over 50 years now) Link to post Share on other sites More sharing options...
ejstubbs Posted May 22, 2015 Share Posted May 22, 2015 Although I have 3 crossovers at the mo' there will be 2 more in the storage/fiddle areas so if it's poss for something to go wrong with me, it will go wrong, trying to keep an eye on 5 crossovers! Sounds to me like you should consider going to full DC cab control if your layout is gettting that sophisticated. It's not particulary complicated, in fact in many ways it simplifies things a lot IMO. Fundamentally, cab control just means having lots of completely separate power feed circuits, which can be grouped together as you wish in order to form a route for a train to run through powered from just one controller. That avoids having to juggle the settings of two controllers to achieve a smooth transition through the crossover, and means that you don't have to try to analyze how a complex network of electrofrog points might switch connectivity and possibly cause short circuits as you select different routes. The basic idea is that you separate the layout in to a number electrically isolated segments*, with the power to each segment being supplied via the centre terminals on a DPDT switch. Power from each controller goes to the two pairs of outer terminals on each DPDT switch, and you can then select which controller powers each electrical segment using that segment's DPDT switch. So with a crossover, you'd set the switches so that the two electrical segments either side of the crossover are powered from the same controller, and Robert becomes your parent's sibling. You should be able to find plenty of additional advice and guidance about DC cab control with a bit of judicious Googling, or in a suitable book. I built a full DC cab control layout when I was about 15: it's really not that hard. * You are basically doing this already anyway, with the insulating joiners between the crossover points which are required for electrofrog points. Post edited to acknowledge that Chimer beat me to it! Link to post Share on other sites More sharing options...
RMweb Premium Neil Posted May 22, 2015 RMweb Premium Share Posted May 22, 2015 Both Titan and Neil have proposed solutions that set up short circuits when mistakes are made in the operation. What you should do is follow the diagram given by Chimer which follows good DC wiring practice and can be extended as the layout grows. Regards Keith (I've been wiring layouts for over 50 years now) Yes it is possible to set up 'short circuits' with my scheme if the linking switch is left 'on' and both controllers are also turned 'on'. However given that MetrOLand has said he's hopeless with electrics I'd still stand by my advice to go simple. It's fairly easy to remember to switch the link off when both controllers are in operation, and of little consequence if one forgets. (I too have a lifetimes worth of layout wiring experience, apprentice trained electrical engineer, etc ...........) Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted May 23, 2015 Author RMweb Gold Share Posted May 23, 2015 Just a little update. I had some single pole switches in the spares box so attempted a quick trial. As you can see it’s very crude but the main thing was to test that I could do this. I’m pleased to say it all worked fine so now I can go back and do the job properly in time. One reason I wanted to rush at it was I’m about to go on hols, so shortly work will have to stop until July. Thanks for all your help guys. I may well attempt DPDT in future but at the moment I want to get on and get the layout running smoothly. One of the reasons I like Peco Streamline Code 100 is that it’s robust and had a ‘plug and play’ ability. So far (famous last words) nothing has derailed anywhere unless I’ve set the points wrongly, or it’s a known problem like the Hornby L1 on facing small radius points (I have a solution for that anyway). One additional question if I may – Can anyone recommend elegant Double Pole Single Throw switches (which is what I think I want)? When I look at suppliers of switches, everything that’s DP seems to be DPDT or On-Off-On or other complications. Link to post Share on other sites More sharing options...
RMweb Premium BR60103 Posted May 24, 2015 RMweb Premium Share Posted May 24, 2015 You can use DPDT for DPST; just ignore the 2 pins on one end. It may be easier to do that that trying to save 50p by getting the exact item. ( it may be overkill, but it's in stock.) Link to post Share on other sites More sharing options...
AndyID Posted May 24, 2015 Share Posted May 24, 2015 No need for additional switches. Just add one wire. I'm assuming both of your controllers have their own built-in transformers (each one is plugged into the mains). If so, all you need to do is add a wire that connects the black wire at C with the black wire at B. When you run through the crossover you will have to make sure that both controllers are set for the same direction otherwise the two controllers will fight each other. That would produce the problem that Grosvenor mentioned. Chimers circuit will prevent that possibility, but if the controllers have their own transformers, it could be implemented with single pole rather than double pole switches. For the technically minded, the reason the Lima engine stops when it is straddling the crossover is because the motor is connected across two completely isolated power supplies. Because they are isolated, no current can flow between them. Adding the wire means that they are now referenced to a common point, and that provides a path for the return current. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted May 24, 2015 Author RMweb Gold Share Posted May 24, 2015 No need for additional switches. Just add one wire. I'm assuming both of your controllers have their own built-in transformers (each one is plugged into the mains). At present I have an old H&M Duette - due for replacement 'in due course' as I only needed one half of it in the past. It only has one mains lead, IIUC it has one transformer but 2 rheostats? Link to post Share on other sites More sharing options...
RMweb Premium Chimer Posted May 24, 2015 RMweb Premium Share Posted May 24, 2015 At present I have an old H&M Duette - due for replacement 'in due course' as I only needed one half of it in the past. It only has one mains lead, IIUC it has one transformer but 2 rheostats? Yes, that's what I've got too - which means if you go for the cab control solution, you can't get away with single pole switches and a common return. Link to post Share on other sites More sharing options...
AndyID Posted May 24, 2015 Share Posted May 24, 2015 At present I have an old H&M Duette - due for replacement 'in due course' as I only needed one half of it in the past. It only has one mains lead, IIUC it has one transformer but 2 rheostats? Ah! My method won't work with a Duette. Best to wire it as Chimer suggests. Link to post Share on other sites More sharing options...
AndyID Posted May 24, 2015 Share Posted May 24, 2015 Ah! My method won't work with a Duette. Best to wire it as Chimer suggests. I'm going to have to take that back! The Duette is suitable for common-return operation, so my one wire solution should solve the problem. According to the H&M ad in August 64 Railway Modeller: "A dual-control Unit, giving two completely independent Power-control Circuits, suitable for Common-return operation" I was thinking about it a bit and it struck me you would not be seeing the problem if the outputs were not independent. I believe the transformer must have independent secondary windings, which electrically comes to the same thing as two independent transformers. Link to post Share on other sites More sharing options...
RMweb Premium Chimer Posted May 24, 2015 RMweb Premium Share Posted May 24, 2015 I'm going to have to take that back! The Duette is suitable for common-return operation, so my one wire solution should solve the problem. According to the H&M ad in August 64 Railway Modeller: "A dual-control Unit, giving two completely independent Power-control Circuits, suitable for Common-return operation" I was thinking about it a bit and it struck me you would not be seeing the problem if the outputs were not independent. I believe the transformer must have independent secondary windings, which electrically comes to the same thing as two independent transformers. I'd better take mine back as well then - you do live and learn on RMWeb! But I won't be rewiring my DPDT control box any time soon ...... Link to post Share on other sites More sharing options...
28XX Posted May 29, 2015 Share Posted May 29, 2015 For those with other combinations of controllers contemplating comoning them up, disconnect from the track, clip a volt meter between the terminals you hope to link and try combinations of forward and reverse settings and see if you get a reading. No reading = good news. Try linking. If one or more is a feedback controller you may still get problems however. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted August 9, 2015 Author RMweb Gold Share Posted August 9, 2015 OK I’m totally flummoxed now. Following the early success (see #13) I replaced the 2 switches with a single switch and everything was fine for about 6 weeks. As of 2 weeks ago I had 2 full circles working, with 6 crossovers. The wiring of the switch allowed me to move pretty much any train from anywhere to anywhere (providing all other locos were in sidings/isolated areas). Today it all seems to be shorting out and I can’t for the life of me see what’s going on. My trackwork has been stable in terms of physical layout for some 3 weeks so it can’t be down to any re-arrangement of track or wiring. I thought perhaps the switch had failed in some way so replaced the switch AND the wiring from the switch to the track. ie until yesterday I had one switch as per #6 and Neil’s guidance but that allowed me to work trains through all crossovers using either controller. The strange thing is, with the switch OFF, trains will run fine on both the up and down lines separately. If I put a voltmeter on the track with no trains, and the knobs fully on, I get ~16v everywhere I should, and no voltage in places I shouldn’t, which is what I’ve been getting all along during track-laying. I’ve changed nothing since everything was fully functional. I can’t see anywhere where there might be anything causing a short, and as I say the voltmeter is giving readings I’d expect. I did try going back to 2 separate switches as per #13 to see if that would give any pointers. All that happened was that throwing the yellow switch shorted the up line and throwing the blue switch shorted the down line. When I say shorted, I’m getting about 0.5v with either switch in the On position whereas up until yesterday it was 16v. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted August 10, 2015 Author RMweb Gold Share Posted August 10, 2015 Sorted! Overnight I was wondering how to start again and proceed in a logical basis. I decided to move the controller to the point diagonally opposite in the room, next to the lift-out section. When I was investigating the wiring underneath, I noticed some bare wires that might have been touching. This is a part of the baseboard I rarely revisit (in terms of going underside). Unfortunately by the time I noticed this, I'd already cut/unsoldered several wires around the layout and the bus-wires so that I could proceed logically outwards in either direct from this point This indeed turned out to be the fault and things are now running ok, but I now have a chance to practice tidying lots of new spaghetti.......... I HATE WIRING!!!! Link to post Share on other sites More sharing options...
RMweb Premium BR60103 Posted August 11, 2015 RMweb Premium Share Posted August 11, 2015 For Christmas last year, I asked for a tool to use on heat shrink tubing. I then bought a box with a selection of different sizes and colours of tube. (It comes in 2 ratings 50% shrinkage and something more) I've been going back and re-insulating what I can. I also ave a can of liquid insulating tape. Link to post Share on other sites More sharing options...
DCB Posted August 11, 2015 Share Posted August 11, 2015 Another example of why one should use separate sections each with it's own isolator switch rather than a bus bar. I just flick switches off one by one until the fault clears, or better still on one by one until it occurs which narrows the problem down considerably. I had a track pin caught in a point blade and shorting it out once which took considerable amount of finding even though I narrowed it down to less than 10% of the layout A layout with a single feed and a single bus bar is my idea of the ultimate nightmare. (Infra red control and battery power is my idea of utopia) Sorted! Overnight I was wondering how to start again and proceed in a logical basis. I decided to move the controller to the point diagonally opposite in the room, next to the lift-out section. When I was investigating the wiring underneath, I noticed some bare wires that might have been touching. This is a part of the baseboard I rarely revisit (in terms of going underside). Unfortunately by the time I noticed this, I'd already cut/unsoldered several wires around the layout and the bus-wires so that I could proceed logically outwards in either direct from this point This indeed turned out to be the fault and things are now running ok, but I now have a chance to practice tidying lots of new spaghetti.......... I HATE WIRING!!!! Link to post Share on other sites More sharing options...
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