Pimlico Tram Posted October 29, 2011 Share Posted October 29, 2011 Hi, I'm new to the forum and am getting to grip with the hobby after a 20 year break. A lot has moved on......not least the fact that you can post silly questions on forums like this. I'm building a layout in Peco Code 55 Finescale in N gauge using electrofrog points switched using Cobalts. I am a bit stuck with the DCC mods to points that many recommend. In short, my question is this: are they really necessary or am I definitely going to end up with shorts from the flanges? I can see why they're achievable in OO gauge, but in N it's getting a bit closer to neurosurgery to make sure the cut to the switch rails is accurate. I've got a couple of early efforts that the Dremel's made a mess of (yeah, OK, poor workman, etc, etc). And that's before I even talk about the bonds to running rails. Is anyone out there running a layout successfully with unmodified points such a this? Is there a better method of making the cut than a Dremel? Will I regret it for ever if I don't make the modifications? How much more of a boost to Peco's profits can I deliver by continuing to butcher points? Many thanks all in advance, Giles Link to post Share on other sites More sharing options...
Edwin_m Posted October 29, 2011 Share Posted October 29, 2011 We've discussed this several times before. My own experience is that it's a good idea to feed the frog polarity from a switch driven from the motor, as rail-to-rail contact can be unreliable. However, as long as the frog polarity only ever changes while neither switch blade is touching its stock rail, there is no need to try to isolate the switch rails from the frog area. The gaps Peco leave between the switch and stock rails are so huge that it's hard to imagine anything shorting between them and still reliably making it through the check rails. This is based on using recent Farish and Dapol stock with relatively fine wheels - the only time I ever get a short on a point is when something derails or in one case when a back-to-back had got too narrow. Link to post Share on other sites More sharing options...
Pimlico Tram Posted October 29, 2011 Author Share Posted October 29, 2011 Thanks, Edwin, that's very helpful indeed. I did search for the topic but couldn't find anything. Somehow I thought I might not be the first to ask.... With your Mikado reference, I'd have thought you'd be running Tomix! Giles Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted October 29, 2011 RMweb Gold Share Posted October 29, 2011 I agree with Edwin: I've been building and operating a large-ish American layout with Peco Code 55 track throughout (other than a short stretch of Atlas) and I've never experienced a short due to contact between the switch rails and wheel flanges. I run steam and diesel from a variety of manufacturers. Unless British N stock is cruder in wheel standards, which I doubt, you should be fine. I do switch the frog polarity, but that's a separate issue, and I'd do it for DC as well, since (like Edwin) I find the switchblade contact to be a little unreliable. Link to post Share on other sites More sharing options...
brossard Posted October 30, 2011 Share Posted October 30, 2011 It's really a question of best practice which has also been discussed at length here. Wiring advice here: http://www.brian-lambert.co.uk/DCC.htm Go to "short circuits on Electrofrog points". You may get away with it but why take the risk. John Link to post Share on other sites More sharing options...
dick rowland Posted October 30, 2011 Share Posted October 30, 2011 A Dremel is too 'vicious' for this job. It will create far too big a rail gap and also, unless you have an extremely steady hand, damage the surrounding parts of the point. Use an old-fashioned 'jewellers saw' hand tool. Basically a very fine-toothed type of fret-saw. You will probably use more than one blade, but they are not expensive. Link to post Share on other sites More sharing options...
Pimlico Tram Posted October 30, 2011 Author Share Posted October 30, 2011 Thank you all. This is all really valuable advice, particularly on alternative tools to using the Dremel (I have a pretty steady hand but it's hard to avoid nicking the outside rails). Once again, many thanks all and I'll let you know how I get on. Giles Link to post Share on other sites More sharing options...
RMweb Premium Steven B Posted October 31, 2011 RMweb Premium Share Posted October 31, 2011 I've used several N Gauge layouts that run DCC with a mix of code 80 and code 55 points together with stock ranging from old Lima to current Farish, Dapol, Atlas or Kato models. None of the layouts ever had anything more than the frog switched via the point motor for reasons of reliability as per the earlier messages. The only time there's been a problem is when a train has derailed, a short has occured and the system shut down. Excatly the same would have happened running DC. Happy modelling. Steven B. Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted October 31, 2011 RMweb Gold Share Posted October 31, 2011 I have an N scale layout on the exhibition circuit at the moment which uses Peco code 55 finescale track. The scenic turnout is Altas code 55 and the frog is isolated from the turnout blades etc. The fiddleyard turnouts were installed as manufactured but with the frog wired to the SEEP solenoid polarity switch. The layout uses the Digitrax DCC system. I have had a number of turnout tie bars melt (presumably when the turnout hasn't thrown fully and the blades have heated up without shorting the command station). Not sure how or why this can happen. I have recently modified most of the turnouts by cutting through the rails between the frog and blades then linking the blades to the stock rails. This was fairly straightforward in a non ballasted non scenic area but would be far more messy if it were in the scenic area. A new layout I have just built had the modifications done to the Peco turnouts prior to laying and thus was much easier to do. To date there have been no problems with these modified turnouts. Also when there have been any back to back problems which metal wheelsets or derailments on the turnout blades, then the whole layout doesn't shut down. So my advise is yes it is well worth modifying the turnouts before installation. Ian Link to post Share on other sites More sharing options...
RMweb Gold Revolution Mike Posted October 31, 2011 RMweb Gold Share Posted October 31, 2011 Another vote for not needing to modify the points here. If you do get shorts then it is likely to be down to derailments or back-to-backs being set incorrectly. If you are really worried about shorts then I would put in a dedicated circuit breaker (which can be set to trip at a lower limit than the command station). Cheers, Mike Link to post Share on other sites More sharing options...
Crosland Posted November 1, 2011 Share Posted November 1, 2011 Another vote for not needing to modify the points here. If you do get shorts then it is likely to be down to derailments or back-to-backs being set incorrectly. If you are really worried about shorts then I would put in a dedicated circuit breaker (which can be set to trip at a lower limit than the command station). Cheers, Mike Given appropriate track and wheel standards, I would be more worried about the unreliablility of the built in power routing than shorting on unmodified points. Andrew Crosland Link to post Share on other sites More sharing options...
brossard Posted November 1, 2011 Share Posted November 1, 2011 Sigh. You can do what you want in the hobby including not paying attention to best practice. However, I don't think it's fair to encourage people starting out to do the same thing. Ian has described the problems he has seen. A few minutes invested in modifying the points as recommended by Brian Lambert will eliminate the vulnerability to problems. John Link to post Share on other sites More sharing options...
RMweb Gold Revolution Mike Posted November 1, 2011 RMweb Gold Share Posted November 1, 2011 Sigh - indeed. Best practice according to who? Brian's site may well be correct for OO, but for N it is just perpetuating an unnecessary mod. Ian's problems suggest a greater problem than unmodified points would cause... As Andrew and others have said - power routing is more important, but that is a different point (no pun intended). Link to post Share on other sites More sharing options...
Nigelcliffe Posted November 1, 2011 Share Posted November 1, 2011 Well, I go for the "Brian Lambert" solution, even with N, or any other scale. It removes the problem completely. And, I do see the problem with Peco N, but my only N locos are US outline Kato, which probably have a different back-to-back by a few tenths of mm when compared to UK outline. Ian's problem is almost certainly that the turnout blade was causing a short, but the resistance in the total circuit was sufficient to limit the current below the command station's cutout. This is a not uncommon situation caused by using command stations which can put 5A or 8A onto the track and will only shut down if they detect the full current flowing. Modifying the turnouts to Brian Lambert's scheme will prevent the problem, though its only part of the issue. The solution to the high current command stations (other than buying lower current devices!) is circuit breakers which will trip at lower currents, plus proper testing of all wiring for correct function in short circuit situations (the coin on track tests). - Nigel Link to post Share on other sites More sharing options...
Guest Moria Posted November 2, 2011 Share Posted November 2, 2011 Nigel, greetings. I accept that the BL method would in fact completely remove the issue, but I am interested in how you would do similar mods to the three way, single and double slips and the scissors as I assume you also have to remoive sleepers from code 55 to hardwire the stock rails to the blades area, and am also concerned about how that can be done effectively in the space available. I admit, I am in the camp of "not an issue" with Peco code 55 but I do run a circuit breaker on each circuit so as not to rely on the booster circuit breaker. Having said that, I have also seen Ixion Manors burn out their spring contacts on a DC layout with a derailment on the point (again, maybe a DC circuit breaker would help) so I don't actually see this as only a DCC issue. Currently I have about 40 points including the three ways, slips and scissors with no mods and I don't even trigger the circuit breaker on normal running, but am looking at an extension so want to double check all possibilities for improvements. I woould also assume, that should you actually seperate the frogs (I guess a dremel would be too big a gap.. a jewellers saw would be better) that you could actually wire the frogs to a hex frog juicer rather than switching from the cobalts as well to further simplify wiring. Regards Graham Link to post Share on other sites More sharing options...
Nigelcliffe Posted November 2, 2011 Share Posted November 2, 2011 Sorry Graham, my N stuff doesn't have 3-ways (etc) so can't answer with specifics on how to split up the electrics through them. In general I would cut things with a piercing saw (like a fret-saw frame with a fine metal cutting blade). A Dremel, or similar, device is likely to just create a huge gap which will lead to erratic running (or worse!). I can't see how a HexFrogJuicer is any simpler than wiring through a Cobalt/Tortoise. Both require a wire from the crossing (frog) and a wire to each stock rail. Only difference is cost of adding the HexFrogJuicer on top of turnout motors. - Nigel Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted November 2, 2011 RMweb Gold Share Posted November 2, 2011 I still have about 3 turnouts still to modify on the fiddleyard. At the weekend at a show, one of them had the tie bar melt (However turnout still useable). I did notice that sometimes there was a spark when the solenoid changed the turnout. I suspect there is a lag between the solenoid with the polarity change switch throwing and then the blades moving a split second later. All the modified turnouts have worked fine since the modification. The fiddleyard is used on both my USA N scale and British N scale layouts. Before modifiying the turnouts the fiddleyard had only been used with the USA stock and we did get the occasional short through the back to back of stock fitted with metal wheels. I can't comment on the British stock as the turnouts had generally been modified by then and on the three remaining unmodified ones I didn't notice any problems but that might have been luck. One other advantage of the modification is that if the polarity switch on the SEEP solenoid becomes unreliable as I have experienced on numerous occasions, then with a smaller section of track being switched (ie the frog area) then most modern locos with all wheel pick up will still travel over the turnout without stopping. On the British layout I have installed Peco solenoids with the double microswitch adaptor base. However getting the microswitches adjusted to work properly has been a real pain and some still need further adjustment. Hopefully once they are all working properly they will prove move more reliable than the SEEP ones. Ian Link to post Share on other sites More sharing options...
Guest Moria Posted November 2, 2011 Share Posted November 2, 2011 Hi Ian.. yes agreed, you're asking for trouble with solenoids and frog switching on DCC (or even on DC though less noticable). In all cases that I have seen, the snap action is quite capable of switching the frog prior to the blades disengaging, or sometimes even bouncing blades. I have seen solenoids snap the blades over so hard that even with the spring in place they have bounced back and not changed the polarity switch, and a bounce back of this type will be an instant short I should, perhaps, in my comments above have highlighted that in my case I only use tortoise or cobalt which have a deffinate break before make to avoid that quick short. Regards Graham Link to post Share on other sites More sharing options...
Karhedron Posted November 2, 2011 Share Posted November 2, 2011 On the British layout I have installed Peco solenoids with the double microswitch adaptor base. However getting the microswitches adjusted to work properly has been a real pain and some still need further adjustment. Hopefully once they are all working properly they will prove move more reliable than the SEEP ones. I found the peco microswitches very easy to adjust and much more reliable than the wiper based switches on the PL-13 and SEEP motors. My only complaint with the PL-15 microswitches is their cost. For the price of a point motor and switch you could almost get a Tortoise. Link to post Share on other sites More sharing options...
Crosland Posted November 3, 2011 Share Posted November 3, 2011 Hi Ian.. yes agreed, you're asking for trouble with solenoids and frog switching on DCC (or even on DC though less noticable). In all cases that I have seen, the snap action is quite capable of switching the frog prior to the blades disengaging, or sometimes even bouncing blades. I have seen solenoids snap the blades over so hard that even with the spring in place they have bounced back and not changed the polarity switch, and a bounce back of this type will be an instant short That's why you isolate the switch rails from the frog. It then doesn't matter how the switch rails move in relation to the polarity switch. If you are going to modify points, you need to do the whole job, as explained on many websites. Andrew Crosland Link to post Share on other sites More sharing options...
Guest Moria Posted November 3, 2011 Share Posted November 3, 2011 Agreed Andrew, but this is not making them DCC friendly, it's making them Solenoid motor friendly and is the same whether DCC or DC. Regards Graham Link to post Share on other sites More sharing options...
Pimlico Tram Posted November 7, 2011 Author Share Posted November 7, 2011 Sorry, all, but I've been away. It seems to have sparked some debate anyway. I'll have a go with the fretsaw and see if I can make them look acceptable cosmetically. Many thanks for all your comments. Giles Link to post Share on other sites More sharing options...
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