Peco crossing shorting issues?

[Jenny Emily]

I'm looking at DCC for my next layout, mostly because to wire the track plan for reliable DC running would be horrendous. I've begun accumulating trackwork for it, and the planned track layout requires at least five Peco code 100 streamline short crossings. However my experiences of one of these on 'Grove street' (DC) is that locomotives tend to short ever so briefly as they roll over it as the wheels bridge between adjacent lines on the frog. On DC this merely results in a moment's hesitation at low speed, but I've heard that DCC locos can be more picky over what amounts to a brief short between the rails.

 

Is this likely to be an issue with running on DCC? If there is a problem, is there an easy solution other than to use wiring to in effect convert the crossing to a similar polarity switching to that which a live frog might use? (Though this does then complicate the wiring in a way that I was hoping that using DCC would take me away from). Any advice would be gratefully appreciated - even if it is only to reassure that there isn't a problem!

 

I'm nowhere near actual tracklaying yet, so I thought it best to ask. The crossings are essential for the trackplan (to give scissors crossovers between several platforms at a junction station) so doing without them isn't really an option. Code 75 with live frogs is also not an option given the cost of trackwork (I already have amassed most of the required forty points through Ebay over the last year)

[Phil Bullock]

Hi there

 

For reliable running really would suggest you switch polarity of the frogs as if they were live

 

Are you using point motors? Cobalt or tortoise have auxillary switches that will do this for you

 

Kind regards

 

Phil

[squeaky]

If you are using live frogs then you need to be able to switch the frog polarity automatically, on my layout I only have one crossing which is a Peco code 75 one. I use a DCC Specialties OG-AR, this is wired to the frog and the DCC supply, when the loco passes over the frog it switches the polarity with no hesitation.

 

You can get cheaper devices that use a relay to switch but I found these difficult to setup.

 

Have a look here http://www.dccspecialties.com/products/onguard.htm

[melmerby]

Is the crossing adjacent to a point which leads to it?

If so use the point switching to change the polarity of the crossing frogs (even if they are Insulfrogs).

 

Before I started track laying proper I had a test set-up using code 100 track and found the same problem of shorts as the wheels cross the frog on Insulfrog crossings.

I am now using Code 75 Electrofrogs and switch the crossing frogs at the same time as the points.

 

Keith

[Lady_Ava_Hay]

If you are using live frogs then you need to be able to switch the frog polarity automatically, on my layout I only have one crossing which is a Peco code 75 one. I use a DCC Specialties OG-AR, this is wired to the frog and the DCC supply, when the loco passes over the frog it switches the polarity with no hesitation.

 

You can get cheaper devices that use a relay to switch but I found these difficult to setup.

 

Have a look here http://www.dccspecia...cts/onguard.htm

 

I agree. Avoid relay switches as they are too slow and the command centre shorts first.

 

Apart from the digital switch if there are always points on the approach to the crossing you can use the point motor to switch the frogs for you. I have used a small DPDT relay board that a MERG member designed for me that operates on 16v AC which is the supply that my motors use (Tillig). The only snag is that the point blade is also instantly switched by the point motor so a short occurs before the point moves. A dob of varnish on the switch blade solved that.

 

I previously tried two Digitrax relay based switches and both are now redundant.

 

I have heard good reports of the Onguard.

[Jenny Emily]

Thanks for the replies.

 

I use Peco PL-10 and PL-10E motors, as I've always found them really reliable, and I recently acquired a joblot of twenty for a bargain price (which always endears something to me!). Several crossings will be in a position where they will feed into double slips. However, I presume that a double microswitch (PL-15?) on one point to change polarity of both rails ought to do the trick?

 

I take it this means that using the crossings as-is without any switching is a big non starter for DCC then?

[Lady_Ava_Hay]

Thanks for the replies.

 

I use Peco PL-10 and PL-10E motors, as I've always found them really reliable, and I recently acquired a joblot of twenty for a bargain price (which always endears something to me!). Several crossings will be in a position where they will feed into double slips. However, I presume that a double microswitch (PL-15?) on one point to change polarity of both rails ought to do the trick?

 

I take it this means that using the crossings as-is without any switching is a big non starter for DCC then?

 

Any dead rails on both sides of a loco will stall short wheelbase ones. I am unfamiliar with the Peco short crossing but if both frogs form a vee that is electrically one piece then those vees will need to switch polarity and always be at opposite polarity to each other. The problem is that there are three of these frogs and the point one will always be at the same polarity as one of the frogs on the crossing but the other crossing frog will always need to be at the opposite polarity. My Tillig motors are only designed for one change. If you can fit two to a PL10 or 10E then those will do the job. Problems could arise if you actually want to run trains through both tracks that form the crossing and close together. You have to remember to change the feeder point before running a train across the crossing track that doesn't use the feeder point.

 

Same applies to DC wiring but DCC is more sensitive to momentary shorts.

[Phil Bullock]

Hi there

 

Had you looked at how you were going to power the PL10s using DCC? Not aware that they are in common use in this control system but others may know better......

 

As Melmerby says the best system is to use the point motors on the points leading to a crossing to switch frog polarity automatically for you. Have used tortoises on Abbotswood but have just brought some cobalts - smaller and more versatile. As you rightly say though DCC control of points aint cheap - are you considering a mixed system eg DCC for loco control and DC for points etc? If so you probably wont benefit from the wiring simplification that DCC brings.

 

Have converted in the last two years and have made some errors but our DCC layout - Abbotswood Jct - is now pretty reliable. We put it up for a running session in the garden a couple of weeks ago - had been stored in garage for 6 months prior to that - connected it all up and off it went. Running is so much better - due to the constant higher AC voltage through the track - but am sure this will serve to exacerbate the shorting problem on your short crossings if you dont switch frog polarity.

 

Kind regards

 

Phil

 

 

 

 

[Oldddudders]

Many ladies - but not all - may have a product that sorts this problem, at least in the short (sorry) term. Try a small patch of nail-varnish on the area of the frog where shorts occur. This insulates and avoids the problem. I have to say providing switching and the other remedies proposed above are more technically-elegant ways of doing things, but the varnish is cheaper, quicker and easier. Clear varnish looks best in my experience.....

[Kenton]

I'm looking at DCC for my next layout, mostly because to wire the track plan for reliable DC running would be horrendous.

... and what makes you think that wiring for DCC will be any different.

 

All that happens for wiring for DCC is that you do not have to worry about switchable section breaks in sidings. Wiring the points and everything else should be just as complex or simple in DCC as it is in DC.

 

 

If you are worried about shorting as locos go through points - IMO the biggest risk is when the stock rail is at different polarity to the switch blade. This is particularly a problem on old stock with chunky wheel profile or with sloppy B2B tolerance. For this reason I would always advocate electrically bonding switch rails to adjacent stock rails.

[mcowgill]

... and what makes you think that wiring for DCC will be any different.

 

I do find 'wiring for DCC' rather amusing. I first built my own track in the late 1970s when I was working with 009, it looked more realistic than Peco 'crazy track' and the live frogs gave better running with tiny narrow gauge locos. I graduated through EM and P4 always wiring things up the same way, then a few years ago after a break in modelling started a new 00 layout and decided to play with this new-fangled DCC stuff with noisy diesels. I was rather amused to find that the world was now being told to wire their turnouts exactly the same way I did back in the 1970s for reliable running on DC.

 

Martin

[kevinlms]

I do find 'wiring for DCC' rather amusing. I first built my own track in the late 1970s when I was working with 009, it looked more realistic than Peco 'crazy track' and the live frogs gave better running with tiny narrow gauge locos. I graduated through EM and P4 always wiring things up the same way, then a few years ago after a break in modelling started a new 00 layout and decided to play with this new-fangled DCC stuff with noisy diesels. I was rather amused to find that the world was now being told to wire their turnouts exactly the same way I did back in the 1970s for reliable running on DC.

 

Martin

 

Exactly so. If you want reliable running, then this is what's required = as much rail as possible to have the correct voltage on it.

 

I'm wondering how much of a bargain the OP's Peco crossings really are if they don't work to the standard required, without extensive modification?

 

Kevin Martin

[Oldddudders]

These are crossings, not points. No moveable parts. They simply behave as Peco Insulfrog points sometimes do with some wheelsets - there is, as JE said, a momentary contact with the alternative pole. Peco have attempted to minimise the plastic portion of the frog to optimise the metal-to-metal contact, but some wheels manage to cover both. My cheap-and-nasty solution is well-known on some DCC lists (where I got it from) as the easy, on-the-spot workround.

[Grovenor]

IMHO, building a scissors crossover from 4 turnouts and two diamond crossings is not a good option, the track centre to centre spacing will be way to much and the length from one point to the other over long so taking up a lot of space in the platform.

Building your own can solve all of these problems, but if you don't feel up to that then I strongly suggest you look for complete ready made scissors, used to be made by Shinohara but I have not seen them advertised for some time so probably been taken over, maybe try Walthers, or Tillig.

Regards

Keith

[Jenny Emily]

... and what makes you think that wiring for DCC will be any different.

 

 

 

On DC I would have to find a way to allow trains running on four tracks be able to access any of six through lines and platforms and several further loops through complex junctions at either end of the station. This would require a lot of rotary switches to allow each track to be switched between any of four trains. On DCC I would wire the whole lot as one section. There - a whole lot of simplification in the wiring.

 

As for building my own track - not my cup of tea at all. I really have no interest in building even a fraction of the fifty or so pieces of trackwork.

 

I looked into ready made scissors crossings, but they seem hard to get in the UK and I'm not convinced of their benefits to me; quite appart from the hefty price tag of the one I found. At any rate two of the scissors will have double slips substituted for one of the points, and a further scissors is actually spread out as it forms part of the junction between two diverging lines. All in all ready built scissors would be of use only for the fourth that I need - not really a great saving at all.

 

The point motors will not be part of the DCC system; I can use microswitches on them though to change frog polarity just as you would on DC.

 

 

[Kenton]

On DC I would have to find a way to allow trains running on four tracks be able to access any of six through lines and platforms and several further loops through complex junctions at either end of the station. This would require a lot of rotary switches to allow each track to be switched between any of four trains. On DCC I would wire the whole lot as one section. There - a whole lot of simplification in the wiring.

I've never seen the need to use rotary switches and the additional wiring they bring unless you are having more than one controller - ie more than one loco running at the same time. Which if you are is an excellent reason for going DCC. Generally speaking though wiring for DC is not difficult it is just a matter of following a set of very clear rules and not taking short cuts. Wiring for DCC is generally exactly the same as correct wiring for DC but without section switches.

 

Of course if it is a big layout and you are running multiple trains together, adding flashing lights, sound and all the other gimmicks gizmos then the deal should already be done and I would never support DC. It is a matter of operating requirements and size of layout rather than saving a few lengths of wire and the odd soldered joint or two.

[Phil Bullock]

Hi there

 

OK so we have a DCC control system with DC point control - hence peco point motors.

 

Therefore suggest you start off by trying the suggested dodge with nail varnish

 

Sounds like cost is a major factor - at around £25 for a motor and accessory controller for each point motor DCC doesnt come cheap!

 

As far as the scissor crossovers go - would it be worth publishing a track plan on here so that the issues are clearer ?

 

Ultimately its your decision - but why not try the nail varnish for starters but put in place a fall back when you lay the track with wiring and droppers in place should you decide to switch frog polarity if this doesnt meet your expectations

 

Kind regards

 

Phil

[Jenny Emily]

I will cerftainly try the varnish method, and will build the layout with the provision to switch frog polarity on crfossings despite them being insulfrog (this seems to be Peco's own recomendation too). It may be that I can use insulfrog points to have much the same effect but without the need for micro switches - I've never suffered from problems associated with relying on the point blades to make contact to supply power to the frog.

 

Thanks for the replies and advice. I have no actual trackplan drawing, as I use scraps of paper and a pencil to design track plans, which are then refined using spare track pieces on the floor until I get a result that works. The track plan will be a somewhat modified version of Bolton Trinity Street in the late 1970s between Bolton East and Bolton West signal boxes. The room it will ultimately go in has yet to be built so I have plenty of time to iron out wrinkles.

 

Interestingly the more recent pictures I have found online of the Peco crossings show modified frogs with slightly wider insulation; presumably to make them more readily DCC friendly.

[Lady_Ava_Hay]

I have just looked closer at an ST250 Code 100 medium crossing which I assume is of similar construction. It is patently Insulfrog and as such should not require any additional wiring to make it any better on DCC than it would be on DC.

 

The problem with DCC is that the decoder is receiving packets of data to the decoder through the track power and if that is briefly interrupted then the packets can become corrupted and the decoder can become confused.

 

If I might suggest it, if you are determined to use Insulfrog you might be better to consider the newer decoders that include a 'stay alive' capacitor. I would direct you to the DCC Concepts latest loco decoder and I think Bromsgrove ( of this parish ) might be the UK stockists.

 

If again you intend to use the point blade to transmit power to the frog of your points you will be well advised to leave the over centre spring in place which, in turn might make the PL10E struggle a bit at times or if the install is less than perfect. If you are NOT using DCC for the point motors ( I don't ) you have no need of the 10E and the standard 10 will be adequate.

 

I don't use solenoids on my layout.

 

I am informed from posts on here that the Peco micro switch is less reliable than others.

[kevinlms]

I will cerftainly try the varnish method, and will build the layout with the provision to switch frog polarity on crfossings despite them being insulfrog (this seems to be Peco's own recomendation too). It may be that I can use insulfrog points to have much the same effect but without the need for micro switches - I've never suffered from problems associated with relying on the point blades to make contact to supply power to the frog.

 

Thanks for the replies and advice. I have no actual trackplan drawing, as I use scraps of paper and a pencil to design track plans, which are then refined using spare track pieces on the floor until I get a result that works. The track plan will be a somewhat modified version of Bolton Trinity Street in the late 1970s between Bolton East and Bolton West signal boxes. The room it will ultimately go in has yet to be built so I have plenty of time to iron out wrinkles.

 

Interestingly the more recent pictures I have found online of the Peco crossings show modified frogs with slightly wider insulation; presumably to make them more readily DCC friendly.

 

Ummm, the diagram is wrong. A & B are the same thing in the diagram. The A's should be pointing to the actual frog and not to the same place as the B's. I do hope Peco haven't printed too many sets of instructions like that.

 

Can't you scan your scraps of paper, so a more accurate over view of your layout can be determined?

 

Kevin Martin

[kevinlms]

On DC I would have to find a way to allow trains running on four tracks be able to access any of six through lines and platforms and several further loops through complex junctions at either end of the station. This would require a lot of rotary switches to allow each track to be switched between any of four trains. On DCC I would wire the whole lot as one section. There - a whole lot of simplification in the wiring.

 

As for building my own track - not my cup of tea at all. I really have no interest in building even a fraction of the fifty or so pieces of trackwork.

 

I looked into ready made scissors crossings, but they seem hard to get in the UK and I'm not convinced of their benefits to me; quite appart from the hefty price tag of the one I found. At any rate two of the scissors will have double slips substituted for one of the points, and a further scissors is actually spread out as it forms part of the junction between two diverging lines. All in all ready built scissors would be of use only for the fourth that I need - not really a great saving at all.

 

The point motors will not be part of the DCC system; I can use microswitches on them though to change frog polarity just as you would on DC.

 

 

 

I would suggest you look at this page

 

http://www.brian-lam...20frog%20points

 

About 80% of the way down (under the turntable) for some options on your scissors crossover(s). The Auto Reverse Module would seem to be well worth the money.

 

 

Kevin Martin

[Kenton]

Another thing to consider if you are hell bent on insulfrogs is the locos that you are using. On DCC, as pointed out above, any interruption of signal can cause problems that simply would not be seen with DC.

 

With DCC it is therefore much more important to maximize the number of pickups and generally avoid 0-4-0 arrangements. As a set of wheels traverse the gap they also have a tendency to drop - the loco effectively becoming a 3-wheeler unless it is well sprung. It is also incredibly easy to distort RTR pointwork by mediocre track laying (especially by hammering the dreadful track pins through the sleepers) All this leads to problems with DCC which are much more evident than DC where temporary loss of power is not so much an issue.

[Oldddudders]

It is also incredibly easy to distort RTR pointwork by mediocre track laying (especially by hammering the dreadful track pins through the sleepers)

While pins may distort flextrack, they should be less pernicious on Peco pointwork, where holes have been thoughtfully drilled from underneath by the manufacturer. These simply need to be pushed through the sleeper-top, again from underneath, before laying. Then the baseboard is drilled through that hole to within 1/8" of the length of the pin, which is finally pushed into place, holding the point without need for any compression or distortion. Simple.

[Phil S]

it was Airfix - when they launched their MTC Multi Train Control System in competition to Hornby's Zero-1 - who made the suggestion of Varnish over the tip of the Insulated-but-not-enough frog of peco Points; it will require renewal at intervals as track-cleaning will wear it away. The problem was worse 'then' because of the coarser wheelsets prevalent on Hornby (Tri-ang) models of the time. ('Steam roller wheels')

 

The Peco advice is to insulate the V by insulating fishplates, so that they are only powered by the moving switch blades... which then require good contact on closure ! - which can be a problem and contrary to the prevalent advice for 'live-frog' wiring of them in which the switch blades are permanently wired to their adjacent running rails.. but then the live-OR-dead frog requires 'polarising' separately - either by switch or electronically using similar ideas to that of many dcc auto-reversers. There are a number of devices available including the 'frog juicer'.

 

You mentioned buying the Peco Points over Ebay .... perhaps this also meant 2nd hand ? - IF SO you may find production variations made over time which affect the problem - as the wheel standards have improved over the years - clearances may have changed, and with live-frog points, the construction still varies between sizes of point. it may also be worth checking the back-to-back gauges of your locos or metal-wheeled stock.

 

You can ALSO MINIMISE the problem, if it does still occur, by using intelligent electronic cutouts such as the PS-X for 'sub-districts' of the layout - so that other parts of the layout are protected from the immediate effects of the passing short - and the PS-X (for example) automatically resets, or attempts to, at intervals.

[Jenny Emily]

The crossings are secondhand, though some of them look never ever used. They're all packed up at the moment for an impending house move so I cannot check at the moment. I know the one that causes issues on 'Grove street' was bought brand new by me in around 2001, though I do not know if the shop had had it lingering in stock for much longer. Certainly the pictures on the Hattons website show a much wider insulation V in the frog than that particular piece of track.

 

I'm lucky in that I will be running only stock produced in the last 12 years, and mostly by Bachmann who seem to have moved away from steam roller wheels long before I started buying the stuff. I will investigate the nail varnish option, as it is something that I have a lot of (including useful leftovers from my teenage Gothling years in matt black).