Points \ turnouts \ switches and polarity on DCC

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centenary
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Points \ turnouts \ switches and polarity on DCC

Postby centenary » Mon Feb 19, 2018 1:30 pm

Oh dear, why is it when you set out to ask a simple question, you rewrite and expand it several times and end up asking for recommendations!? I think Ive rewritten this one several times and still maybe not happy with it!

OK, sorry if some of these questions have been asked before and hopefully this doesnt stir an hornets nest. Bit of background, Im only going to be running newly manufactured DCC stock ie Bachmann, Hornby, Heljan etc models made no older than 2017, either sound fitted or added at a later date. I was intending having manually operated points to keep costs down and, all points would be within easy reach. The layout will be about 4m x 1.2m Control is by a Hornby Elite running latest firmware (v1.44).

For simplicity, I was going to use insulfrog points on a DCC layout but, the concensus seems to be DCC sound models especially short wheelbase ones and perhaps others, may experience issues with these. Also, by their very nature you have a dead spot on the points which may not always result in smooth running. I believe you can insert clips in Hornby's offering to combat this to a degree. Is the perceived wisdom to avoid insulfrog if you can or, have manufacturers improved them in the last year or two such that you have to be a bit unlucky (or just lazy in not doing adequate track maintenance) to have issues with these?

Conversely, having viewed numerous You Tube vids, while these result in smoother running, it seems a different set of problems present themselves if you use electrofrog points. One of these (to me) is the changing polarity required to the electrofrog when switching the blades from one side of the track to the other.

In all the YT vids Ive watched. people using electrofrog all seem to use point motors to switch them. I see the benefit of this especially as it help smoother running and as power is provided to the point, why not utilise it? But this also seems to bring in the need for a polarity switcher. Now the cost is going up because now we need a points motor, a polarity switcher and associated fixings if you want to operate them via DCC.

Is a polarity switcher essential with electrofrog points? Can an polarity switcher be used on manually operated electrofrog points? If I use electrofrog points 'out of the box' am I likely to have issues if I do not make the 'modifications'?

As far as budget and points motors are concerned, I notice a few people who use 'seep' have reported they work fine for a while then the switching contact starts to wear out causing deadspots and issues. I appreciate everything wears out but, working on a budget, what are the recommendations for reliable points motors?

Well, I think that is it although maybe some replies may result in further questions. Thanks for bearing with me.

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Re: Points \ turnouts \ switches and polarity on DCC

Postby mahoganydog » Mon Feb 19, 2018 2:34 pm

Hi Centenary,

Seep motors work OK and in proportion are by some way the cheapest motor with a built in switch. Peco's venerable PL10's don't go wrong but they don't come with a mounting plate nor a polarity switcher which increases the price considerably. Gaugemaster do a copy but it doesn't appear to have a switch available for it.

You only need a polarity switcher on the slips, crossings (code 75) and three way point (both code 100 and 75). All others self isolate.

Jim
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Bufferstop
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Re: Points \ turnouts \ switches and polarity on DCC

Postby Bufferstop » Mon Feb 19, 2018 2:57 pm

Lets go through them point by point (was that a pun)

Insulfrog points have a dead section at the tip of the frog, there are some things that people have done to overcome it, they all come fairly close to a bodge. The clips that Hornby sell are for an entirely different problem. An insulfrog point can't pass power to the non selected track, without bonding the switch rails to the adjacent stock rails, that's what the clips do.
There's only one way to lessen the dead frog effect and that's to make it smaller, then you risk wide wheel rims on passing stock bridging to the unselected road.
Electrofrog points require some small mods to their wiring for DCC and will need some means of switching the frog polarity. Providing you have fitted insulating rail joiners to the two V rails, you could leave it to the point blades to do the switching, but it's not a good idea with DCC as you may still get a poor connection whilst passing through the point, and the tips of the point blades were never designed to be able to carry the full output of a DCC power supply, and so in a derailment might draw enough current to get very hot without reaching the tripping current of a large DCC power supply. The cure is to isolate the blades from the rails at the frog, by cutting either a link provided for the purpose or on older points the rails themselves.

You the need a means of providing a supply to the frog and in the process setting its polarity. You can either use the so called "frog jiucer" which does it automatically, or you can wire it through a switch on the point motor, you don't need both, even if you use the frog jiucer you still need the point motor and the engineer in me keeps saying using its switch is the "proper" way to do it.

Using electrofrog straight from the box but fitting insulated rail joiners on the V rails and putting a feed to the track beyond is the equivalent of the scenario above. You would be relying on the point blades to switch the frog, they'll do it, and your proposed DCC controller shouldn't be able to supply more current than they can handle, but you may have problems in the future if you upgrade it.

You could use a frog jiucer with hand/mechanically operated points, or you could use a small slide switch,connected to the tie bar with a stiff wire to move the blades. You drill a hole through the plastic dolly of the switch and put the bent end of the wire through it.
I'll leave it to others to tell you about Seep and other point motors mine are entirely mechanical.
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Bigmet
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Re: Points \ turnouts \ switches and polarity on DCC

Postby Bigmet » Mon Feb 19, 2018 4:23 pm

I use live crossing ('electrofrog' in Pecospeak) everywhere, and have done mostly since the 1960s. (For outdoor DC operation it had to be Peco dead crossings as reliable low voltage all weather switching was then not achievable at low cost. Very easy now with a 'frog juicer'.)

In yards, I do exactly as Bufferstop describes, slide switch with pushrod. Efficient and cheap.

Where a point motor is required, slow motion is much to be preferred over solenoid. Quiet and gentle action instead of 'Whap'. You can do it 'Costa del Fortuna' style with Tortoise motors if you want, and it's a good product. Or if ingenious and prepared to invest the effort, the Fulgurex motor can be used to switch a pair of points that always work together, for the same money as a pair of solenoids. That's what I do, because I am cheap, to operate all the main line point pairs: and they always are pairs, either crossovers, or trap and main line point when a branch or siding joins the main running lines.

Not being funny at all, I feel the RTR track producers have 'missed the point' in DCC. An integral point motor and DCC decoder on the point is quite possible, either with dipswitches on the point or an accessory programming connector offered in the track range to assist with set up in conjunction with the major DCC systems.

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Re: Points \ turnouts \ switches and polarity on DCC

Postby Suzie » Mon Feb 19, 2018 4:59 pm

To answer your questions one at a time:-

centenary wrote:...For simplicity, I was going to use insulfrog points on a DCC layout but, the concensus seems to be DCC sound models especially short wheelbase ones and perhaps others, may experience issues with these. Also, by their very nature you have a dead spot on the points which may not always result in smooth running. I believe you can insert clips in Hornby's offering to combat this to a degree. Is the perceived wisdom to avoid insulfrog if you can or, have manufacturers improved them in the last year or two such that you have to be a bit unlucky (or just lazy in not doing adequate track maintenance) to have issues with these?...


Manufacturers have started to provide better pickups on stock now so that insulated bits of track and dirt are a lot les of a problem than they once were, but some still has traction tyres on half the wheels, and some locos only have four wheels so these are still going to suffer even on clean track if you have dead frog points. You specifically mention 'Insulfrog' and Peco Streamline Insulfrog is not compatible with DCC when all the track is powered at once because the small frog optimised for self isolating DC is too small to properly insulate the frog rails from the wheel treads. If you do still want to go with dead frog points do not use Peco Streamline.

centenary wrote:...Conversely, having viewed numerous You Tube vids, while these result in smoother running, it seems a different set of problems present themselves if you use electrofrog points. One of these (to me) is the changing polarity required to the electrofrog when switching the blades from one side of the track to the other...


With live frog you will always have to switch the frog polarity to match the way the point is set. Peco Electrofrog has a rudimentary switching system built in as supplied that will switch the frog polarity - but it is not the most reliable so you really need to look at replacing it with an external frog switching solution. Bear in mind that the Peco PL13 and SEEP built in switches are not much better in the reliability stakes so don't consider these as reliable options.

centenary wrote:...In all the YT vids Ive watched. people using electrofrog all seem to use point motors to switch them. I see the benefit of this especially as it help smoother running and as power is provided to the point, why not utilise it? But this also seems to bring in the need for a polarity switcher. Now the cost is going up because now we need a points motor, a polarity switcher and associated fixings if you want to operate them via DCC...


This is when you need to look at the whole system to evaluate the cost. When using solenoids, you need to add on the frog switching and decoder costs and that can end up being quite a lot, usually much more than using slow motion motors with built in frog switches and decoders, and much more than using RC servos with suitable frog switching decoders. Solenoids are (usually) easy to obtain, slow motion motors are bulky and not all makes are as reliable as others, and servos often need a bit of careful purchasing to get the system that suits your skill/budget/requirements.

centenary wrote:...Is a polarity switcher essential with electrofrog points? Can an polarity switcher be used on manually operated electrofrog points? If I use electrofrog points 'out of the box' am I likely to have issues if I do not make the 'modifications'?...


You can use the polarity switching built in to (most) live frog points, but it is unlikely to be sufficiently reliable even with fastidious maintenance - but will be less of a problem than using dead frog points!

centenary wrote:...As far as budget and points motors are concerned, I notice a few people who use 'seep' have reported they work fine for a while then the switching contact starts to wear out causing deadspots and issues. I appreciate everything wears out but, working on a budget, what are the recommendations for reliable points motors?...


For reliability look at Peco solenoids with PL15 switches, Tortoise slow motion motors, or servos. Tortoise are not normally considered budget though, and a Peco PL10 with a PL15 switch will probably cost even more. Servos can be set up to operate microswitches to switch the frog if you don't mind the extra work involved and if you want to control the points from DCC this will probably be the reliable budget option.

Suzie x

Mike Parkes
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Re: Points \ turnouts \ switches and polarity on DCC

Postby Mike Parkes » Mon Feb 19, 2018 6:34 pm

Also consider Cobalt IP Digital motors - slow motion like tortoise but come with a decoder and switches built in (also slightly smaller than a tortoise). Available in bulk which may be cheaper but it pays to have a good luck round as prices for one or a number vary wildly between suppliers.

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TimberSurf
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Re: Points \ turnouts \ switches and polarity on DCC

Postby TimberSurf » Mon Feb 19, 2018 7:20 pm

Suzie wrote:Servos can be set up to operate microswitches to switch the frog if you don't mind the extra work involved and if you want to control the points from DCC this will probably be the reliable budget option.

Suzie x


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tspotter
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Re: Points \ turnouts \ switches and polarity on DCC

Postby tspotter » Mon Feb 19, 2018 8:44 pm

Or use a servo with this decoder. Use a MERG mount.


Screen Shot 2018-01-31 at 12.50.29.png



Contact me for details.

Julian

Suzie
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Re: Points \ turnouts \ switches and polarity on DCC

Postby Suzie » Mon Feb 19, 2018 9:48 pm

There are quite a few alternatives for driving servos and switching frogs. I use these Signalist SC2 decoders with on-board frog switching:-

Image

And these Signalist SB1 servo motors:-

Image

You can fit a couple of microswitches on to the servo motors if your decoder does not have the frog switching.

Suzie x

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centenary
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Re: Points \ turnouts \ switches and polarity on DCC

Postby centenary » Fri Feb 23, 2018 11:12 am

Thanks for those replies folks. BTW if you need to buy replacement servos, I get a lot of electronic stuff for my RC Helis from this internet site. 9kg torque mini servos for £1.97. https://hobbyking.com/en_us/turnigytm-t ... ec-9g.html

Be careful to select the UK store and check purchase is made via the UK store else you may get a shipping charge from Hong Kong together with associated import duty.

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Bufferstop
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Re: Points \ turnouts \ switches and polarity on DCC

Postby Bufferstop » Fri Feb 23, 2018 1:40 pm

Bigmet wrote:Not being funny at all, I feel the RTR track producers have 'missed the point' in DCC. An integral point motor and DCC decoder on the point is quite possible, either with dipswitches on the point or an accessory programming connector offered in the track range to assist with set up in conjunction with the major DCC systems.

If you are talking UK track this is definitely the case, Hornby are still talking the just two wires mentality, Peco have no one to compete with. I like the idea of a point with decoder and motor built in, but it would be burdensome on retailers inventory levels, perhaps the decoder built into the point motor, would be the better solution.
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tspotter
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Re: Points \ turnouts \ switches and polarity on DCC

Postby tspotter » Sun Feb 25, 2018 1:44 pm

the decoder built into the point motor,


Like this?


IMG_7807.jpg



The decoder I mentioned earlier, fixed to a sg90 servo. With a MERG mounting bracket.

Julian

Mike Parkes
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Re: Points \ turnouts \ switches and polarity on DCC

Postby Mike Parkes » Sun Feb 25, 2018 6:45 pm

tspotter wrote:
the decoder built into the point motor,


Like this?



There is the slow motion Colbalt IP digital that has a decoder built in as I mentioned earlier https://www.track-shack.com/cgi-bin/sh0 ... ml#SID=339 while Gaugemaster do a normal Peco style solenoid with deoder https://www.track-shack.com/acatalog/Ga ... gLRaPD_BwE and a a slightly crude above surface solenoid & decoder combination https://www.track-shack.com/cgi-bin/sh0 ... ml#SID=339.

All available from other suppliers as well as Track Shack.


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