Jump to content

Recommended Posts

47 minutes ago, The Stationmaster said:

As it comes out of the pack (i'm using the bullhead version as an example annd assuming the FB ones are similar) everything, including the wing rails beyond the 'frog' is live and bonded to ensure it is live - ideal for DCC.  The only thing which is dead is the 'frog' (actually the crossing nose area) which therefore requires power to be switched to it if it is to be made live.

 

However being bonded as it comes does not mean the point would function like a normal 'live frog point' where the wing rails beyond the 'frog' draw their power feed from, effectively, the 'frog' itself.  So in order to convert the point to a traditional 'live frog' wiring the following changes are needed 

1.  The 'frog' supply needs to be fed via a switch controlled by the position in which the ponts blades are set, and 2.

2. The wing rails need to be bonded to the 'frog' instead of  their as supplied cross-bonding to the relevant opposite running rail.

Do that and you have a live 'frog' point which would make a dead end siding self isolating when the point is not set towards it,

 

If you use the point as it comes, irrespective of whether or not you add a feed to the 'frog',  both routes coming out of the heel end of the point are always live when the running rails leading into the toe end of the point are live.  So in this case to isolate a dead end siding coming out of the point you need an isolating gap/rail joiner in one rail and an on/off switch in order to effect isolation of that dead end siding.  

 

Thanks. And that's consistent with the Railway Modeller article that said that DC users just need to add extra sections to all their sidings to use these points.

 

However....either the non bullhead ones are different (and thus there is more than one type of unifrog) or the people who say that they can be made power isolating by cutting/making links have somehow got it wrong.

 

Actually this - from Peco themselves - seems to make it quite clear.

No power routing no matter what you do.

 

It's certainly not the "best of both worlds" to anyone on DC who is used to relying on the isolating properties of points.

 

  • Agree 3
Link to post
Share on other sites
2 hours ago, Coryton said:

 

That's what I thought.

 

But what I can't get a consistent answer on is whether getting power switching to the track beyond the points like an insulfrog point (so that anything on the route that the points are set against is isolated):

- Requires just cutting two wires

- Requires soldering extra links

- Can't be done without an external switch linked to the point position

 

 

 

All three. Perhaps this diagram will help explain. I have taken the Peco PDF of their code 75 unifrog bullhead and coloured it as it comes wired. Both routes are live at all times and the frog is dead. You will thus see that an external changeover switch of some kind is required to power the frog. This is also needed if you want to have power switching because you have to cut the connections marked A + B and change the exit road rails C + D polarity to suit. Wire power to them as with the frog.

 

1299760494_RMwebPecoBH75wiring.jpg.23e5b75fd4f9d459265e85b186d33e63.jpg

 

Now if you want to just have the branch/siding route isolated when not chosen you only have to do that one, cut the B connection and use the changeover switch as an on/off one. Or both C + D for the more normal power routing type of wiring. the choice is yours. And of course the changeover switch can power the frog at one and the same time as either C or D or both.

 

Edited by Izzy
had two images for some reason.....
Link to post
Share on other sites
3 minutes ago, Free At Last said:

 

Actually the wiring/switching in option 2 baffles me.... 789107579_Unifrogswitching.JPG.47d34f1bfe0da9d34c6d02965c179d4d.JPG

 

It's just taking a feed from "red" and another from "blue" isn't it? So that the frog can have whichever one is appropriate to the way the points are set.

 

I think I'm starting to understand. From here it's clear that the bullhead points and N gauge ones are not the same.

 

The N gauge points seem to have a rather odd looking asymmetrical arrangement where power to the inner rails on the diverging side of the frog for one route is taken around the frog as in an insulfrog point, but for the other is taken from another rail on the diverging side of the frog. (I know there are proper words for all these bits of points but not ones I'm familiar enough with to use).

 

This would need an extra link around the frog making in order to act as an insulfrog point as well as two links cutting.

 

Maybe the code 83 H0 ones are different and route power across the frog both ways, and would therefore only require cutting two links?

 

If so that would explain the general disagreement on what needs doing.

 

So far as I know the regular streamline 00 points have yet to appear so we don't know what they will be like.

 

I would have thought these would be their best sellers (apart from 00 setrack maybe?) so it seems odd that these weren't among the first to be done.

 

 

 

 

Link to post
Share on other sites
9 minutes ago, Izzy said:

 

All three. Perhaps this diagram will help explain. I have taken the Peco PDF of their code 75 unifrog bullhead and coloured it as it comes wired. Both routes are live at all times and the frog is dead. You will thus see that an external changeover switch of some kind is required to power the frog. This is also needed if you want to have power switching because you have to cut the connections marked A + B and change the exit road rails C + D polarity to suit. Wire power to them as with the frog.

 

1299760494_RMwebPecoBH75wiring.jpg.23e5b75fd4f9d459265e85b186d33e63.jpg

 

Now if you want to just have the branch/siding route isolated when not chosen you only have to do that one, cut the B connection and use the changeover switch as an on/off one. Or both C + D for the more normal power routing type of wiring. the choice is yours. And of course the changeover switch can power the frog at one and the same time as either C or D or both.

 

 

Thanks. That's very clear.

 

In principle though, it seems to me that by cutting the all the links and appropriately re-connecting, you could route the power across the frog as in an insulfrog and get power switching back.

 

And it's clear that the N gauge ones are not wired in the same way because the photo of the underside shows one wire running across the frog just as in an insulfrog.

  • Agree 1
Link to post
Share on other sites
1 minute ago, Coryton said:

 

Thanks. That's very clear.

 

In principle though, it seems to me that by cutting the all the links and appropriately re-connecting, you could route the power across the frog as in an insulfrog and get power switching back.

 

And it's clear that the N gauge ones are not wired in the same way because the photo of the underside shows one wire running across the frog just as in an insulfrog.

 

Yes, in principle you could, but you are then back to the age-old problem many suffered with, and which PECO have tried to address, of relying on blade contact for electrical connection. Plus the added problem of shorting via wheel backs in places. They have tried to produce a design that can be either insulfrog or electrofrog and I think in the main it's a good idea. I believe all the unifrog points are wired electrically in the same manner. However for practical purposes where the wiring runs are located with different scales/sizes of point might vary.

 

Link to post
Share on other sites
28 minutes ago, Izzy said:

 

Yes, in principle you could, but you are then back to the age-old problem many suffered with, and which PECO have tried to address, of relying on blade contact for electrical connection.

 

That's true, but I've been getting away with it for 10 years or so and I know I'm not the only one. 

 

After all, if route isolation was so undesirable, Peco could have changed their points to non isolating a long time ago, I'd have thought.

 

28 minutes ago, Izzy said:

I believe all the unifrog points are wired electrically in the same manner. However for practical purposes where the wiring runs are located with different scales/sizes of point might vary.

 

 

I do not think that's true, at least not in the sense I mean.

 

Looking at the photos earlier in the thread of the underside of the bullhead and N gauge points, the bullhead points don't have any wiring running from the heel to the toe side of the points.

The N gauge ones have a wire bypassing the frog as with an insulfrog point (for only one route).

 

That's topologically different, not just a different wiring run.

 

So far a I can see the Bullhead points would require two links making to get power routing, the N gauge points only one.

 

(And maybe code 83 H0 need none?)

 

Link to post
Share on other sites
9 hours ago, Coryton said:

 

It's just taking a feed from "red" and another from "blue" isn't it? So that the frog can have whichever one is appropriate to the way the points are set.

 

In the 3rd example the frog and outside rail are the same polarity.

Link to post
Share on other sites
2 hours ago, Free At Last said:

In the 3rd example the frog and outside rail are the same polarity.

It took me a while to realise that that example was wrong

I have rehashed the Option 2 drawings & they should be correct now

The rail colours have been changed so that the left rail is blue & the right rail is red

I suspect that the original poster of this drawing made the mistake of having both rails of each route the same colour

rather then having rails of the same polarity(phase) the same colour

 

 

1397347436_unifrogswitching.png.ed71327040b82986a464f7e96475b32b.png

John

Link to post
Share on other sites
4 hours ago, John ks said:

It took me a while to realise that that example was wrong

I have rehashed the Option 2 drawings & they should be correct now

The rail colours have been changed so that the left rail is blue & the right rail is red

I suspect that the original poster of this drawing made the mistake of having both rails of each route the same colour

rather then having rails of the same polarity(phase) the same colour

 

 

 

John

 

I wouldn't call it a mistake.

 

I presume it was a deliberate choice to use the colours to indicate "appropriate polarity for this route".

 

I don't think it's how I would have done it, and maybe it could have been explained more clearly as people are likely to assume the colours indicate polarity and get confused, but I don't think it's actually wrong.

 

 

  • Agree 2
Link to post
Share on other sites

 

 

 

22 hours ago, Free At Last said:

Actually the wiring/switching in option 2 baffles me.... 

It baffled me to 

5 hours ago, Coryton said:

I don't think it's how I would have done it, and maybe it could have been explained more clearly as people are likely to assume the colours indicate polarity and get confused, but I don't think it's actually wrong.

 

Here is the original image from Railway Modeller June 2018

I have added the green lines to indicate where the frog connects & extended the rails to complete the point

Option 2A  the frog(red) is connected to the same red rail via the switch as it should be  (follow the green line)

Option 2B the frog (now blue) is connected to the RH blue rail when it should be connected to the LH blue rail (dotted line shows where it should go)

Each time a loco goes though that route there will be a short as the wheels cross from the rail to the frog because the frog is connecter to the RH rail & not the LH rail as it should be

To me this is wrong

 

 

1745516700_unifrogwrong.png.f7cdc7fe159bfafeaf453206bb073180.png

 

John

Edit to remove duplicated image

 

 

Edited by John ks
Link to post
Share on other sites
2 hours ago, John ks said:

 

 

 

It baffled me to 

 

Here is the original image from Railway Modeller June 2018

I have added the green lines to indicate where the frog connects & extended the rails to complete the point

Option 2A  the frog(red) is connected to the same red rail via the switch as it should be  (follow the green line)

Option 2B the frog (now blue) is connected to the RH blue rail when it should be connected to the LH blue rail (dotted line shows where it should go)

Each time a loco goes though that route there will be a short as the wheels cross from the rail to the frog because the frog is connecter to the RH rail & not the LH rail as it should be

To me this is wrong

 

 

John

Edit to remove duplicated image

 

 

 

Agreed.

 

I think the colours are right (for the way they've used them) but the wiring doesn't work out.

  • Agree 1
Link to post
Share on other sites

What's wrong in the option 2 diagrams is that both legs of the switch are going to rails that are bonded together, even though shown in different colours.

The author has confused things by using red for both rails of the left route when it should have been red for the left rails of both routes. IMHO an illustrator who does not understand what they are illustrating.

  • Agree 1
Link to post
Share on other sites

They've used colours to designate routes, rather than polarities, and it is blasted confusing.

 

On another point(!): I used some of these points last year, and was surprised by how fragile the soldered connections to the frog on the underside are. One was already broken in the package, and I managed to break one as I installed it.

 

Check before you install, and install very carefully!

  • Informative/Useful 1
Link to post
Share on other sites
2 hours ago, Nearholmer said:

They've used colours to designate routes, rather than polarities, and it is blasted confusing.

 

And looking at how they showed the wiring, they seem to have managed to confuse themselves...

 

 

  • Agree 2
Link to post
Share on other sites
  • 2 months later...

Looking at this Peco code 83 unifrog I'm in befuddlement where the switch blade rail pivot point is located and "one-piece machined switch blades"?

 

 

129758602_10158945248719214_7832905716408170085_o.jpg

Edited by maico
Link to post
Share on other sites

Maico

I would think the " One-piece Machined switch blades " explains it all

One piece, = the rail is one piece from the frog to end of the switch blade & like the bullhead points the switch rail flexes rather than having a pivot.

Machined switchblades,= the switch blades are machined to shape from solid rail rather than being flat metal that is stamped & folded to shape( like most existing Peco points)

 

Top marks to Peco for improving these points

Will this be the way that all Peco points will be improved in the future?

One problem i can see is with code100 & above rail is if it is flexible enough to be able to eliminate the pivot on the switch blade

John

  • Informative/Useful 1
Link to post
Share on other sites

Tillig seem to use the same idea of flexing the switch blade

 

https://www.tillig.com/eng/Produkte/produktinfo-85383.html

 

https://www.tillig.com/eng/Produkte/produktinfo-85445.html

 

My code 83 Trix C-track is completely different. A short solid cast switch blade that is loosely mounted and moves a bit when the wheels go over it.  The polarity of the metal frog changes with the direction lever. I'll have to buy a Peco Unifrog to compare!

Edited by maico
Link to post
Share on other sites
  • 2 weeks later...

The Unifrog point frog design is a backward step compared to the Electrofrog design for DC and DCC. It continues the design fault (for DCC) of the insulfrog design as you get momentary short circuit conditions when using wide tread 00 wheels and live wired  turnouts from both ends. Also the new Unifrog does not look as good as an all metal electrofrog as it has an unprotypical frog point and diverging rails plus large plastic filled gaps.  It is also easy for the factory fitted wires under the frog to be bent and cause a short circuit. A step forward would be to have made a new Electrofrog  with metal wing rails and solid point blades with the insulated gaps in the point blades about in the same location as the old Electrofrog design. As supplied the new 00 Unifrog is not DCC friendly IMO.

Edited by nswgr1855
Link to post
Share on other sites
8 hours ago, nswgr1855 said:

...It continues the design fault (for DCC) of the insulfrog design as you get momentary short circuit conditions when using wide tread 00 wheels and live wired  turnouts from both ends...

The treads would have to be pretty wide to be a problem, the sort of wheels which would be unsuitable for code 100 track.

  • Agree 1
Link to post
Share on other sites
11 hours ago, nswgr1855 said:

The Unifrog point frog design is a backward step compared to the Electrofrog design for DC and DCC. It continues the design fault (for DCC) of the insulfrog design as you get momentary short circuit conditions when using wide tread 00 wheels and live wired  turnouts from both ends. Also the new Unifrog does not look as good as an all metal electrofrog as it has an unprotypical frog point and diverging rails plus large plastic filled gaps.  It is also easy for the factory fitted wires under the frog to be bent and cause a short circuit. A step forward would be to have made a new Electrofrog  with metal wing rails and solid point blades with the insulated gaps in the point blades about in the same location as the old Electrofrog design. As supplied the new 00 Unifrog is not DCC friendly IMO.

 

While shorting may be an issue on code 100 with coarser wheels, Bullhead Unifrog is code 75 only, so any coarse wheels which may be wide enough to cause a shorting issue won't run through it properly anyway because the flanges are too deep for code 75.

If Peco decide that their code 100 range will all be Unifrog from now on, then this may be a concern, but I am unaware of them having taken such a decision.

I am not sure what you mean about Unifrog having "unprotypical frog point and diverging rails". The geometry of the large turnout it the same as the large radius flatbottom streamline.

The insulating gap is debatable. I agree that this part does not look as good as Electrofrog but the 1 piece switch rail is an improvement, with no hinge or gap. This offsets the difference in frog appearance & any argument that 1 is better than the other is therefore subjective.

Link to post
Share on other sites

 

20 hours ago, nswgr1855 said:

. A step forward would be to have made a new Electrofrog  with metal wing rails and solid point blades with the insulated gaps in the point blades about in the same location as the old Electrofrog design. As supplied the new 00 Unifrog is not DCC friendly IMO.

 

But that would mean that the frog has to be switched via an external device - be that a switch, integral contact within a point motor or frog juicer.

The current design of electrofrog does not immediately require a switch and does mean simpler wiring for those that either:

1. Want manually operated points without the need to fit a separate switch, or

2. Sometimes cannot understand the requirements of an electrically switched frog.

(Whilst insulfrog is an option for the above, even an unswitched electrofrog is a step forward IMO)

 

In both cases above, relying on the blade to stock rail contact to provide power to the frog.

 

Most of us probably know that relying on blade contact isn't ideal, but at least Peco have made it easy to adapt the majority of electrofrog points in their range to isolate the frog and feed via a switch for those of us that wish to do so, yet making them immediately usable out of the box for those that do not require switched frogs.

 

I think Peco are correct in this philosophy as otherwise, it would rule out anyone from using an electrofrog that fitted the two criteria above, but having them easy to modify includes everyone.

 

Going down the Unifrog route now effectively provides all options with only one catalog item instead of 2

 

With regard to "DCC friendly" - this is a misnomer.

The modification to Peco electrofrog points to make them a switched frog with blades insulated from the frog  - is valid for both DCC and DC.

I had shorting issues running Code 75 on DC when they were first released in the early 1990s, where a wheel would bridge the gap from stock rail to open blade - usually a wide tread wheel and/or a narrow bck-to-back.

 

As Pete points out, the common cause of a short on an insulfrog is between the two rails just beyond the vee and is attributed to older wheel standards.

Going forward, there must come a stage at which the improved track range is no longer backwards compatible with wheels standards from 30 years ago.

 

 

 

  • Agree 2
  • Informative/Useful 1
Link to post
Share on other sites
On 05/04/2021 at 18:33, Suzie said:

The treads would have to be pretty wide to be a problem, the sort of wheels which would be unsuitable for code 100 track.

It'a long proven problem with the Peco insfulfrog turnout if you power it for DCC. The Unifrog has the same geometry at the frog, the only difference at the frog is the frog tip is metal. Most RTR 00 wheels are at least 2.8mm wide, more than enough to cause a momentary short.

 

Edited by nswgr1855
correction
Link to post
Share on other sites
On 05/04/2021 at 22:00, Pete the Elaner said:

 

While shorting may be an issue on code 100 with coarser wheels, Bullhead Unifrog is code 75 only, so any coarse wheels which may be wide enough to cause a shorting issue won't run through it properly anyway because the flanges are too deep for code 75.

If Peco decide that their code 100 range will all be Unifrog from now on, then this may be a concern, but I am unaware of them having taken such a decision.

I am not sure what you mean about Unifrog having "unprotypical frog point and diverging rails". The geometry of the large turnout it the same as the large radius flatbottom streamline.

The insulating gap is debatable. I agree that this part does not look as good as Electrofrog but the 1 piece switch rail is an improvement, with no hinge or gap. This offsets the difference in frog appearance & any argument that 1 is better than the other is therefore subjective.

Current RTR 00 wheels are more than wide enough to cause shorting on the Unifrog. Yes the new point blades are an improvement, but the Unifrog is a is still a short circuit problem and looks like a toy frog.

Link to post
Share on other sites
17 hours ago, newbryford said:

 

 

But that would mean that the frog has to be switched via an external device - be that a switch, integral contact within a point motor or frog juicer.

The current design of electrofrog does not immediately require a switch and does mean simpler wiring for those that either:

1. Want manually operated points without the need to fit a separate switch, or

2. Sometimes cannot understand the requirements of an electrically switched frog.

(Whilst insulfrog is an option for the above, even an unswitched electrofrog is a step forward IMO)

 

In both cases above, relying on the blade to stock rail contact to provide power to the frog.

 

Most of us probably know that relying on blade contact isn't ideal, but at least Peco have made it easy to adapt the majority of electrofrog points in their range to isolate the frog and feed via a switch for those of us that wish to do so, yet making them immediately usable out of the box for those that do not require switched frogs.

 

I think Peco are correct in this philosophy as otherwise, it would rule out anyone from using an electrofrog that fitted the two criteria above, but having them easy to modify includes everyone.

 

Going down the Unifrog route now effectively provides all options with only one catalog item instead of 2

 

With regard to "DCC friendly" - this is a misnomer.

The modification to Peco electrofrog points to make them a switched frog with blades insulated from the frog  - is valid for both DCC and DC.

I had shorting issues running Code 75 on DC when they were first released in the early 1990s, where a wheel would bridge the gap from stock rail to open blade - usually a wide tread wheel and/or a narrow bck-to-back.

 

As Pete points out, the common cause of a short on an insulfrog is between the two rails just beyond the vee and is attributed to older wheel standards.

Going forward, there must come a stage at which the improved track range is no longer backwards compatible with wheels standards from 30 years ago.

 

 

 

The Unifrog does not look like a real crossing V, the old electrofrog did. That is a backward step. The short circuit wheel issue is real, another backward step, that was not a problem with the Electrofrog. Today's RTR 00 wheels are more than wide enough to cause short circuits on  the Unifrog turnout, irrespective of track code.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.