DC track power issue at points.

[barney121e]

I am building a small OO gauge layout. Have power on the outer line and power on the inner line, both work perfectly. I have a pair of insulfrog points as a cross over but my train keeps stopping on when i try and swap tracks. Have both controllers set at same power level and have plastic rails at join of points. What am i missing?

[Pete the Elaner]

It is quite likely that 1 or more of the point blades are dirty.

 

If you have a multimeter, set it to measure resistance & turn the layout power off. measure 2 sections on rails which should be in contact then move along & test the next section. You should see zero. If you see a higher reading than this, you have found your fault.

 

If you don't have a multimeter, run a loco until it stalls then starting nearest first, try holding the point blades against the rail with a little (not a lot) more force than the blade holds itself. This should increase the contact area.

[ITG]

1 hour ago, barney121e said:

plastic rails at join of points

I was under the impression that such plastic joiners were of benefit with live frog points, but not necessarily insulfrogs. That may be magnifying the problem if dirty switch blades, as the power from the opposite direction cannot then compensate for any loss in power.

[barney121e]

36 minutes ago, Pete the Elaner said:

It is quite likely that 1 or more of the point blades are dirty.

 

If you have a multimeter, set it to measure resistance & turn the layout power off. measure 2 sections on rails which should be in contact then move along & test the next section. You should see zero. If you see a higher reading than this, you have found your fault.

 

If you don't have a multimeter, run a loco until it stalls then starting nearest first, try holding the point blades against the rail with a little (not a lot) more force than the blade holds itself. This should increase the contact area.

 

The points are new, could they still be dirty. Silly question, what would happen if i put metal joiner in place of the plastic ones?

[barney121e]

1 hour ago, ITG said:

I was under the impression that such plastic joiners were of benefit with live frog points, but not necessarily insulfrogs. That may be magnifying the problem if dirty switch blades, as the power from the opposite direction cannot then compensate for any loss in power.

With trepidation tried metal rail joiners and train will now run thru points.  Now i'm confused.

[ITG]

28 minutes ago, barney121e said:

With trepidation tried metal rail joiners and train will now run thru points.  Now i'm confused.

Where are the power feeds to the track? A diagram would clarify.

[barney121e]

[barney121e]

Power feeds on right hand side, blue line is where i was having problems, and changed to metal joiners. All points are insulfrog.

 

Using a Gaugemaster Q controller, so DC control.

Edited April 12, 2022 by barney121e

[Pete the Elaner]

That should work.

 

There are several considerations:

The points around the circuit need to be set correctly.

Rail is made from Nickel Silver. This is nice because it stays fairly clean. For a common metal, it is not such a good conductor. This should not be a problem for a layout of your size, but it more significant if you plan something larger.

On the outer loop, current needs to pass across joints at 11 rail joiners & 3 point blades. These are all potential weak areas. These should not be problems with new rail.

When feeding current through several points, things can become complicated.

 

But don't go changing anything because it should work!

 

In order to help further, I need to create a diagram of how an insulfrog point conducts current.

I'll be back..

 

[ikcdab]

so you are saying that a train will run round the inner oval OK

And that it will run round the outer oval OK

 

but when you try and use the crossover, it stalls on the crossover?

 

where does it stall? if it stall before it gets to the insulated joiners, then they are not the problem and the problem is power getting to the point blades. so check that there is continuity there. 

if it stall as it crosses you insulated joiners then have you checked that the polarity is the same across both ovals? Just try swapping one set of power supply cables over.

 

a mutimeter or a very simple track tester (i make my own for pennies) is worth its weight in these situations....

 

ian

 

[barney121e]

5 minutes ago, ikcdab said:

so you are saying that a train will run round the inner oval OK

And that it will run round the outer oval OK

 

but when you try and use the crossover, it stalls on the crossover?

 

where does it stall? if it stall before it gets to the insulated joiners, then they are not the problem and the problem is power getting to the point blades. so check that there is continuity there. 

if it stall as it crosses you insulated joiners then have you checked that the polarity is the same across both ovals? Just try swapping one set of power supply cables over.

 

a mutimeter or a very simple track tester (i make my own for pennies) is worth its weight in these situations....

 

ian

 

Hi Ian

 

Yes outer and inner track train runs fine but stalls at the crossover. Loco is a class 42, first bogie goes over irj's and then stalls. Checked polarity and that was fine. Changed the irj's for metal ones and train swapped tracks. I won't use the crossing very much so if it works with metal rail joiners and correct point direction that might just be the answer. 

 

On the outside track train is happy at all points. I do have another plan in my mind, similar but with sidings at the front which i could power with a 3rd power connection, see below. But it as 3 crossovers so need to work things out first. 

[smokebox]

Guessing that the class 42 picks up power from one rail on the front bogie and from the other rail on the rear bogie, therefore stalling when the loco is straddling the two different power suplies.

[Pete the Elaner]

I have attached an electrical diagram of an insulfrog point (please excuse the fact the photo I have used is actually a bullhead Unifrog point).

The 2 running (stock) rails are coloured red & blue. On full power, you should have 12v across these.

The yellow & green sections are the blades & frog ends.. These get power by touching the stock rails. They should be held over by the point spring with enough pressure to make contact. With an insulfrog point, yellow is connected to blue or green is connected to red. Not both.

In the diagram, the point is set to straight ahead, so the yellow section should be dead & the green should be electrically connected to red.

It is usual practise to power the point from the toe end (at the right on this diagram). If you ever start using Electrofrog points, you will need to ensure power is applied from this end.

If metal rail joiners are making this work then you are either not getting power to the right end of the blue rail, or it is not passing power to the yellow section. The power is being supplied from the left hand (heel) end of the point. You can get away with this with insulfrog.

[DCB]

7 hours ago, barney121e said:

I am building a small OO gauge layout. Have power on the outer line and power on the inner line, both work perfectly. I have a pair of insulfrog points as a cross over but my train keeps stopping on when i try and swap tracks. Have both controllers set at same power level and have plastic rails at join of points. What am i missing?

The plastic rail joiners are the problem. with Insulfrog points  replacing the plastic fish plates with metal ones will fix the problem in 99% of situations. I have run my floor layout with a similar configuration of points with no insulated fishplates with no problems.   Using a bog standard resistor controller I just switch the crossover and drive the loco over.  With the crossover set  both controllers will be connected to the same track so I switch one off.  If they are in opposition you may get a dead short, probably won't just sluggish running, if set the same way you might get 200 mph.   To properly cure the problem you need cab control so the tracks both sides of the crossover can be connected to the same controller, but only to one controller at a time.      

[RobinofLoxley]

My advice is that while replacing the insulated joiners with metal ones may solve the problem for now, leaving an unknown problem in place is not a good idea. Its part of the learning process to trace and understand electrical flow on a layout and specifically on turnouts, because this is where most of the problems occur.

 

So first of all, with insulated joiners still in place, does the problem exist when the loco approaches from both sides, and both orientations? (what kind of loco is it?)

 

You have four sections of rail meeting at the join of the two points, one of which is probably dead, as Mr Elaner says, although on the basis of the situation poor contact rather than no contact is more likely. You are trying to identify which one. As a rail on one side of the 'join' will be dead, the approach of the loco and the point it stops should be different. It will normally be the frog rail that will be without power (green or yellow above) but this isnt 100% certain.

 

If you are still unsure, change ONE of the fishplates from plastic to metal, repeat the approaches. If the loco stalls the fault will be on the insulated side. If it doesnt, the fault was on the metal fishplate side.

 

Long term, the solution to loss of power through a point is to solder a section of wire across each pair of fixed rails, which ensures that power in the stock rail is always passed to the frog rail no matter what is going on at the pivots. Its also possible to get wire jumpers as stock items for the same purpose, I think.

 

Lastly, Barney, looking at the second layout, those two ST-241's with the separating ST202 dont do anything for the layout and might lead to dead shorts if you had metal fishplates everywhere.

 

Also, go to www.brianlambert.co.uk to get clues up on basic railway electrics

[kevinlms]

That crossover should ALWAYS have 2 insulated joiners there.

If you ever want to have 2 controllers, to control 2 trains, you risk a short under some conditions. 

Better to solve the problem, before you go further. 

[Pete the Elaner]

50 minutes ago, kevinlms said:

That crossover should ALWAYS have 2 insulated joiners there.

If you ever want to have 2 controllers, to control 2 trains, you risk a short under some conditions. 

Better to solve the problem, before you go further. 

I would also always use insulated joiners then re-feed & also use cab control too.

 

But

 

This takes a little more work & understanding. For some, this is just too much hassle & a distraction from modelling, even a permanent turn-off from the hobby.

I've heard plenty of layouts described by others as 'running ok' but I would consider them a complete disaster.

[kevinlms]

1 minute ago, Pete the Elaner said:

I would also always use insulated joiners then re-feed & also use cab control too.

 

But

 

This takes a little more work & understanding. For some, this is just too much hassle & a distraction from modelling, even a permanent turn-off from the hobby.

I've heard plenty of layouts described by others as 'running ok' but I would consider them a complete disaster.

You used to get quite a few articles in magazines, that said something on the lines of ''John wired the layout for me , as I don't have a clue". Which is better than struggling in unknown territory, an advantage of belonging to a club.

[Pete the Elaner]

13 minutes ago, kevinlms said:

You used to get quite a few articles in magazines, that said something on the lines of ''John wired the layout for me , as I don't have a clue". Which is better than struggling in unknown territory, an advantage of belonging to a club.

 

It can tend to be that way at clubs sometimes. There are good & bad things about that, but to go on about it here would be thread hijack 😁

[WIMorrison]

Quote

... Which is better than struggling in unknown territory, an advantage of belonging to a club.

 

I have known many clubs that rely on John to do the wiring and when John is no longer available then they are completely snookered at the first fault, which is often the day after he becomes unavailable.

 

Always best to have, as a minimum, an understanding of first principles (the basics) and what is or has been done as that will help in the troubleshooting of faults. 

[barney121e]

Thanks for all the replies. Electrics are a dark art to me. Have had cab control mentioned to me, which i had not heard of, so will look into that for sure.

 

Maybe it is just a case of double checking exactly what i want. Do i really need a crossover? It certainly wont be an exhibition layout, and just run for me.

[Pete the Elaner]

40 minutes ago, barney121e said:

Thanks for all the replies. Electrics are a dark art to me. Have had cab control mentioned to me, which i had not heard of, so will look into that for sure.

 

 

Cab control is considered by many to be better than handing off from 1 controller to another, but it does involve more wiring.

You would need a switch for each circuit to choose which controller you want to use. In order to drive a train from 1 circuit to the other, you would switch both to the same controller, then when it has cleared the first circuit, you can set that to another controller.

That probably won't make much sense until you see or use it for yourself.

[barney121e]

53 minutes ago, Pete the Elaner said:

 

Cab control is considered by many to be better than handing off from 1 controller to another, but it does involve more wiring.

You would need a switch for each circuit to choose which controller you want to use. In order to drive a train from 1 circuit to the other, you would switch both to the same controller, then when it has cleared the first circuit, you can set that to another controller.

That probably won't make much sense until you see or use it for yourself.

So would i run power to lets say the inside circuit from both  controllers and use a switch to decide which one to use? Do you know of anywhere with either a youtube video or simple diagram that might make it make sense?

[barney121e]

8 hours ago, RobinofLoxley said:

My advice is that while replacing the insulated joiners with metal ones may solve the problem for now, leaving an unknown problem in place is not a good idea. Its part of the learning process to trace and understand electrical flow on a layout and specifically on turnouts, because this is where most of the problems occur.

 

So first of all, with insulated joiners still in place, does the problem exist when the loco approaches from both sides, and both orientations? (what kind of loco is it?)

 

You have four sections of rail meeting at the join of the two points, one of which is probably dead, as Mr Elaner says, although on the basis of the situation poor contact rather than no contact is more likely. You are trying to identify which one. As a rail on one side of the 'join' will be dead, the approach of the loco and the point it stops should be different. It will normally be the frog rail that will be without power (green or yellow above) but this isnt 100% certain.

 

If you are still unsure, change ONE of the fishplates from plastic to metal, repeat the approaches. If the loco stalls the fault will be on the insulated side. If it doesnt, the fault was on the metal fishplate side.

 

Long term, the solution to loss of power through a point is to solder a section of wire across each pair of fixed rails, which ensures that power in the stock rail is always passed to the frog rail no matter what is going on at the pivots. Its also possible to get wire jumpers as stock items for the same purpose, I think.

 

Lastly, Barney, looking at the second layout, those two ST-241's with the separating ST202 dont do anything for the layout and might lead to dead shorts if you had metal fishplates everywhere.

 

Also, go to www.brianlambert.co.uk to get clues up on basic railway electrics

It's funny you quote Brian Lambert. Just found a book, looked at the electrics and still doesnt make sense. But will have a nice quiet read and hopefully it might sink in.

[Graham108]

47 minutes ago, barney121e said:

So would i run power to lets say the inside circuit from both  controllers and use a switch to decide which one to use? Do you know of anywhere with either a youtube video or simple diagram that might make it make sense?

Do a search, either in this forum or through a normal search engine, for Cab Control - as already mentioned.