Chard Junction and Hatch (trial and error)

Sorry to hear of your trials and tribulations with your pointwork.  I've just looked again at your previous blog "My first handbuilt point is finished", and one thing that is immediately obvious to me is the check rail gap at the bottom of the second picture is clearly wider at one end than the other (indeed you can clearly see where the check rail should be on the RH end on the template below).

 

When testing pointwork, I've always found that pushing a wagon or coach through doesn't always prove anything (especially if it is a single wagon with your finger on it pushing), I tend to slightly incline the track and allow the stock to roll through under gravity.  Clearly you can't do that with a loco though as they don't freewheel.  What I would try is pushing the loco through from a wagon behind (that way you will not be exercising undue influence on the wheels of the loco).  Push it through slowly and watch the wheels to try to identify at what part of the point any derailment happens.  Repeat a few times including turning the loco around so it runs through backwards to isolate the exact part of the point that is causing any issues.

 

Hope that is helpful,

Ian

Thanks for the comment. I will try as you say using gravity

Vistean,

 

Although I can't find any pics of your points, and therefore have no idea which type of system you have used to construct your points. I would say that your problem sounds like a classic case of your check rails being too tight. I don't know what type of roll gauges you use, and whether these are correct for your track. Do you use code 100, or code 75 rail, and are the roll gauges the correct ones for the rail you use ?

 

Your roll gauges should have check rail slots if they are to be useful, and these slots are set at slightly different positions for different sizes and thicknesses of rail !

 

The fact that wagons and coach bogies go through your points without problems, but not you 0-6-0 or 6 wheel rigid part of a locos chassis (your Prairie) implies that it is likely to be the check rails next to the frog that are too tight, as you said the locos "Jam". This being the classis indication of check rails simply being possibly only 0.5mm too tight.

 

To move the check rails next to the frog out slightly, will unfortunately disprupt the position at which the blade rails bend to form the check rails. The position of these bends will have to be moved slightly towards the tiebar, to allow the check rail part to also be moved out slightly to create a wider gap. 

 

I have built hundreds of points in all scales from Z to O gauge. Some of my latest "OO" scale handbuilt points will be seen in my thread "Basingstoke in "OO" 1958-67" in the category "Modelling real locations". Run through that thread to find the pictures of these points before I ballasted them, which may help you visually to pinpoint your problem. You can always leave a further Post there if you have further questions and I'll try and help !

 

The Duke 71000   

Dear "Vistiaen"(?)

I've had a look at the 3 points and adjusted one (the long left hander - could be called PL368. I shall call it Bob). The only thing I have changed though,is the slide chairs on the diverging stock rail, as that part of the point was slightly too narrow. I've also resoldered the tie bar/timber with 0.8mm copper shim under the rails to give it the correct height. But all the important bits though the common crossing and check rails are super as they are, as far as I can test (Jinty and various wagons and coaches). So don't beat yourself up!

 

The point with the dcc rail I might do the same thing to - I think you need to be extra careful to keep everything in gauge through the switch/stock rail area as you have the same problem here. But my Jinty still went through without snagging. I won't solder the tie timber as I have shown myself incompetant with the steel rail.

 

I have a few suggestions for  the point building method, beyond making quadruply sure that everything is in gauge, and (as we discussed verbally) making all the component parts the right shapes using the template before covering the template with timbers.

- Make the tie timber number S2 and not S1. If you do that then the switch rails are supported both in front (on S3) and behind (on S1) the moving timber.

- is there any reason you've soldered the feed to the common crossing to the top of a timber instead of the underside of a rail where you won't see it. Would you mind if I moved it?

- The small wires soldering the stock rails to the switch rails are between two timbers with slide chairs, which stops the switch rails moving there. I think it would be better to move them a little closer to the common crossing after the slide chairs end.

 

Otherwise things are going fine. Perhaps you can bring your Prairie tank over with you, as that was the one which was getting stuck and shouldn't (ie. has finescale wheels).

 

Mount that plasterboard!

 

Yours

A friend

Thank you Oh master :-)