First attempt at O-MF

[DaveyH]

I am enjoying making my first handbuilt copper clad based point. This is to O-MF clearances and settings though, as it is to represent a light railway feed, it is being made with code 100 rail on a Templot template.

 

My question regards how to secure the switch blades (point blades). Obviously, these need to be anchored at one end yet moveable at the other and I have found limited information on how the experts achieve this. How far from the frog do people solder/ glue the point blades? Does it matter? Does this vary with the code of rail being used?

 

Could someone advise me or point me in the direction of a helpful article/thread please?

 

I am really enjoying this but have reached an "impasse"...............

 

Thanks

 

Dave

[gordon s]

When building turnouts in 00-SF, I generally solder my switch blades three sleepers from the crossing. This allows plenty of flex in the blades and reduces the stress on the motor.

The exception to this would be in smaller angles or within slips etc where I try to leave as much flex as possible.

 

Edit:  Apologies, I didn't have my brain in gear.  I make the cut to isolate the switch blades three sleepers from the crossing.  With the blades, I leave 12 sleepers unsoldered and the solder the rest up to the crossing.  

 

I have no idea what I was thinking about with my first answer....:-)

[66C]

Hi Dave

 

What size is your turnout?  It would help if we know the angle and type of switch used.

 

Another consideration is the method you intend to use for the stretcher bar(s) as this will also impact on the flexibility of the switch.

 

If the switch rail plus the rail length to the break for the common crossing is longer than about 5 inches / 125mm then you will probably be able to solder the end of the rail at the crossing end and use the flex in the rail.  It will probably be best then if you use a hinged fixing for the stretcher bar.

 

If the switch rail is shorter then you may wish to consider a loose heel type of fixing - that is a pivot at the end of the rail similar to that used by Peco et al.  My suggestion for this would be to solder a countersunk head 8BA screw to the underside of the rail and insert in a countersunk hole through the timber and also the baseboard (if possible).  The bottom end of the screw should be secured with a nut and washer.

 

I am sure others will have their own favourite way of tackling this.

 

Regards.

[DaveyH]

Thanks for both your replies.

 

The template I used was called BH - OMF - semi-curved A + V 4.5 LH Regular V Crossing straight (no curving) - as printed across the bottom of page 2. I think I understand all of this, but it's early days!

So far I have made and fitted the V, fitted the stock rails and one of the check rails.....and need to understand how to proceed now.

[martin_wynne]

My question regards how to secure the switch blades (point blades). Obviously, these need to be anchored at one end yet moveable at the other and I have found limited information on how the experts achieve this. How far from the frog do people solder/ glue the point blades? Does it matter? Does this vary with the code of rail being used?

 

Hi Dave,

 

This is what you are building:

 

 

An 'A' switch is a flexible switch, meaning that the switch blades (points) are rigidly fixed at the heel and move across at the toe by flexing the metal.

 

With the blade clipped to the stock rail in the closed position, solder one timber at a time working towards the blade tips, testing as you go after each one. For 0-MF, when the blade is open by 3mm at the tip you need at least a clear 1.5mm all along behind the open blade. When you get that, stop soldering any more fixings.

 

(The prototype opening is 2.5mm in 7mm scale, but you likely need a bit more to get 1.5mm clear all along, especially with stiffer flat-bottom rail.)

 

Some notes about fitting flexible switches in a model are here (for 4mm scale): http://www.rmweb.co.uk/community/index.php?/topic/99645-flexible-switch-copper-clad/&do=findComment&comment=1903928

 

Don't get the blades too thin at the tip, otherwise only the tip part will flex and you won't get sufficient clearance. Some notes about filing flat-bottom switch blades are here: http://www.rmweb.co.uk/community/index.php?/topic/95378-crossing-vs-and-point-blades/&do=findComment&comment=1760666

 

p.s. Note that an A-4.5 is a very small turnout -- as you can see the radius is showing as only 39" which is sharp in 0 gauge. If you need a lot of short turnouts for your layout, there are design changes you can make in Templot to ease the radius.

 

more p.s. If you are using 4mm scale code 100 rail for 7mm scale, it will be significantly under scale width. Ideally you would have adjusted the rail width in Templot, because it affects the position of the planing marks and stock gauge marks on the template.

 

regards,

 

Martin.

[DaveyH]

 

This is the one Martin!

The wooden sleepers are the same thickness as the copper clad and are removed and replaced with copper as the need arises. I have really enjoyed doing this and am looking forward to adding the switch blades following all the advice I have received, thanks. Gauges and slips by Debs.

 

 

This photograph shows the V, formed by bending a rail in half and then filing to shape, and the Temlot template taped to the bench.

 

In my naivety, I thought if the inner edges of the rail were in the same place as the inner edges of the original code 124 stuff, then I would be alright. Your advice, Martin, about changing the rail size settings in Templot would suggest that was a "schoolboy error"? I intend to soldier on and see what the finished article is like as I can always take it apart and start again! There are no chairs as the whole will be buried in ballast as "light rail".

 

Once again, thanks for the advice everyone.

[martin_wynne]

I thought if the inner edges of the rail were in the same place as the inner edges of the original code 124 stuff, then I would be alright.

 

Hi Dave,

 

Yes, that's correct, the running edges of the rail will be in the same place. Here is a template print showing that:

 

 

On the left is a standard 0 gauge template assuming the default scale 2.75" rail width.

 

I don't know the size of the rail which you are using, but let's say it scales at 7mm/ft to a head width of 1.5" and a foot width of 3". On the right I have entered these settings at real > rails > rail section data... and changed to real > rails > head and foot (flat-bottom rails).

 

You can see that the geometry of the running edges and timber positions remains exactly the same. But notice that the positions marked as stock gauge and planing are different. These indicate where the planing (filing) of the rail head finishes and the rail tops begin to diverge. You can see that if you followed these marks on the original template you would get in a mess with the narrower rail.

 

I'm a bit puzzled by your use of wooden timbers. Usually for copper-clad construction all the timbers are copper-clad, attached to the template with double-stick tape or some other adhesive. Moving timbers about during construction could be troublesome -- how are you intending to fix the rails to the wooden timbers?

 

It is odd how often beginners make things difficult for themselves.   I can't help feeling it would have been so much easier to use ordinary 0 gauge bullhead rail on ordinary copper-clad timbers for a first go at track building. It is much easier to work with bullhead rail than with flat-bottom, and it would fit Debs 0-MF gauges properly.

 

regards,

 

Martin.

[DaveyH]

Thanks for taking the trouble to answer so completely Martin. Off to a wedding today so no modelling time

 

I'll be having another bash tomorrow and will take all your advice on board. I admit to not knowing what the "stock gauge" and "planing" marks were for, how embarrassing!

 

I'll post some more pictures when there is some more progress.

[martin_wynne]

I admit to not knowing what the "stock gauge" and "planing" marks were for

 

Hi Dave,

 

That's a bit worrying because you should have used those marks in setting the curved stock rail. If you haven't got it correctly set and positioned it will be difficult to get the switch blades to seat against it properly and to gauge. More about all that here:

 

http://www.rmweb.co.uk/community/index.php?/topic/56661-cl-turnout-in-a-bag-kits-in-7mm-scale-o-gauge/&do=findComment&comment=696561

 

regards,

 

Martin.

[DaveyH]

Okay, decision made to take it apart and start again with a template similar to the one Martin kindly printed above.

 

Read a lot more on here and the Templot forum, so should be a bit easier now. (RTFM :-) )

 

Thanks all.

[DaveyH]

But before I do............

 

Decided to press on and finish as a trial run at doing stuff. Despite the looks, it works quite well, though some of the solder on the sleepers stopped the point blades going properly against the stock rails until filed off.

 

 

The standard of finish is poor, but I was so happy that I carried on as I have have learned a lot for the real proper go...

 

 

So all in all a successful trial that taught me a lot (especially how not to do stuff)!

 

 

You can see the kinks in the last photo....and I need a bigger file for the point blades!

[jim.snowdon]

It's a good start, and you will have learned a lot from it. The critical elements are the crossing and the switches and, with regard to the former, it will help to build the whole cf the crossing first and then fill in around it. Get the vee and wing rails assembled as a unit on all of its four or five bearers, setting and aligning the wing rails using a 1.5mm strip gauge. I use a piece of stripwood, largely as it is unsolderable.

Once the crossing is in place, the stock rails can be set in place, followed by the check rails (which will then come out parallel). As you are using a lighter weight rail than the usual for 0 gauge, you will need to ensure that the gauging face of the check rail is pushed tight against the face of the gauge farthest from the crossing nose.

 

What isn't clear yet is how you are going to deal with the tie bar at the other end of the turnout.

 

Jim

[DaveyH]

Thanks for your advice Jim.

 

I had fitted the tie bar - a narrower piece of copper clad sleeper - and it worked well. Only issue was that when I soldered the stock rails in place I "pulled" the solder under the rail from the outside to in and, as a consequence, ended up with some solder blobs where the switch rails should rest against the stock rail. I have printed a crossover out now from Templot, using the correct rail sizes that Martin told me how to do, and will be starting construction later next week when work stops getting in the way!

 

I also thought it may be easier to use code 100 bull head rail rather than flat bottom, but do you think I can find any?

[jim.snowdon]

Despite being a traditional method, using copper-clad pcb for stretcher bars has disadvantages. Apart from the problems of solder creep that you had, they have a tendency, after a while, to break. It may not seem much, but as the points are changed, the end of the switch rail has to rotate through a small angle. Fixed rigidly to the pcb stretcher, either the solder joint eventually gives up, or the copper breaks away from the substrate.

 

What is really needed is to introduce some give into the whole assembly, either by allowing the switch rails to pivot on the stretcher, or by making the stretcher bar flexible. A common method for achieving the former in my days in EM modelling, was to use a standard ply sleeper with the switch rails attached to the brass rivets. Because these could rotate in the sleeper, the strain was eliminated.

 

An alternative that I came across in 7mm, and wrote up in the Guage 0 Guild Gazette, was the use of small double-sided pcb pads connected by a length of phosphor bronze wire. The wire went underneath the pads, and the switch rails on top, so the bar was insulated. On the assumption that you haven't access to the Gazette (and for any other readers who haven't) I have attached a downloadable copy of the article. (For those with access, it is in Volume 19, No. 6)

 

Stretcher Bars.pdf

 

 

 

As for rail, I am not sure that using bullhead would bring you much benefit, apart from being untypical. By the fact that you are using a smaller rail section I would guess that you are modelling light or industrial railways, where the rail was spiked to the sleepers rather than being put in chairs, in which case flatbottom is entirely appropriate. It does need more work than with bullhead as the foot needs to be filed off on one side of the stock and switch rails, but then the same is true for the closing side of a bullhead switch rail. The rest of the work is in profiling the gauge side of the switch rail head, which is the same for both bullhead and flatbottom.

 

Regards,

 

Jim

[Izzy]

I used peco code 100 flatbottom for my O gauge light railway (flatbottom does mean more work filing!) and found that it was a good compromise as regards size/weight for a such a railway in 7mm scale. If you are working against space constraints as I was you might like to consider using wye points as a means of keeping points short while having a reasonable radius to the trackwork. It does mean the track doesn't look quite so prototypical but with care in design a reasonable result can be achieved. A minimum space layout needs compromise somewhere and I felt this better than very tight radius track.

 

Izzy

[AndyID]

Despite being a traditional method, using copper-clad pcb for stretcher bars has disadvantages. Apart from the problems of solder creep that you had, they have a tendency, after a while, to break. It may not seem much, but as the points are changed, the end of the switch rail has to rotate through a small angle. Fixed rigidly to the pcb stretcher, either the solder joint eventually gives up, or the copper breaks away from the substrate.

 

What is really needed is to introduce some give into the whole assembly, either by allowing the switch rails to pivot on the stretcher, or by making the stretcher bar flexible. A common method for achieving the former in my days in EM modelling, was to use a standard ply sleeper with the switch rails attached to the brass rivets. Because these could rotate in the sleeper, the strain was eliminated.

 

An alternative that I came across in 7mm, and wrote up in the Guage 0 Guild Gazette, was the use of small double-sided pcb pads connected by a length of phosphor bronze wire. The wire went underneath the pads, and the switch rails on top, so the bar was insulated. On the assumption that you haven't access to the Gazette (and for any other readers who haven't) I have attached a downloadable copy of the article. (For those with access, it is in Volume 19, No. 6)

 

Stretcher Bars.pdf

 

IMG_1804r.JPG

 

IMG_1805r.JPG

 

As for rail, I am not sure that using bullhead would bring you much benefit, apart from being untypical. By the fact that you are using a smaller rail section I would guess that you are modelling light or industrial railways, where the rail was spiked to the sleepers rather than being put in chairs, in which case flatbottom is entirely appropriate. It does need more work than with bullhead as the foot needs to be filed off on one side of the stock and switch rails, but then the same is true for the closing side of a bullhead switch rail. The rest of the work is in profiling the gauge side of the switch rail head, which is the same for both bullhead and flatbottom.

 

Regards,

 

Jim

 

A similar 00 tiebar/stretcher made with PB strip rather than wire. The PB strip is a bit more flexible than wire.

 

Starts at this post - http://www.rmweb.co.uk/community/index.php?/topic/97958-turnout-tools/page-5&do=findComment&comment=1871615

[hartleymartin]

Another two possible methods, which I am yet to try myself are:

 

1.) Take a small piece of brass strip (scratch etch will do) soldered to the underside of the rail. Drill a hole into the strip and thread a small brass pin through it. Bend the pin over and solder to the tie-bar, which may be a narrow strip of PCB material or some sort of plastic rod.

 

2.) With flat-bottom rail, when you make up the switch-blades, try to preserve as much of the inside foot as possible. You will then be able to drill a small hole through the foot of the rail and use either a brass pin as mentioned above, or a small-diameter long bolt from scale hardware. Failing that, a long 14BA screw and a nut will do the trick.

 

Not personally tried either method just yet, but that was only because we had a good exchange rate for a while a number of years back and I was able to buy Peco online cheaper than building my own points for about 18 months.

[jim.snowdon]

A similar 00 tiebar/stretcher made with PB strip rather than wire. The PB strip is a bit more flexible than wire.

 

Starts at this post - http://www.rmweb.co.uk/community/index.php?/topic/97958-turnout-tools/page-5&do=findComment&comment=1871615

The wire is only 0.5mm diameter, which is more than flexible enough, yet still stiff enough to take the compression forces when the switches are pushed across.

 

And, much simpler to put together.

 

Jim

[AndyID]

The wire is only 0.5mm diameter, which is more than flexible enough, yet still stiff enough to take the compression forces when the switches are pushed across.

 

And, much simpler to put together.

 

Jim

 

Hi Jim,

 

I tried 0.5 mm PB wire first, but I wasn't very happy with it for 00 (it might work a lot better in 0 gauge).

 

The way I made it with PB strip is a bit more complicated but I like the way it keeps the surfaces of the pads rigidly aligned in the same horizontal plane while allowing plenty of flex in the vertical plane.

 

Cheers!

Andy