OMF Double Slip - switch blades

[Alan Kettlewell]

I've built a dozen or more turnouts and now I'm having a go at my first double slip (OMF) and need a bit of help regarding how to construct the switch blades.  In my picture you can see I've made the blades separately and attached them using plastic fishplates (super-glued).  The blades are only fixed ie held down by a single chair quite near the fishplate, and of course by the stretcher bar which I did later.

 

I'm finding that as the blades are quite short, there's a lot of resistance to their ability to pivot or spring - too much for the motor actuator to overcome (I'm using Tortoise with stiffer wire).

 

My query is, is this the best way to do the blades or is it better to leave them all in one piece and rely on springing for the movement (as I do with a standard turnout)?  Or do folk manufacture some sort of pivot?  Also, with the method I've used, there's the question of where to fit bonding wires for power from the stock rail. 

 

Many thanks.  

 

Cheers … Alan     

[Stephen Freeman]

Better to use etched brass fishplates, only one needs to be soldered both rails.This will give much more flexability. Also for stretcher bars do the two pairs independently and then join them together to move as one.

[Alan Kettlewell]

58 minutes ago, Stephen Freeman said:

Better to use etched brass fishplates, only one needs to be soldered both rails.This will give much more flexability. Also for stretcher bars do the two pairs independently and then join them together to move as one.

 

Hi,

 

Thank you, I did wonder about that but good to have it confirmed.  Solves the power supply to the blades nicely too.  Looks like another C&L order coming up and a bit of deconstruction.

 

Cheers ... Al

 

[hayfield]

I was shown another method where you use Exactoscale H shaped cast fishplates, only solder to the center rail. the builder was using copperclad tiebars which stopped the switch rails moving forward, the rail break was after the chair,  

Edited May 19, 2020 by hayfield

[adriank]

I'm about to embark on the construction of my first double slip and my first point and crossing work using plastic components. I am very pleased to be able to view such an excellent photograph. Thanks for posting.

 

Adrian

 

 

 

[hayfield]

15 hours ago, Alan Kettlewell said:

I've built a dozen or more turnouts and now I'm having a go at my first double slip (OMF) and need a bit of help regarding how to construct the switch blades.  In my picture you can see I've made the blades separately and attached them using plastic fishplates (super-glued).  The blades are only fixed ie held down by a single chair quite near the fishplate, and of course by the stretcher bar which I did later.

 

I'm finding that as the blades are quite short, there's a lot of resistance to their ability to pivot or spring - too much for the motor actuator to overcome (I'm using Tortoise with stiffer wire).

 

My query is, is this the best way to do the blades or is it better to leave them all in one piece and rely on springing for the movement (as I do with a standard turnout)?  Or do folk manufacture some sort of pivot?  Also, with the method I've used, there's the question of where to fit bonding wires for power from the stock rail. 

 

Many thanks.  

 

Cheers … Alan     

 

 

Your tiebar solution looks very interesting, please could you describe it please

[Alan Kettlewell]

1 hour ago, adriank said:

I'm about to embark on the construction of my first double slip and my first point and crossing work using plastic components. I am very pleased to be able to view such an excellent photograph. Thanks for posting.

 

Adrian

 

 

 

 

Hi,

 

Thanks.  It's my first too, it's not perfect and took a lot longer than a standard turnout.  One more to do for my layout.  Enjoy.

 

Cheers … Alan

 

[Alan Kettlewell]

1 hour ago, hayfield said:

 

 

Your tiebar solution looks very interesting, please could you describe it please

 

Hi,

 

I came across the idea somewhere on here or the Gauge 0 Guild forum.  It's just small tabs of copper clad soldered to the underside of each blade.  Then they are joined using a length of stiff spring wire - guitar or piano wire.  The copper clad prevents contact with the blades so there's no shorting.  As you can see I put a small hole in one end for the actuator wire but other there may be other ideas.

 

It's not too authentic looking but it works and is less obtrusive than the 'magic floating sleeper' method often used.  Here's my double slip with the stretcher bar soldered on ...

 

 

Cheers … Alan

 

[hayfield]

Alan

 

Thanks for the photo, sowed a seed or two

 

Coming back to your issue, some of your slide chairs are too short and the rail may even be catching on the bolts, whilst a bit un-prototypical try unsticking the first bridge chair to see if it frees up the movement a tad.

[Alan Kettlewell]

21 minutes ago, hayfield said:

Alan

 

Thanks for the photo, sowed a seed or two

 

Coming back to your issue, some of your slide chairs are too short and the rail may even be catching on the bolts, whilst a bit un-prototypical try unsticking the first bridge chair to see if it frees up the movement a tad.

 

Yes I agree, thanks.  I've since done a couple of improvements - one being to file those bolts down a bit - not a great solution but helps to rule out that as a cause, next time I'll do a better job.  The other things I've done are to remove the first chair on the blade and replace it with a slider, and I soldered a very small length of wire underneath between the end of the blade and the adjoining rail.  My cruel closeup shows what I mean.  The tiny wire acts as a bond and provides power to the blade.  I lost one or two plastic fishplates in the process through melting so I've had to stick new ones on afterwards.  You can also see I've provided power to all these rails via the longer piece of brass wire soldered to the stock rail.  Next time I may buy some cast brass fishplates but they're a bit expensive.

 

The upshot is - success!  Although untidy underneath it all works, there's power everywhere and importantly the resistance to movement previously encountered is now much less.  A quick test with my rigged up Tortoise motor shows it moves all 4 blades across nicely - albeit with upgraded actuator wire.  

 

Thanks again for all the advice - much appreciated.  Now for the second one!

 

   

Cheers … Alan

 

[hayfield]

Alan

 

I hope you dont think its criticism, but rather constructive comments.

 

I like your idea about the wire from the switch rail to the center switch rail, a bit more difficult but a U shape may be a bit more flexible.

 

The problem is unlike the Exactoscale 4 mm comprehensive chair system, 7 mm scale is poorly provided for in this area, a 3D printed system is available via Shapeways

 

Regarding longer slide chairs one thing I do, is to use a standard chair on the fixed rail suitably trimmed then add a slide plate (again suitably trimmed), on only slightly longer slide chairs I take off the bolts and add a suitably trimmed additional slide plate 

[Alan Kettlewell]

4 minutes ago, hayfield said:

Alan

 

I hope you dont think its criticism, but rather constructive comments.

 

I like your idea about the wire from the switch rail to the center switch rail, a bit more difficult but a U shape may be a bit more flexible.

 

The problem is unlike the Exactoscale 4 mm comprehensive chair system, 7 mm scale is poorly provided for in this area, a 3D printed system is available via Shapeways

 

Regarding longer slide chairs one thing I do, is to use a standard chair on the fixed rail suitably trimmed then add a slide plate (again suitably trimmed), on only slightly longer slide chairs I take off the bolts and add a suitably trimmed additional slide plate 

 

Hi,

 

Thanks, constructive criticism or comment is always welcome.  Regarding the joining wire underneath, I had a go at making a small omega shape but it got too fiddly in the small space available.  But a U shape, yes I can see that should  work.

 

When researching kit available for hand building track I was surprised at the limited range of chairs available in this scale and that a lot of 0 gauge modellers resort to a chop and cut method to make it look reasonable.  However I'll have a look into Shapeways - thanks.

 

Cheers .. Alan

 

[hayfield]

There is a modeller who is providing certain additional special chairs in 7mm scale, sadly none for slips. The shop is called Off The Rails

 

https://www.shapeways.com/shops/otr

 

I have some and they look excellent, but not used any yet

[jim.snowdon]

On 20 May 2020 at 09:37, Alan Kettlewell said:

 

Hi,

 

I came across the idea somewhere on here or the Gauge 0 Guild forum.  It's just small tabs of copper clad soldered to the underside of each blade.  Then they are joined using a length of stiff spring wire - guitar or piano wire.  The copper clad prevents contact with the blades so there's no shorting.  As you can see I put a small hole in one end for the actuator wire but other there may be other ideas.

 

It's not too authentic looking but it works and is less obtrusive than the 'magic floating sleeper' method often used.  Here's my double slip with the stretcher bar soldered on ...

 

 

Cheers … Alan

 

Thanks  - it's an idea that I wrote up and had published in the 0 Gauge Guild Gazette some years ago. I won't claim to have originated the idea, but I hadn't seen it anywhere else. 

 

Jim

[Alan Kettlewell]

4 hours ago, jim.snowdon said:

Thanks  - it's an idea that I wrote up and had published in the 0 Gauge Guild Gazette some years ago. I won't claim to have originated the idea, but I hadn't seen it anywhere else. 

 

Jim

 

Well, tis a good idea, thanks.

 

Alan