Add stretcher-bar data to Templot templates

[Phil G]

@Phil G

Another day, yet more boxes:

View attachment 8498

View attachment 8497

And the result is slider ribs between switch timbers S1 and S2, and between S3 and S4:

View attachment 8496

You can have up to 5 sets of switch slider ribs, for long switches which need more than one drive (tie-bars and/or prototype stretcher bars/rods).

Enter the first timber number in the boxes, and the ribs will appear between that timber and the next one. Leave blank if not wanted.

You could add the ribs to any timbers, not only switch timbers -- but I can't see any likely need for that.

Switch timbers count S1, S2, ... from the toe timber (the one with the blade tips and soleplate). To see all the timber numbers, start the shove timbers function.

More about the switch slider ribs at:

https://85a.uk/templot/club/index.php?threads/experimental-plug-track-continued.673/post-7628

Will be in 244a shortly.

cheers,

Martin.

Hi Martin,
just a quick question re 2nd or 3rd tie-bar/stretcher bars/rods
is there anyway this can shown as per the 1st tie bar may be separately switch on or off and therefore only visible in the control template if required?
Failing that what would be the best way to have a representation of exactly where the third tie-bar should go, assuming there is a third bar. The second bar being quite simply in the next pair of timbers behind the first tie bar which is represented in the control template.
cheers
Phil

 

[Martin Wynne]

Hi Martin,
just a quick question re 2nd or 3rd tie-bar/stretcher bars/rods
is there anyway this can shown as per the 1st tie bar may be separately switch on or off and therefore only visible in the control template if required?
Failing that what would be the best way to have a representation of exactly where the third tie-bar should go, assuming there is a third bar. The second bar being quite simply in the next pair of timbers behind the first tie bar which is represented in the control template.
cheers
Phil

@Phil G

Hi Phil,

It's all done and ready to go in 244a, as previously posted, see:

https://85a.uk/templot/club/index.php?threads/more-plug-track-software-developments.792/post-10165

The slider ribs show on the control template as:

cheers,

Martin.

 

[Phil G]

@Phil G

Hi Phil,

It's all done and ready to go in 244a, as previously posted, see:

https://85a.uk/templot/club/index.php?threads/more-plug-track-software-developments.792/post-10165

The slider ribs show on the control template as:


View attachment 8822


cheers,

Martin.

Hi Martin,
Yes I know the slider ribs are done. I was expanding on this. What I was taking about is a visual representation of a tie bar exactly the same as the one you have showing in the 1st tie bar position This would then highlight not only the slider but also where the cranks would need to go for the rodding etc. and give a good staring point for positioning a mechanism such as James point servo drive
if you wanted to use one servo to drive two or maybe even three switch tie bars
cheers
Phil

 

[Steve_Cornford]

Hi Phil,
Surely you should not need to drive the 2nd or 3rd switch blade tie bars?
Steve

 

[Martin Wynne]

Hi Martin,
Yes I know the slider ribs are done. I was expanding on this. What I was taking about is a visual representation of a tie bar exactly the same as the one you have showing in the 1st tie bar position This would then highlight not only the slider but also where the cranks would need to go for the rodding etc. and give a good staring point for positioning a mechanism such as James point servo drive
if you wanted to use one servo to drive two or maybe even three switch tie bars
cheers
Phil

@Phil G

Hi Phil,

You mean the drive slot marker? It is extended at one end to show the hand of a turnout when the curving makes it difficult to know:

I will see what I can do. But I'm trying desperately to get a line drawn under 244a and get it released.

cheers,

Martin.

 

[Phil G]

Hi Martin,
Yes I mean the drive slot makers, it struck me if its possible, that would be a great way of showing prototypically where the stretcher bars should be, IE as the turnouts gets bigger the slot markers move, also going from 2 to 3 stretcher bars at I believe on REA anyway a D switch and bigger.
The idea is in the end we could resin 3D dummy stretcher bars, that aligned with the sliders underneath that are doing the real switch rail positioning work. There is no need to add the 244A. I was just wondering if its possible.
I guess switch anchors are also something we could in the end also resin print a representation of.
cheers
Phil,

 

[Martin Wynne]

Hi Martin,
Yes I mean the drive slot makers, it struck me if its possible, that would be a great way of showing prototypically where the stretcher bars should be, IE as the turnouts gets bigger the slot markers move, also going from 2 to 3 stretcher bars at I believe on REA anyway a D switch and bigger.
The idea is in the end we could resin 3D dummy stretcher bars, that aligned with the sliders underneath that are doing the real switch rail positioning work. There is no need to add the 244A. I was just wondering if its possible.
I guess switch anchors are also something we could in the end also resin print a representation of.
cheers
Phil,

@Phil G

Hi Phil,

You are jumping out of the plug track project and back into Templot track planning and prototype switch settings.

Which is fine, just so long as I can have another boiled egg.

And shift this post from the plug track section into an entirely separate topic of its own.

• now done

At present, Templot doesn't include any stretcher bar positions in the switch data. When I set it up 40 years ago I assumed that anyone track building with such prototype fidelity would have the relevant prototype data or the Exactoscale drawings to hand and not need it to be shown on construction templates. In those days at least, stretcher bars if represented at all would be added long after the turnout had been removed from the construction template and laid on the layout.

But time moves on, and there is no reason to exclude stretcher bars from the printed construction templates if there is a desire for them. It's not difficult to add, the only tricky part being deciding what defaults to apply to any custom switches loaded from existing BOX files from previous versions -- which would include the custom switches in the slips and tandems.

The physical flexing characteristic of model rail is unlikely to match what is required for prototype switches. As designed, the 3D switch slider rib positions are independent of the position of any dummy stretcher bars which might be added. Put the extra sliders where needed for the point motor linkages to give the required model switch opening. Position the dummy stretcher bars according to the prototype, not necessarily in the same place as the slider ribs.

Thanks for the suggestion. The stretcher bars are now on the to-do list, but they won't be in 244a. Everything is already doable in 244a -- add whatever slider ribs you want, and fix dummy stretcher bars wherever you want them.

cheers,

Martin.

 

[Phil G]

Hi Phil,
Surely you should not need to drive the 2nd or 3rd switch blade tie bars?
Steve

Hi Steve,
I agree you don't need to. But my question would be way not? If we know the exact position of the slider bar its would not be that hard to add a linkage system.
I am not suggesting more than one servo per switch here, Simple that the forces acting on the blades are more equalized as per the prototype,
Currently because the switch is filed to almost a knife edge there is little in the way of resisting material meaning the switch blade travel has to be overstated to ensure there is sufficient gap after the 1st tie bar.

I understand we can't have a true prototypical gap, 4.5 inches at the switch blade I believe, because of not being truly accurate on wheel dimensions.
However with a linkage system, we should be able get it a lot more prototypical. I have not though out exactly how that would work as the servo would not be directly under the first tie bar, in theory it can work though.
It may in fact be better to mount the servo under the second tie bar.
cheers
Phil,

 

[Steve_Cornford]

Hi Phil,
I think you are over complicating this.
In the prototype there is only one drive rod. The stretcher bars just keep the blades a consistent distance apart . the drive rod drives the tip of the blade does it not?

Or are you experiencing a problem with your very long switches?
Steve

 

[Phil G]

Hi Martin,
thanks

The physical flexing characteristic of model rail is unlikely to match what is required for prototype switches. As designed, the 3D switch slider rib positions are independent of the position of any dummy stretcher bars which might be added. Put the extra sliders where needed for the point motor linkages to give the required model switch opening. Position the dummy stretcher bars according to the prototype, not necessarily in the same place as the slider ribs.

Yes Agree totally with you, my thinking is to have in very basic terms a frame type arrangement where the two switch rails and the slider bars made up part of that frame, the linkage makes up the rest. by then moving the frame more prototypically we should see a much more realistic sort of movement of the switch blades.

I agree its not strictly plug track, it is as you say more Templot but it does lend itself to using plug track with let's call them detailed addons.

The Idea in its most basic for is just to identify where the second and third tie bars should be, and then the individual can position the sliders where they want. I am picking it won't be long before we all realise there is a most logical place for everything.
cheers
Phil

 

[Phil G]

Hi Steve,
There are two parts to my answer, Firstly yes its much more obvious on the longer turnouts.
which was my prime motivation.
However there is noting wrong with trying to get things as accurate as possible. If you think I am overthinking or overcomplicating it, and agree there is certainly more work involved, that's if fine. I am not forcing you to change anything.

I would suspect though, once you had more sliders to try and control the switch blade movement, your also going to add more frictional resistance, so the linkage idea will over come this short fall.

Just as an aside don't you think 25 plus years ago, people who suggested individual chairs, with bolt representation and even loose keys or loose jaws would have been accused of overcomplicating it !!
cheers
Phil,

 

[Steve_Cornford]

Hi Phil,
I believe that the stretcher bars are of unequal length, the 2nd is longer than 1st, and the third longer than the 2nd.
When activated do they move an unequal distance?
Steve

 

[Steve_Cornford]

Hi Phil G,
You might be interested in this topic on Scaleforum:-
https://www.scalefour.org/forum/viewtopic.php?f=5&t=9169#p103763

The link is to a reply halfway through the topic featuring a C10

Steve

 

[Phil G]

Hi Phil G,
You might be interested in this topic on Scaleforum:-
https://www.scalefour.org/forum/viewtopic.php?f=5&t=9169#p103763

The link is to a reply halfway through the topic featuring a C10

Steve

Hi Steve,
Interesting topic thanks for the link.
What is also interesting, and to be honest somewhat surprising, is James brilliant idea of using an eccentric to convert the rotary motion of a servo into the liner motion required for the switch blade movement, has not been picked up as a more main stream idea, maybe its a sign of how traditional model railways can be.

In my honest opinion its the way to go, even if its not the preparatory product James is marketing, the idea is now out there as a practical concept.

Personally I am eagerly awaiting the realise of 244A as I believe a combination of Martin's idea of a hidden vee sliders, combined with the eccentric concept, will open the door for a very sturdy hidden mechanize, which in turn will lead to very accurate dummy tie bars likely made of resin. Once you can do the first tie bar it follows to do the rest including the point rodding. I have a few ideas on a resin slider that runs on Martin's vee rails and uses the eccentric approach. By my current calculations one control eccentric can drive two or three vee slide bars, meaning two or tree dummy tie bars are very doable.
Time will tell.
cheers
Phil,