Experimental Plug Track: continued

[Martin Wynne]

.
Thanks Steve.

We can do the same for the 2-D exports (for laser cutting, CNC milling) using Inkscape (free):

I imagine most 2-D DXF users are already using Inkscape as their viewer, but a direct preview button from Templot will be handy.

cheers,

Martin.

 

[Steve_Cornford]

Yes, I already use
Inkscape, and very useful it is too, especially for inspecting all the layers in the 2D DXF exported files.
Another day another button!
Steve

 

[Martin Wynne]

.

How to view unfixed STL files from Templot in the 3D-Tool viewer.

The primary reason the unfixed STL files from Templot need mesh fixing before use is that intentionally I have not differentiated between front and back faces in the code. The reason is that it would almost double the amount of program code needed for every element in the file. The mesh fixer program sorts it all out afterwards, plus some other fixes needed.

The 3D-Tool viewer can deal with it too, to display the unfixed files direct from Templot, if you make this setting:

In the Display settings, set Back Faces like Front Faces on the lower drop-down. It can be set as the default via the Preferences:

This setting can also be quickly switched on by clicking the Cross-Section mode.

It's a good idea to de-select the Shiny Colors option for a better view of the details.

It's worth playing with all the Display options to find the viewing options you prefer.

It is possible to change the green colour to something else:

cheers,

Martin.

 

[Martin Wynne]

Another day another button!

And for today (a very small button):

It can be a small button because that dialog opens automatically if you attempt to preview without installing a viewer first.

cheers,

Martin.

 

[Martin Wynne]

.
I fear I may have taken a wrong turning with the chairing interface. Although it's difficult to put a finger on the crux of it, or what to do about it, or whether it really is a problem.

If you want all solid jaws, or all loose outer jaws, there is no difficulty building the track, and you can easily click the buttons to make the required chairs.

But it's becoming clear that mixing solid jaws with loose jaws in the same track raises some problems. It will very difficult to mix solid and loose jaws on the same physical piece of rail and assemble it into the timbering base. So we may need both versions of the same chair type on a template.

Consider for example:

There is a rail break needed at the wing front rail joint. Which is fine -- it means all the chairs on the wing rail with the knuckle bend can be loose-jaw and easy to assemble into place. It would very tricky to assemble the knuckle with slide-on solid jaws. That means the blue L1 bridge chairs should also be loose-jaw.

But the closure rails on the left are separate rails and can have solid jaws if preferred. That means the red L1 bridge chairs need to be solid jaw.

But there is only one setting for all the L1 chairs on a template:

It seems clear that we need to specify a solid or loose jaw by reference to its position on the template, not by the type of chair. That would be a minefield of more tickboxes and buttons to implement.

But maybe it's not so much of a problem -- we could easily get what we want by splitting the above into 2 partial templates to create the chairs. All the chair settings are template-specific.

But hang on -- all the L1 chairs are interchangeable on any template. So we just need to print a stock of loose-jaw and solid-jaw L1 chairs. And use whichever we prefer in any L1 socket position when constructing the track. Likewise for the other interchangeable chairs. Is there any need to specify which type of those chairs on a template?

Answers on a postcard.

Meanwhile there are signs of progress -- here's my work-in-progress on the ZY crossing chairs:

These are the first chairs where the chair base is skewed on the parent rail. I got there in the end. Hopefully the other rail tomorrow.

cheers,

Martin.

 

[Steve_Cornford]

Well done on the ZY crossing chair.

As far as the need for mixing solid jaw and loose jaw chairs of the same type on a template, I would agree that this is not a necessary complication.

I believe that as far as chairs are concerned it us going to be easier to have a "raft" library of the different chair types and their options, rather than generate a specific raft of chairs for each individual template.

For instance we could have a raft of left handed B7 1P to 4P loose jawed chairs & their jaws.

For 4mm & a Mars 2 pro, I managed to fit 4 of these onto the build plate at a resin cost of 31p.

For certain chairs (like these ) it is useful to print a set of chairs and jaws on the same raft so that each has corresponds with its relevant chair (as these are chairs with black font on your jaw option dialogue).

I am assuming that the chairs on this library raft could be used for any Left handed B7 turnout irrespective of curvature?

Steve

 

[Phil O]

Steve

On the real thing, the common crossing chairs are standard for either left or right configuration regardless of curvature, what alters is the way you put the point and splice rail together.

 

[Steve_Cornford]

sorry
, got carried away.
What I meant to say is that (for now at least) an happy to print a set of L1 with solid jaws, and a set of L1 with loose jaws and use them as stock to pick from as required.steve

 

[Martin Wynne]

For instance we could have a raft of left handed B7 1P to 4P loose jawed chairs & their jaws.

@Steve_Cornford

Hi Steve,

You can create a stock of such chairs -- but ONLY for switches where you haven't shoved the switch timbers:

Here I have shoved forward timber S8 carrying the 2P chairs (excessively, for clarity) on this B-switch. You can see that the 2P chairs have grown in length to match the rails, and are no longer interchangeable with any other B-switch 2P chairs.

Prototypically you shouldn't be shoving switch timbers like this. But on a model you might need to shove them a little to fit a cramped space, and you might be tempted to shove them quite a lot in complex formations -- in the second switch of a tandem turnout for example.

If you model in P4, S7, etc., you can say that you just follow the prototype and shouldn't need to shove such timbers. Although even the prototype doesn't lay a tandem turnout on a 4 chains radius transition curve.

But in 00/EM etc., the reduced gauge and wider flangeways change the geometry, and you might find that the only way to make things fit is to shove such timbers along a bit from the strictly prototypical positions.

The same goes for the crossing chairs.

Templot creates the chairs programmatically so that they will always fit shoved timbers, and you need to be careful not to assume they are interchangeable after some creative timber shoving.

How to keep records of all this so that chairs and their loose jaws can be cross-referenced to their respective timbers in a timbering brick, from say the middle of a complex station throat, is an issue yet to be faced. It is going to need some careful record keeping and labelling.

cheers,

Martin.

 

[Martin Wynne]

Steve

On the real thing, the common crossing chairs are standard for either left or right configuration regardless of curvature, what alters is the way you put the point and splice rail together.

@Phil O

Hi Phil,

This will be the same on the plug track -- for the crossing chairs. That's because they are equalized to the centre-line of the crossing.

But not for the switch chairs, because switches are not equalized, they are always square-on. This means that the 3P chair, say, from the turnout-side of a left-hand switch is not identical to the 3P chair from the main-side of a right-hand switch. There is a slight difference in rail offset and chair length*.

Or at least there is in Templot. On the prototype the same chairs are used for both, which means there is a slight gauge-reduction through the turnout-side of prototype REA switches. I have mentioned this discrepancy in the REA switch designs before.

* the difference will be barely noticeable on 3D-printed chairs in 4mm/ft scale, bearing in mind the resolution of 3D printers and track construction tolerances. But it will become noticeable in the larger scales such as Gauge 1, for example.

cheers,

Martin.

 

[Steve_Cornford]

please don't mention chair heaving!
I am just about to board a ferry across the Irish Sea

 

[Phil G]

Hi Martin,
having carefully read all the comments, I believe Steve's, point re how the chairs are actually made on a 3D printer is a very important point.
My question would be, is there any real need to make exactly the right type and amount of chairs for one template, in one go?
I feel in practice there is already enough flexibility in plug track to achieve what is required, but not by making one complete template. As you mentioned Martin, maybe its a simple as two or more part templates at the printing stage?
It maybe better for more effort to be put into the right instructions to achieve specific chairs. Which to be honest Martin may well be where uses can come into play and write the instructions for you. leaving Martin to concentrate on making the magic happen.
just my thoughts.
cheers
Phil

 

[drduncan]

Chaps,

If anyone would care to send me an STL file for some 18.2 and 28mm gauge (yes Brunei’s broad gauge) timbering with chairs I’ll see how it prints and what settings for the photon mono.

Regards

Duncan

 

[Martin Wynne]

Chaps,

If anyone would care to send me an STL file for some 18.2 and 28mm gauge (yes Brunei’s broad gauge) timbering with chairs I’ll see how it prints and what settings for the photon mono.

Regards

Duncan

@drduncan

Hi Duncan,

Unfortunately it's not that simple.

You need to specify whether you want solid or loose outer jaws.

And also what rail section you are using (and preferably dimensions from the batch of rail you are using). The default settings in Templot match some 10-year-old C&L nickel-silver code 75 bullhead rail which I have here. It might or might not match your rail. Indications from others are that the chairs are a fraction loose on the current C&L rail. There are also indications for the Mars printers that the rail fit for solid jaws varies according to the orientation of the chair raft on the build plate.

At present plug track is available only for chaired bullhead rail using REA chairs, i.e. the 1925 designs.

GWR broad gauge bridge rail is well down the list!

p.s. I'm still far from convinced that a resin-printed one-piece timbers+chairs base is a sensible way to go. There are shrinkage and warping considerations, and the home printer build plates are so small. The last thing I need at present is yet another viable option to take into consideration in the code and user interface.

My working default position is that the vast majority of users will want to go for FDM-printed bases:

cheers,

Martin.

 

[Martin Wynne]

Hi Martin,
having carefully read all the comments, I believe Steve's, point re how the chairs are actually made on a 3D printer is a very important point.
My question would be, is there any real need to make exactly the right type and amount of chairs for one template, in one go?
I feel in practice there is already enough flexibility in plug track to achieve what is required, but not by making one complete template. As you mentioned Martin, maybe its a simple as two or more part templates at the printing stage?
It maybe better for more effort to be put into the right instructions to achieve specific chairs. Which to be honest Martin may well be where uses can come into play and write the instructions for you. leaving Martin to concentrate on making the magic happen.
just my thoughts.
cheers
Phil

@Phil G

Hi Phil,

As I've mentioned I'm itching to get back to 3D printing so that we can sort out all these practical aspects. There are lots of ideas to try, but until I have got all the crossing chairs done, it would just be a distraction.

For example I could easily provide button(s) to create a raft of the common chairs or chair parts, all nicely bunched up to save space and resin. Say a raft of solid P chairs, or a raft of loose jaws for L1 chairs. Just choose your scale and rail section.

But that's not possible with the chairs and jaws which are unique to a particular template. So how to indicate which chair goes where and whether it can be a standard one from stock? I can't see a practical way to add ID marks to the timbering base, so it probably needs a printed paper template as a key to the required chairs. But I have done nothing yet about including the chair outlines on the paper templates or other output.

We are already splitting the original track templates into partial copy templates to create a timbering brick. Splitting them again on different boundaries to make the chairs feels like a recipe for confusion. I just hope someone else will be doing all the explaining.

In the meantime I must simply push on with the crossing chairs. I'm wondering if it would make sense to pause the whole project until I have got them done? Writing this stuff now before having full answers is just going to confuse beginners coming to this topic.

See you at the Zoom meeting tonight?

cheers,

Martin.

 

[Steve_Cornford]

Hi Martin,
Apologies for non attendance this evening as I am away in the Emerald Isle with limited internet access.
cheers Steve

 

[Terry Downes]

.
I fear I may have taken a wrong turning with the chairing interface. Although it's difficult to put a finger on the crux of it, or what to do about it, or whether it really is a problem.

If you want all solid jaws, or all loose outer jaws, there is no difficulty building the track, and you can easily click the buttons to make the required chairs.

But it's becoming clear that mixing solid jaws with loose jaws in the same track raises some problems. It will very difficult to mix solid and loose jaws on the same physical piece of rail and assemble it into the timbering base. So we may need both versions of the same chair type on a template.

Consider for example:

View attachment 5813

There is a rail break needed at the wing front rail joint. Which is fine -- it means all the chairs on the wing rail with the knuckle bend can be loose-jaw and easy to assemble into place. It would very tricky to assemble the knuckle with slide-on solid jaws. That means the blue L1 bridge chairs should also be loose-jaw.

But the closure rails on the left are separate rails and can have solid jaws if preferred. That means the red L1 bridge chairs need to be solid jaw.

But there is only one setting for all the L1 chairs on a template:

View attachment 5812

It seems clear that we need to specify a solid or loose jaw by reference to its position on the template, not by the type of chair. That would be a minefield of more tickboxes and buttons to implement.

But maybe it's not so much of a problem -- we could easily get what we want by splitting the above into 2 partial templates to create the chairs. All the chair settings are template-specific.

But hang on -- all the L1 chairs are interchangeable on any template. So we just need to print a stock of loose-jaw and solid-jaw L1 chairs. And use whichever we prefer in any L1 socket position when constructing the track. Likewise for the other interchangeable chairs. Is there any need to specify which type of those chairs on a template?

Answers on a postcard.

Meanwhile there are signs of progress -- here's my work-in-progress on the ZY crossing chairs:

View attachment 5814

These are the first chairs where the chair base is skewed on the parent rail. I got there in the end. Hopefully the other rail tomorrow.

cheers,

Martin.

Sorry for late reply, I have just returned to UK. Also, I do not want to slow progress or add complication so, please ignore if this is irrelevant Or too complicated.
I was wondering whether solid/loose jaw selection should be set globally as you have it now and then ‘special/individual‘ chairs could be altered within the shove timbers dialogue box where you can switch individual chairs on/off on each timber.?

 

[Martin Wynne]

Sorry for late reply, I have just returned to UK. Also, I do not want to slow progress or add complication so, please ignore if this is irrelevant Or too complicated.
I was wondering whether solid/loose jaw selection should be set globally as you have it now and then ‘special/individual‘ chairs could be altered within the shove timbers dialogue box where you can switch individual chairs on/off on each timber.?

@Terry Downes

Hi Terry,

I had been looking at that, but it's a lot of work in the code, and the BOX file. It should properly be left until we get to the full "chair heaving" function, where every individual chair in a template can be selected and edited to whatever you want, including customised chairs, GWR, flat-bottom baseplates, etc. That's all still a long way off.

But it would be very tedious to have to go through every timber on every template changing a solid/loose jaw setting.

We are over-thinking this. It just needs some buttons to create neat rafts of the bog-standard chairs, S1, S1J, P, L1, CC, SC etc., and/or loose jaws for them. You can then choose which to use in any given socket during construction.

Only the special chairs need to be tied to a specific position on a specific template. And for those I think loose jaws is the only practical assembly option as the default. Anyone wanting them solid can easily split the templates as required.

But nothing more can be done on anything until until until I have got all the crossing chairs done! Otherwise they never will get done -- it's just turning into one distraction after another.

I didn't want to spend sunny summer days indoors on the computer. So I have now obtained a cheapo laptop computer which I can use sitting in the garden (or parked up in the hills) in a desperate effort to get a full turnout finally possible. But I can't even get on with that this weekend because there are 200 bedding plants to get planted first!

cheers,

Martin.

 

[Terry Downes]

@Terry Downes

Hi Terry,

I had been looking at that, but it's a lot of work in the code, and the BOX file. It should properly be left until we get to the full "chair heaving" function, where every individual chair in a template can be selected and edited to whatever you want, including customised chairs, GWR, flat-bottom baseplates, etc. That's all still a long way off.

But it would be very tedious to have to go through every timber on every template changing a solid/loose jaw setting.

We are over-thinking this. It just needs some buttons to create neat rafts of the bog-standard chairs, S1, S1J, P, L1, CC, SC etc., and/or loose jaws for them. You can then choose which to use in any given socket during construction.

Only the special chairs need to be tied to a specific position on a specific template. And for those I think loose jaws is the only practical assembly option as the default. Anyone wanting them solid can easily split the templates as required.

But nothing more can be done on anything until until until I have got all the crossing chairs done! Otherwise they never will get done -- it's just turning into one distraction after another.

I didn't want to spend sunny summer days indoors on the computer. So I have now obtained a cheapo laptop computer which I can use sitting in the garden (or parked up in the hills) in a desperate effort to get a full turnout finally possible. But I can't even get on with that this weekend because there are 200 bedding plants to get planted first!

cheers,

Martin.

understood and agree 100%. enjoy the sunshine....