Experimental 4mm COT track

[Phil G]

@Phil G @Hayfield @James Walters

Hi Phil,

As usual, I move a few inches forward, and you want to jump yards ahead.

My hobby is tinkering with the computers and machines to see what is possible, what works, what doesn't work. For my own amusement and recreation. What other folks want do with it, if anything, is entirely up to them. I'm not here to make recommendations.

Even if I was, I would be nowhere near ready to make any. So far I have got a pile of 4mm FDM COT test pieces, and I've tried threading rail into a few of them. It's looking good, but I haven't even got as far as building a full turnout in 4mm COT yet.

---

There are three separate considerations, it's confusing if they get mixed up:

​

1. integral chairs on timbers (COT track) -- OR plug-in separate chairs.​

​

2. resin OR FDM printing for each of those,​

​

3. how separate jaws are handled -- clip-in loose jaws with pins (resin only) OR glue-on stub jaws (resin or FDM).​

1. For myself, I'm not much interested in using integral chairs on timbers (COT). Sliding rail into place from one end goes against the grain of my original motivation for 3D-printed track, which is to build track by dropping rails into place vertically.

For single turnouts, sliding rails is doable and matches commercial kits. But I'm not really interested in single turnouts, I want to build more complex bespoke formations and junctions, for which sliding rails into place is impossible or difficult. Plug-in chairs makes it much easier. It's possible to combine COT and plug-in chairs in the same timbering base, but anyone doing that knows what they are doing and won't be reading this.

But I know many modellers do just want single turnouts. Whether Templot is the best way to get them is a moot point. But to the extent that Templot makes it possible to produce them as FDM COT track, I want to provide the options and settings to get the best results.

Also in 4mm at least, COT track (in resin or FDM) makes it possible to match the height of commercial flexi-track. Again, that's of no great interest to me, but I know it's important for many modellers, and it's not possible with plug-in chairs in 4mm scale.


2. resin printing provides the best chair detail. No question -- and I can't see that changing any time soon, although FDM is getting closer. It is up to modellers how important that is to them. Resin-printed COT is iffy (see recent posts), and for most if you want COT it will have to be FDM.

For plug-in chairs the same quality difference applies. But if you don't want the faff of resin-printing and are happy with FDM quality you can produce FDM plug-in chairs using the COT chair settings. This can be for FDM timbering bricks or for laser-cut bases:

That could be a difficult decision in 7mm scale, where the quality difference between resin and FDM is not so obvious.


3. Whichever method you choose, some rails can only be assembled if the outer jaws are applied separately.

In resin, with full-depth timbers, those can be done using the clip-fit loose jaws with pins. It's possible to use them for every chair, in which case assembly of complex formations is much easier, there is never any need to slide anything onto a rail, and the check and wing rails can have neat prototypical flat square ends.

In FDM, separate jaws need to be the glue-on stub jaws instead. Much more fiddly to handle, and you wouldn't want to use them for every chair. Which means the other chairs will have to be solid jaw slide-on, and the rail ends will need to be chamfered to make that possible.

---

Phil, I've written all that at least once before. I can't keep repeating myself. I switched this site off over Christmas so that I could have a break from writing stuff.

My priority is to get 556b released as soon as possible, and there is still a lot to do.

cheers,

Martin.

Hi Martin,
I am sorry if you feel you are repeating yourself, that was not my intention at all.
. I am very awere your have created a brilliant system, that has quite a few options, because there are so many options, there needs to be decisions made by the user.
Once again you have summarized these above, although I think maybe one thing you did not cover above was the question of tensile strength or durability of PLA+ filament vs Resin. Maybe this question does not yet have any answers, as time is a factor here for sure!


Anyway clearly there are lots of options, each with there own pros and cons if we are being honest. At the end of the day each individual is totally free to make there own choices. ( yet another feather in your cap for that)

The real reason for asking you the question, what would you do with hindsight, was simply I value your input. It was never meant to be Martin says or anything like that.
cheers
Phil,

 

[Martin Wynne]

The real reason for asking you the question, what would you do with hindsight, was simply I value your input.

@Phil G

Hi Phil,

There isn't a single answer. What I might do for a 00 roundy-roundy would be different from an EM branch terminus, and different again for a 7mm shunting plank. I also have some Gauge 3 track to make, for a wharf alongside my fishing boat kit. That's not likely any time soon!

And having made a decision on any of the above, I would very likely change my mind after a boiled egg.

Whatever, I do prefer the full depth timbers, even for COT. That way you can have the hidden switch sliders, the dropper wire retaining ridges, and robust track which can be pinned in place instead of glued. Easy to lift, relay, tweak alignment, etc. I think the longer FDM print times are worth it.

What I didn't mention in my reply above was the CNC-milled option. I haven't looked at that for ages, but I'm determined to progress it at some stage.

cheers,

Martin.

 

[Hayfield]

Hi Martin,
I am sorry if you feel you are repeating yourself, that was not my intention at all.
. I am very awere your have created a brilliant system, that has quite a few options, because there are so many options, there needs to be decisions made by the user.
Once again you have summarized these above, although I think maybe one thing you did not cover above was the question of tensile strength or durability of PLA+ filament vs Resin. Maybe this question does not yet have any answers, as time is a factor here for sure!


Anyway clearly there are lots of options, each with there own pros and cons if we are being honest. At the end of the day each individual is totally free to make there own choices. ( yet another feather in your cap for that)

The real reason for asking you the question, what would you do with hindsight, was simply I value your input. It was never meant to be Martin says or anything like that.
cheers
Phil,

Phil

My interest is now focused on 7mm scale, I think with 4mm scale at the moment is changing but errs to resin chairs

Firstly I agree with Martins vision for Templot 3D printing being able to seamlessly being able to create complex track designs and formations, in 7mm scale this seems to be slightly ahead of 4mm scale in practicalities

I personally have found resin printing a big minefield and something I have had great difficulty with. However with the developments in FDM printing, in 7mm scale I have found it is much easier to work in FDM printing only.

Firstly in cost, you only need 1 printer, secondly there is no messy clean up of parts which if done incorrectly will result in unusable parts. In short far easier for some to use. OK it may take longer to print against resin and resin may still have slightly better detail. But in the end for me its simplicity wins out every time

I have also found COT track to be far superior over plug track, again as simplicity in manufacture and build is concerned. This is for turnouts as these are the only automated option available, plus FDM printing is less fragile than resin

I respect Martins view of track building against it necessarily being compatible with RTR trackage, in fact I totally agree with this as I find it easier and perhaps cheaper to build plain track using COT track method, especially when both taking P&P and buying rail at competitive rates.

I do however look at trackage slightly differently from Martin, in my opinion many modelers will not be coming into 7mm scale from new, but will require it to be compatible with commercial products. I am not saying either is right or wrong, just different requirements.

The fact is COT track is exceptionally adaptable, where I have been able to successfully experiment with both dual gauge track and diamond crossings. Granted I have had to fudge some chairs and use more advanced Templot design methods, thirdly this build method is slightly harder. Whatever method we use there will be compromises, and what is correct for one modeler will be not acceptable for another

What I would say is we all should be putting our own thoughts into action and try and develop our own understanding of the process. Simply to further our knowledge of how the system works

For my part I am building a plug track turnout in 7mm scale with resin chairs to further my understanding
Secondly I will have a test track working for the Albury Scale 7 meet in April
Thirdly build a cameo layout to demonstrate COT/plug track works and looks far better than its commercially available counterparts

Martin is at his best when he is having fun experimenting lets give him some space

 

[Martin Wynne]

I respect Martins view of track building against it necessarily being compatible with RTR trackage, in fact I totally agree with this as I find it easier and perhaps cheaper to build plain track using COT track method, especially when both taking P&P and buying rail at competitive rates.

I do however look at trackage slightly differently from Martin, in my opinion many modelers will not be coming into 7mm scale from new, but will require it to be compatible with commercial products. I am not saying either is right or wrong, just different requirements.

@Hayfield

Hi John,

The difficulty with pure COT is that some quite simple stuff is tricky or impossible. Here is a very ordinary crossover:

How are you going to slide the red vee rail into position? Clearly it must be done before the stock rail and check rail are inserted at A. But you would still have the check rail chairs in the way. It would be a lot of faff to slide it all the way through the stock rail chairs from the switch end.

The answer is to omit 2 or 3 of the check rail chairs, but include sockets for them. There is then space to flex the vee rail enough to clear the remaining chairs and slide it into position:

After which you can plug in the missing chairs (FDM-printed) and insert the stock rail and check rail.

But is this hybrid construction still called COT track? It might be helpful to have lots of such plug-in chairs. At some point it would have to be called plug track instead. Does it need a separate name? If so, what, and how much more confusion can we sow?

In 7mm the above hybrid method can match Peco flexi timber thickness and still have sockets deep enough to work:

(All integral COT except the straight stock rail. Thickness matching Peco 0 gauge flexi.)

But in 4mm it needs the thick timbers to be workable, so not height-compatible with flexi.

cheers,

Martin.

 

[Hayfield]

Martin I did say that in some cases COT track may be slightly more difficult to construct and I was talking about 7mm scale only.

The solution I have found is that the bricks mat need to be made smaller, not ideal but a compromise I have found has worked in 7mm scale, which may only be achievable in the larger scales. Also mar also only relate to FDM printing where I have found that FDM printed chairs are more flexible than resin printed

As you say this is all experimental and leans heavily on the builders ability/experience.

Talking about traditional track building methods, firstly there are 3 main construction methods, each having their own pros and cons, within each type many have their own way of doing things.

I expect with 3D track printing each will have their own favorite methods, these will also be defined by scale as you can do somethings in one scale that is not as good in another scale

I think you have designed a wonderful system and I am sorry if some of us err from the straight path, but in 7mm scale Plug and COT track is a real winner. Thank you

 

[Phil O]

Hi Martin,

The red V rail will need to be isolated from the A turnout stock rail, otherwise there will be electrical shorts when using the crossover.

 

[Hayfield]

The other thing is, with all other track building methods their are processes which need to be overcome and learnt

Your design process must be congratulated for its simplicity making turnout construction available to many more modelers who otherwise fail using traditional methods

Off now for lunch, not boiled eggs but home made parsnip, apple and honey With a touch of cider) and freshly baked bread

 

[Martin Wynne]

I am sorry if some of us err from the straight path, but in 7mm scale Plug and COT track is a real winner. Thank you

@Hayfield

Hi John,

I wasn't suggesting that you were erring from the straight path.

In fact there isn't a straight path, it has been twists and turns all the way -- and we are not finished yet.

But clearly COT is a diversion, or a fork in the road. I'm just wondering how best to handle it without causing further confusion. As I found yesterday it's hard work to summarise all the options concisely -- if it's hard for me it must be very confusing for others.

I'm wondering if COT track should have its own web site, help notes, etc. for those who simply want to create single turnouts -- effectively make your own turnout kit, similar to the commercial ones. With the added benefit of doing any gauge, size or curving radius you want.

cheers,

Martin.

 

[Martin Wynne]

Hi Martin,

The red V rail will need to be isolated from the A turnout stock rail, otherwise there will be electrical shorts when using the crossover.

@Phil O

Yes Phil. The insulating fishplates are still on the to-do list, although there are some in the Resources section. It would be good to see one behind a check rail (where the prototype rail joint often is). You don't often see that modelled.

cheers,

Martin.

 

[Stephen Freeman]

@Phil O

Yes Phil. The insulating fishplates are still on the to-do list, although there are some in the Resources section. It would be good to see one behind a check rail (where the prototype rail joint often is). You don't often see that modelled.

cheers,

Martin.

There is a reason for that!

 

[Hayfield]

Martin

I am not sure it needs its own website, but perhaps its own section. After all its a part of Templot and works in tandem with plug track.

It grew from plug track and for the 7mm scale modeler a real tangible asset to the hobby

I understand your vision for Templot and Templot 3D, But building individual templates in Templot has been going on for years, I would assume most folk who use Templot use it in its basic form and love it for its accuracy.

Whilst building a single turnout is not using Templot to its full capacity it fulfills a very useful purpose. I think Templot 3D especially in these challenging times is a wonderful facility for the model railway community. I can design and build a bespoke 7mm turnout for well under £10, if this is not good enough on its own, it will be to a higher detail standard than the best professional track builders can achieve.
Then the simplicity of the build is not realized until you have tried both methods.

Sorry I think its pure genius which gets better every time I use it

 

[Phil O]

There is a reason for that!

Hi Stephen,

Yes there is a reason, and that is the original length of rail. Originally rail was in 30ft lengths, followed by 45ft and finally 60ft, sometimes minus 6 inches. The minus 6 inches was/is to equalise the ends through curves. 2nd hand rail might also have been shortened to remove worn fishplate holes, or a damaged end due to hammer blow or cracking, either one end or both.

 

[Phil G]

@Hayfield

Hi John,

I wasn't suggesting that you were erring from the straight path.

In fact there isn't a straight path, it has been twists and turns all the way -- and we are not finished yet.

But clearly COT is a diversion, or a fork in the road. I'm just wondering how best to handle it without causing further confusion. As I found yesterday it's hard work to summarise all the options concisely -- if it's hard for me it must be very confusing for others.

I'm wondering if COT track should have its own web site, help notes, etc. for those who simply want to create single turnouts -- effectively make your own turnout kit, similar to the commercial ones. With the added benefit of doing any gauge, size or curving radius you want.

cheers,

Martin.

Hi Martin,
I think that could actually be a very practical solution for everybody.

As you rightly say COT, by deign concept is a fork in the road. Not better or worst just different.
To keep it as you are suggesting as a means of making your own cost effective single turnouts, any gauge size or curve, thus being a huge plus over anything in the trade already would be a great idea. you could almost liken it to a starter kit concept.

Because by definition if you want to do more than simple kits built turnouts. You would step back into the Plug track design concept thought process, even if what the user then does, becomes a hybrid of both design concepts.

John is also quite right, modellers are by definition quite often tinkers, so no matter what is avaible, they will often put there own slant on things. Sometimes this can be a very good thing, as it opens up the possibility of doing something nobody else thought about.

After all, there are no right or wrong and ways to do things, there my well best practice though.
Cheers
Phil,

 

[Steve_Cornford]

Hi Martin,

I'm wondering if COT track should have its own web site, help notes, etc. for those who simply want to create single turnouts -- effectively make your own turnout kit, similar to the commercial ones.

Think I agree with John on this matter.
Just needs its own discussion forum within Templot club, but perhaps we could all try and avoid going off topic within any particular discussion. Hands up, I am guilty of this, but will try harder.
I would not worry too much about giving each method its own acronym or name, especially while its all still experimental and under development



Steve

 

[Phil G]

Hi Steve,

Just needs its own discussion forum within Templot club

I understand what your saying and I don't disagree. However I believe Martin is thinking about it bit more deeply, when he talks about a possible separate web site.
It then really becomes a question of how to manage everything, That is both site management and peoples expectations management.
You can see that both Templot 5 Plug track and Templot 5 COT are not such a silly idea at all.

If you look at the idea of a sperate web site/program, then clearly a downside is more direct site/program management, and most likely some duplication.
The plus side is your directing people with COT thinking directly to that site/program. (so you are de-facto uncluttering the plug side of the equation) IE not increasing the number of tick boxes required for choices as a simple example. The question then is, does the uncluttering make up for the extra work of operating a separate site/program?

I personally believe COT thinking will grow, maybe even quicker than plug track. For example if the resin curling issue can be resolved or at least better understood. Then 2mm COT is a very logical application, it maybe viable in both 3 and 4 mm resin as well. Its already looking as though 4mm FDM is doable and 7mm COT is certainly doable, if your happy with stylized chairs. (note that not meant as a negative, simply acknowledging, as the scale increases stylization is more obvious)
So its not that unrealise to see that COT has a lot of independent growth potential.

I am not advocating one way or the other on a sperate site or program concept to be honest. I will let Martin decided which why he wants to to approach this.
cheers
Phil,

 

[Hayfield]

Hi Martin,

To keep it as you are suggesting as a means of making your own cost effective single turnouts, any gauge size or curve, thus being a huge plus over anything in the trade already would be a great idea. you could almost liken it to a starter kit concept.

Because by definition if you want to do more than simple kits built turnouts. You would step back into the Plug track design concept thought process, even if what the user then does, becomes a hybrid of both design concepts.

After all, there are no right or wrong and ways to do things, there my well best practice though.
Cheers
Phil,

Martin, Phil etc

I think of COT track as being far more than an item/way/process that produces single turnouts. At the moment its really comes into its own for 7mm + scales, and I am sorry but that's where my own interests lay and I am talking about my own experiences in using it

I have proved it can easily make diamond crossings, simply by evolving/altering the build process, I have also made a working dual gauge junction. In other words COT track may be far more adaptable than we assume and soo I hope to design a small formation including a single slip

OK there are issues where plug track overcomes build challenges in a simplified manner, but plug track also has its own drawbacks

Is it wrong to use Templot in its basic format ? Or is it going to be beneficial to have a two speed Templot Club, so we have an area where those who want a basic resource can go too, where things are not muddied by more technical matter, this could actually be a great idea

Yes COT track is a format at its basic level can easily and simply be an avenue to build a single turnout, but like Plug track with a bit of application it can do far more.

Martin has come up with a simple fix for the common crossing to make the build easier, perhaps a similar design could be made for obtuse crossings? Or achieve the same result by just adapting the build process.

Do not forget 7mm scale has different properties to 4mm scale, for instance I have found no need for trackbase clips, as the interaction between rail and chairs is sufficient to keep all in place

But it is also very wrong to think of COT track only being able to do the most basic functions, I think it is far more adaptable. But that's my view as a track builder rather than as an engineer, and my apologies to those that way inclined.

As Phil rightly said there is not only one way to do things.

 

[KHC1]

My pennies worth. What is happening on both the COT and plug track is brilliant along with Templot. These advances are helping more people to consider track building. I do appreciate that at the end of the day these are to be seen as another set of tools open to modellers. We know that Templot templates are widely used for track building and layout planning with different methods like copper clad wooden sleepers and various parts from suppliers like C & L. For my own part starting off in EM I am considering COT for plain track and plugs for turnouts as being the best compromise. However when it comes to 7mm COT gives me a chance to consider a small layout that will not cost a great deal something I could not have considered until a few months ago. I do appreciate that this is essentially Martins hobby and for that we are all great full that he has allowed us to have access.

Keith who just had a boiled egg for breakfast.

 

[Martin Wynne]

I'm wondering if COT track should have its own web site, help notes, etc. for those who simply want to create single turnouts -- effectively make your own turnout kit, similar to the commercial ones. With the added benefit of doing any gauge, size or curving radius you want.

Thanks for your thoughts.

My thinking above was to restrict the term COT track to describe 3D-printed single turnouts, diamond-crossings, slips, etc. i.e. the Templot equivalent of set-track. And to give it a separate wiki/web site with simplified instructions for how to export and print them. Users might typically cut and carve the printed bases for more complex formations in the same way as when using kits.

Then to revert to calling it plug track for more complex stuff and full bespoke track planning. With some or all of the chairs being integral with the timbers as just one of the available options.

cheers,

Martin.

 

[Hayfield]

Thanks for your thoughts.

My thinking above was to restrict the term COT track to describe 3D-printed single turnouts, diamond-crossings, slips, etc. i.e. the Templot equivalent of set-track. And to give it a separate wiki/web site with simplified instructions for how to export and print them. Users might typically cut and carve the printed bases for more complex formations in the same way as when using kits.

Then to revert to calling it plug track for more complex stuff and full bespoke track planning. With some or all of the chairs being integral with the timbers as just one of the available options.

cheers,

Martin.

This sounds interesting and I misunderstood your thinking about it

One question is if you call the other option plug track what do you call integral chairs with track ?

But he idea of having a simple no fuss area is very interesting, one thought is that the "how to" threads should not be too large. As the meaty parts seem to get lost in waffle.

John

 

[Martin Wynne]

But he idea of having a simple no fuss area is very interesting, one thought is that the "how to" threads should not be too large. As the meaty parts seem to get lost in waffle.

@Hayfield

Hi John,

I wasn't thinking of having any "how to" forum topics. Just some videos and a separate wiki site with basic instructions instead of this one:

https://c7514493.myzen.co.uk/dokuwiki/

Hopefully written by someone else, because it is all getting too much for me.

cheers,

Martin.

 

[Steve_Cornford]

Hi Phil,

It then really becomes a question of how to manage everything, That is both site management and peoples expectations management.

The less management involved the better, as this is meant to be a hobby.

I would think keeping it all under one umbrella minimises this aspect.

Another aspect is that it is quite conceivable for users to want to be able to mix & match methods within one overall design (ie box file).
For instance plugtrack with plywood bases in highly visible areas, FDM plugtrack in less visible spaces, and then COT in non-visible spaces for economy (fiddle yards etc).

Another good reason for keeping us all together is the cross-fertilisation of ideas, and last but not least the many ways of consuming

Steve

 

[Hayfield]

@Hayfield

Hi John,

I wasn't thinking of having any "how to" forum topics. Just some videos and a separate wiki site with basic instructions instead of this one:

https://c7514493.myzen.co.uk/dokuwiki/

Hopefully written by someone else, because it is all getting too much for me.

cheers,

Martin.

Martin

A great Idea of a tell but not contribute site

How about recycling existing material, selective copy & paste

 

[KHC1]

Dare I say it. Maybe James could another of his excellent videos. I must admit his videos have been a great help to me.

Keith

 

[Richardb]

I am blown away by your progress @Martin Wynne I'm so glad you decided to persevere with your FDM experiments. Sadly, I went down a huge cadquery rabbit hole but learnt a thing or two about CAD, so not a total loss. that said I did bodge a point together with some very, shall we say, cave man finesse. Whilst the site was down I reffered to Iain Rice's finescale track building book which is helpful however, the wealth of knowledge in here is supremely useful to- I did miss it.

I need to read through all your posts and I'm keen to learn how you managed with a 0.4mm nozzle.

 

[Martin Wynne]

I need to read through all your posts and I'm keen to learn how you managed with a 0.4mm nozzle.

@Richardb

Hi Richard,

It will all be in 556b shortly. However, I can provide pre-sets and a printer profile only for dried Sunlu PLA-Plus + Cura 5.6 + Neptune4 + 0.4mm nozzle. For everything else you are on your own, or you will need to wait until I have got more machines to try -- and the time to try them.

cheers,

Martin.

 

[Richardb]

It will all be in 556b shortly. However, I can provide pre-sets and a printer profile only for dried Sunlu PLA-Plus + Cura 5.6 + Neptune4 + 0.4mm nozzle. For everything else you are on your own, or you will need to wait until I have got more machines to try -- and the time to try them.

Fantastic work Martin, thank you.

 

[Martin Wynne]

I agree that separating concerns might be the way to go, and I believe many would value a simple interface that just generates a point.

This is what I had in mind but using CadQuery, which is a Python library for building parametric 3D CAD models. The documentation describes it as “intuitive and easy-to-use,” and while I do think it’s quite straightforward, it’s not always as intuitive as it sounds. It is, however, great fun—especially when you use the free extension in VS Code.

CadQuery can be installed in a web application with a Python package manager; I used pip in a Django project (currently on hold while I experiment with the editor). I also considered a SQLite database for storing CadQuery data, letting users dynamically render objects from track component data via a web interface.

This would take me a good couple of months and I'd need to think how to deploy such a program without detrimental cost to myself.

Below is a screenshot of VS Code with the OCP extension enabled, knowledge of VS Code and how extensions work is required. In the picture below I'm developing a parametric baseboard (some tweaking required to the design) and plan to create other parametric models like platforms, canopies etc once I get the hang of it.


View attachment 13543

@Richardb

Hi Richard.

Thanks, but you have rather lost me. I was thinking of a separate section in the Templot Info wiki with click-along videos and tutorials showing how to create single turnouts in Templot COT track.

To avoid confusing anyone looking here for such content* I have moved your post to a separate topic:

https://85a.uk/templot/club/index.php?threads/cadquery.1118/

*it can't be written yet, there are a lot of changes coming in 556b.

p.s. we are talking about turnouts, not points.

cheers,

Martin.

 

[Richardb]

@Martin Wynne

Ah I see, I am sorry. I got the complete wrong end of the stick! And thank you for the correction in terminology it is greatly appreciated.