FDM chairs in 0 gauge - COT track

[Hayfield]

Martin
Through my clumsiness 3 chairs were damaged in the build process, but quickly glued back in place

I think you have just put a lot of 7mm track builders out of work. The track bases are easy to build, rail slides through the chairs well, but also holds itself in place excellent

As you have said we need to tweak the jigs a bit, but that is a known issue

Can I say thank you, for me just what I wanted

 

[Martin Wynne]

View attachment 11425

Martin

I think you have just put a lot of 7mm track builders out of work. The track bases are easy to build, rail slides through the chairs well, but also holds itself in place excellent

Can I say thank you, for me just what I wanted

@Hayfield @James Walters @Steve_Cornford

Hi John,

I'm glad you are pleased, but I really don't know what to say. I never set out to put anyone out of work. The intention of Templot is, or at least was, to be an aid for modellers who already build their own track. But now that it is open source, it is not really for me to say where it should go from here -- others are involved who may have different ideas.

Are you saying you prefer to build COT track over plug track? Although COT track works surprisingly well in 7mm scale, I can't see it having much to offer in 4mm scale, so I don't know what anyone at Scaleforum will make of it. And it might be ok for a single turnout, but it won't be easy to do complex formations such as a tandem turnout or outside slip. Even the check rails and wing rails for an ordinary K-crossing will be tricky.

Attaching dropper wires won't be easy, as the PLA is so easily damaged at soldering temperatures, even using low-temperature solder (which isn't normally advised for electrical work). Perhaps the rail could slide through a pre-wired metal rail joiner placed between the chairs? If the track can be turned over after assembly, it might be possible to spot-solder a thin wire to the underside of the rail using an RSU.

When I started experimenting with FDM chairs in 7mm, I had in mind only to replace the resin plug-in chairs with FDM as a possible option for folks without a resin printer. A Neptune 4 could be run in a living room or back bedroom (if you don't mind the noise) without the mess and faff of a resin printer -- not to mention the saving in costs:

That makes it easier to do complex formations, although it still requires glued loose jaws for at least one of a pair of bent wing rails. The chairs are surprisingly not too far behind the resin versions in terms of quality, especially when painted. Also of course for laser-cut timbering in 7mm scale.

I'm going to continue tinkering with these ideas, but any of it might still change in the designs before we are done. Please don't let folks rush ahead and start building COT layouts on the basis that it's all ready to go. Thanks.

Proper plug track in 7mm, with loose jaws:

cheers,

Martin.

 

[Hayfield]

@Hayfield @James Walters @Steve_Cornford

Hi John,

I'm glad you are pleased, but I really don't know what to say. I never set out to put anyone out of work. The intention of Templot is, or at least was, to be an aid for modellers who already build their own track. But now that it is open source, it is not really for me to say where it should go from here -- others are involved who may have different ideas.

Martin, this was a joke I may have said this before but you have opened up Templot to a new whole audience. 10+ years ago 7mm was the province mainly of kit builders,the abundance of cheaper 7mm RTR stock, but a group that is not really into DIY

Wayne with British Finescale has opened up a new market with his 3D kits, admittedly he files the vees and switch rails, but they are loved by 00/00sf/EM/P4 modellers who would in the past either struggled to hand build or put up with RTR.

You said your interest now is 0 gauge, you have no excuse now

Are you saying you prefer to build COT track over plug track? Although COT track works surprisingly well in 7mm scale, I can't see it having much to offer in 4mm scale, so I don't know what anyone at Scaleforum will make of it. And it might be ok for a single turnout, but it won't be easy to do complex formations such as a tandem turnout or outside slip. Even the check rails and wing rails for an ordinary K-crossing will be tricky.

The two should go hand in hand, plug track has certain advantages over COT track, and COT track for some advantages over Plug

What I can say is that it was so easy to build, once printed a bit of rail forming is required, but its more like plug and play

As for diamonds, its always been my next project (initial in 4mm plug track) but it may be similar to the wing rails

Scale forum attracts modellers of all scale/gauges, many model in more than one gauge. I will focus on simple Templot and have4mm plug and 7mm plug and COT. They loved plug track and Templot last year. Why should this year be different ?

Attaching dropper wires won't be easy, as the PLA is so easily damaged at soldering temperatures, even using low-temperature solder (which isn't normally advised for electrical work). Perhaps the rail could slide through a pre-wired metal rail joiner placed between the chairs? If the track can be turned over after assembly, it might be possible to spot-solder a thin wire to the underside of the rail using an RSU.

Soldering is a next job, I can solder with 4 & 7mm plastic chaired track. I will have a go on soldering after the show, I will cross that bridge when I get to it

When I started experimenting with FDM chairs in 7mm, I had in mind only to replace the resin plug-in chairs with FDM as a possible option for folks without a resin printer. A Neptune 4 could be run in a living room or back bedroom (if you don't mind the noise) without the mess and faff of a resin printer -- not to mention the saving in costs:

That makes it easier to do complex formations, although it still requires glued loose jaws for at least one of a pair of bent wing rails. The chairs are surprisingly not too far behind the resin versions in quality, especially when painted. Also of course for laser-cut timbering in 7mm scale.

I'm going to continue tinkering with these ideas, but any of it might still change in the designs before we are done. Please don't let folks rush ahead and start building COT layouts on the basis that it's all ready to go. Thanks.

cheers,

Martin.

As I said a notice will say "EXPERIMENTAL"

However could you share the plug track chair file please I tried and failed. Would be an excellent talking point if only to show what can be done

Martin, thanks again I am really enjoying myself. I was (and still am) amazed how easy the rails threaded, far easier than threading injection moulded chairs and no gauging issues!!

 

[Martin Wynne]

I may have said this before but you have opened up Templot to a new whole audience.

@Hayfield @James Walters @Steve_Cornford

Hi John,

I didn't set out to open up anything to anyone. All I'm saying is this is what I'm experimenting with, does anyone else want to try it?

I'm feeling very jittery about the whole thing now. I fear a hailstorm of emails and questions about it, and I can't cope with that.

Would you and James and Steve be willing to take over the entire "front of house" stuff? Leaving me in peace to tinker about behind the scenes? Without the feeling that I can't change anything because folks have already started using it, and every little thing I do will have to be explained over and over again.

James has already made a start with his Bexhill West pages and the videos. Thanks James.

Otherwise COT has just made everything 10 times worse.

Martin.

 

[James Walters]

Hi Martin,
I'm head-down at the moment preparing stuff for Scaleforum, including (if I get it finished), a help-sheet of common problems/frustrations, such as rail-heads tending to pitch inwards, plugs too tight or loose - and how to correct the issues, including basics such as how to measure rail correctly. I think this will take care of a lot of the queries and save folks scrolling through posts on here to find what they're after.
I'm hoping that Scaleforum, and in particular the classroom session will give a really good idea of what people want and need in terms of support and understanding
Once Scaleforum is out of the way, let's have a mini-zoom and see if between us we can lift the burden of explaining things from you.
In the meantime, if your hobby feels burdensome, or worse, like a job, then things need to change. Overwhelm, can be very caustic, I speak from experience. Sometimes it's best to just stop and re-calibrate one's head.

I've a couple of practical suggestions which might help to reduce your workload, but would rather not float them on here just now as my head is focussed upon the coming weekend.
Steve, will you be at Scaleforum? It'd be nice to have a catch-up and maybe discuss what Martin is suggesting above.

In the meanwhile, take a break Martin.
Rest on your laurels for a bit and enjoy this nice weather while it lasts.

 

[Hayfield]

Martin

I am happy to field questions on COT track, whilst I am not technically inclined I have enjoyed experimenting with you. As with James I am trying to be prepared for the weekend, and as I have said I will emphasize that this is an experiment. The last thing we want is a log jam on Templot club

I am happy to be a tester for this part of Templot and report back on my findings, Also I will stop posting other than on here

Tomorrow its on to the 4mm plug track for the show and as I said the Kingroon will be printing a P4 B7 and thanks to James I have resin chairs to both have a finished model and to demonstrate using the system

If things are getting too hectic happy to pause on 7mm

 

[Steve_Cornford]

Hi James,
@Martin Wynne , @James Walters , @Hayfield

Steve, will you be at Scaleforum? It'd be nice to have a catch-up and maybe discuss what Martin is suggesting above.

I am hoping to get there for a catch up etc, but not yet a definite.

Steve

 

[Phil G]

Are you saying you prefer to build COT track over plug track? Although COT track works surprisingly well in 7mm scale, I can't see it having much to offer in 4mm scale, so I don't know what anyone at Scaleforum will make of it. And it might be ok for a single turnout, but it won't be easy to do complex formations such as a tandem turnout or outside slip. Even the check rails and wing rails for an ordinary K-crossing will be tricky.

Hi Martin, that is an interesting comment.
To me as John has actually replied its all about choices, I personally love the inherent flexibility of options you are building into plug track, be it in things like options to use FDM printers, Lasers or even CNC machines to build timbers/sleepers.

or now an option to use either resin or FDM printers for the chairs in 7 mm scale. ( personally I don't think FDM chairs are viable in 4 mm) and from all the photos shown on this forum the FDM chairs even in 7 mm have nothing like the level of detail you can create with Resin, (that is my personal bias) (that does not mean they don't have a place thought) Ultimately on this point thats nothing more then a function of build level thickness and ergo the type of printer process you use to create them.

There are however two slight down side to all these options we can choices.
One is obvious, all the incremental increase of options also results the number of questions people will ask increasing, and thus greatly also increasing the amount of explaining that is required. Please don't see that as a barrier to your creating thinking however.
As James has said there are others myself included who can help here.

The second one is more options, will also create more diverse thinking in peoples minds on how to use or even tinker with the options.
At that point some folks will start to do things you don't like, or possibly in your mind become counter intuitive to your original though process.
This can not be helped and to some extant will be more like a branch to the original decision concept. Whether it works or not will be both in the mind of the original developer, and other people if they also see the intension of the branch.

One thing that is desperately needed though in my opinion, is a collective on how we should pool our combined resource and move forward in unison.

To this point I fully enders James comments we need a zoom meeting where all interested people can have input and collectively chart a path forward in terms of who and how questions are answered.

One other thing I think we are already starting to see, is two slightly verging views on how to go about building track in the first place.
On the one hand some people see all the new tools ( FDM and resin printers) as nothing more than aids to carry on building track the way they always have do it.
On the other hand some people see the new tools as an initiative to really think about different methods of track building.

Both are quite valid in there own right and we should really try to see that both can in fact live in harmony, although how people answers questions is likely to be influenced by which way you think about track building.

Again a zoom meeting to sort out who feels they are better to answer the various type of questions has to be the best way forward.

Ultimately the goal is to take away the pressure you are now feeling to constantly keep explaining your though process, which by virtue of your inquisitive mind is always evolving.
Cheers
Phil

 

[Phil G]

Hi Guys,
Just a question,
which could be me getting a bit confused. I always though Scaleforum was exclusively a S4 show? So way is the all the talk of COT and 7mm developments being intermingled with the Scaleforum coms?
cheers
Phil,

 

[James Walters]

Hi Phil,
Scaleforum is the 'main event' in the Scalefour Society calendar, as as such will always be an S4 showcase, although there are plenty of members of the Scalefour Society who model in other scales and gauges. All are welcome, and all (I think) share a common purpose/ambition with regard to fidelity within their modelling.
This year Scaleforum has a couple of 7mm guest layouts, so maybe there will be an increased 7mm presence among the visitors, who knows?
I don't think the 7mm COT track developments are necessarily becoming intermingled with Scaleforum coms, it just seems to be the way of Templot Club. A thread comes along about one thing, and before you know it we've got distracted and are discussing the price of eggs.
No wonder it becomes hard to find the info we want.

Martin keeps telling us off - but we keep doing it.

 

[Phil G]

@James Walters
Hi James,
Thanks for the clarification. I was not aware Scaleforum had guest 7mm layouts, whatever next live steam. On re reading the posts I see what you mean about its more likely there are crossover issues, especially now I understand there is also a 7mm presence at Scaleforum it makes more sense.
From a Templot/plug track perspective, I do wonder if we are in danger of having too many active projects. Not that I am suggesting there is any correct order to this. Just an observation.
cheers
Phil

 

[Martin Wynne]

The second one is more options, will also create more diverse thinking in people's minds on how to use or even tinker with the options.
At that point some folks will start to do things you don't like, or possibly in your mind become counter intuitive to your original thought process.

@Phil G

Hi Phil,

Can I say that I'm entirely happy for folks to use Templot any way they like, or build track any way they like. If someone prefers to use the rail upside down because it is held more firmly in the chairs, that's fine by me.

But there is a difference between doing things your own way, and letting the world think that it is the intended way with Templot. It's not fair to beginners to let them go away with the idea that your way is the intended way.

What often annoys me on other forums and web sites is that someone says "Templot does this" or Templot doesn't do that" when they are simply describing a default setting at start-up. Which they could have easily changed to something else if that is what they would have preferred.

What upset me in this particular case is that the very first photo of assembled COT track shown to the world showed a break in the wing rail at the knuckle. There will now be folks thinking that is the intended way with Templot, especially as it is the established way on commercial track and some pointwork kits.

What would have been better, and what I might have eventually posted myself if folks weren't continually jumping ahead of me, would be a crossing with a one-piece wing rail on one side, and a break in the wing rail on the other side. So that folks could understand the experimental nature of the entire thing, and that many different options are possible (and in this case how much better the more prototypical option looks).

Ideally also showing a mixture of integral COT chairs and plug-in chairs (FDM or resin) in the same track, so that folks might realise how the more complex formations could be built up where not all the rails can be slid into position. And possibly with glued on loose jaws in some cases too.

But we can't show that YET, because I haven't finished the chair heaving functions to allow a mixture of COT chairs and plug-in chairs on the same track. Which is what I mean by folks jumping ahead of me, and putting me under pressure (real or imagined) to get on and get everything finished as fast as I can before folks get the wrong idea about what is intended.

In many ways it might have been better if I had kept quiet about 3D-printed track until I had got every last detail finished and finalised. But in that case I would have missed out on all the valuable feedback and encouragement I have received on here and elsewhere. For which I am extremely grateful, and without which the whole idea would probably have gone nowhere.

Martin.

 

[Phil G]

hi Martin,
Thank you for your thoughts, to be honest I personally totally agree with you re the split wing rail issue, I also have quite a bit of trouble understanding how soldering said joint can possibly work, given the very low flow temperatures that are used in FDM printing. I am not saying total flow temp here, but soft enough to deform the shape which is in the region of 70 to 80 degrees C Almost most the same temp as even low temp solder. I do think ultimately somebody will need to try it though.

I am not sure where these photos your talking about were posted. If it's a web site other then this forum, then I can totally see what your saying.
In that case I for one would totally agree and endorse. Nobody should be posting anything which can be see as misleading, even if it was with the intension of promoting how good Templot/ plug track or COT track is. I speak from experience here as I have in fact fallen into making this mistake myself.

However in the confines of this forum, I don't have a problem with people airing there views, there either going to be good ideas, or bad ideas or even ideas that have been tried and did not work as may be originally conceived. The point being information sharing is a good thing.

I also share some of your thoughts around the logical sequence of evolving the concept as it is. That does not mean you should not have played around with COT track. That is of course your proactive. But maybe its to early in its infancy to say its even ready for anything other then a bit of in house playing with.

I also think now that the the concept of Plug track is now more in the pubic domain, than say 3 years ago, when it was if not quite a closed project it was certainly more clandestine then it is today. It is now incumbent on all of us not to put the cart in front of the horse in the public domain.

I guess what maybe missing here is the option to share views in a more direct manor. I guess with hindsight that is also a subject that could well be resolved by having more regular zoom meetings?

It could be the best way forward is to have say monthly zoom meetings, where we share ideas and then agree in a path we can all move forward on, and yet still have enough individuality to experiment in our own right. (this would not be recorded zooms but more like a committee scenario)
cheers
Phil

 

[Martin Wynne]

.
Another tick-box:

This is already working for COT track in 555a.

In 556a it will apply to plug-in FDM chairs too. On by default and intended to be left on -- but can be switched off if not wanted.

The actual settings for it are on the shrinkage (FDM)... button (already there in 555a).

cheers,

Martin.

 

[Hayfield]

Martin

Would you prefer that I don't take COT Track to Scaleforum

Secondly the break at the knuckle has been resolved, I did it initially simply as a first test, once I fitted the check rail chairs I realized FDM chairs are far more robust than resin chairs and I think chairs printed on the Neptune 4 may be more flexible than those printed on the Kingroon

Phil

Before the latest software tweak Martin said FDM chairs were possible close to being as good in detail as injection moulded chairs, I personally think your comment about the quality of FDM chairs is based on the prints I produced with the Kingroon

The latest turnout brick came out with the odd minute string, the level of detail is superb (with a magnifying glass you can clearly see the crisp bolt heads).

OK I do not see things from an engineering process but looking at 7mm resin chairs against FDM chairs there is little difference if any between the two

I do agree the first priority must be plug track and getting K crossings up and running

Thirdly as you know I am involved with the L&B on the coach building side, as far as the L&B is concerned there are 2 distinct groups, the trust and Exmore Associates, both with the same objective but there is a lot of bad blood between leading lights in both groups. There is also a L&B forum which has nothing to do with either group, but two of my friends get very upset over what is written. They think the whole world is getting the wrong idea about the L&B and it could be harming the work of the trust

Thankfully the rest of the whole world is oblivious to the writings and the Trust keep on growing (planning for the new extension goes in this month, the new carriage shed planning application has just gone in). These spats going on in the background actually fall on deaf ears, and count for nothing

I remember in one of the splats between Arsen Wenger and Sir Alex Ferguson, Wenger once said everyone thinks their wife is more beautiful. Did not go down well in Manchester, Like my err with the knuckle it will soon be forgotten.

Martin please do continue in the background tweaking, and let us know if perhaps we get ahead of the game

Thanks for what you are doing, its really first class

 

[Martin Wynne]

Would you prefer that I don't take COT Track to Scaleforum

@Hayfield

Hi John,

No, take whatever you want to take, including COT track.

But preferably not anything from Templot showing a break in the wing rails.

Ideally along with the COT track you could take some 0 gauge plug track with both resin and FDM plug-in chairs. I hadn't finished tweaking the plug/socket sizes for plug-in FDM chairs, but I will try to put some in the post to you today if I can get some made.

I wanted to get a brick done with mixed COT and plug-in chairs to illustrate how complex formations can be built up. But that is going to take a bit longer. I would like to get folks thinking in terms of assembling bricks having parts of multiple templates side-by-side, rather than thinking about single stand-alone turnouts (as traditional templates and kits).

It's all getting a bit of a rush, and several other posts I haven't replied to, but no sun so far today.

cheers,

Martin.

 

[Phil G]

@Hayfield
Hi John,
My comments about FDM chairs and Resin chairs are based on this type of photo. which clearly shows the fidelity of the resin is better. I have not actually tried to produce any chairs in 7mm using the FDM Process. So I can't comment on how they look to the naked eye.

Please note I am not saying they don't work, simply the layer height of a resin printer is 0.035 to 0.05mm. The layer height of the FDM printer is quite a bit more, unlikely to be less then 0.12, in truth more likely to be 0.15mm to 0.2 mm at best.
I do agree FDM will be more flexible in nature, but it will also be far more prone to thermal influence, especially if a soldering iron is used in close proximity.

As to your comments after "thirdly" I am afraid you have totally lost me, with what you are saying here.
cheers
phil

 

[Hayfield]

@Hayfield

Hi John,

No, take whatever you want to take, including COT track.

But preferably not anything from Templot showing a break in the wing rails.

Ideally along with the COT track you could take some 0 gauge plug track with both resin and FDM plug-in chairs. I hadn't finished tweaking the plug/socket sizes for plug-in FDM chairs, but I will try to put some in the post to you today if I can get some made.

I wanted to get a brick done with mixed COT and plug-in chairs to illustrate how complex formations can be built up. But that is going to take a bit longer. I would like to get folks thinking in terms of assembling bricks having parts of multiple templates side-by-side, rather than thinking about single stand-alone turnouts (as traditional templates and kits).

It's all getting a bit of a rush, and several other posts I haven't replied to, but no sun so far today.

cheers,

Martin.

Martin

Please don't post them if they are to be FDM printed PM me a file for the Neptune and I will print them

Yes I was planning to take 7mm plug track (along with my earlier misprints of 7mm chairs) I will reprint the bricks with the Neptune if I have time.

 

[Martin Wynne]

The layer height of the FDM printer is quite a bit more, unlikely to be less then 0.12, in truth more likely to be 0.15mm to 0.2 mm at best.

@Phil G

Hi Phil,

For FDM chairs and COT track we are using 0.10mm layer height.

cheers,

martin.

 

[Martin Wynne]

Please don't post them if they are to be FDM printed PM me a file for the Neptune and I will print them

@Hayfield

Hi John,

It will have to be the gcode file, because I'm using the minibo backlash corrector. I have found that it improves Neptune 4 results, but with knock-on effects on the rail-fit adjustments.

I just need more time to get everything right before I'm happy. Everyone is trying to go too fast.

cheers,

Martin.

 

[Steve_Cornford]

Hi Martin,
Do you need a bigger build plate?

https://uk.elegoo.com/products/orangestorm-giga

Hope this is not yet another distraction!

Steve

 

[Martin Wynne]

Hi Martin,
Do you need a bigger build plate?

https://uk.elegoo.com/products/orangestorm-giga

Hope this is not yet another distraction!

Steve

Thanks Steve. Track for my Gauge 3 wagon?

Martin.

 

[Phil G]

@Phil G

Hi Phil,

For FDM chairs and COT track we are using 0.10mm layer height.

cheers,

martin.

Hi Martin,
That is indeed better than I was expecting. Are you still using a 0.4 mm nozzle or have you switch to a 0.2 mm nozzle as well?
cheers
Phil,

 

[Phil G]

Thanks Steve. For my Gauge 3 wagon?

Martin.

Is that not an XY printer?
your other option is to go to N gauge and print the whole layout in one go
cheers
Phil,

 

[Martin Wynne]

Are you still using a 0.4 mm nozzle

@Phil G

Hi Phil,

Yes. 0.4mm standard nozzle.

Martin.

 

[Hayfield]

As some were questioning suitability of soldering. Temp controlled iron set at 400c standard Carrs red solder and normal (175c? solder) Just tinned wire and rail then soldered together

No chairs were hurt making this joint (Its an old scrap test piece printed on a Kingroon using old settings)

 

[Martin Wynne]

No chairs were hurt making this joint (Its an old scrap test piece printed on a Kingroon using old settings)

@Hayfield

Hi John,

That's great.

Here is a file to make 32 plug-in FDM chairs. Solid jaw slide-on. 16 S1 and 16 L1 on a raft. For code 125 rail:

Print time 1hour 20mins.

These are snap-fit (not clip fit) so need a firm push to install in the sockets. It's easier if you put a bit of rail through them to push down on. They snap home. I will look at making them a bit easier to fit.

Shallow plugs for thin timbers (matching Peco flexi). Hence must be snap-fit, clip fit needs the full depth plugs in FDM.

THIS FILE IS READY-TO-USE GCODE FOR NEPTUNE 4 ONLY.

Put it straight on the USB stick and into the printer. Do NOT open it in Cura or try to slice it -- re-slicing it would spoil it.

I have made some for you and I will try to catch the post with them this afternoon.

cheers,

Martin.

 

[Hayfield]

Martin

Thanks very much, printer working now I have some 7mm plug track turnouts and was going to rely on some chairs I printed in resin, having both FDM chairs with the correct rail is a bonus. I will try and print some straight panels on the Neptune for better quality sleepers

John

 

[Phil O]

Thanks Steve. Track for my Gauge 3 wagon?

Martin.

Looks like, I'll need to win the lottery, so that I can buy a property with enough space, to have a printer that size. I could print a whole layout in a few bricks, including all the buildings.

 

[Martin Wynne]

You can also get wifi boosters such as these, which include an ethernet socket. But I don't have one so I can't say if it would work. But you may already have one for your existing wifi?

https://www.amazon.co.uk/dp/B07ZWBBPQN

@Hayfield

Hi John,

https://www.amazon.co.uk/dp/B07ZWBBPQN

Having borrowed one of these I can now say that it works fine. If you plug it in near your Neptune printer you can connect an ethernet cable between it and your printer. And then control your printer over wifi from your laptop if it doesn't have an ethernet socket, instead of using the USB stick. It's easy to set up.

It also acts as a wifi booster, so you could also connect your desktop computer, tv, etc., to it if you wish. Or leave them connected directly to the router as now, if the router is closer and/or is working fine.

Martin.

 

[Hayfield]

I wondered why you when I reread the previous post. WiFi works very well in my house (we have a booster) even in front and back gardens.

At the moment things are working and I will get another USB stick

Elegoo actually replied today and suggested trying to repair the sticks and gave me a link, if I can be bothered

 

[Martin Wynne]

@Hayfield

Hi John,

I have put a few bits and pieces of COT track and some 7mm FDM plug-in chairs in the post to you. You should have it tomorrow.

The 7mm FDM plug-in chairs are the same as the gcode file I posted earlier - code 125 rail, snap-fit, shallow plugs for thin timbers (Peco match). The gcode was backlash-corrected by 0.1mm in the minibo corrector, and it definitely improved the dimensional accuracy of the chairs. Although maybe 0.1mm is a fraction more than needed. More testing required -- and correction not needed as far as I can tell on the Kingroon. Whether that's because of the lower speed, or the linear guide rails instead of rubber rollers, I don't know.

The filament I used today seems less strong than I was using yesterday -- I broke a couple of them while testing the rail in them. So that is yet another variable in the mix to be determined before we have things finalised -- recommended filament for FDM chairs. I'm now testing PLA-ST to see how it compares.

The resin plug-in chairs are for code 131 rail, clip-fit, full depth plugs for full-depth plug track timbers. Water-wash resin.

cheers,

Martin.

 

[Hayfield]

Martin

Plug in track to match Peco is a great move forward, after loading up a P4 B7 turnout with plug chairs for an old codger 7mm seems so much easier. For some I think if plug track can work in the same sleeper/timber size could be important

Do I take it the timber depth for plug track is 3.3mm ? I spent late last night printing a timber brick full depth as I did not realize the plugs were thinner. Not to worry as the print was to show the difference between the Neptune and Kingroon

I must admit I have got fonder of my Kingroon as its so much smaller than the Neptune

I am no painter and someone with an artistic ability could do much better. But the detail of the chairs really stands out proudly (grey spots are the inside of the jaws). I have some weathering varnish somewhere I must find it

 

[Martin Wynne]

But the detail of the chairs really stands out proudly

@Hayfield

Hi John,

Looks good.

Have you thought of gently picking out the chair screws, or maybe just a few of them.

REA chair screws are galvanized, so weather to a lighter colour than the cast-iron chairs. Depending on how dirty the track is, the colour difference often remains evident for years:

GWR chair screws appear to be plain steel. Which means they weather to a more rusty brown than the chairs, the same colour as the steel rails:

GWR screw heads always look a bit small to me. I imagine it is necessary in order to get a box spanner on them between the jaw ribs.

cheers,

Martin.

 

[Hayfield]

Happy to give it a go

One thing I noticed was a layer of film of brake dust covering the rails, chairs and sleepers in the areas around the chairs, guess this is modern era, steam era oil and the odd bit of toilet waste !!

 

[Martin Wynne]

Do I take it the timber depth for plug track is 3.3mm ? I spent late last night printing a timber brick full depth as I did not realize the plugs were thinner. Not to worry as the print was to show the difference between the Neptune and Kingroon

@Hayfield

Hi John,

You can set the timber depth to whatever you want. But it has got into a bit of a muddle and I need to sort it out:

1. 7mm scale:

To match Peco flexi using code 125 rail, the timbers need to be 3.15mm thick in ordinary COT track.

To match Peco flexi using code 131 rail, the timbers need to be 3.0mm thick in ordinary COT track.

If we want to mix plug-in chairs with integral COT chairs (which we do for complex formations such a tandem turnout), neither of those thicknesses is sufficient for clip-fit plugs if FDM-printed. If resin-printed it can be done if we use 4mm sizes for the plugs. For FDM-printed we need to use snap-fit instead. I have sent you some -- you should get them today.

If we simply scale up the 4mm settings to 7mm, the timber thickness will be 5.9mm with open sockets or 6.3mm with blind sockets. This was my original intention for 7mm plug track, but it is clearly unnecessarily thick and needs further thought.

---

2. 4mm scale:

This is a 7mm topic so I will write about 4mm in a separate one.

However, there is an option setting for 7mm timber depths, plugs, and sockets to match the 4mm sizes, or some % setting in-between:

This is still experimental, and isn't necessarily yet working fully as I intended.

This is where I feel I'm being pushed ahead faster than I want to go.

The real answer to your question about timber depths is that I don't know yet. For example in 4mm using a PEI printer bed with or without glue makes a difference -- without glue needing thicker timbers with blind sockets.

cheers,

Martin.

 

[Phil O]

@Hayfield

Hi John,

Looks good.

Have you thought of gently picking out the chair screws, or maybe just a few of them.

REA chair screws are galvanized, so weather to a lighter colour than the cast-iron chairs. Depending on how dirty the track is, the colour difference often remains evident for years:


View attachment 11454


GWR chair screws appear to be plain steel. Which means they weather to a more rusty brown than the chairs, the same colour as the steel rails:


View attachment 11455


GWR screw heads always look a bit small to me. I imagine it is necessary in order to get a box spanner on them between the jaw ribs.

cheers,

Martin.

Hi Martin,

That's not a screw, it's what's called a fang bolt, the bottom couple of inches is threaded (can't remember what thread) there's a dished square plate under the sleeper, with a central threaded hole to match. The dishing of the plate allows it to bite into the sleeper as the bolt is tightened.

On the ESR when we replaced the sleepers we cut the bolts off, taper reamered the holes in the chairs and fitted ferrules and chair screws. Not prototypical, but you can't get fang bolts and plates off the shelf any more.

 

[Martin Wynne]

Hi Martin,

That's not a screw, it's what's called a fang bolt, the bottom couple of inches is threaded (can't remember what thread) there's a dished square plate under the sleeper, with a central threaded hole to match. The dishing of the plate allows it to bite into the sleeper as the bolt is tightened.

On the ESR when we replaced the sleepers we cut the bolts off, taper reamered the holes in the chairs and fitted ferrules and chair screws. Not prototypical, but you can't get fang bolts and plates off the shelf any more.

@Phil O

Thanks Phil.

I thought the through bolts were used only on plain track, with a fang washer underneath and the nut on top?

Burying a threaded part in the ballast doesn't seem a good idea, and if it is a bolt, why not use it nut-on-top in pointwork in the same way as plain track? Off to look at the Paddington drawings again...

p.s. David Smith page 97 agrees with you.

Martin.

 

[Phil O]

Martin,

I have no idea as to the idea, we have never managed to undo the bolts, even with impact wrenches.

When I return home, I will have a look through my photo archive and see if I have any photos, but don't go holding your breath.

 

[Phil O]

Further info on the plates, they are about 3 inches square and about 5/16ths thick. I don't think that we actually bothered to measure one.