[MOC] My LEGO Renfe S-130

[Imanol]

9 hours ago, Hod Carrier said:

You're very welcome. This is the beauty of the community. Everyone is willing to pitch-in and help share their ideas, experience and expertise. Never be afraid to ask whenever you feel you need some help or feedback.

Thanks, all of you have helped a lot and all are essential to this project.

9 hours ago, Hod Carrier said:

It looks promising. It's a little hard to see what you've done inside from that angle, though.

I think in this photo it can be better appreciated, as you can see the side of the car covers part of the mechanism:

Remolque Turista Renfe S-130 Prototipo Union Completo 2 by Imanol, en Flickr

9 hours ago, Hod Carrier said:

That depends on a number of things, including the wheelbase of the vehicle (the distance between the axles). The longer the wheelbase or the tighter the curve, the more movement you will need. I don't have a mathematic formula that allows you to calculate how much movement is needed and arrived at the required amount through trial and error, which is the reason why sometimes you have to test build things and try them out.

Happily the wheelbase of your end car looks similar to that of my freight wagon. For that model, I found that I needed around 16 degrees of movement for a wagon with a 25 stud wheelbase to match an R40 curve. You could get away with less if you're prepared for the axle not to turn all the way into the curve, but the trade-off with that approach is that the wheels will "scrub" across the inside of the rails and cause friction.

Well, I ´ve trying to improve the design of the individual bogie but I can´t make it turn more than 10 degrees and it´s driving me mad, If any one has any solutions please feel free to say it. The biggest problem is that the bogie assembly touches the static part of the undercarriage. The only way of making it work is removing part of the lower slopes as seen here:

Bajo Extremo S-130 Bogie independiente by Imanol, en Flickr

9 hours ago, Hod Carrier said:

It looks very chunky. I'd keep things simple and just use a 2x2 turntable plate attached to the four holes on the bottom of a 3x3 plate built into the floor of the end car. It's surprisingly strong and gives you the half-stud offset you need for a 7-wide design.

As for the turntable, it was in the original design, but I thought it was a weak link I will change it when I have a solution for the other problem.

[Hod Carrier]

2 hours ago, Imanol said:

I think in this photo it can be better appreciated, as you can see the side of the car covers part of the mechanism:

That looks good. I think that it should work fine like that, subject to real-world build and testing. I know you said you were thinking of removing the top link, but I see you have found another way instead of attaching the top of the mechanism in a way that suits your design better. Well done. 

2 hours ago, Imanol said:

Well, I ´ve trying to improve the design of the individual bogie but I can´t make it turn more than 10 degrees and it´s driving me mad, If any one has any solutions please feel free to say it. The biggest problem is that the bogie assembly touches the static part of the undercarriage. The only way of making it work is removing part of the lower slopes as seen here:

I did a quick and dirty mock-up in Stud.io to see what the problem might be. I don't know if I got all your parts choices, measurements and spacings correct so I might be way off, but I managed to get to the magic 16 degrees without affecting the look of the model. The problem is not the slopes themselves but the supporting parts that the slopes are attached to; specifically the dark bley inverted slopes underneath. You just need to create some space for the corner of the bogie to move into, as the bogie part will move sufficiently far over the top of the inverted slopes to give you those extra few degrees of movement.

2 hours ago, Imanol said:

As for the turntable, it was in the original design, but I thought it was a weak link I will change it when I have a solution for the other problem.

I have found them to be OK and not too weak, and I think others would agree. Your solution does look much stronger for sure and would take away any worries about performance of the part, especially on a heavy train. Ultimately it's up to you to choose the design that works best for you.

[Imanol]

12 hours ago, Hod Carrier said:

That looks good. I think that it should work fine like that, subject to real-world build and testing. I know you said you were thinking of removing the top link, but I see you have found another way instead of attaching the top of the mechanism in a way that suits your design better. Well done. 

Thanks, but I´m sorry to disappoint you but the upper link is not attached or at least not secure, the idea still is to look for a better attachment as it´s now attached to a technic brick and a headlight brick.

12 hours ago, Hod Carrier said:

That looks good. I think that it should work fine like that, subject to real-world build and testing. I know you said you were thinking of removing the top link, but I see you have found another way instead of attaching the top of the mechanism in a way that suits your design better. Well done. 

I did a quick and dirty mock-up in Stud.io to see what the problem might be. I don't know if I got all your parts choices, measurements and spacings correct so I might be way off, but I managed to get to the magic 16 degrees without affecting the look of the model. The problem is not the slopes themselves but the supporting parts that the slopes are attached to; specifically the dark bley inverted slopes underneath. You just need to create some space for the corner of the bogie to move into, as the bogie part will move sufficiently far over the top of the inverted slopes to give you those extra few degrees of movement.

Thanks, I will look into implementing it.

12 hours ago, Hod Carrier said:

I have found them to be OK and not too weak, and I think others would agree. Your solution does look much stronger for sure and would take away any worries about performance of the part, especially on a heavy train. Ultimately it's up to you to choose the design that works best for you.

I think here I´m going to keep the turntable but in the power car I´m going to go for the pin attachment as I think it can make it stronger

[Ferro-Friki]

On 6/6/2023 at 3:31 AM, Hod Carrier said:

The rodal design shown by @Ferro-Friki looks sound and should give you the axle steering that your train will need. However, as he says, you will need to make sure that you allow enough space between the cars for them to articulate without the car bodies striking the axles (which I suspect is what is stopping his Alvo from using R40 radius curves).

That’s indeed the issue with the rodales of my Avlo. Due to their length, a 3-stud gap between coaches isn’t enough to allow it to navigate R40 curves. If I want to keep the same rodal design I need to make the gap even wider. The thing is a 3-stud gap (as common as it is for Lego trains) is already too wide for what I’m trying to represent. Talgo coaches have a remarkably short distance between them, to stay accurate to the source material it should be at most a 1 stud gap!

Although a 1 stud gap isn’t impossible to achieve. @Nikonissen managed to make it (to great looking effect) with the use of rubber bands, although as he pointed out in his Talgo 350 thread, it isn’t infallible. I know there are working close-coupling designs for conventional coaches, however, I don’t think anyone has ever combined them with any Talgo rodal. I might look into it.

For now, I’ve decided that instead of the rodales, the R40 curves have to go. They are too limiting and no well-proportioned train looks good on them. Besides, I’m pretty sure my Avlo would have no problems traversing R56 and higher curves. I’ll need to get at least a full circle eventually since I don’t have any.

On 6/6/2023 at 3:31 AM, Hod Carrier said:

I don't recommend this. I tried using free swiveling axles on a long-wheelbase freight car and they don't work. There needs to be some mechanism to allow the axle to steer and turn when it needs to (and to make sure that it turns the right way) and to bring it back to the central position when it goes onto straight track. Free swiveling axles just flop about in any direction they feel like going and then get stuck in the wrong orientation.

Well that’s unfortunate :/ I had the hope a small turning radius might work, although in hindsight I guess it wouldn’t be enough for tight curves anyway.

On 6/6/2023 at 10:57 AM, Imanol said:

This is the current design of it, I don´t now if it will need to be improved

For the end car rodal, If I were you I would try to align the connection point on the same vertical axis as the wheel holder, otherwise, in my experience it would cause the entire coach to slightly shift to the side when turning, causing unnecessary effort when pulling. It likely isn’t necessary, and trying to implement this might create more problems than it fixes, it’s just something that I would watch out for.

On 6/6/2023 at 1:17 PM, Nikonissen said:

In a year, when everyone has each their own Talgo done and built IRL, we should do a meet-up and run all of them together and take some photos.

I'll look forward to that ! :D

That sound great! :) Although my Avlo would probably not arrive on time (Classic Renfe…)

17 hours ago, Imanol said:

I think in this photo it can be better appreciated, as you can see the side of the car covers part of the mechanism:

It’s looking great! I see you’ve placed the rodal closer to one of the coaches, just like the real thing, that would be the coach the rodal “belongs” to. If I had to guess I’d say that misalignment is caused by the gauge changing technology forcing the rodal turning mechanism to the side. In comparison, the series 112 rodales (which can’t change gauge) are perfectly centered between each coach. If you get the chance to see one of these 130/730 units from up close you should see a small circle above wheel with a fan-shaped peephole. That’s the disc brake indicator, if it shows red, the brakes are applied, if it’s green then they’re loose. That’s one of the many particularities of the Talgo coaches (a couple of little fun-facts).

Also, make sure that the technic axle connector (32039) has some room to turn, otherwise it could collide with the adjacent bricks. From the render it looks like it wouldn’t have this issue, but keep it in mind.

[Imanol]

2 minutes ago, Ferro-Friki said:

It’s looking great! I see you’ve placed the rodal closer to one of the coaches, just like the real thing, that would be the coach the rodal “belongs” to. If I had to guess I’d say that misalignment is caused by the gauge changing technology forcing the rodal turning mechanism to the side. In comparison, the series 112 rodales (which can’t change gauge) are perfectly centered between each coach. If you get the chance to see one of these 130/730 units from up close you should see a small circle above wheel with a fan-shaped peephole. That’s the disc brake indicator, if it shows red, the brakes are applied, if it’s green then they’re loose. That’s one of the many particularities of the Talgo coaches (a couple of little fun-facts).

Thanks, as you mentioned a 3 stud gap is not enough but I think this can be considered 4 stud gap (maybe even 5) as underneath the car there is space to turn. All of the pictures of Talgo cars that I´ve seen have the rodal in one side (underneath the car that is permanently attached to it) so I didn´t know about the S-112. The disc indicator i´ve seen it sometimes but I never imagine what it was.

[Ferro-Friki]

I hadn’t thought of it that way, I guess you’re right, although I was referring to the shortest distance between the coaches, which (at least in my train) is 3 studs above the rodal.

The series 102/112 is the exception in the Talgo family, since it’s the only one of its kind that can’t change gauge.

I find the disc-brake indicators amusing since they look exactly like the indicators on public toilets that show if they’re occupied or not. I tried to represent them in my own 130 Alvia, although they didn’t make the jump to the 112 Avlo because they could cause trouble when applying the decals for the brushstrokes.

[Imanol]

Well, I bring more bad news after solving the problem with the end car bogie rotation a new problem has appeared in the same area. The sideskirts and undercarriage of the moving part can´t be easily attached to the bogie assembly as they are displaced 0,5 studs in each direction so I need two jumper plates to connect it and the only part where I can is underneath.

So for now all of that weight is supported by two jumper plates as is obvious that this will not work so I once again asking for help because this part is driving me mad.

This is the structure of the bogie and car now: The maximum it can turn without moving the other parts is 9,03 degrees so is still very far from the 16 degrees that it needs 

Extremo Bogie independiente superior by Imanol, en Flickr

Thanks for helping

 

Edited June 7, 2023 by Imanol

[Hod Carrier]

9 hours ago, Imanol said:

Thanks, but I´m sorry to disappoint you but the upper link is not attached or at least not secure, the idea still is to look for a better attachment as it´s now attached to a technic brick and a headlight brick.

That might not be a massive problem. If the weight is being supported by the bottom link the attachment at the top is there really just for dynamic stability (in other words, so that the cars don't wobble too much), so you may not need to build it as strong.

6 hours ago, Ferro-Friki said:

Although a 1 stud gap isn’t impossible to achieve. @Nikonissen managed to make it (to great looking effect) with the use of rubber bands, although as he pointed out in his Talgo 350 thread, it isn’t infallible. I know there are working close-coupling designs for conventional coaches, however, I don’t think anyone has ever combined them with any Talgo rodal. I might look into it.

It's possible that I might just have something in the pipeline that could help you gentlemen. I have been working on an adaptation of the close coupling technique I used on the LMS Articulated Railcar, specifically for articulated trains using Jacobs bogies. Depending on how this works out, it might just work for a Talgo also. The problem at the moment is that I don't have a lot of spare time to get the thing built and tested, but when I do I will report back and let folk know how it went together with some ideas about how it might apply to Talgos.

6 hours ago, Ferro-Friki said:

For now, I’ve decided that instead of the rodales, the R40 curves have to go. They are too limiting and no well-proportioned train looks good on them. Besides, I’m pretty sure my Avlo would have no problems traversing R56 and higher curves. I’ll need to get at least a full circle eventually since I don’t have any.

I mean, it's a high-speed train so it needs bigger curves so that it can stretch it's legs a bit. 

It's nice if a train can be made to work even on R40s because then it can run anywhere, but you are right about them being limiting. If you want to get close to anything like scale modelling with LEGO they really are useless for anything other than trams.

1 hour ago, Imanol said:

Well, I bring more bad news after solving the problem with the end car bogie rotation a new problem has appeared in the same area. The sideskirts and undercarriage of the moving part can´t be easily attached to the bogie assembly as they are displaced 0,5 studs in each direction so I need two jumper plates to connect it and the only part where I can is underneath.

I'm unsure if I've understood what you're trying to make happen. Are you trying to get the light bley brackets holding the side skirts to connect with the bogie arm? Is there not enough space inside the skirts to have them fixed to the body and still leave enough room inside for the bogie arm to swing?

You might have to approach the problem from the opposite end. Sometimes the solution to a design issue is not obvious and there could be more than one solution to the problem. Brackets, as with any part that has an open stud (as opposed to a solid stud), can provide you with the means to create a half stud offset. Any plate that is 1 x N has little studs on the back which will fit inside an open stud and secure parts together, which is a feature that Stud.io supports. So rather than starting off by fitting the brackets to the inside of the skirts and then stressing about how you can attach them to the bogie, maybe fix the brackets to the bogie first and then see what options you have for fitting the skirts to the brackets.

Edited June 7, 2023 by Hod Carrier

[Imanol]

15 hours ago, Hod Carrier said:

I'm unsure if I've understood what you're trying to make happen. Are you trying to get the light bley brackets holding the side skirts to connect with the bogie arm? Is there not enough space inside the skirts to have them fixed to the body and still leave enough room inside for the bogie arm to swing?

You might have to approach the problem from the opposite end. Sometimes the solution to a design issue is not obvious and there could be more than one solution to the problem. Brackets, as with any part that has an open stud (as opposed to a solid stud), can provide you with the means to create a half stud offset. Any plate that is 1 x N has little studs on the back which will fit inside an open stud and secure parts together, which is a feature that Stud.io supports. So rather than starting off by fitting the brackets to the inside of the skirts and then stressing about how you can attach them to the bogie, maybe fix the brackets to the bogie first and then see what options you have for fitting the skirts to the brackets.

That´s exactly what I´m trying to do, but the problem is that the stud conversion is not perfect so I may try to change the bogie structure to 3 studs instead of 2 as it might be easier to connect, nevertheless I will try your approach.

On 6/6/2023 at 1:53 PM, Hod Carrier said:

Sounds like a great plan. We can have a pan-European Talgo-Fest. I might have to have a go at building one myself. 

May I suggest to try building the Talgo Avril, is the only High-Speed Talgo that no one has ever try to made and after seeing the Tfw Stadler that you built and your bogie mechanisms I think you might be able to pull it through

[Hod Carrier]

10 hours ago, Imanol said:

That´s exactly what I´m trying to do, but the problem is that the stud conversion is not perfect so I may try to change the bogie structure to 3 studs instead of 2 as it might be easier to connect, nevertheless I will try your approach.

Ah, I get it now. You've got two problems with attaching the skirts to the bogie. The first one is the half stud offset I discussed yesterday, which should be easy enough to fix. The second is that big issue that affects all 7-wide builds, which is that you have a quarter plate left over on each side and there isn't a part with a quarter plate thickness to deal with it. This is a much tougher puzzle.

I always like to try and keep things simple if it avoids having to deal with a really tricky problem head-on. The first thing I would explore is whether the side-skirts can be attached to the body of the car and still leave enough space inside for the bogie to move as much as you need it to. If you can make this happen it will completely avoid all the other problems as well as look better when the train is running. Only when I have exhausted all the possibilities over this would I start to consider how I might try to attach the skirts to the bogie.

[Imanol]

13 hours ago, Hod Carrier said:

Ah, I get it now. You've got two problems with attaching the skirts to the bogie. The first one is the half stud offset I discussed yesterday, which should be easy enough to fix. The second is that big issue that affects all 7-wide builds, which is that you have a quarter plate left over on each side and there isn't a part with a quarter plate thickness to deal with it. This is a much tougher puzzle.

I always like to try and keep things simple if it avoids having to deal with a really tricky problem head-on. The first thing I would explore is whether the side-skirts can be attached to the body of the car and still leave enough space inside for the bogie to move as much as you need it to. If you can make this happen it will completely avoid all the other problems as well as look better when the train is running. Only when I have exhausted all the possibilities over this would I start to consider how I might try to attach the skirts to the bogie.

Well, I ´ve trying to make it turn without moving the sideskirts but the problem is that as the turning point is offset it touches the bogie itself touches the front sideskirts, I tried moving the turning plate half a stud inward but then it touches both front and rear sideskirts. So the only way around is to find a way to attach the sideskirts to the bogie assembly and this implies dealing with the quarter plate problem, the only brick that covers this gap is the hinge brick without turning but is impossible to add it to the design so the only other way around is to change the bogie structure to be 3 studs wide which is the next thing I will try to do.

If you have any other idea please feel free to talk about it. I´m now with studies so I don´t have a lot of time (and mental capacity) to deal with this problem but I want to have the prototype as soon as I finish but first I need to fix some problems like this.

[Imanol]

Good news, after many tries I have finally made a working prototype for the bogie assembly of the end car, the trick was the thin liftarm that when is connected to a technic brick makes the perfect offset.

This is the design with the internal structure visible:

Bajo Extremo S-130 Bogie independiente 4 by Imanol, en Flickr

And this is the bogie turned 20 degrees proving the concept:

Bajo Extremo S-130 Bogie independiente 3 by Imanol, en Flickr

So now the only problem is finishing the coupling between cars.

But there is also one other problem, I don´t have any LEGO trains so if I make a prototype I would need to push it by hand so my question is, should I make one of the power cars or wait until the car designed is proved and tested? I´m not going to lie, I would love to have at least half of the train for testing but I don´t now if it´s a good idea.

[Imanol]

After finishing with the end car design I´m making the final touches to the coupling between the cars and I have a question for @Ferro-Friki, the upper diagonal bar that joins the two sides of the bogie is connected by brick 43857 or 60843? It appears that  it´s connected with the second one (60843) but this liftarm don´t allow (apparently) the sideways movement of the joint and the turning of the cars but as I´m still trying to understand the mechanism of the bogie I can´t say that for sure.

Thanks for helping

[Hod Carrier]

On 6/11/2023 at 10:03 PM, Imanol said:

After finishing with the end car design I´m making the final touches to the coupling between the cars and I have a question for @Ferro-Friki, the upper diagonal bar that joins the two sides of the bogie is connected by brick 43857 or 60843? It appears that  it´s connected with the second one (60843) but this liftarm don´t allow (apparently) the sideways movement of the joint and the turning of the cars but as I´m still trying to understand the mechanism of the bogie I can´t say that for sure.

This is part of the reason for building and testing, so that you can see how things work and whether or not they will work in your own build.

It's part #60483. The axle hole is threaded onto the tan axle while the diagonal linkage fits into the pin hole. It will articulate very nicely and give you the steering effect that you need for the rodales. It's basically just a double-hinge mechanism with the diagonal linkage ensuring that movement on one side of the hinge is replicated on the other.

On the subject of the articulation and coupling between the cars, I know that both you and @Ferro-Friki were looking at ways of trying to reduce the gap between the cars. As mentioned earlier, I have been working on an adaptation of the close-coupling system that I used on my LMS Articulated Railcar that might also work for Talgos and would be an alternative to the design that @Nikonissen came up with. Scroll to the end of that thread to see the design.

I haven't tested it with a Talgo wheel arrangement because the length of the cars is much longer than for your train, but if you swapped out the regular bogie for a fixed axle it should work just the same. The only thing I would say is that I would try and avoid any tight S-bends, such as my test track has, as I fear the system would cause a lot of friction and possibly a derailment too. Coupling to the cars is using the upward-pointing pins and axles, with the pins joining the mechanism firmly to one car while the neighbouring car rests on the axles. All you need is some pin connectors securely fastened into the structure of each car to carry the weight of the car and any forces through the coupling.

[Imanol]

7 hours ago, Hod Carrier said:

This is part of the reason for building and testing, so that you can see how things work and whether or not they will work in your own build.

It's part #60483. The axle hole is threaded onto the tan axle while the diagonal linkage fits into the pin hole. It will articulate very nicely and give you the steering effect that you need for the rodales. It's basically just a double-hinge mechanism with the diagonal linkage ensuring that movement on one side of the hinge is replicated on the other.

On the subject of the articulation and coupling between the cars, I know that both you and @Ferro-Friki were looking at ways of trying to reduce the gap between the cars. As mentioned earlier, I have been working on an adaptation of the close-coupling system that I used on my LMS Articulated Railcar that might also work for Talgos and would be an alternative to the design that @Nikonissen came up with. Scroll to the end of that thread to see the design.

I haven't tested it with a Talgo wheel arrangement because the length of the cars is much longer than for your train, but if you swapped out the regular bogie for a fixed axle it should work just the same. The only thing I would say is that I would try and avoid any tight S-bends, such as my test track has, as I fear the system would cause a lot of friction and possibly a derailment too. Coupling to the cars is using the upward-pointing pins and axles, with the pins joining the mechanism firmly to one car while the neighbouring car rests on the axles. All you need is some pin connectors securely fastened into the structure of each car to carry the weight of the car and any forces through the coupling.

Thanks, I´m trying to make a prototype of your design to test if it´s able to fit in the cars, but I don´t know the angles of the upper bar and with stud.io is very difficult trying to guess it. Also I´m doubting, Is the third hole in the technic half liftarm the mounting point of the train axle?, and will it be posible to use a normal bogie assembly (with obvious tweaks) as it may be easier. I´m still busy with exams but I´m hoping to finish in a week and have full time to make the final details to the design and order pieces to make a full prototype.

And talking about the prototype I´m wondering if is worth to make one locomotive to pull it or if pushing it by hand will be enough to test if it works.

Thanks, Imanol

 

[Hod Carrier]

2 hours ago, Imanol said:

Thanks, I´m trying to make a prototype of your design to test if it´s able to fit in the cars, but I don´t know the angles of the upper bar and with stud.io is very difficult trying to guess it.

You mean the red one? I got those set to 58 degrees, but I had to work it out using trial and error.

What is more important when you build the train for real is to get the length of the red bar correct otherwise the cars won't centre correctly. The axle is about 3.5 studs long, but no such part exists so I have used axles 3 studs long and glued them into the pin connectors to fix the linkage to the correct length.

If you mean the black arms, these are set at 30 degrees. The mounting to the cars is 5 wide where they attach and 3 wide where they link to the central member (white).

2 hours ago, Imanol said:

Also I´m doubting, Is the third hole in the technic half liftarm the mounting point of the train axle?, and will it be posible to use a normal bogie assembly (with obvious tweaks) as it may be easier.

The half liftarms are just there to join the various components in the central member together. There's a Technic axle and pin connector (32184) in the middle of it and the bogies for my railcar connect and pivot through that part using a 2x2 tile with pin (2460). For a Talgo you would want to mount your axle to this white section so that it is fixed to it. You can use different parts to make this happen if it's easier, as this specific design is really for articulated trains with bogies like my railcar.

2 hours ago, Imanol said:

I´m still busy with exams but I´m hoping to finish in a week and have full time to make the final details to the design and order pieces to make a full prototype.

Focus on those first and come back to this later. Employers will be more interested in your exam results than in your ability to build Talgos out of LEGO. 

2 hours ago, Imanol said:

And talking about the prototype I´m wondering if is worth to make one locomotive to pull it or if pushing it by hand will be enough to test if it works.

It's up to you. If you're just testing out the articulation between the cars, you can just push the train by hand.

[Imanol]

12 hours ago, Hod Carrier said:

You mean the red one? I got those set to 58 degrees, but I had to work it out using trial and error.

What is more important when you build the train for real is to get the length of the red bar correct otherwise the cars won't centre correctly. The axle is about 3.5 studs long, but no such part exists so I have used axles 3 studs long and glued them into the pin connectors to fix the linkage to the correct length.

If you mean the black arms, these are set at 30 degrees. The mounting to the cars is 5 wide where they attach and 3 wide where they link to the central member (white).

Thanks, I tried to center the red axle but stud.io doesn´t make it easy so I will use the angles you provided, I will tweak it when I have a real prototype. 

12 hours ago, Hod Carrier said:

The half liftarms are just there to join the various components in the central member together. There's a Technic axle and pin connector (32184) in the middle of it and the bogies for my railcar connect and pivot through that part using a 2x2 tile with pin (2460). For a Talgo you would want to mount your axle to this white section so that it is fixed to it. You can use different parts to make this happen if it's easier, as this specific design is really for articulated trains with bogies like my railcar.

Okay, I now see it, I will try to decide between attaching a bogie assembly or only an axle depending on the clearance with the roof and the space it takes in the cars. 

I have another question, is the design in the photos complete or is missing another axle as I can´t understand where is the turning point, as it looks like the only moving part is the black liftarms and if they are connected to the car so I suppose I´m missing something.

13 hours ago, Hod Carrier said:

Focus on those first and come back to this later. Employers will be more interested in your exam results than in your ability to build Talgos out of LEGO. 

I can only say that you may not be right 

13 hours ago, Hod Carrier said:

It's up to you. If you're just testing out the articulation between the cars, you can just push the train by hand.

I won´t hide that I would like to have the locomotive build as soon as possible but I also know that this will delay the prototype build so I´m still deciding 

[Hod Carrier]

3 hours ago, Imanol said:

I have another question, is the design in the photos complete or is missing another axle as I can´t understand where is the turning point, as it looks like the only moving part is the black liftarms and if they are connected to the car so I suppose I´m missing something.

No, it's complete. The only thing that is missing is the railcar bogie which, because it's a two axle bogie and needs to rotate freely around the central member, is attached using a tile with pin as described last night. The design uses non-friction pins where necessary (all shown in light bley) to ensure free movement.

Unlike the double hinge design you've used so far, this design does not give a precise turning point. Instead, the geometry of the parts and the way they turn creates a floating pivot point, which is why it can allow for close coupling compared to a conventional fixed pivot (see first proof of concept photo below).

3 hours ago, Imanol said:

I will try to decide between attaching a bogie assembly or only an axle depending on the clearance with the roof and the space it takes in the cars. 

For a Talgo you don't want a free pivoting bogie with just a single axle, as you will have no control over steering. The same as @Ferro-Friki's double hinge design, mine gives you the steering you need to make sure that your train goes around corners smoothly and without derailment. All you need to do is to attach the wheels to the central member (white) in a similar way so that it gives the axle the steering inputs that you need.

3 hours ago, Imanol said:

I can only say that you may not be right 

Looks like a few of us here might be getting a cut, then. 

[Imanol]

1 hour ago, Hod Carrier said:

No, it's complete. The only thing that is missing is the railcar bogie which, because it's a two axle bogie and needs to rotate freely around the central member, is attached using a tile with pin as described last night. The design uses non-friction pins where necessary (all shown in light bley) to ensure free movement.

Unlike the double hinge design you've used so far, this design does not give a precise turning point. Instead, the geometry of the parts and the way they turn creates a floating pivot point, which is why it can allow for close coupling compared to a conventional fixed pivot (see first proof of concept photo below).

Thanks, I´m still discovering how this type of mechanisms work. I now see that the bar can pivot sideways. With this information I will try to integrate it in my Talgo and see if it works. It appears that it only needs 5 studs of space to swivel freely so this will be very compact. 

1 hour ago, Hod Carrier said:

For a Talgo you don't want a free pivoting bogie with just a single axle, as you will have no control over steering. The same as @Ferro-Friki's double hinge design, mine gives you the steering you need to make sure that your train goes around corners smoothly and without derailment. All you need to do is to attach the wheels to the central member (white) in a similar way so that it gives the axle the steering inputs that you need.

Yeah, I know but I´m talking about making a technic axle holder to connect it to the current structure or adapting in some way the actual bogie assembly that I used for the other design but firmly secured in place to avoid rotation.

1 hour ago, Hod Carrier said:

Looks like a few of us here might be getting a cut, then. 

For now I can´t say more because I don´t know if it will occur but we will see. The only thing that I can say is that You, @Ferro-Friki and @Nikonissen have been instrumental to the project 

[Hod Carrier]

1 hour ago, Imanol said:

Yeah, I know but I´m talking about making a technic axle holder to connect it to the current structure or adapting in some way the actual bogie assembly that I used for the other design but firmly secured in place to avoid rotation.

I'm ahead of you.

I've done a very quick mod to the LMS Railcar to turn temporarily into a Talgo. This is how I (illegally) attached the wheelset to the close-coupling system. There are a couple of 1x2 jumper plates (in red) hiding deep inside the render which are joined to the pin holes on a pair of 3L Technic pins. I'm not suggesting that this is necessarily the best solution or the one you should follow, but I wanted to make the modification easily with the minimum of new parts to fit the existing layout of the Railcar. The top half of the mechanism isn't shown because I've not changed anything there.

So does it work? You know when you've been Talgo'd.  (Click on the image for the video)

Look between the cars and you can see the self-steering effect. It's not perfect but it's working OK. I suspect that there is an issue with the unequal length of the cars or maybe the weight distribution that could be affecting things.

1 hour ago, Imanol said:

For now I can´t say more because I don´t know if it will occur but we will see. The only thing that I can say is that You, @Ferro-Friki and @Nikonissen have been instrumental to the project 

Well, for now I shall wish you luck in your plans and wait to hear what happens. 

Edited June 20, 2023 by Hod Carrier

[Imanol]

2 hours ago, Hod Carrier said:

I'm ahead of you.

I've done a very quick mod to the LMS Railcar to turn temporarily into a Talgo. This is how I (illegally) attached the wheelset to the close-coupling system. There are a couple of 1x2 jumper plates (in red) hiding deep inside the render which are joined to the pin holes on a pair of 3L Technic pins. I'm not suggesting that this is necessarily the best solution or the one you should follow, but I wanted to make the modification easily with the minimum of new parts to fit the existing layout of the Railcar. The top half of the mechanism isn't shown because I've not changed anything there.

So does it work? You know when you've been Talgo'd.  (Click on the image for the video)

Look between the cars and you can see the self-steering effect. It's not perfect but it's working OK. I suspect that there is an issue with the unequal length of the cars or maybe the weight distribution that could be affecting things.

Wow, thanks a lot, you can´t even imagine how it helps to have a proof of concept of your design. You have earned a seat in "Preferente" in my Alvia 

I´m now trying to connect it with the current structure of the car but I think it will fit without issue and if not I trick of the car gangway to extend one stud the mechanism but the gangway itself needs to be 7 studs wide or be made up of tiles, I haven´t yet decided about it.

2 hours ago, Hod Carrier said:

Well, for now I shall wish you luck in your plans and wait to hear what happens. 

Thanks, I hope I can tell you more soon and that it will be good news

[Hod Carrier]

I should flag one issue with the design, which I suspect will be a problem whichever solution you choose. The test train struggled to take the points/switches on the test track at low speed and I didn't want to try it any faster because of the risk of derailing. The issue is that the axle is being steered by the movement of the cars relative to each other rather than by the geometry of the track as would be the case with a convention bogie. This means that sometimes it's not being steered in the correct direction to follow the bends. Therefore I do not recommend having lots of corners, bends and points/switches close to each other. It may be worse with my railcar because the cars are longer than would be the case with a Talgo, but testing your finished train on different track configurations will prove the case.

[Imanol]

2 hours ago, Hod Carrier said:

I should flag one issue with the design, which I suspect will be a problem whichever solution you choose. The test train struggled to take the points/switches on the test track at low speed and I didn't want to try it any faster because of the risk of derailing. The issue is that the axle is being steered by the movement of the cars relative to each other rather than by the geometry of the track as would be the case with a convention bogie. This means that sometimes it's not being steered in the correct direction to follow the bends. Therefore I do not recommend having lots of corners, bends and points/switches close to each other. It may be worse with my railcar because the cars are longer than would be the case with a Talgo, but testing your finished train on different track configurations will prove the case.

I´ve been thinking about it and the solution may be in the train itself as the real life Talgos need to be guided by the first axle to take curves. I don´t know if this will help in this case.

Another solution will be to reduce the turning radius to the bare minimum to be able to take the curves but I don´t know if this is possible.

Thanks, Imanol

[Imanol]

I have made the first prototype with the new coupling design but it looks like I will need to make a lot of space inside as it can´t fit right now. But the problem is that it invades the interior, so I will need to probably use the gangway as an extension of the car.

This is how it looks right now

Remolque Turista Renfe S-130 Union Def 2 by Imanol, en Flickr

My idea is to have one stud left of free space between the cars.

[Imanol]

Okay, I ´ve been making some modifications to the cars and the attachment of the bogie assembly and I´ve reduced the space 1 stud and I think this is the perfect distance between them.

Remolque Turista Renfe S-130 Union Def 2_2 by Imanol, en Flickr

As you can see in the picture is now tidier and more compact and I think the joint will be strong enough