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Thanks!!! You're right, they are quite unaccessible - I think I'll attach a bar on them - I want to experiment a coupling like H0 ones, but I still don't know :wink:

I'm just building a wagon to test the behaviour of rolling stock during curves and switches :laugh:

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:thumbup::thumbup::thumbup:

But two important things are missing:
A comfortable deckchair at the end of the line and a freight car bringing cold drinks... :grin:

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A brilliant, cute little locomotive, with excellent proportions. There's something rather nice about seeing a narrow gauge engine pottering along overgrown trackwork, even if it can't actually manage it!

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On 4/9/2018 at 8:03 PM, ColletArrow said:

A brilliant, cute little locomotive, with excellent proportions. There's something rather nice about seeing a narrow gauge engine pottering along overgrown trackwork, even if it can't actually manage it!

Thank you!!! :laugh: I think the track, with a bit of  "terrain preparation" (e.g. bricks  and plates under the track to cover holes) can be manageable - let's see the weather during weekend!

In the meantime, I'm studying how to manage couplings and the wagons behaviour on R40 track. :sweet:

This is the new buffer with coupling system I want to share with you - for comments and suggestions;

WP_20180411_08_18_37_ProWP_20180411_08_18_44_Pro

The buffer can turn left and right - together with the coupling. The coupling can be folded up when not in use (the buffer must be removed and put again in place)

WP_20180411_08_19_30_Pro

Here above it is in extended position. Here below, the prototype of the two- axle wagon is ongoing - the buffer is turning like the locomotive one - but it will also turn the wheels (I found some solutions of G scale wagons with two axles adopting a similar steering system). The coupling is easy to perform - even if it is the most unreal thing on earth - turn one buffer right, turn the other left - connnect the two couplings with the 3L axle. Each wagon will have a place to store the two 3l axles (only one should be used, the other one is a spare part)

I know it is an idiotic way of coupling :tongue:, but it is simple to build and, for the moment, it seems to work  (and keeps the two buffers attached).

WP_20180411_08_19_52_Pro

I'm planning to adopt a steering linkage like the one used in the below wagon (prepared some months ago for the castering effect study) which is very similar to the G gauge solutions I saw around.

Since there is some overhang from buffer to wheels, I think the wheels and buffers of these big wagons cannot be turned by the same angle - since you could have an axle which is turning too much, even if in the right direction.

WP_20180207_23_09_20_Rich

Doubling the size of rolling stock creates a double amount of problems when it comes to manage a track radius which already is narrow (now it is narrower :laugh: by two times). I found especially difficult to manage narrow S curves (left track + right track o  2 left track + 2 right track).  

This evening I will prepare some photos  to show you how the buffers are "stressed" during an "S" curve. 

I do not want to think about specific track geometries accepted by this rolling stock until I try all the technical  possibilities to manage the  R40 radius properly :laugh:

Ciao!

Davide

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On 4/7/2018 at 10:26 PM, Tenderlok said:

:thumbup::thumbup::thumbup:

But two important things are missing:
A comfortable deckchair at the end of the line and a freight car bringing cold drinks... :grin:

Wagon chassis will surely tested with a cocktail on it - I put this test on the list!!!:laugh:

On 4/7/2018 at 11:42 PM, LEGO Train 12 Volts said:

Beautiful and fast! :wub:

The picture in the garden with daisies is amazing!

maybe too fast :laugh: - I tried other gear ratios - but until I'm not sure on how much the wagons weigh and stress the transmission I cannot tell  which is the best one :wink:

I love trains with nature background - it is somehow relaxing! :laugh:

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The supersized train is great

 

On 4/7/2018 at 4:26 PM, Tenderlok said:

:thumbup::thumbup::thumbup:

But two important things are missing:
A comfortable deckchair at the end of the line and a freight car bringing cold drinks... :grin:

You really are a G-scaler (grin)

 

On 4/11/2018 at 9:02 AM, Paperinik77pk said:

I know it is an idiotic way of coupling :tongue:, but it is simple to build and, for the moment, it seems to work  (and keeps the two buffers attached).

Are you kidding? The simpler the better.

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On 4/13/2018 at 6:34 AM, zephyr1934 said:

The supersized train is great

 

You really are a G-scaler (grin)

 

Are you kidding? The simpler the better.

Hi @zephyr1934 , thank you!  :laugh:-

After a week without working on the big train, I prepared a prototype wagon to test the new couplings and the axle-steering system - I can confirm the simple coupling works fine, and it is a decent way to keep rolling stock together. It also has a bit of flexibility, which is not bad.

So, let's see how it works:

First case - switch with straight line track (also valid for switch with one straight and one curve) - this is the optimal track solution to help the axles and the couplings in doing their work.

 

WP_20180414_10_35_04_Pro

Second case - original Lego track geometry with counter-curve after the switch (harder to manage, but very realistic in this big scale - two trains can cross each other without touching, and they are very close. :laugh:

WP_20180414_10_36_19_Pro

Now, let's take a look to the steering system on the wagon:

WP_20180415_11_16_07_Rich

It is the same used on my yellow wagon - I used big wheels, but also BBB medium wheels can be used without problems. The steering pivot of the coupling is quite far from the coupling itself, but it allows a good, decentralized movement of the coupling from side to side.

WP_20180415_11_16_18_Rich

 

WP_20180415_11_17_18_Rich

The steering system works as you can see in the pictures, the coupling actually steers a bit  more than the axle. The fake suspension used for locomotive is replicated also on wagon and covers quite fine the wheels. The first picture shows wheels spaced to work on standard Lego gauge , in the second one you can see the wheels positioned to work on 45mm G-Gauge. Probably I'll rework the fake suspension to look like a leaf-spring type instead of a double-spring type.

And this is how the wagon manages the second type of track geometry: Locomotive is travelling on the switch - this is the most critical moment: locomotive coupling is quite at its maximum articulation and brings the wagon steering to move a bit in the opposite direction. This is a problem of the locomotive coupling pivot, which is too near to the chassis end.

But I cannot move it, there are batteries and motor on the other side - so I have to accept this.:sceptic: ...at least the unwanted turning movement is mitigated by the linked steering (so wagon wheels are not steered too much to touch the rail with borders.

WP_20180415_11_14_49_Rich

Step two - the wagon is managing the switch, axle is turned according to curve.

WP_20180415_11_15_09_Rich

Step Three - the locomotive is now on the straight part of the track and pulls the wagon in the right way - axle is steered to follow the curve (maybe a bit too much).

WP_20180415_11_15_27_Rich

It seems to work both pulling and pushing - I'm not satisfied 100% by that unwanted steering - I'll try to move the axles inwards by one stud and to make the steering links a bit longer (4 studs instead of 3).

I tried also to put the locomotive red body (the "prototype") on the wagon chassis - it is quite heavy, but it is pulled without problems. Wagons will surely be lighter than the locomotive, since the bodies will be 1-stud wide instead of 2-wide.

Last but not least...an S-Brick arrived as a gift...now I can drive a blue....tooth locomotive :tongue: :laugh:.

Bye!

Davide

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31 minutes ago, Tenderlok said:

This coupling kinematics is absolutely ingenious! :thumbup:

Thanks!!! It was inspired from some information I found in internet about custom wagons in G-Scale - allowing tight radius cornering.

It is completely unreal , but I have to adapt  (improvise, adapt, overcome! :laugh:)  the behaviour of rolling stock to the worst track case possible. I made no photo but in standard curves the side edges of the locomotive and wagon are veeeeeery near.

Basically I'm trying to make what looks like a metric gauge train to run on a Decauville track  radius:laugh:

The locomotive is still in 2wd mode with rubber bands on traction wheels - I have the new chains, but I did not install them yet :sweet:

 

Bye!

Davide

 

 

 

 

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Hi all, a little update on this topic - which was stopped a bit by some experiments with the new 3D printer.

I finally had the time to design something to put on the wagon base - trying to keep it simple and cost-effective (and able to transport a cocktail in pure G-Gauge style :grin: ).

It is a simple gondola car in gray/or reddish brown - based on LGB 41031 gondola car.

Gondolagrey

As you can see the wagon base is still the old one without pivoting couplings (which maybe will be changed for a simpler version than the ones shown some posts ago). Having some spare time, I began to build the third type of locomotive chassis (steamer) and to experiment a bit. Unlike the diesel chassis, it has less internal space (especially in its central part), so the battery, transmission (gear-based this time) and motor are arranged in a different way. It keeps the double-gauge feature so it still is compatible both with G and L-gauge. Tomorrow I will order the parts on Bricklink, so I can have something to pull with the 7720.

Here you can see the Steamer chassis with a well-known body on it.

7810xxlassembly[689].lxf

Regarding the diesel-chassis, the chain solution for powering both axles has some flaws. It needs to be tensioned, and it jumps (only in one direction - strange behaviour :hmpf_bad:).

I will probably keep the chain drive on one axle only and transfer the power to the other axle in another way.

That's all for the moment!

Bye!

Davide

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Hi all, today I had the opportunity to work a bit on the garden train, especially on the transmission, which was completely changed.

Here's the result:

WP_20180512_17_56_25_Pro

The  chain system was removed (I will keep the idea for lighter locomotives or other uses), and a new geartrain was installed. currently the gear ratio is 1:1 and it's achieved using two Z16 gears. It can be changed to:

  • 1:1.667
  • 1:3
  • 3:1 (overdrive)
  • 1.667:1 (overdrive)

In this way I can manage different speeds and torque according to the weight or purpose of the locomotive.

WP_20180512_17_59_00_Pro

 

WP_20180512_17_58_24_Pro

The PF motor now is centrally mounted, I rearranged a bit the cables and found a new way to lock the S-Brick inside the hood.

It works smoothly, and traction now is very good :classic:

I thougt Lego gears were less strong, luckily I was wrong! :laugh:

 

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In addition to the new drivetrain of the Diesel Chassis, I also had some time to get a better picture of what G-Scale trains offer today.

I threrefore dowloaded the LGB catalogue in .pdf format and found a nice surprise:

lgb-90463-startset-bausteinzug-spur-g-neuheit.2017-4

 

516X5cfs9ZL

It is a small wagon with a Lego-compatible bed full of studs...it's veeeeeery niiiiice (It costs around 30 Euros - pity I do not have G-gauge tracks ready to be used).

The bed is 12 studs wide and 28 studs long . Quite amazingly it matches the 7720XXL size (a bit smaller in lenght) - I did not bother to use any specific scale  apart doubling the original Lego locomotive size. It was a lucky shot! :grin:

The LGB wagon has two axles which can steer independently and do not use any particular or complicated steering system. The coupling pivots together with the axle.

So I tried to recreate it in Lego with the parts I had around...it has no undercarriage details, but I'll re-design it in LDD after some tests, so I can make it prettier. Same exact dimensions as the LGB original.

WP_20180512_18_03_19_Pro

 

WP_20180512_18_03_30_Pro

 

WP_20180512_18_03_39_Pro

 

WP_20180512_18_04_09_Pro

 

WP_20180512_18_08_19_Pro

It is very simple,cost effective and a good base for building also longer wagons. But it has a flaw - you have to use some "tricks" when building the track (so a piece of straight track before/after points and between S-shaped curves).

I think its simplicity can make me accept this limit. I still don't know if I'll use this steering solution for the gondola wagon I designed in LDD.

I hope you like it! Comments and suggestions are welcome as usual ! :laugh:

Ciao,

Davide

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Hi Davide!

19 hours ago, Paperinik77pk said:

[...] and able to transport a cocktail in pure G-Gauge style :grin: [...]

:thumbup::thumbup::thumbup::wink:

40 minutes ago, Paperinik77pk said:

Hi all, today I had the opportunity to work a bit on the garden train, especially on the transmission, which was completely changed.
[...]
I thougt Lego gears were less strong, luckily I was wrong! :laugh:

Yes, that looks much more reliable than the chain drive.
From my experience, I can confirm that most Lego gears are quite strong. The inglorious exception are the 12-teeth conical bevels, which are prone to tooth wear/loss under high torque. The 12z double conical gear wheel performs better.
A greater problem is to keep the drivetrain bearings in place. Especially when you lubricate the drivetrain for less friction, lubricant may penetrate between the bricks and cause them to lose grip, to the extent that parts may fall off under load. As of late, I'm using Teflon spray instead of silicone oil to avoid that effect.

That simple steering solution is found on many 2-axle LGB cars. It works well when being pulled, but the axles tend to cant within the rails when the car is pushed (btw: a piece of straight track between S-curves is also standard on real railways, so I don't consider that a "trick", but a tribute to the prototype... :wink:). On my 2-axle Lego cars, I simply restricted the axles' steering angle, and it works fine both being pulled and pushed.

Best regards,
Sven

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1 hour ago, Tenderlok said:

Hi Davide!

:thumbup::thumbup::thumbup::wink:

Yes, that looks much more reliable than the chain drive.
From my experience, I can confirm that most Lego gears are quite strong. The inglorious exception are the 12-teeth conical bevels, which are prone to tooth wear/loss under high torque. The 12z double conical gear wheel performs better.
A greater problem is to keep the drivetrain bearings in place. Especially when you lubricate the drivetrain for less friction, lubricant may penetrate between the bricks and cause them to lose grip, to the extent that parts may fall off under load. As of late, I'm using Teflon spray instead of silicone oil to avoid that effect.

That simple steering solution is found on many 2-axle LGB cars. It works well when being pulled, but the axles tend to cant within the rails when the car is pushed (btw: a piece of straight track between S-curves is also standard on real railways, so I don't consider that a "trick", but a tribute to the prototype... :wink:). On my 2-axle Lego cars, I simply restricted the axles' steering angle, and it works fine both being pulled and pushed.

Best regards,
Sven

Hi Sven, thank you for your always kind and helpful feedback...you were right at the beginning of this thread...the chain drive is not so good for this purpose.

Or, better,  the chain drive works fine only if it is well tensioned - but in this way you must add something to add tension - which I did it - but it made the solution too complex and  increased the friction. This problem did not occur on when the chain was driving only one axle (the chain was self-tensioning), but when I extended the chain, problems began to show up.

Gears work way better for a locomotive of this kind. Plus, the possibility to choose a wider range of gear ratio is a good point of the new drivetrain.

Great suggestion on the lubricant - I was thinking what to use (no WD40 for sure - maybe Tamiya Grease) - but the teflon spray can be the real solution (also on old 12v trains? :laugh: let's try!)

The unwanted tilting (what was identified as "spaghetti effect" in the castering thread) is something I was wondering looking at the LGB coupling - which seems to leave the hook to move sideways. To be honest it seemed not too much "precise" at a first glance, especially in pushing mode. I never saw one in action - in fact I was tempted to buy the LGB "Lego" wagon only to study it). The multilink system shown some threads ago limits this behaviour and accepts a more standard track geometry. But for such a small wagon...it seems not worthy.

The coupling I'm using now is quite rigid and the rubber band helps to limit the excessive turning of the axles - but it is always a solution to manage a tight curve radius - a compromise by any means :laugh: .

To be sincere, I'm quite afraid to try it on a bogie-based wagon :wink: - but I'll do it one day!

 

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As you seem to be interested, another word on the Teflon spray: It’s almost impossible to apply it directly to the bearings without affecting the surrounding parts (when dried up, it leaves a white film). So I use to spray a good amount into an egg cup, and then apply it to my model with a cotton swab.

As I explained in the thread on my Bulgarian loco, I don’t use standard LGB couplers, so I can’t say anything about them. But the link-and-pin-type (you can replace the standard coupling with them, but sometimes need to cut off the buffers) is a rather flexible connection, which allows the axles to steer at the correct angle.
Take all this with a grain of salt, however, as I made these experiences with considerably larger curve radiuses.

Don’t know if I understand your last sentence correctly – bogie wagons shouldn’t need this rubber band IMO, as the bogies stabilize themselves.

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You are right - I explained badly - the band is not needed on bogie wagons. :laugh:

My doubt is related to the coupling system between loco and wagon , which was tried only on the 7720 and on some two axle cars. I wonder if it will be good also an a bogie wagon, I hope it is not too rigid, otherwise I'll have to adapt it somehow - my concern is that it could steer too much the bogie, forcing it to derail.

Tomorrow I'll try to to put together a bogie wagon - now I'm curious :wink:

Ciao!

Davide

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Ah, now I understand.
To overcome this problem on my wooden passenger wagon, I just made the bogie's drawbar articulated:

600x230.jpg

 

But again, I don't know if this simple solution works on your curve radius and with your quite rigid coupling. I suppose you'll need a kinematics like on your 2-axle car.
Good luck with the bogies!

 

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Thanks Sven!

I came by trial and error to a similar solution, but you anticipated the problem...the radius is very tight and the couplings swivel in a very unrealistic way.  I'll try your solution to see how it works on small radius (BTW your bogie is spectacular).

Apart the bogie wagon trial, I analyzed different sizes of 2 axle wagons, according to a calculation I made starting from wagon lenghts reported on LGB catalogs.

Fixed width: 12 studs - Buffers: approximately 2 studs on each side.

  • 26cm (28 studs base - interaxle 17 studs - coupling bar lenght from axle to buffer 8 studs) - 94063 "Lego car"
  • 30cm (34 studs base - interaxle 17 studs - coupling bar lenght from axle to buffer 10 studs) - 40032 "Gondola"
  • 34cm (38 studs base - interaxle 21 studs - coupling bar lenght from axle to buffer 10 studs) - 43356 "Refrigerator Car" 
  • 45cm (52 studs base - interaxle 25 studs - coupling bar lenght from axle to buffer 13 studs) - 33551 "RHb Passenger car"

For two axles cars I prepared a very simple chassis which can be extended to desired size.

For the first three sizes 26cm, 30 cm and 34cm - the test was successful, even on standard Lego curves. For the 45cm one (52 studs)...well...you can judge by yourself :grin:  - it's really too much for the R40 radius...and 48 studs is not better with two axles - but can be the good size for bogies :devil:

By the way, the 52 studs-two axle could really be a nice wagon to build and run on larger track.

WP_20180513_21_45_20_Pro

So, I think that doubling also the lenght of standard lego wagons could help - so 32+ studs for the two axles and 48 studs for the bogie - based wagons. It seems a good compromise.

Adjusting a bit the coupler lenght I managed also S curves without straights, but it's ridiculous to see it going around the track! :grin:

Back to LDD - I need to focus a bit on carriages style :wink:

Bye!

Davide

Edited by Paperinik77pk

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On 12.5.2018 at 8:15 PM, Paperinik77pk said:

The LGB wagon has two axles which can steer independently and do not use any particular or complicated steering system. The coupling pivots together with the axle.

Has to be similar to the old Playmobil wagons:

28215938048_d9d69beeb1_b.jpg

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1 hour ago, 3797 said:

Has to be similar to the old Playmobil wagons:

28215938048_d9d69beeb1_b.jpg

Yes - same solution :wink: :thumbup: - and it seems to me...also the same size :classic:

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On 5/12/2018 at 1:06 PM, Paperinik77pk said:

Hi all, today I had the opportunity to work a bit on the garden train, especially on the transmission, which was completely changed.

Here's the result:

 

The  chain system was removed (I will keep the idea for lighter locomotives or other uses), and a new geartrain was installed. currently the gear ratio is 1:1 and it's achieved using two Z16 gears. It can be changed to:

  • 1:1.667
  • 1:3
  • 3:1 (overdrive)
  • 1.667:1 (overdrive)

In this way I can manage different speeds and torque according to the weight or purpose of the locomotive.

The PF motor now is centrally mounted, I rearranged a bit the cables and found a new way to lock the S-Brick inside the hood.

It works smoothly, and traction now is very good :classic:

I thougt Lego gears were less strong, luckily I was wrong! :laugh:

 

Nice work.  The XL motors have enough torque to strip the small bevel gears if the wheels are stalled.  I used the same gears for my Techball robot.  It wasn't pretty when I had to push another robot.  It is likely you'll be spinning your wheels before that happens.  :laugh:

 

 

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8 hours ago, dr_spock said:

Nice work.  The XL motors have enough torque to strip the small bevel gears if the wheels are stalled.  I used the same gears for my Techball robot.  It wasn't pretty when I had to push another robot.  It is likely you'll be spinning your wheels before that happens.  :laugh:

 

 

Thanks!!! :sweet: I think this is what will happen - for the moment I did not pull very heavy loads - I'm curious to see how much a passenger car like the 7710 will weight when "doubled" :sweet:

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