Switches controlled by external levers

[Bartosz]

Controlling the switches remotely is recurring topic which has been solved by various approaches. The ones I'm aware of involved a motor/servo controlling either the throw itself or just going underneath the switch and moving the springed part there while switch is in open position.

So far so good. But then one wants some user interface. Again, couple of options: automating with powered up app, Brick Automation project, probably lots more.

But what if one wanted levers, just not the yellow ones directly on switch but in some other place? In a brick-built control panel?

With powered up i have no idea how i could "read" something that's not coming from the App. It is smart device focused, it allows building interfaces - i think that's great, but when I want to play with bricks, i don't want to play with touch screen. To much of those in our lives nowadays.

So maybe a motor-less solution? I think one could build lever that would transfer movement via gears/axles (but I'm not a technic guru). Obviously it would be limited in range, but maybe it'd be fine (and bit cheaper as not requiring motors) - has anyone tried something like that?

And if not, is there some system in which one could build levers whose motion would then be picked up by some controller driving motors (I'm afraid I'm restrained to powered up now, but would gladly hear about other approaches)?

[John Hill]

Controlling the switches is something that is too easy to over think!   Look at the switch and we see that only a small bit  (the 'frog')  actually moves and that it is moved by  the lever and a spring.  No matter which position the lever is in the movable track frog can be easily moved to the other position.

The easy way to remotely control the switch is to thread a piece of string  (please use only genuine Lego string!) through the lever side rail and glue the end to the moving piece of the switch.  

Move the switch to the turn out position and leave it there and just pull the string when straight through is required.  You can use whatever mechanism you like to pull the string.

It is true that string is not ideal for the job and perhaps a stiff wire could be bent to do the job.

 

 

[cptkent]

I knocked up a simple switch control servo a couple of years ago, during a period when I didn't have access to my LEGO sets.

I figured a 'wired' solution may be easiest for what I wanted at the time, just a remote way of powering and controlling a switch.

I wanted to learn how the servos worked, and roughly prototyped something, but stopped at this point knowing it was a solution I could use, but a decent implementation would have to wait for another day:

Link

 

Edited March 24, 2021 by cptkent
Link

[dr_spock]

Would LEGO Technic pneumatics work as switch actuators?

 

[Andy Glascott]

46 minutes ago, dr_spock said:

Would LEGO Technic pneumatics work as switch actuators?

 

I've seen posts showing a pneumatic system but can't remember if it was here or elsewhere. 

[Duq]

There is another option. As @John Hill pointed out, there's only a small part of the switch that actually moves and that part is spring loaded. All you need is a way to push it to one side.

A while ago I played around with a way to control the double crossover and came up with this mechanism:

Crossover Control V2 by Duq, on Flickr

In the description on Flickr there's also a link to a video that shows the full crossover in action.

[Lok24]

Hi,

nice topic!

Here are some ideas how to do, as already described by others here:

Find the complete article with may pictures here:
https://www.1000steine.de/de/gemeinschaft/forum/?entry=1&id=369752#id369752

And here my preferred solution with strings:

 

Find the complete article with may pictures here:
https://www.1000steine.de/de/gemeinschaft/forum/?entry=1&id=400488#id400488

It shows a layout with 3 switches, 2 signals, 1 crossing, 1 minifig.

Driven by 2 Sbricks, 5 PF Motors, 1 9V Motor ans 1 Micro-Motor
It was shown on two exhibitions for two days each running automatically the hole day without any problems.

And for those who want levers:
A mechanical solution for 2 Signals (right), 3 switches (middle) and a key (left), not yetfinished, but you can see the strings in the upper section.

 

Edited March 25, 2021 by Lok24

[Bartosz]

8 hours ago, Lok24 said:

And for those who want levers:
A mechanical solution for 2 Signals (right), 3 switches (middle) and a key (left), not yetfinished, but you can see the strings in the upper section.

The link to image doesn't seem to work?

What a great layout. The solution is really clever , I always feared that it'd be hard to be precise with strings and they would have to be adjusted all the time...

[Toastie]

Not really a stiff lever - rather more flexible ... I am using this to switch 7994 from either all straight to all diverging, as I don't (or maybe no one doesn't really) need any other combination ...

Here's a little more detail - the driving mechanism builds on using the flex system tubes and some nylon wire stiff enough to firmly push the point blades to the corresponding rail when in diverging position (or whatever that is called ...) and securely retracting them for going straight.

This is a very invasive mod though as I removed all the stuff from the bottom of 7994 (covers springs, levers) but the blades, then drilled four holes receiving the flex tube terminals. And into the blades of course The nylon wire responds nicely to heat; it is straight forward to make that sharp bent ("hook") at each blade terminal. When cooled down again it is pretty rigid. The wire is not glued to the blade, just sitting there. The wires are flexible enough though to smoothly move within the flex tubes: One PF M motor easily takes care of operating "four" points by pulling (and pushing) the strings.

Other than that it is all genuine LEGO.

And it is entirely TLG's fault that I had to do it . Here is to feeling good!

I have no idea but firmly believe that this must have been done by others before. If so: All credit goes to them. Haven't done a decent search on this, I have to admit. When you know about that, let me know, I'll reference that here immediately!

All the best,
Thorsten 

P.S.: Forgot: It tolerates "8 + a bit wide" trains max. I am almost exclusively running "6 + stuff on the side" wide trains. This limitation is caused by the location of the driving mechanism - I thought it would look good on my layout to have it rather close (almost "on") 7994.

Edited March 25, 2021 by Toastie

[ALCO]

I built a purely pneumatic system to do just this and posted about it here on eurobricks. I'm on my mobile right now so I cannot find it and link the topics but I can in a few when I sit down at the computer.

Ok, here is a link: On Eurobricks

I know @Roadmonkeytj has also built some along with a pneumatic uncoupler.

The only non-Lego parts I used was tubing due to cost. At $.17 USD per ft. from my local hardware store vs. Official tubing at arm+leg per stud. 

Edited March 25, 2021 by ALCO
Added link

[Black Knight]

If you want something akin the old 12V train-switch system, TrixBrix probably gets closest with their system. I haven't tried it myself, so I can't say anything about the quality.

 

[Lok24]

16 hours ago, Bartosz said:

The link to image doesn't seem to work?

What a great layout. The solution is really clever , I always feared that it'd be hard to be precise with strings and they would have to be adjusted all the time...

The last image is not a link...?

No, there was, not even after transport and setup, no need to adjust. During two days .

But adjusting is very simple: the string ends in a technic pin (at the "motor" end)  and is winded three or four times, so you just have to turn a little bit ,  like with a guitar string.

 

Edited March 26, 2021 by Lok24

[brick-builds]

 

Hello train-fans,

some time ago, I built this with Trixbrix tracks. My intention was a very simple solution and to hide later the motor in a small house....

 

 

Edited March 26, 2021 by brick-builds

[Bartosz]

53 minutes ago, Lok24 said:

The last image is not a link...

Sorry, I meant it's not displayed for me in-line - just get the "broken image link" picture.

Edited March 26, 2021 by Bartosz

[Lok24]

I see.... here it is:

 

[zephyr1934]

19 hours ago, Toastie said:

Not really a stiff lever - rather more flexible ... I am using this to switch 7994 from either all straight to all diverging, as I don't (or maybe no one doesn't really) need any other combination ...

That's brilliant!

[Roadmonkeytj]

On 3/24/2021 at 6:26 PM, dr_spock said:

Would LEGO Technic pneumatics work as switch actuators?

 

Mine worked well for an entire show season running an inglenook puzzle

 

 

 

 

 

[Toastie]

7 hours ago, zephyr1934 said:

That's brilliant!

Thank you very much. I really take your assessment as most relevant for me. As you know, I don't do shows, I am not affiliated with any group, I just do my stuff "upstairs" - because I can.

Which in turn means that I am easily losing touch with what I am doing ("for" the community) - and things easily become egocentric.

On a side note: When the Zoom meetings roll through the day - just looking left, right, straight ahead and back ... reassures me that all that is real, whereas a Zoom meeting is virtual 

Thanks again and all the best
Thorsten