Lowa

Train Automation - Track Switch Motors

112 posts in this topic

To all LEGO train automation enthusiasts,

This is a short clip of the final version of our LEGO compatible track switch motor.  It has a digital servo embedded in a 3D printed housing.  This is a 'plug & play' solution: the motor is strong enough that it doesn't require any modification of the switch (you don't need to open the switch and remove the notch to reduce the force needed to flip it).  I also added a picture of the back side so you can see how it can fit onto a LEGO® switch.  The housing is made in a custom dark bluish gray ABS filament that matches the LEGO® tracks.  The motor has a 6 by 6 stud footprint and it's 2 bricks + 2 plates high.  We'll be making controllers for these motors as well, so you can connect them to your PC.  However, the motors are fully Arduino compatible, so you can integrate them in you own DIY control system.

What do you think ?

We're working on a full range of automation gadgets for LEGO trains.  What other automation challenges would you like to see solved ?

4dbrix-track-switch-motor-back.jpg

 

 

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I'm definitely interested in these.  I've been trying out some of the mods that are on the internet, but I have no luck with the PF M motors since they can be too powerful to throw the switch.

In most cases, the M motor comes off the bricks/plates or the design causes the bricks to fly apart.  

I'm a purist at heart, but would be willing to try these out.  I'm interested to see how these connect to your PC and would like it if you had a separate control box to flip them by hand.  

Brian

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1 hour ago, legobanker said:

I'm interested to see how these connect to your PC and would like it if you had a separate control box to flip them by hand.  

You indeed need quite a lot for force to flip a LEGO switch, and this strains the connection between the motor and switch.  Making sure the motors don't come lose was one of the main challenges during the development process...  but we managed.

The control boxes connect to a PC with a USB cable.  We have a  track planning / automation software (nControl) that allows you to flip the switches and monitor your layout.  The advantage of a software is that you can fully automate your layout, e.g. interlink sensors, motors, traffic lights, etc.  You can download nControl for free from: https://www.4dbrix.com/downloads/index.php

However, it would be possible to create a 'manual controller' that allows you to flip the switches by pushing buttons.  We could make the 'skeleton' of the buttons and the you could use regular LEGO brick to build a control panel around the buttons.  I could give you something similar to the old 12V switch controls.  Is that what you had in mind with 'flip them by hand' ?

nControl-1.jpg

Edited by Lowa

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I see.  I was thinking of a control box that could be used instead of the computer.  I see now why you use the computer since it is automated, which sounds pretty good. I was thinking something along the lines of a powered switch box that you could have and then if you wanted to switch tracks, you could just move the "lever" back and forth.

How much does one of these things cost?

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I really wanted a part like this for serveral years.

A few ideas for other parts:
-A switch motor for the double crossover (7996)
-An adapter to power the motor with power functions/9V

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Very good idea!

But I really think you should make buttons like in 12V. I think that would be easier for AFOLs and more interesting for kids to operate the buttons instead of computer.

Just one idea for the software - make the level crossing and buffers for the track.

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4 hours ago, legobanker said:

How much does one of these things cost?

If  you use our 4DBrix controllers:

  • the motors will be $15 / motor.
  • the controllers will be $40 / controller, each controller can handle 4 motors.  (The controller is embedded is a brick that has a 4 x 6 foot print and is 2 bricks + 1 tile high)
  • the control software is free.

If you use your own Adruino controllers:

  • the motors will be $15 / motor.
  • the controllers: your own Arduino
  • the control software: you will need a subscription which will be $12/ year

We're currently making the first systems.  If all goes well they should be available by the end of the year / beginning next year !

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2 hours ago, Tcm0 said:

-A switch motor for the double crossover (7996)

It should be possible to modify the connection of the motor so it fit on the double crossover.  We'll certainly take a look at that.

2 hours ago, Tcm0 said:

-An adapter to power the motor with power functions/9V

This is not as straightforward as it might seem.  LEGO has released the power functions RC protocol (http://www.philohome.com/pf/LEGO_Power_Functions_RC_v110.pdf) however the document clearly states you can only use this for non-commercial purposes (page 2) and we want to respect that...  I'm looking at a radio frequency based system as a better alternative: large range and not directional like the IR (you don't need to aim at the receiver).

1 hour ago, Elektrychka said:

Very good idea!

But I really think you should make buttons like in 12V. I think that would be easier for AFOLs and more interesting for kids to operate the buttons instead of computer.

Just one idea for the software - make the level crossing and buffers for the track.

Thank you!

Personally, I also like the idea of 12V style buttons.  I have the feeling that a functional control center build out of LEGO bricks would look very cool.  I haven't started working on it, so I don't have a clear view of the components that I would need, but it will be more expensive than a software based system...

Level crossings and buffers will certainly be added to the software as we're working on special (small) servo motors for level crossing barriers; we also designed a LEGO compatible buffer track.  The picture below shows our prototypes of the buffer track (right), half straight track (middle) and the quarter straight track (left).

4dbrix-buffer-track.jpg

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16 minutes ago, Elektrychka said:

Will there be any motor-controller and controller-computer wire extenders?

Yes, we have motor-controller extension cables.  We currently have:

  • 30cm / 1ft
  • 45cm / 1.5ft
  • 1m / 3.3ft

We also found a 2m / 6.6ft cable but we haven't tested it.

The controller will come with a 1.3m / 4.3ft USB cable.  We haven't looked into controller-computer extension cables but we will.  The controller uses a standard USB cable, so you could use any USB extension cable that you can find.  

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Are you using some of the generic 9-gram hobby servos for this? Is there a custom part that's connecting to the switch mechanism itself? I've been investigating using this style of servo (see below) to drive the switches, but the trick has been figuring out how to have them actuate the switch - let alone them having enough power to actuate it in the first place.

662.jpg

Edited by Phoxtane

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can the brix control run a program ?, reset button?, power stop button?

years ago i used a "usb-relaycard Kemo #162" that was fun but only a time-loop.

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Would you be able license the use of the Power Functions protocol from LEGO for your commerical venture?

 

 

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4 minutes ago, Phoxtane said:

Are you using some of the generic 9-gram hobby servos for this?

Yes, we're using a '9g' type servo but a high end version: the Tower Pro SG92R; that's a (more powerful) digital servo that has carbon fiber reinforced gears.  The one you showed is most likely an analog servo; it has nylon gears which are less durable.  Also be aware of the fact that there are a lot (really a lot...) of fake ones out there.  I'm not familiar with the details of the HEXTRONIK product range but the picture you show looks like a counterfeit one.  The little rectangle on top of the servo normally has the name of the manufacturer molded into it.  If that rectangle doesn't have a name, like on your picture, that's usually an indication it's a fake.  I got received some fake Tower Pros a while ago and they clearly under performed during our reliability tests; they were also less powerful.  We now get them directly from Tower Pro just to be sure we get genuine ones.

We designed a brick to connect to motor to the switch, it has an internal mechanism to actuate the switch.  We designed the mechanism in such a way that the motor has enough power to flip the switch 'as is' (= you don't need to remove the notch of the switch to reduce the force you need to switch it)  It was indeed a challenge... but it works now!

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Is this compatible with the 9V switch? Those don't have the single, solid 'click' when switching from straight route/diverging route like PF/RC switches. I don't know if the video addressed that because I'm unable view it where I am at the moment.

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This is definitely interesting, and as said above, I think a system like the 12v ones would definitely be worth the money for a nice layout. :)

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1 hour ago, Q3671 said:

can the brix control run a program ?, reset button?, power stop button?

The controllers have their own 'operating system' that you cannot change; this is needed to have a robust / fail proof system.  However, you have full access to the functionalities of the controllers from the nControl software through Python scripting.  This gives you full flexibility in what you can do.  Standard users can use the preprogrammed tiles (on screen buttons) while advanced users can write their own functionalities and link them to tiles.  We try to provide as much flexibility as possible, if you ever encounter a limitation in accessibility, let us know and we'll check to see if we can overcome it...  

We choose for an approach were the main process is not running on the controllers but on the computer.  This allows easily interaction between the controllers, for example, if one controller detects a train, the software can respond by sending signals to flip switches, traffic lights, crossing barriers, etc.  Communication between different controllers is native in nControl, you don't need to pull any special tricks to do this.  To goal is to create a platform to build custom central control centers for your layouts.  Look at it like a 'LEGO brick' concept but with electronics and software instead of plastic bricks.

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2 hours ago, Lowa said:

Yes, we're using a '9g' type servo but a high end version: the Tower Pro SG92R; that's a (more powerful) digital servo that has carbon fiber reinforced gears.  The one you showed is most likely an analog servo; it has nylon gears which are less durable.  Also be aware of the fact that there are a lot (really a lot...) of fake ones out there.  I'm not familiar with the details of the HEXTRONIK product range but the picture you show looks like a counterfeit one.  The little rectangle on top of the servo normally has the name of the manufacturer molded into it.  If that rectangle doesn't have a name, like on your picture, that's usually an indication it's a fake.  I got received some fake Tower Pros a while ago and they clearly under performed during our reliability tests; they were also less powerful.  We now get them directly from Tower Pro just to be sure we get genuine ones.

We designed a brick to connect to motor to the switch, it has an internal mechanism to actuate the switch.  We designed the mechanism in such a way that the motor has enough power to flip the switch 'as is' (= you don't need to remove the notch of the switch to reduce the force you need to switch it)  It was indeed a challenge... but it works now!

It was the first decent picture of a generic 9-gram hobby servo that I could find. At least now I know that they should work for my application, assuming I can get them mounted and connected properly. You have the advantage of using custom parts to help you out!

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First off, let me say I really am a fan of this system. I'm definitely interested in trying out a motor or two. I like the remote control feature and it seems to work very well.

My only concern is that the assembly seems to sit very high. PennLUG uses very long passenger cars and equipment, which my cause a problem if we were to use these motors. Personally, I am a fan of the classic pole switch, something more like the old 12V buttons or something easily implemented into the Lego system. My idea here is to build an interlocking tower around a group of these switches.

Great work so far!

-Glenn

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I can't wait to try these out.  Keep us posted when you have these available.  Make sure you have enough to go around for the first run.  I'd take 2 motors and a controller box to start. :-)

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10 hours ago, Lowa said:

This is not as straightforward as it might seem.  LEGO has released the power functions RC protocol (http://www.philohome.com/pf/LEGO_Power_Functions_RC_v110.pdf) however the document clearly states you can only use this for non-commercial purposes (page 2) and we want to respect that...  I'm looking at a radio frequency based system as a better alternative: large range and not directional like the IR (you don't need to aim at the receiver).

Sorry for not making that clear: I mean a power functions plug that you can connect directly to a battery box, to an official PF IR receiver and even to the SBrick. You don't need the protocoll for that (just the pinout which is very straight forward).

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7 hours ago, dr_spock said:

Would you be able license the use of the Power Functions protocol from LEGO for your commerical venture?

At this point, we're too small for licensing deals as they normally involve minimal production quantities ...

I understand the reflex of wanting to use the LEGO remotes / receivers, I had it as well.  But keep in mind that the LEGO system is infrared (IR) based.  After studying and experimenting with the IR technology I came to the conclusion that it's far from optimal for advanced train layouts.

There are several issues with IR: 

  • it has a limited range ~5m/15ft beyond that it becomes tricky
  • it's very directional.  The IR beam usually is about 20 degrees wide.  So you cannot use IR when you have a fixed transmitter and receivers at different locations, it only works when you have hand-held device that you can aim at the receiver.
  • the IR signals are blocked by any obstruction, e.g. if there a LEGO building in between the transmitter and receiver it won't work.

LEGO's choice for IR makes sense if you look at their target application: small / simple layouts for children.  But I think IR technology is too limited for AFOL type of layouts / applications... they require a radio frequency based technology and that's what I'm experimenting with at the moment.

 

 

10 hours ago, fastlane250 said:

Is this compatible with the 9V switch? Those don't have the single, solid 'click' when switching from straight route/diverging route like PF/RC switches. I don't know if the video addressed that because I'm unable view it where I am at the moment.

To be honest, I haven't tested the motors on 9V switches yet.  I talked with a few train enthusiasts about the differences between the 9V and PF/RC switches at Brickworld Tampa a couple of week ago and they told me that 'there are no essential differences between the 9V and PF/RC switches'.  Maybe they were just referring to the geometry...   Anyway, this is a crucial question that has to answered so I just bought a 9V switch so I can test it.  I'll keep you posted!

 

8 hours ago, Thomas Waagenaar said:

This is definitely interesting, and as said above, I think a system like the 12v ones would definitely be worth the money for a nice layout. :)

Thank you for letting me know what you think!  

I'm first going to focus on getting the computer based system out.  Once that's done I'll see what we need to build an 'button operated' version.

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Beautiful system ... the best I've seen so far ! :wub:

I am only concerned about the overall dimensions greater than those of the yellow lever...

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ok, i will try the Brix nControl, 4 track switch motors and a controller for me.

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7 hours ago, Lowa said:

At this point, we're too small for licensing deals as they normally involve minimal production quantities ...

I understand the reflex of wanting to use the LEGO remotes / receivers, I had it as well.  But keep in mind that the LEGO system is infrared (IR) based.  After studying and experimenting with the IR technology I came to the conclusion that it's far from optimal for advanced train layouts.

There are several issues with IR: 

  • it has a limited range ~5m/15ft beyond that it becomes tricky
  • it's very directional.  The IR beam usually is about 20 degrees wide.  So you cannot use IR when you have a fixed transmitter and receivers at different locations, it only works when you have hand-held device that you can aim at the receiver.
  • the IR signals are blocked by any obstruction, e.g. if there a LEGO building in between the transmitter and receiver it won't work.

LEGO's choice for IR makes sense if you look at their target application: small / simple layouts for children.  But I think IR technology is too limited for AFOL type of layouts / applications... they require a radio frequency based technology and that's what I'm experimenting with at the moment.

I'm first going to focus on getting the computer based system out.  Once that's done I'll see what we need to build an 'button operated' version.

There's already SBrick which is a good alternative to the IR system lego uses. It's bluetooth based and it's range should be sufficient for about everything.

Are you going to open source the pinout of the motors?

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