77 replies to this topic

[dlp4341]

Is there any intrest in how to modify your Lego Train track switches to operate on 6 to 14 volts. Each Lego track switch has  a DC solenoid added to the frame of the switch. Two wires connect each RR switch to an electric switch and a low voltage power supply.  Or maybe someone has published how to do this.
Don

[aZz]

dlp4341, on 03 August 2010 - 07:35 AM, said:

Is there any intrest in how to modify your Lego Train track switches to operate on 6 to 14 volts. Each Lego track switch has  a DC solenoid added to the frame of the switch. Two wires connect each RR switch to an electric switch and a low voltage power supply.  Or maybe someone has published how to do this.
Don

M8 I'd love to see how you have done this :)

[peterab]

dlp4341, on 03 August 2010 - 07:35 AM, said:

Is there any intrest in how to modify your Lego Train track switches to operate on 6 to 14 volts.

Oh yes there is intrest, and btw on the internet it's photos or it didn't happen  

[dlp4341]

Photo of mod switches. Note the bricks for L & R are different to attach to the track.
Don

Attached Images

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[peterab]

dlp4341, on 03 August 2010 - 07:09 PM, said:

Photo of mod switches. Note the bricks for L & R are different to attach to the track.
Don

They're not subtle, I'd hoped for something easily hidden or below the baseboard like the Peco point motors. These are not much smaller than some of the power functions solutions. I wish I could afford the 9V micromotors, as I think they're the best solution I've seen, and they are a pure lego solution. If I consider a non-lego solution, it would have to have advantages over pure lego ones, such as being easily hidden or small. Still a good effort to get a working solution.

[dlp4341]

peterab, on 04 August 2010 - 04:00 AM, said:

They're not subtle, I'd hoped for something easily hidden or below the baseboard like the Peco point motors. These are not much smaller than some of the power functions solutions. I wish I could afford the 9V micromotors, as I think they're the best solution I've seen, and they are a pure lego solution. If I consider a non-lego solution, it would have to have advantages over pure lego ones, such as being easily hidden or small. Still a good effort to get a working solution.

The best thing about the solenoids is : they are free
These were removed from Chevys automobile anti pollution controls that were sticking. My GM mechanic told me each repair shop replaces a few each week.
Don

[peterab]

dlp4341, on 04 August 2010 - 04:20 AM, said:

The best thing about the solenoids is : they are free

Well, free is always good  

[Commander Red Hat]

They could be made subtle, by making the switches under your train table, attaching them perhaps a bit differently to the switches. I love these ideas, thanks for sharing!  

[Kolaf]

I've done something similar using standard servos . My solution suffered from the same problem as the train I recently posted, it lacked any finesse. I like tohe Solenoid-idea, and I have been keeping my eye out for a smaller version of what you have.

[Jan]

I have a question, I am not so in to electronic devices, but I googled the tohe Solenoid and if I am right a pin is sliding in or out if you put power on it, or not?
Does it mean that you have to have power on it all the time to keep it in a certain state? Or does it just switch when you put power on it for a moment?
And what are you using to power these, 12volt transformator?
This looks very usable and cost efficient, but also a bit big as already mentioned.

Jan

[dlp4341]

Jan, on 04 August 2010 - 11:55 PM, said:

I have a question, I am not so in to electronic devices, but I googled the tohe Solenoid and if I am right a pin is sliding in or out if you put power on it, or not?
Does it mean that you have to have power on it all the time to keep it in a certain state? Or does it just switch when you put power on it for a moment?
And what are you using to power these, 12volt transformator?
This looks very usable and cost efficient, but also a bit big as already mentioned.

Jan

[dlp4341]

Jan
You are correct. With the power on the plunger moves in and stays in until the power is turned off. When the power is turned off a coil spring pulls the plunger out.
The power supply I use is an old telephone supply : 7 volts  3 amps. You could use a auto battery charger.
don

[roamingstudio]

dlp4341, on 05 August 2010 - 06:27 AM, said:

Jan
You are correct. With the power on the plunger moves in and stays in until the power is turned off. When the power is turned off a coil spring pulls the plunger out.
The power supply I use is an old telephone supply : 7 volts  3 amps. You could use a auto battery charger.
don

Actually the best is to look for a latching solenoid - whose state changes depending upon the initial current supplied; but then it can stay in the alternate state without power (or minimal power).

[Jan]

Thanks both for the quick reply to my issue, one last question before I start to experiment myself. Did you modify the interior part of the switches to remove the friction of the switch, or is the solenoid able to overcome this friction, And will a 9 volt micromotor being able to work with an unmodified switch (is it strong enough)?

Jan

[dlp4341]

Jan, on 05 August 2010 - 11:09 PM, said:

Thanks both for the quick reply to my issue, one last question before I start to experiment myself. Did you modify the interior part of the switches to remove the friction of the switch, or is the solenoid able to overcome this friction, And will a 9 volt micromotor being able to work with an unmodified switch (is it strong enough)?

Jan

Jan
Yes, the stock switch has way  too much friction for small motors or solenoids.
Snap off the back ( bottom ) of each switch. If it takes too much force , drill the plastic rivets 1 mm shorter.
Both the sliding arm and the switch frame need trimming with an Exacto blade.
Don

[peterab]

roamingstudio, on 05 August 2010 - 07:48 AM, said:

Actually the best is to look for a latching solenoid - whose state changes depending upon the initial current supplied; but then it can stay in the alternate state without power (or minimal power).

The Peko point motors didn't use latching solenoids, as the points had a 'latching' spring in them. If you used a strong enough solenoid to overcome the friction of the Lego point, you wouldn't need to modify the point or use a latching solenoid. I guess both methods are worth considering.

[eric87]

can we please get some pictures?

[dlp4341]

eric87, on 06 August 2010 - 08:30 PM, said:

can we please get some pictures?

What would like to see ?
The solenoid mod ?
The switch mod ?
The Lego base for the solenoid ?

Don

[Kolaf]

Reading about your modification inspired me to rework my own solution. I exchanged the standard servo I previously used with a micro servo, and removed the internal friction points in the switch. This allowed me to make it quite compact solution. The solution is displayed in the image below, where I have moved a cog onto the servo. I did this for another project, and I do not think it is  necessary to do that here, simply use a standard servo arm which fits in between the two pins on the switch control slider. With the appropriate bricks, this could be built into a neat little switch house.

[Kolaf]

I forgot to mention that the upside of using servos is that they do not draw much power when stationary, and that they can easily be powered by a microcontroller. This means that I can use a single microcontroller to control all my switches, either programmatically or based on sensor input along the track or my infrared remote control :)

[dlp4341]

Kolaf
Congrats... very elegant.
Are all the parts Lego ? Micro servo ?
Please provide us a list of parts ( Legos too )
Don

[Kolaf]

dlp4341, on 08 August 2010 - 03:49 AM, said:

Kolaf
Congrats... very elegant.
Are all the parts Lego ? Micro servo ?
Please provide us a list of parts ( Legos too )
Don

Umm, there isn't really a list of bricks. This was just a proof of concept, I will try to build a better looking solution when I'm back from holidays. With regards to the parts, I'm using a micro servo which is typically found in small model aeroplanes. This is the only non-Lego part. To avoid ruin the servo I had to remove the resistance in the train switch with a pen knife. Then, to make things simple, I just glued the servo to a small Lego plate and built it up to the proper height. In this case I also glued a cog on to the servo because this was what I had lying around. I could also use a regular servo arm which comes with the servo, avoiding the need for the cog wheel.

The servo is connected to an arduino microcontroller. Specifically, I'm using the roboduino board, an arduino clone which supports simple connections of servos and stuff. I connect a regular IR receiver bought at my local electronic parts store, and I control these using a regular TV remote control (more precisely my DVD player remote control). The servo I used is called HiTec HS-55.

Edited by Kolaf, 08 August 2010 - 08:13 AM.

[aprendiendo]

I used this solution, it's 100% Lego:



I used the old RCX motors, but you can use any Lego motor.

You can view how it works in this video:

[dlp4341]

aprendiendo, on 08 August 2010 - 03:32 PM, said:

I used this solution, it's 100% Lego:



I used the old RCX motors, but you can use any Lego motor.

You can view how it works in this video:

aprendiendo
I love your motor solution. It looks like you added a new connection to the moving trrack
Kolaf
I got a HS 55 servo, but it came without instructions or a wiring diagram. I can not get it to operate with just 6 VDC. Any hints?
Don

[peterab]

aprendiendo, on 08 August 2010 - 03:32 PM, said:

I used this solution, it's 100% Lego:

I think the gem in this is the very clever conection to the track, it could be very usefull for an under track motor (either purist or not since it would be hidden anyway).