Duplo Trains discussion

[Guy_Walker]

Yes - web security has stifled so many programmers. Not sure what the answer is.

Anyhows, back to trains, I’ve redrawn my previous counter circuit as a Duplo layout, in case anyone ever wishes to build it. Here is a single stage:

And this is all 3 stages. It needs 10 points (3 new and 7 old)

It counts up to binary 7 (111) and then rolls over back to 0 (000). Add more stages to count higher. The loop on the right just serves to return the train.

The solid red points are ‘new’ lazy points. They show the data count.

The others are ‘old’ sprung points. I’ve drawn the diagram so that the train always follows the track with the red tongue.

The layout is APV. Maybe this answers cortex31 request for a “train that will go everywhere by itself”

You could add this layout to any existing layout to display the number of times the train had passed a certain point.

[Peter Nolan]

Wow, I haven't checked this thread for a while, and things have certainly progressed... Guy, I reckon there is an Ig Nobel in this for you... (http://www.improb.com/ig/ig-top.html). I don't have quite enough switches, but if I come across some on eBay I'll try making a counter layout.

[Guy_Walker]

Good link -I’ve not heard of Ig Nobles before -I’ll keep a watch out for next years topic ;-)

Btw Peter, if you don’t have enough of the old (sprung) points to make a counter layout, then you can emulate them using new (lazy) points. However these need to be gang linked in pairs so both points switch together. This is an important train track component. So much so that I’ve used it as my photo (see left). Here is the Duplo layout:

and if you run out of cross-overs then you can mimic these too:

The train is automatically routed to the opposite side. You can also construct a cross-over with old type points. This might help anyone building a perpendicular cross-over :-)

I’ve added a page on equivalent circuits here. The DigiComp emulator is now finished a few pages further along. Now working on a multiplier layout -not as easy as I had expected...

Edited December 4, 2014 by Guy_Walker

[Robert Cailliau]

Guy, I think this deserves a book on the subject!

Plus, perhaps, an Ig-Nobel. Ig-Nobels started as somewhat derogatory, but now have acquired a certain standing. Indeed, there is suspicion that some researchers purposely write papers in order to win an Ig-Nobel: it attracts a lot of attention.

But write that book first. "Turing Trains" is a good title.

[Guy_Walker]

Thank you folks for all the positive support - really appreciated.

Not sure I’m ready for a book yet… I’ll add more information to the cr31 site and see what form the subject takes.

The principle of ‘trains on tracks’ could apply to ‘rats in a maze’ or 'cows in a field of gates' and many other systems. As long as they only move forwards. A rat computer may be quite fast and compact.

Also I've completed the multiplier, which could be useful - as soon as I can work out what for!

[Robert Cailliau]

:-D :-D

A "rat computer"!

What about a labyrinth with little kids? My granddaughter (who got me into this thread) would probably love it. Would it be child labour? It might be slow though and consume a lot of sweets per bit.

[Peter Nolan]

A kids playground that doubles as a computer would be great--perfect for a science and technology centre. We have Questacon (http://www.questacon.edu.au) here in Australia, but yes, the child labour aspect may be problematic ;-)

Back to Duplo though, I picked up three second-hand packs of the original sprung switches yesterday (6 switches in total). Once I get a couple more of the new switches I'll have enough to make the three-stage counter track. I made a two stage counter yesterday, but it has since been disassembled by my son... I'll make a video when I get a chance to put together a new layout (probably in a weeks time).

[Elegostl]

Looking forward for new results!

[Guy_Walker]

Yes do let us know if the counter circuit actually works ... physical proof of concept is most important :-)

Btw, these are 2-way sort gates, for diverting or merging livestock

They can also be bought spring loaded -just like Duplo points

Can't find any for children though!

[Peter Nolan]

Hi all, I've successfully made the 3-stage binary counter. I've put together a video which shows it in action:

Enjoy :-)

[Robert Cailliau]

WOW!

:-)

[Peter Nolan]

Thanks :-) It was quite a satisfying layout, especially with the train visiting all parts of the track without any intervention. I'm trying to think of my own (non-computational) layout that also visits all points. Ideally I'd like to come up with something symmetric--I'll post another video if I come up with something interesting.

Edited January 15, 2015 by Peter Nolan

[Guy_Walker]

Brilliant a really fantastic video - love the way you’ve got a camera on each point, and show the rollover clearly.

I’ll add links to it from Turing Trains.

I’ve added Javascript to two layouts (adder and random number generator) so you can flip points and set the train running round the track. I will make more layouts ‘interactive’, eventually maybe all. Let me know any features you want / don’t want.

It is quite satisfying when the train visits all parts of a layout without intervention. A sort of demo mode for a display layout you can leave running. I’ll try to think of a suitable layout which is more ‘round’ and not a long line of points, -and maybe symmetrical too!

Well done on a good looking video :-)

Edited January 18, 2015 by Guy_Walker

[Guy_Walker]

Peter -you could take a two stage counter and bend it round and overlap the end loops like this:

As before, solid red points are ‘new’ lazy points.The others are ‘old’ sprung points, where the train follows the track with the red tongue (always the lower track in this layout). The lower right loop is the return loop where the train starts.

No one need know it’s computational ;-)

Edited January 24, 2015 by Guy_Walker

[Peter Nolan]

Thanks for that Guy

[keslian]

Guy - Showing the lazy points positions and making it possible to change them really helped me to follow the diagrams on www.cr31.co.uk/stagecast/trains/tt1_points.html

Being able to watch the moving train animations made it even easier. This is probably the best visual demonstration of digital computer processes I've ever seen.

Congratulations too to Peter Nolan on his Youtube video of a working duplo layout for the binary counter.

Would any of the science museums (or modelling exhibitions) be interested, I wonder?

Keslian

[Guy_Walker]

Glad you like it -yes it makes following the layouts much easier on screen. I will continue to add javascript to as many pages as possible

It’s all quite educational (for me at least) but i’m not sure of the final destination or how useful any of it will eventually be…

A lot depends on turning on-screen theory into plastic Duplo practice

So next I hope to build a double gang ‘co-operative’ point by mechanically linking a couple of Duplo lazy points. Be interesting to see if the points switch easily

If anyone has done this before or has ideas on how to do it please let me know !

[Robert Cailliau]

This is great! Fortunately Guy puts it all on his cr31 site. I wonder if the Duplo kids who inspired it all will be interested when they have gorwn up. :-)

[Guy_Walker]

Here is my solution for gang linking Duplo points.

A diagonal cross-over track keeps the points a standard 16 Lego studs apart.

A linking rod from the Lego Technic range (in red of course) spans 15 units.

There is no fixing available on the underside of a Duplo point so a Lego Technic ‘2x1 block with pins’ is secured with a drop of glue. The block is placed ‘up’ against the red lever side and ‘left’ against the grey ‘bridge’ (see photo).

Additional linking rods can be easily added to the unused pins to gang link further points (not shown).

The points must sit on Duplo blocks for clearance. From above only the red linking rod can be seen.

There is very little ‘play’ and both points move exactly in unison -by either hand or train.

Edited February 4, 2015 by Guy_Walker

[Robert Cailliau]

Owwww....

I need another life to explore all this.

Next stop: a universal Turing machine?

Maybe Douglas Adams had sensed something, except that in reality the computer the mice were building used Duplo switches.

Fortunately we know the answer without having to wait for the locos to reach the end: 42.

Guy, I wished I had your stamina in all this.

My granddaughter has now switched to regular Lego.

[Peter Nolan]

Nice work Guy. I have a feeling that a Turing-complete layout is only a matter of time...

Robert--my son too has been playing with regular lego a lot lately. He's very keen on the Lego Cargo train set, but he'll have to wait for some time yet for that one. As for whether the kids whose train sets we've been playing with will appreciate the finer details of APR, APV and computational duplo track layouts, who can say? However, the 11-year-old brother of my son's friend was rather taken with the binary counter layout. He is an aspiring coder, as well as a lego fan, so the whole concept was rather appealing to him.

I've been thinking of a couple of new symmetrical Duplo track layouts that should be APV. When I next have the time (and the floor is free of lego) I'll try to make another video.

[Robert Cailliau]

Peter: I may have mentioned this in an earlier post, but your son's friend's brother, the aspiring coder, might want to have a look at LiveCode, get the free system, and instantly do some interesting stuff. I have a beginner's page here:

http://www.cailliau.org/Alphabetical/L/LiveCode/Annotated%20Examples/

He will probably be most interested in the fact that he can make his own apps for his smartphone (which 11 year old does not have a smartphone these days?)

[Peter Nolan]

Great, thanks for that--I'll pass it on.

[Xris]

Aye!

All the stuff you present here ist really amazing. Seems I underestimated the usability of the DUPLO trains system.

Getting some crates of DUPLO track and some engines would make up all you need for a beginner's CS practical course.

Next stop: a universal Turing machine?

However, even using DUPLO rails, creating a tape of sufficient length for this task might remain a too big challenge - at least for my wallet .

Xris

[Robert Cailliau]

:-)

There was/is a real Lego Turing machine:

http://www.turing2012.fr/?p=530〈=en

Note that there were a few others built around the same time (Turing 100th anniversary), like this one :

http://www.legoturingmachine.org

which however is NOT a Lego machine: the Turing code is inside the NXT brick, so that is cheating.

The one from the people in Grenoble is the only one I know of that is entirely made of Lego components with no hidden tricks. As I live close to Grenoble, I'll go and have a look sometime.