We're bringing back the Monorail - 3D printed!

Lowa

I love the Monorail System, it is a childhood dream of mine, but always wished we could have more flexibility - especially the straights, ramps and switches. So we took the plunge and worked on making 3D printed versions (before you ask, all patents are long expired and are therefore available to the general public). They worked and looked so good (after a lot of tweaking :-) that in the end we decided to create 4DBrix and make them available for sale (and we have more interesting stuff to come).  You can check out a review of the straight tracks made by one customer - thanks MRN Bricks!: https://www.youtube.com/watch?v=bBjilyYJrNU

Now, what else do you wish your Monorail could do?

SprinkleOtter

Unfortunately, the rails don't mean much if you don't have the expensive motors...

catwrangler

Does the monorail need different motors than ordinary Lego trains? Is it because inclines are involved?

Russell844

Are you willing to send a couple samples to a LUG to test on our layout?

davee123

catwrangler said:

Does the monorail need different motors than ordinary Lego trains? Is it because inclines are involved?

It's a 9V motor that uses its own motor with a gear tooth:





It definitely needs the gear to climb the inclined tracks!

The old monorail patents are pretty neat, too-- they feature things like "45 degree" straights, ramp extenders, and automatic-switching cross-tracks, none of which ever got produced.

DaveE

Lowa

Russell844 said:

Are you willing to send a couple samples to a LUG to test on our layout?

We'd be happy to send samples, any LUG is welcome to contact us on our website 4dbrix.com

natro220

For those of us who DO have a monorail setup, this is pretty awesome.  I was just thinking about how hard it is to do an extended straight section because the straight pieces are so hard to come by (I'm talking no incline).  I own 6990 and 6991, and the two sets combined have a whopping 3 straight long track pieces.  They run $20-30 a piece on Bricklink.

Where are you selling them, here in the marketplace?

Lowa

davee123 said:

catwrangler said:

Does the monorail need different motors than ordinary Lego trains? Is it because inclines are involved?

It's a 9V motor that uses its own motor with a gear tooth:





It definitely needs the gear to climb the inclined tracks!

The old monorail patents are pretty neat, too-- they feature things like "45 degree" straights, ramp extenders, and automatic-switching cross-tracks, none of which ever got produced.

DaveE

Yes! We actually have made some prototypes of the 45 degree turn, 45 degree straight and ramp extension :-)

Lowa

natro220 said:

For those of us who DO have a monorail setup, this is pretty awesome.  I was just thinking about how hard it is to do an extended straight section because the straight pieces are so hard to come by (I'm talking no incline).  I own 6990 and 6991, and the two sets combined have a whopping 3 straight long track pieces.  They run $20-30 a piece on Bricklink.

Where are you selling them, here in the marketplace?

Hi natro220, we are selling them on bricklink (under 'custom items') for $12.45 per long straight and soon on our website...

davee123

Lowa said:

Yes! We actually have made some prototypes of the 45 degree turn, 45 degree straight and ramp extension :-)

Neat!

I assume you're already aware, but you should fix the connectors for the 45-degree turns and 45-degree straights so that they're compatible with LEGO's existing 45-degree turns!  LEGO tried to be extra sure that kids couldn't screw them up by attaching a "normal" straight piece to a 45-degree point-- hence why they have the differently-styled notches!

DaveE

SprinkleOtter

Is the price ever set to go down? I cant see paying ~half the price of a legit piece for a fan copy (that has almost no value if I ever want to sell).

Legopassion8

Trioval ^^

Nice. Pocono railway

sklamb

These new track pieces look very exciting! Will try to check them out at Bricklink--is Lowa also your ID/store name there?

Dedgecko

It's too bad TLG doesn't sell its old tool designs to a dedicated spares supplier.  Or TLG should do a kickstarter system for old molds / parts-- I believe this was discussed elsewhere.

TigerMoth

Dedgecko said:

It's too bad TLG doesn't sell its old tool designs to a dedicated spares supplier.

Then what would happen if they decided they wanted to produce that part again? There have been pieces that have reappeared after many years.

Lowa

sklamb said:

These new track pieces look very exciting! Will try to check them out at Bricklink--is Lowa also your ID/store name there?

Thanks! The store is called 4DBrix Store

TheBigLegoski

Never had it, but I totally drooled over over those pictures of this space monorail as a kid:  #6990  Must be an epic set own.
Isn't it strange that TLG only ever made four monorail sets? The one #6990 in 1987, a parts pack for that set in the following year to expand it with. A city themed monorail in 1990, and in 1994 another space monorail. And ever since that.... absolutely nothing!

Istokg

Very interesting.... this is just the tip of the iceberg for 3D image parts. As the price comes down, I can imagine a LOT more 3D parts will be created, making for quite a secondary market.  Such as the pricey Cypress Tree....
http://www.bricklink.com/catalogPG.asp?P=3778&colorID=6

People can finally build this.... ;-)

Dedgecko

TigerMoth said:

Dedgecko said:

It's too bad TLG doesn't sell its old tool designs to a dedicated spares supplier.

Then what would happen if they decided they wanted to produce that part again? There have been pieces that have reappeared after many years.

The contract would end, and fabrication brought back in-house, or TLG could source the part(s) from the supplier, like base plates!

Other industries do this already.  Has this never been discussed before?

mathew

SprinkleOtter said:

Unfortunately, the rails don't mean much if you don't have the expensive motors...

I mean yeah, but they are rock solid.  I have 2 motors and both run near perfect.  These are almost 30 years old.  Even the little light still works after all these years.  Lego cared about quality back then and their stuff was made to last.  

mathew

TheBigLegoski said:

Never had it, but I totally drooled over over those pictures of this space monorail as a kid:  #6990  Must be an epic set own.
Isn't it strange that TLG only ever made four monorail sets? The one #6990 in 1987, a parts pack for that set in the following year to expand it with. A city themed monorail in 1990, and in 1994 another space monorail. And ever since that.... absolutely nothing!

Story goes that the monorail system was a financial loss for Lego.  Long thread here on Brickset from a few years ago detailing it.  Nobody likes to defend it except for the diehard monorail geeks (like myself).

6990 is my favorite Lego set.  It wasn't on my radar as a kid (I was into video games and computers by the time it was released) but it was one of the first sets that I drooled over as an AFOL and I knew I had to have it.  

CCC

SprinkleOtter said:

Is the price ever set to go down? I cant see paying ~half the price of a legit piece for a fan copy (that has almost no value if I ever want to sell).

It does seem expensive for a fake compared to the genuine thing (used), especially when the surface finish looks quite poor and you can hear a click/jump when it goes from piece to piece. As these are printed rather than molded, I'd also worry about the long term wear on the gear teeth on the tracks. I guess the difference in colour doesn't matter too much if you go for all fake track rather than mixing it with genuine.



But like the fake Chinese sets, I guess it depends whether you don't mind fake but cheap or genuine but expensive.

I'd also imagine if they sell, then the price will come down as someone else will copy the idea and do their own 3D printed versions.

dougts

A bit of a tangent, but given that most AFOLs consider using non Lego brand parts and pieces as complete blasphemy, It will be interesting to see how this same group of people adapts to the idea of using 3D printed parts. 

I've always found it odd that a group that would never consider using a mega Blok's part has no problem using stuff from brickforge, for example. Functionally, there is no difference, as neither is LEGO

TigerMoth

Dedgecko said:

The contract would end, and fabrication brought back in-house, or TLG could source the part(s) from the supplier, like base plates!

Why do you think baseplates are dwindling? TLG don't let their IP go very far from home, and allowing somebody else to produce their older pieces would open a bag of worms they'd never manage to close.

And talking of bags of worms...

dougts said:

A bit of a tangent, but given that most AFOLs consider using non Lego brand parts and pieces as complete blasphemy, It will be interesting to see how this same group of people adapts to the idea of using 3D printed parts. 

I've always found it odd that a group that would never consider using a mega Blok's part has no problem using stuff from brickforge, for example. Functionally, there is no difference, as neither is LEGO

People generally do what suits them, and find excuses for doing things that don't fit their version of the rules.

davee123

TheBigLegoski said:

Isn't it strange that TLG only ever made four monorail sets? The one #6990 in 1987, a parts pack for that set in the following year to expand it with. A city themed monorail in 1990, and in 1994 another space monorail. And ever since that.... absolutely nothing!

Technically, they made 7 sets that had monorail elements in them!  3 "main" sets (6990, 6399, 6991), two large accessory track kits (6921, 6347), one start/stop switch (5039 - Service only, not in stores), and one replacement motor (5040 - also Service only).







They also made a short 9v wire, which they labeled as a monorail wire (even though it could be used for the 9v system as well):


I wouldn't count that last one, honestly, but at the time it was released, monorail and "Light & Sound" sets were the only things using that type of connector, and the monorail was the only one that actually used a wire (the rest of the L&S lineup used the conductive plates), so the labeling sorta makes sense.

DaveE

CCC

dougts said:

I've always found it odd that a group that would never consider using a mega Blok's part has no problem using stuff from brickforge, for example. Functionally, there is no difference, as neither is LEGO

In my case, I tend not to use megabloks parts because in many cases they are the same as lego parts, so there is no real need. Whereas I will use brickforge for parts where lego doesn't make them. It gets tricky when you buy a custom parts and then lego decides to make something similar. Although I normally stick with brickforge as they are often better designs than lego. One notable exception is the Roman shield though. Lego's is nicer than brickforge's.

TheBigLegoski

@davee123
Thanks for that bit of info.

mathew

dougts said:

A bit of a tangent, but given that most AFOLs consider using non Lego brand parts and pieces as complete blasphemy, It will be interesting to see how this same group of people adapts to the idea of using 3D printed parts. 

I've always found it odd that a group that would never consider using a mega Blok's part has no problem using stuff from brickforge, for example. Functionally, there is no difference, as neither is LEGO

This situation is different.  First, we're talking about a discontinued product (Monorail System) and Lego has un-officially stated that they will never make again.  They even let the patents expire (something I was not aware of).  Second, after market prices are not exactly cheap.  Especially straight track which go for $20-30 a segment on eBay.  Third, 3D printing allows for production of Monorail track of different shapes and sizes that Lego never produced.  

I personally have enough "official" track that I purchased in a eBay lot a couple of years ago to suit me.  However, if I were planning a large scale setup like those seen at conventions then the after-market 3D printed option would be a "good enough" solution.

dougts

I don't see the situation as any different for the staunch purists.  Either a part is made by LEGO, or it isn't. Whether it one time was, never was, isn't anymore, etc, etc, is all just noise on top.

I'm not necessarily a purist myself mind you, I just find it an interesting case study.  In the end, perhaps what @TigerMoth said is most accurate: "People generally do what suits them, and find excuses for doing things that don't fit their version of the rules."

mathew

dougts said:

I don't see the situation as any different for the staunch purists.  Either a part is made by LEGO, or it isn't. Whether it one time was, never was, isn't anymore, etc, etc, is all just noise on top.

Staunch purists can bite me ; )

Aanchir

dougts said:

I don't see the situation as any different for the staunch purists.  Either a part is made by LEGO, or it isn't. Whether it one time was, never was, isn't anymore, etc, etc, is all just noise on top.

I'm not necessarily a purist myself mind you, I just find it an interesting case study.  In the end, perhaps what @TigerMoth said is most accurate: "People generally do what suits them, and find excuses for doing things that don't fit their version of the rules."

Any person who is fine using custom parts but not clone brand parts is not a "staunch purist". There are other factors that inform people's preferences besides just "is it LEGO or not?" A lot of LEGO fans probably feel better about supporting their fellow LEGO fans than about supporting LEGO competitors. And some may simply prefer the designs available from customizers over the designs available from clone brands (especially when it comes to fig-related parts, since LEGO minifigures have a very different design language than modern Mega Bloks and Kre-O figs).

For my part I like the idea of supporting innovative AFOL customizers, although I rarely wind up using any of the custom-molded or custom-printed parts I've bought at conventions. They don't tend to be suited to the types of creations I build, plus I enjoy challenging myself to find solutions using official LEGO bricks. I do eventually want to work on challenging myself to create my own custom parts and decorations, though, since it would be valuable experience the next time I apply for a job at LEGO.

I would not mind buying sets from the more reputable clone brands like Mega Bloks or Kre-O if they had products I really liked enough to spend money on them. After all, it's not as though I've ever sworn off non-block-based toys from Mattel or Hasbro.

CCC

Aanchir said:

A lot of LEGO fans probably feel better about supporting their fellow LEGO fans than about supporting LEGO competitors.

Although both do what they do for the same reason - to make money out of selling them. I don't think the motivation is to do it for "the community" as much as to do it for profit. The prices are still fairly high for these reproductions. It is also taking away from another set of lego fans - the ones that are trying to sell the genuine items.

mathew said:

Second, after market prices are not exactly cheap.  Especially straight track which go for $20-30 a segment on eBay. 

Should the price have any bearing on it? Surely it is just as acceptable to copy cheap parts as it is expensive ones - so long as there is enough profit in it for the customizer / faker to make it worthwhile.

TigerMoth

mathew said:

This situation is different.  First, we're talking about a discontinued product (Monorail System) and Lego has un-officially stated that they will never make  have again.

TLG have retired the old Death Star and, particularly bearing in mind there's a new one that's very similar, will never make the old one again. Does that make it acceptable for LEPIN to produce it instead?

Or is that different?

Somehow, everything is always different - which is why I said what I said.

They even let the patents expire (something I was not aware of).

What would you expected them to do? It's not as if they had any choice in the matter. Patents expire - these days, typically after 20 years. Talk of renewing patents relates to preventing them expiring even earlier.

Very few parts are still protected - they've all been around for too long. It's why, most of the time, there isn't much you can do about clones  - and why most of them are in the same boat. It's also one reason why the minifig is a trademark - there's no time restriction.

mathew

CCC said:

Aanchir said:

A lot of LEGO fans probably feel better about supporting their fellow LEGO fans than about supporting LEGO competitors.

Although both do what they do for the same reason - to make money out of selling them. I don't think the motivation is to do it for "the community" as much as to do it for profit. The prices are still fairly high for these reproductions. It is also taking away from another set of lego fans - the ones that are trying to sell the genuine items.

Honestly, we could go round and round with this discussion.  You come across as a "purist" therefore you know where I stand ; )

Lowa

davee123 said:
Lowa said:

Yes! We actually have made some prototypes of the 45 degree turn, 45 degree straight and ramp extension :-)

Neat!

I assume you're already aware, but you should fix the connectors for the 45-degree turns and 45-degree straights so that they're compatible with LEGO's existing 45-degree turns!  LEGO tried to be extra sure that kids couldn't screw them up by attaching a "normal" straight piece to a 45-degree point-- hence why they have the differently-styled notches!

DaveE

Hi DaveE,

It’s not as straightforward as is might look. Based on an initial geometrical study, it seems the LEGO short curve is not a pure 45 degree turn. LEGO seems to have used a slightly different shape so you would be able to split a track into two parallel tracks using a switch. Using this shape would not work to make a 45 degree turn in the track. I’m not sure why LEGO decided to use the funky connector for their short curves, but it might be to avoid confusion with a pure 45 degree turn in case they would ever release that.

Lowa

SprinkleOtter said:

Is the price ever set to go down? 

Not in the near future. In the long run it might, depending on how 3D printing evolves. 3D printing allows you to start small batch manufacturing with a reasonable investment cost, but creating one brick with 3D printing is clearly more expensive than injection molding one. There is also no economy of scale – each track costs about the same whether you make one or 1 million. About a year ago, there was another attempt at bringing 3D printed monorail tracks. The price for a full straight track was at $40+; and it was not available in classic gray like our tracks. So compared to that, I think we offer our track at a competitive price.   

davee123

Lowa said:

It’s not as straightforward as is might look. Based on an initial geometrical study, it seems the LEGO short curve is not a pure 45 degree turn. LEGO seems to have used a slightly different shape so you would be able to split a track into two parallel tracks using a switch. Using this shape would not work to make a 45 degree turn in the track. I’m not sure why LEGO decided to use the funky connector for their short curves, but it might be to avoid confusion with a pure 45 degree turn in case they would ever release that.

Hm, I'm not sure quite what you mean-- the short curves that LEGO makes are meant to be 45 degree turns.  Hence, you can add two of them together to get a full 90 degree turn (using a "left" and a "right"), or you can make a jog in the path (using two "lefts" or two "rights"):

So, the connection points on those are different, obviously.  And they did that so that you CAN'T connect a long 32-long track to the end of a 45-degree curve, because if you did, the geometry would be off by an oddball fraction (since you're dealing with an annoying square-root-of-2 in 45-degree angles).

Their solution (in the patents, never released) was to make a length of straight track that had the special ends to connect to the 45-degree bends (also seen on the points), which was a non-integer length, and would line up appropriately with studs.  Hence, kids couldn't screw it up.

The ramp extenders probably COULD have been made to fit an exact matching geometry (since their upwards angle is arbitrary), BUT, then the studs for the supporting pillars would be at an angle, so they had to make a NEW type for ramp extenders, too, which had angled connections for supports, and similarly couldn't be attached to either the normal straights or the 45-degree curves.

DaveE

natro220

If your track proves popular in the community, no doubt genuine track will drop in price as it won't be as rare and scarce, assuming the quality of your track is on par.  You may need to drop your price at that point.  If genuine track drops to $12 a segment, due to competing with your product...do you have a plan in place?  Will it still be viable to create new track at that price, if you have to drop to, say $6-8?

CCC

natro220 said:

If your track proves popular in the community, no doubt genuine track will drop in price as it won't be as rare and scarce, assuming the quality of your track is on par.  You may need to drop your price at that point.  If genuine track drops to $12 a segment, due to competing with your product...do you have a plan in place?  Will it still be viable to create new track at that price, if you have to drop to, say $6-8?

If it sells at $12 I imagine others will start printing their own and selling at $10 and so on. Once someone finds a market others will copy and undercut. 

mathew

TigerMoth said:

mathew said:

This situation is different.  First, we're talking about a discontinued product (Monorail System) and Lego has un-officially stated that they will never make  have again.

TLG have retired the old Death Star and, particularly bearing in mind there's a new one that's very similar, will never make the old one again. Does that make it acceptable for LEPIN to produce it instead?

Or is that different?

Somehow, everything is always different - which is why I said what I said.

Let's be real:  There's a difference between a defunct, 30 year old product line that didn't sell well to begin with and a much more recent licensed flag-ship set that is still profitable for Lego.  I doubt that Lepin would touch a Lego system monorail knock-off.  And if they did, then so what?  If Lego has abandoned the Monorail System (which they have) then really the only people who care are Brickset troglodytes.

mathew

CCC said:

natro220 said:

If your track proves popular in the community, no doubt genuine track will drop in price as it won't be as rare and scarce, assuming the quality of your track is on par.  You may need to drop your price at that point.  If genuine track drops to $12 a segment, due to competing with your product...do you have a plan in place?  Will it still be viable to create new track at that price, if you have to drop to, say $6-8?

If it sells at $12 I imagine others will start printing their own and selling at $10 and so on. Once someone finds a market others will copy and undercut. 

Yep, and your point is?  

Lyichir

mathew said:

TigerMoth said:

mathew said:

This situation is different.  First, we're talking about a discontinued product (Monorail System) and Lego has un-officially stated that they will never make  have again.

TLG have retired the old Death Star and, particularly bearing in mind there's a new one that's very similar, will never make the old one again. Does that make it acceptable for LEPIN to produce it instead?

Or is that different?

Somehow, everything is always different - which is why I said what I said.

Let's be real:  There's a difference between a defunct, 30 year old product line that didn't sell well to begin with and a much more recent licensed flag-ship set that is still profitable for Lego.  I doubt that Lepin would touch a Lego system monorail knock-off.  And if they did, then so what?  If Lego has abandoned the Monorail System (which they have) then really the only people who care are Brickset troglodytes.

Let's be real—setting aside the dubious description of Monorail enthusiasts as troglodytes, there's probably plenty of monorail fans who prefer other forums than this one. ;)

(Though I agree that Lepin probably has little incentive to create monorail sets. Unlike the expensive D2C sets they tend to clone that have wide appeal for modern audiences, monorail's appeal is limited largely to the small number of FOLs who already own decades-old monorail sets and are looking to expand.)

mathew

natro220 said:

If your track proves popular in the community, no doubt genuine track will drop in price as it won't be as rare and scarce, assuming the quality of your track is on par.  You may need to drop your price at that point.  If genuine track drops to $12 a segment, due to competing with your product...do you have a plan in place?  Will it still be viable to create new track at that price, if you have to drop to, say $6-8?

I doubt it.  3D printing is still expensive.  And even when 3d printing becomes more economical there will still be a limited market for the limited supply of official Lego monorail track.  

Lowa

davee123 said:

Lowa said:

It’s not as straightforward as is might look. Based on an initial geometrical study, it seems the LEGO short curve is not a pure 45 degree turn. LEGO seems to have used a slightly different shape so you would be able to split a track into two parallel tracks using a switch. Using this shape would not work to make a 45 degree turn in the track. I’m not sure why LEGO decided to use the funky connector for their short curves, but it might be to avoid confusion with a pure 45 degree turn in case they would ever release that.

Hm, I'm not sure quite what you mean-- the short curves that LEGO makes are meant to be 45 degree turns.  Hence, you can add two of them together to get a full 90 degree turn (using a "left" and a "right"), or you can make a jog in the path (using two "lefts" or two "rights"):

So, the connection points on those are different, obviously.  And they did that so that you CAN'T connect a long 32-long track to the end of a 45-degree curve, because if you did, the geometry would be off by an oddball fraction (since you're dealing with an annoying square-root-of-2 in 45-degree angles).

Their solution (in the patents, never released) was to make a length of straight track that had the special ends to connect to the 45-degree bends (also seen on the points), which was a non-integer length, and would line up appropriately with studs.  Hence, kids couldn't screw it up.

The ramp extenders probably COULD have been made to fit an exact matching geometry (since their upwards angle is arbitrary), BUT, then the studs for the supporting pillars would be at an angle, so they had to make a NEW type for ramp extenders, too, which had angled connections for supports, and similarly couldn't be attached to either the normal straights or the 45-degree curves.

DaveE

Hi DaveE,

This is an interesting discussion, what I meant is that when you use a perfect 1/8 45 degree turn you get the situation on the left-hand side where you end up with a 3.2mm gap.  To close that gap you need a different turn (right-hand side); one that is very close to but not exactly a 45 degree turn.  The differences are too small to notice if you don't study the geometry in detail.  The differences are also difficult to measure with standard equipment.  I'm not sure how many people looked at the shape of the short curves in detail ?  Sariel must have when he made his monorail planner and he seems to have come to a similar conclusion.  On his site he says: "This error is caused by the complex shapes of a track point and the short curve which make it difficult to draw them..."  (http://sariel.pl/2011/05/monorail-network-planner-tool/)  I don't think he's referring to the shape of the connectors here, but to the shape of the track.  

Anyway that's what I got from my initial study of the geometry...  Has anyone else looked at this ?

Lowa

natro220 said:

If your track proves popular in the community, no doubt genuine track will drop in price as it won't be as rare and scarce, assuming the quality of your track is on par.  You may need to drop your price at that point.  If genuine track drops to $12 a segment, due to competing with your product...do you have a plan in place?  Will it still be viable to create new track at that price, if you have to drop to, say $6-8?

Hi natro220,

At this point, I don't see how it would be viable to 3D print at $6-$8 a track, that would not be sustainable from a business point of view.    Evolution in 3D print technology could change that...  Also note that $12.5 includes free shipping within the continental US (if you buy 4 or more).

What is our plan ?  The straight track is a starting point, we want to be community driven and expand our product range depending on what people want - including automation.

datsunrobbie

CCC said:

Aanchir said:

A lot of LEGO fans probably feel better about supporting their fellow LEGO fans than about supporting LEGO competitors.

Although both do what they do for the same reason - to make money out of selling them. I don't think the motivation is to do it for "the community" as much as to do it for profit. The prices are still fairly high for these reproductions. It is also taking away from another set of lego fans - the ones that are trying to sell the genuine items.

mathew said:

Second, after market prices are not exactly cheap.  Especially straight track which go for $20-30 a segment on eBay. 

Should the price have any bearing on it? Surely it is just as acceptable to copy cheap parts as it is expensive ones - so long as there is enough profit in it for the customizer / faker to make it worthwhile.

May not have actually been Churchill, but seems applicable regarding use of non-LEGO parts...

Churchill: “Madam, would you sleep with me for five million pounds?”

Socialite: “My goodness, Mr. Churchill… Well, I suppose… we would have to discuss terms, of course…”

Churchill: “Would you sleep with me for five pounds?”

Socialite: “Mr. Churchill, what kind of woman do you think I am?!”

Churchill: “Madam, we’ve already established that. Now we are haggling about the price.”

TigerMoth

mathew said:

Let's be real:

You mean "let's put a particular interpretation on it".

There's a difference...

As I said, it's always different.

davee123

Lowa said:

Anyway that's what I got from my initial study of the geometry...  Has anyone else looked at this ?

Yeah, that's basically the fact that the geometry of a circle doesn't work the way that LEGO wanted to.  In fact, the actual patent for the monorail track explicitly is for a "snap-to-grid" system, where you can get curved and 45-degree units that line up perfectly on a square grid.

Basically, 4 curved monorail tracks are NOT a perfect circle.  They're ever-so-slightly extended.  You can see some of the discussion I had on it back in 2010:

http://news.lugnet.com/general/?n=55530

But others have discussed this much earlier (I think the oldest one I found was from Todd Lehman back in the early 2000s).

Here's a crude ms-paint of the geometry that I just made (roughly to scale):


So, the fact that it aligns perfectly in the center means that they can "split" the curve at the midpoint, and make it a 45-degree angle curve, and do exactly what they did.  It also means that they can line up a support pillar DIRECTLY under the midpoint of the curve, rather than offset.

Anyway, THAT was the key part that one of their patents focused on, and they expounded by demonstrating other track types (like 45-degree straights) that used different connection points.  Essentially, the patent said "Hey, we have a way of doing a grid-based track geometry that allows 45-degree angles!  Nobody else can do that for a toy train/track system!"  There were other patents as well, but that was an interesting part of it.

DaveE

Lowa

Hi DaveE,

Thanks for the feedback!  I'm going to study that in detail.  What patent are you referring to ? Is it US patent 4,726,515 ? 

davee123

Lowa said:

Thanks for the feedback!  I'm going to study that in detail.  What patent are you referring to ? Is it US patent 4,726,515 ? 

I think so-- my notes say it was either 4726515 or 4861306.  I found 7 all together, but those two I think were the most enlightening.

DaveE

davee123

davee123 said:

But others have discussed this much earlier (I think the oldest one I found was from Todd Lehman back in the early 2000s).

Here we go-- Todd talking about it a bit in March of 2000:

http://news.lugnet.com/town/?n=757

DaveE