[WIP] Lego monorails. [Custom Rail Systems (CRS)]

[Trekkie99]

Hey @Mark Bellis, I was curious if the length of 19 studs for your curved track section has any math behind it. For example, does it corelate somehow with 32x32 baseplates? Thanks! 

[M_slug357]

I've got a 1-stud wide technic monorail that I was working on; lemme see if I can dig it up! It uses thick beams/liftarms as the rail...

[Trekkie99]

19 hours ago, M_slug357 said:

I've got a 1-stud wide technic monorail that I was working on; lemme see if I can dig it up! It uses thick beams/liftarms as the rail...

Cool! I remember seeing one suspended monorail on Flickr that used technic beams for the rail. 

[djm]

I revised the physical build of the trigger track, to eliminate a bit of a bump. The revised design now looks like:

The spring in the NXT touch sensor is weak enough so that the weight of the train can push the axle down but strong enough to push the axle up after the train has run over the track. Building instructions are available for downloading.

I've got a preliminary NXT program written (a joint activity with my son, to improve his programming skills) which successfully makes the switch move to the appropriate position for a train inbound to the switch. It requires two trigger track sections, one for the straight through and one for the turnout. Some additions are required to the program e.g. it currently assumes the switch begins in the straight position. Once the changes have been made, I'll make the program available for download.

I may scratch an itch to see if I can come up with a mechanism to enable the touch sensor to be mounted horizontally. The premise being that it will reduce the mounting height required for the track.

Regards,

David

[Link to my previous posting containing track building instructions].

Edited August 12, 2019 by djm

[Trekkie99]

Nice improvements @djm! I can see your latest design working quiet well since once one 2x4 tile is pushed down by the monorail, the other 2x4 tile will also go down because of gravity thereby making a perfectly flat 2x8 surface for the monorail to run across.

 

Edited January 26, 2018 by LegoMonorailFan

[Brickthus]

On 22/01/2018 at 8:32 PM, fred67 said:

Hmmm.... my tracks are three bricks high (I didn't have a lot of plates to use at the time), and I was thinking that using all plates, with an extra layer of offset/not offset (which makes the curve work) would be a lot sturdier.... but also a lot more costly.

...

 

Sturdy is very important, both for a set to be played with by children (build quality) and for exhibition reliability.

45 metres of curves cost around £380 for the three pieces in quantity.  Still a significant cost but manageable for a circle of curves in a set.  It works out at £26 for the curves but cheaper for the straights, so with a train motor, IR receiver, AAA battery box and train handset it should meet the train-set price point.  Plus there is extra value as you can make a double-bend as a second-model variation.

On 24/01/2018 at 4:13 PM, LegoMonorailFan said:

Hey @Mark Bellis, I was curious if the length of 19 studs for your curved track section has any math behind it. For example, does it corelate somehow with 32x32 baseplates? Thanks! 

I found that 19 2x2 sections fits on a 48-stud radius for the larger baseplates.  This is the minimum feasible radius without straining the bricks (which would be an "illegal move").  The tighter the radius, the more strain it will put on the train's motor(s).  I did consider the 1-3-1-3 building technique but it is less adaptable to curves because the track is 2-studs wide.  The gaps would be bigger, leading to bumps.  I avoided using under-studs because those would wear out the tyres quicker.  I tried the original idea of tiny tyres (2 lots of 3 on Technic half-bushes under a 14-stud long carriage) but switched to the 18mm tyres because they grip well and are common in City and Classic themes.

Then I found that 23 sections fits a radius of 58, 27 fits 68 and 31 fits 78.  Beyond that a small adjustment is needed, such as a 3-long section.  The aim was to make the original free-form curves fit a regular grid system so that I could make a set like the 1990s monorail curves but with multiple radii that has been a craving of train and monorail enthusiasts alike for many years.

48M minimum radius with modulo-16 straight lengths, but reserving the capability to go down to modulo-2 or 1 for special shapes, seems to work well.  A double-bend, to slew a track across by 10, is like a 32M straight made with curve sections but it needs an extra 1 in the middle.  There are no restrictions on track shapes using patterns derived from the curve and straight construction techniques.  That makes it cheaper than 3D printing (re-use the bricks) and also unrestricted for the user (not waiting for TLG to make a new mould like PF railway track; they said it was more feasible to make track shapes in just plastic but we have had only the short-lived crossover and the flexi-track with check-rails).

5-plates high is tidy and allows the train guide pins to clear the adjacent studs of a brick used to support the track, or even a hoop or tunnel fixed underneath the track.  Consider also that a child would like the smallest cross-section of track for easy holding in smaller hands.  The hills have to have a deeper profile at the slope-change places in order to get enough strength.  I have used 2 clips and a push contact at those joints, rather than just a single clip that would be flimsy.  This kept up the product focus.  The aim is to be able to replace the original monorail in form and function and have the system never go obsolete.  Obsolescence hurts AFOLs in the pocket.  LEGO products need to stick to the brick and avoid being too bespoke.

Mark

[Trekkie99]

Updated! My Lego monorail switch track is now up on my Flickr. Link to full album is on the main post of this topic.

I've taken plenty of pictures so it'll be easy for people to copy the design. (Not that there's anything complex about the it.  ) My intention when building the switch was to make an extremely simplified version of Masai Hidaka's switch design, and I think it works pretty good. 

Cheers.

LMF.

[Asper]

This thread is so much fun to read and follow! Thank you for sharing all this!

In 2013 "arminpfano" posted his brick-built monorail system "Solorail" on "1000Steine". The text is in German, but I think the pictures and movie is enough to understand what he did. He used the old tracks from the 12v train system, which is very cost effective (2€ / m).

Forum entry: http://www.1000steine.de/de/gemeinschaft/forum/?entry=1&id=297870#id297870

 

[Trekkie99]

Thanks @Asper! 

Yes! I've seen that design, and it is one smooth sailing monorail! Very impressive! 

[M_slug357]

WOW, that's super slick! Though I wonder about the parts' longevity b/c it looks like they have those 2x2 "sliding shoe" pieces gliding over the top of the rails? Since almost all of the rail head is of the notched variety, won't that cause a significant amount of wear&tear?

[Trekkie99]

Found this on YouTube under "lego monorail", most resent. Very impressive to say the least! Two thumbs up to the creator! 

 

Edited February 10, 2018 by LegoMonorailFan

[fred67]

Hmmm.... that "solorail" one seems very interesting to me.  The technic one is really interesting, too.

I haven't commented here in a while, but I've put a lot of effort (and bricklink orders) into trying to make something I'd be happy with.  My biggest complain about my own monorail is how roughly it seems to run, and I actually see a similar problem with pretty much all the ones running on the "stressed" 2-wide rails that we've created out of 2x2 and 1x2 bricks/plates.

The technic one is actually very intriguing; I'm more concerned right now about getting something to run smoothly than look nice.  The problem with the technic one (not to take anything away from how great it is), is that it neither runs particularly smoothly, nor does it really look that great (it wouldn't fit with a minifigure city, IMO).

The solorail one looks like it runs really smoothly, and it also looks pretty good (although I think both the track and train could be improved, maybe eliminate the gliding parts and use wheels).  Until I saw LegoMonorailFan use 1/2 bushings as rims, I wouldn't have known you could do something like that - it could possibly be used in the solo rail style.

I am considering going back to the full tire, though.  I don't seem be getting anywhere with the smaller size and low profile I've been trying to get.  And it's amazing to me how so many things just don't work by a fraction of a mm - if the gear was a tiny bit bigger, or the axle a tiny bit shorter....

 

[Trekkie99]

17 minutes ago, fred67 said:

Hmmm.... that "solorail" one seems very interesting to me.  The technic one is really interesting, too.

I haven't commented here in a while, but I've put a lot of effort (and bricklink orders) into trying to make something I'd be happy with.  My biggest complain about my own monorail is how roughly it seems to run, and I actually see a similar problem with pretty much all the ones running on the "stressed" 2-wide rails that we've created out of 2x2 and 1x2 bricks/plates.

The technic one is actually very intriguing; I'm more concerned right now about getting something to run smoothly than look nice.  The problem with the technic one (not to take anything away from how great it is), is that it neither runs particularly smoothly, nor does it really look that great (it wouldn't fit with a minifigure city, IMO).

The solorail one looks like it runs really smoothly, and it also looks pretty good (although I think both the track and train could be improved, maybe eliminate the gliding parts and use wheels).  Until I saw LegoMonorailFan use 1/2 bushings as rims, I wouldn't have known you could do something like that - it could possibly be used in the solo rail style.

I am considering going back to the full tire, though.  I don't seem be getting anywhere with the smaller size and low profile I've been trying to get.  And it's amazing to me how so many things just don't work by a fraction of a mm - if the gear was a tiny bit bigger, or the axle a tiny bit shorter....

 

I find that larger tires have a harder time taking curves compared to smaller tires. Also, the higher your monorail is above the track, the higher the center of gravity. The higher the center of gravity, the less stable your monorail will be. Most notably on curves. So in turn, I think this makes smaller wheels the better candidate. I also like my monorails to be able to take very sharp curves, all while having very little stress being put on the motor.

Any chance you could post a video or an image of your monorail? I'd very much like to see it, as well as maybe offer some tips and advice if you'd be interested. 

[fred67]

Next time I have something that actually runs (I've gone through about a half dozen tries with various gearing and "stabilizers," which I think I've got right now) I will take a video of it.  My curves are not sharp - I think we discussed it before, I use about twice as many 2x2 segments as you in my curves.  I'm also using full bricks (2x2 and 1x2) and not plates, although I'm looking into it to make the "rail" not so big.  I don't mind it the way it is, but I wouldn't want it bigger and might want another layer for stability.

I also use this:

So that I don't have to carry around a full battery box.  I bought a handful of rechargeable batteries and charging station that will charge them all at once.

https://smile.amazon.com/gp/product/B01DZ8JSYC

https://smile.amazon.com/gp/product/B00RL7E2MC

[Trekkie99]

Those Minizips have always interested me. What run time do you get when using a rechargeable nine volt battery?

[fred67]

I can't tell you because I've never run something long enough to see.  I will be honest, when I have my winter display up, in my living room, I walk by and play with the trains for 10 minutes, then walk away (they're 9V anyway).  If I had a complete LEGO city (which it looks like I may actually be able to make a "permanent" layout sometime this year, finally), I would still play with it for a while and then walk away.  My kids are grown.  When we have guests with young kids, then I may get a chance to see how long they last.

In any event, here's what I have at the moment (still wobbly, but no more so than Masao Hidaka's):

I ultimately had something similar to Masao's, but some changes from his - I could simply not make a horizontal motor work the way I wanted to (last test fell off the rail, and to keep it balanced the engine needed to be too long), so I went vertical.  He used only three wheels across so that his gear - offset by a half bushing, wouldn't rub against the tire.  I kept all four tires and, instead, added another gear in-between.  By eliminating his whole central section, I was able to make my engine three studs shorter.  That makes the guides fit better through the curves.  There's still a couple of things I'd like to do - I think I can go a little (perhaps two plates) shorter by using 3/4 pins to hold the motor.

EDIT: still frustrated at how wobbly, I tried the bigger wheels and even added an extended double-swiveling guide system.  Still wobbles.  I'm pretty sure this is due to the wheels wanting to go straight, but my whole test layout is on a curve - the wheels don't swivel.  I don't think I can make the drive wheels swivel without making a monstrously large engine (given the scale).

Sorry - I don't know why EB puts that huge gap after the link to flickr for a movie file.  I will now be packing up what I have so far - I'm actually not thrilled, but happy enough with the latest engine, but I'm not going to have a lot of time to play with it for a while.  Keep up the the great work, guys.... I'm glad you made me interested again.

And one last edit - I've been running all my tests with same, charged once, 9V battery.  I think they can last quite some time.  I bought a four pack, and the charger can charge like 8 of them at a time.

Edited February 11, 2018 by fred67

[Trekkie99]

I've been meaning to cover Masai Hidaka's monorail design for awhile now. 

One of the biggest problems with it is the trouble it has taking curves. 

Over some time of experimenting, I've come to the conclusion that the guiders aren't the problem, but the distance between the drive wheels. Ideally the drive wheels should be as close together as possible. Like this for example.

 

This however can cause some obvious problems. Most notably if to much weight is applied to the far front or far back, the monorail may "buck up" when starting.

The other option is to remove one of the drive wheels, and replace it with a guider wheel. Like this for example.

 

Both these examples work very well IMO, and can even take fairly tight curves.

As for non motorized monorail cars, the same principal applies. 

Keep the wheels as close together as possible without compromising stability.

 

Edited February 14, 2018 by LegoMonorailFan

[DaFokka]

Did you consider moving the driving wheels to the sides of the track? That way you could lower the center of gravity considerably, which should lessen the wobbling by quite a bit. It might also help with the steering.

Edited February 13, 2018 by DaFokka

[fred67]

Actually, I have thought about that quite a bit, but the geometries have been difficult, IMO testing, just to even have guide wheels instead of posts.  HOWEVER, on that last day of testing (Sunday, so I had all day to play around - almost), if finally realized that Masao was using 1x2 technic bricks with two holes (or 1x1) to offset distance between gears mounted on "standard" technic bricks.  That's the only reason the newer one (pictured) works at all.

I'm convinced that the higher center of gravity might give it lean, but not wobbles - that it's the drive wheels going straight in the curve.  There is, actually, a bit of the fact that - especially on the smaller tires, there is some inconsistency in the tires themselves, but I don't think that's the bulk of the problem.  I may just order new ones (I even had ones that were dried out).  I think I may have a work around, but I packed up all my bits and pieces for a while - I can still come here and post, but I won't have much "play" time for a while.  I may roll this suggestion back into my thinking, I'd already given up on it.

EDIT: and yes, LegoMonorailFan, I agree (wheels need to be closer using that configuration), but there's also the guides themselves - if they are too far apart, they won't fit on the track well (they will be tight, if they fit at all), because they aren't swiveling, either (which is why I made mine swivel, and it helped a little bit, anyway).  It's obviously why your swiveling tire-gear-guide solution works so well.  The reason the wheels need to be closer, given that configuration, is exactly because it's in a turn, and the farther apart they are, the harder it will be for them to turn in unison.  Your original idea works great because of the single drive axle being turned along the curve by the two cars.

I ultimately just want to have an engine and be able to add and remove cars - like a normal train.  However, I would be thrilled to have one like yours running in my city in the meantime.

EDIT2: BTW, one of the ideas that I think you may be interested in is to, more of less, use an engine configuration like you did for the train in the first post of this thread... and then link it to another similar to what you did with the cars.  So you would have a fixed swivel between the two motors, but then you wouldn't need the fixed swivel between them and the cars - which means you should then be able to incline.

Edited February 13, 2018 by fred67

[FiliusRucilo]

I've build a train according to the motor boogie design of MonorailFan99. This train runs smooth in a 52cm circle. (96 Tiles 2x2).
There is no noticeable speed difference between straights and the 52cm curve. 

...and YES! Parts in the "correct" color are ordered already on BrickLink.

Edited February 14, 2018 by FiliusRucilo

[Trekkie99]

1 hour ago, FiliusRucilo said:

I've build a train according to the motor boogie design of MonorailFan99. This train runs smooth in a 52cm circle. (96 Tiles 2x2).
There is no noticeable speed difference between straights and the 52cm curve. 

*snip*

...and YES! Parts in the "correct" color are ordered already on BrickLink.

Hey @FiliusRucilo! Didn't know you were on Eurobricks!  

Sweet monorail! I also love your boogie wheel design.  Would love to see a video of it running. 

BTW, you've done some splendid work on improving the Masao Hidaka monorail design! 

Cheers! 

LMF

Edited February 14, 2018 by LegoMonorailFan

[koalayummies]

This is honestly one of the best threads ever. The sharing of ideas, the discussion and the results are all very inspiring. Outstanding work. 

[Trekkie99]

1 hour ago, koalayummies said:

This is honestly one of the best threads ever. The sharing of ideas, the discussion and the results are all very inspiring. Outstanding work. 

Thanks!   

[Paperinik77pk]

Uhmmmmm...that Solorail reminded me I have literally tons of unused blue era rails without sleepers...time to think about a monorail system!!!  

[Trekkie99]

4 hours ago, Paperinik77pk said:

Uhmmmmm...that Solorail reminded me I have literally tons of unused blue era rails without sleepers...time to think about a monorail system!!!  

 Well you could also make one of these.