jlassen

really nice! thank you for sharing

Thank you for the link to this design. I appreciate the feedback. This "connected triangle" issue was why I thought using the "Triangle arch Lift arm Piece" would be a better source of both strenght and force transfer, rather than sepearete straight lift arms to create triangles. Again, I really appreciate your (and eveyrone elses) feedback and the many different thoughts and approaches. I've ordered a bunch of pieces and am about to put some theory into practice.

So an external shell, completely isolated from the cantilever structure, except via the track. Something like this: Kind of prototypical of an open deck plate girder bridge. Hell. Despite the added weight, the exterior shell might make the overall structure MORE stable. And for those suggesting I take a look at real bridges.... here is some serious Bridge porn i found. Enjoy! A Context For Common Historic Bridge Types NCHRP Project 25-25, Task 15

With my narrow cantilever design right now the primary lift arms that are attached at either end of each track junction-pieces *are* the primary track support. The Two vertical arms connecting the lower arms and the upper arms also serve as track supports at the center. These leaves at most 3 studs worth of track on either side not directly supported. I am wondering if it is a net positive or negative in this design to not have the tack attached to most of the support structure... so any rotational force applied by train movement on the tracks won't be transmitted to the cantilever structure... except at those 4 attachment points. that force would let the track move and flex and expand/contract without most of that force being transmitted to the cantilever. Sort of an "earth quake proofing" technique. Conversely, I could put a Tile across either end, which would fit in the open space between the rails at each point. That might prevent more movement and shaking of the track if it was more tightly fit. Honestly the fun of this is trying to do it in Legos. And I'm learning a lot. Honestly The geometry of Lift arms and technics pieces is not my strong suit --Thats why my first attempts were so brick focused. So this is forcing me to learn in.

I really appreciate all the feedback I've received on this thread. And of course, "The right tool for the right job" principal shows axles ain't gonna get it done. clearly. Lift arms and pins is where I need to go. I feel like maybe *I* might not be able to stand on this, but my daughter probably could. Thoughts? I'm using both the arched lift arms and the interconnects between the top arm and bottom arm to transfer the contrasting sag forces (compression at the top, extension at the bottom) against each other. The interconnects between tracks (and modular cantilever sections) are being held together by the 4 lift arms, and the 4x4 plate. and with this narrow cantilever, I could encase it if I wanted to change up the aesthetics...

I appreciate this concise description of the problem and the forces at work. Than you.

version 3. Okay, this went from "Looks kind of lightweight and elegant" to Built like brick shithouse. But this now connects the break point across 4 brick widths and at has the axle stoppers pushing the force down the length of the cables. I can't wait to see how many jars of pennies this will hold up. :) Time to have a competition with my daughters to see which design holds the most. Light weight black and orange or red black and yellow brick s* house. Also time to stop playing with virtual legos, and go make dinner. Thanks again for your feedback, coaster and Jimmy. DInner is being made... Overkill

Hey @jimmynick and @coaster I really apprecaite your patience in walking me through the failure of the the red and black design. I do understand what you are talking about, regaurding the downward force not being actually pushed out along the axles. I am going to work on a couple of alternate ideas, to figure out how to best transmit that force down the lenght of the axles. version 2 of the red and black bridge. I need to transmit the force of the two bricks pulling apart down the axels. That is the assumed break point when downward force is applied at the rail join. so in this design, as the bricks pull apart in failure... two of the four axels will have that force applies to their stoppers... that will Push it downward, against the other axles. This design requires alternating top to bottom, or left to right. I feel like top to bottom will provide more reliable strength at any given join. In this picture, a failure at the right join will cause the bottom cables to take that pressure... that will then transmit that force, along both bottom axles, to the left... which will then push it up against the head to toe lenghts of the axles. and a failure at the left join will cause the oppoite.. the top two axels will push to the right, along the lenght of the spans axles. In addition to properly trasmiting the tension horizontally, this also puts an axel across the possible seperatoin/break point of the two breaks. Not sure if that helps at all, given they are not inside an axle hole, but rather inside a pin hole. The other thing that should probably happen is the 'Guid bricks" 1/4 of the span on each side should be moved over next to the join bricks... so there is a block of 4 bricks at each join, instead of the two... 2 4x4 plates should acomplish this task... hmmm... more to come.

I really appreciate the feedback. certainly an undertress is the way to go on s lonhrt dpsn. But I want to make sure I'm understanding you on the tension forces... First... I'm assuming that from track end to end, the track itself is strong enough to support the tension forces for any given car that will be on that span. It is when the tension forces are applied at the track join spots that the track needs "Support". So that would be downward pressure at the join, that we are trying to accomdate... right? You and @coaster both indicate that there is nothing holding the axels in place. My understanding of my design is the stoppers are not really holding anything.. The adjacent axle's stopper are what is holding the axles in place... I guess maybe I wasn't clear... this is a modular design..I plan to stack a bunch of these together... LIke this... both you and coaster indicate that nothing is holdingn the axles in place... but my understanding is at each one of the rail joins, the axles are stopper to stopper. They hold each other in place. and at the undetrack meeting of the two noses, they are facing each other, and holding each other in place. at the end of the span, there will be a big block, as secure as need be, to hold the force being pushed against the it from the axles. From your responses, it seems like I am missing something . The tension created by weight of train at the track joins pushes down on that joint, and the bricks below them, any tenshion that pulls those bricks apart will transferd from a downward force to a horizontal force in the axle... that force will then be sent the lenght of the span, across ever one of the axels, until it reaches the end of the span and the embudmant there... which we can assume for our purposes will be infinatley strong. .... wait wait wait... hmmm. so if the bricks are being pulled apart... the bricks are not actually PULLING on the stopper.. so the friction that coaster was mentiong was the friction created as the bricks pull apart... up against the side of the brick... But the axles still an't move t the left and to the right... (theoretically) and as those bricks pull apart... they are going to be putting up and down torqe on the axel... but there really isn't anything forciing that to go along the axels.. I think I see what you both were tellingn me now. hmmmm. Thank you. If I reversed it, and the stopper was on the outside instead of the inside... because the failure will be the bricks coming apart at the join... pulling away from each other... so if the stopper was on the outside... that failure pull would THEN, via stopper, be transmitted to the axle. Right? this is assuming the failure point is at the track join, and the failure is the two bricks at the top pulling away from each other.

"leaving you only the little bit of clutch the technic brick w/ axle hole exerts on the axle to hold it in place." No. the Adjacent axles hold it in place. The brick just prevents and horizontal or vertical movement, keeping the axles aligned. My thought was the adjacent axles are what keep it in place. They are all lined up nose to nose, and stopper to stopper. Are you saying there would be vertical force that would pull the axel and the brick is is through up, disconnecting it from the upper track bed? which woudl cause the axle "noses" to come out of alinement? Honestly, I hadn't considered that because I didn't think the force would be cause updward or downward, or sidewise force... but certainly "downward" would be the weak link, if that end of the axle applied downward force, due to load at the track connection end. "If you want to be able to see the trains, you can flip the truss over and put it beneath the tracks. Doing so you could also then use the side of the shelves to push against the truss, giving you further support. " yes. Something like this was definately my intention for when a span exceeded the support stenght of my modular deisgn... I appreciate you ephasizing this point -Jeremy

How would the axles be pulled out of the bricks? There is a stopper on the axle end and the axels would be pusshing against other axles? I mean, I understand, under a faulure load, one of the joins would fail, and the axles would push out at that break point. But where are the axles going to move to? That was the design intention, to put the weight and tension on the axels. instead of the track and bricks underneatht he track join. Basically, I wanted to see how much of a span I could do with just this type of modular load spreading. And then build up some kind of under deck cantalever support for any span that is two much for the "basic" structure. Ultimately, I know this is a build it, and find out kind of situation. But I do appreciate everybodies expierence and feedback. I know I'm reinventing a wheel here. Also, I had contemplated an intial design that had the axles running THROUGH the track join section, but that would require more axels and more bricks at each 1/4 point, increasing weight, and would put the load downward on the axle... My goal was to have the Any speration force pusing lenghtwise against the axel, and every axel "anchoring" all the other axles, right up to the bridge towers which could be buttresses as much as needed, depending on the span and expected force... I don't know. Maybe I'm thinking about this wrong. All critiques appreciated.

So I've been thinking about creating a train shelf and want to suspend my Lego tracks along the ceiling about 2 feet down. I'm trying to come up with a functional tressel that will give me the most support... that is, the most lenght of tracks without needing support. I'm more interested in showing off the trains, rather than making the bridge look "real" so I'm looking at pure functionality here. Part of that, I suspect means light weight... what can I do with the fewest amount of bricks, that provides the most support at the track junctions. I know I'm probably reinventing the wheel here... but here are a couple different techniques I've been pursuing #1, my Orange and black bridge. This makes use of tiles and facingn studs, as a way to hold bricks together horizontally. I have to admit, I was inspired by this technic because of the "Lego masters" tv show I watched with my kids... The Lego bridge that held over 1000K pounds used this method. In the above pictures, I would expect the rail join to be directly above the one 1x4 brick with facing studs... I only made the span 1 brick and one plate, because the track provides most of the support, and any flex should be covered by the horizontal plates that are tying the bricks together. #2 Lighter weaight Axle/technic wight distribution. I beleive the stenght in this one comes from the axles... if the two technics bricks are being pushed apart by downward stress at the rail join, that will transfer the force horizontally to the axles, which will push it to the other joins... thereby creating a feedback loop.. pressure in one spot has the strength of all of the joins together... This one I wonder about... As built now, I only have a axle hole bricks in the center. I could probably prevent some axle flex if I put the 1x2 axel bricks halfway betwee the current bricks. But 1) that adds more weight, and 2) the spress is going to theoretically be pushing from an end, and axle flex is most likely to be induced from downward pressure, not pressure from the end, so the added weight might not be benificial. Any thoughts?

Here's a quick peak at the status of my Black and orange fleet. The Twin Starfire(1499) was a particularly Painful rebuild, with the cockpit bays needing to be built from scratch, and my insistence on rebuilding the engine and tail section to get actual available colors. I kicked around some other cockpit glass shapes, but stuck with the original octagon, though the black transparent piece only comes with an axel hole... so I stuck "caps" on top of em to ensure the vacuum seal. :) Also my insistence on the Orange motorcycle helmets for my crew has led to most of the cockpits needing to be a plate deeper for helmet clearance. 928 or perhaps the weird (and spectacularly silly looking) "supermodel" 1593 Might be the next additions to my fleet. If you have a one you would like to see me attempt, let me know.

The 442 (Shuttle) The platform sometimes designated a shuttle, and sometimes a “space Scooter (891)” is more of a skiff than anything else. Original designed as a supplement to inter-ship transport when docking bays and airlocks were not available, this platform has been continuously updated and modified… the current 442g shuttle is a 3 person craft, still used for inter-ship transport, as well as for thin atmosphere, low g planetoid transport. In addition to the 3 person configuration (longer body) The G can be recognized by its twin vertical tail stabilizers, Larger horizontal stabilized and upgraded avionics. One of its original uses of the shuttle in the Imperial fleet was as a low profile scout craft, and the High Power tight beam laser communications on this particular model has been retained, though many variants abound through-out the Republic Fleet, and in various Commercial services.

That is really nice of you to say so. Thank you. Can't wait for my re-skinned "classic Fleet" to grow. I've done a 3 man "Shuttle" (442: Space Shuttle) and have spent way to much time paying around with a new engine housing for the 1499: Twin Starfire My aesthetic goals involve recreating the feel of some of the classic space Lego sets, but using modern/available parts/colors. and cleaning up some of the weird anachronism of the sets (steering wheel controls, etc). Some of the design descisions I think were for part count and simplicity sake. Stuff I don't have to worry about with my rebuilds. :) The twin Stafire for example... The tail engine piece, and the 2 $12 cockpit windows? and the cockpit boxes? uhhg. I think this one would run about $60-100 if you tried to recreate it by parting it on bricklink.