Phoxtane

Doing this means I don't have to use actual track, which is always in short supply. In addition, this design doesn't require me to find an attachment point under the train car, since it traps the wheels and prevents the car from moving that way. It's certainly not the easiest way to do this, but since I have the CAD skills and a 3D printer I thought it would be fun to work on. I'll probably rework the shape to look a bit more like a Lego track piece anyway; I started with the profile shape of a Lego track piece, and worked from there to get the wheel traps on the inside of the rails. I think the even easier solution would have been glue, but nobody's happy when you try to use that... My 'shelves' are more like the tops of plastic drawer units and bookcases - things that you can't really level anyway.

Whenever I put train cars on display in my room, they tend to roll away unless I put them at a funky angle, since the shelves aren't level. I designed a set of holders that the Lego train wheel piece sits on so they don't run away: The nice render above is sized for bogies with two studs between the wheel pieces - I designed up holders for single wheel bogies, and holders for bogies from zero to two studs between the wheels as seen below: These should help keep my trains from rolling away. I'll have to do them in gray the next time I have gray loaded into the printer.

The sticking point here is the price, though! I can't imagine a Lego trains set that isn't a large fancy model aimed towards the older crowd that's that expensive. Unless, it has a lot more track. Presumably Lego's market research has told them that train sets of such prices don't sell well unless they're aimed towards adults.

Hmm, looking back over the last few pages, I think I've got a solid theory as to what will be happening next year: There's at least two, potentially three, set numbers reserved for trains in 2018. One of the sets (the 'confidential' set) looks to have a much higher MSRP than you'd expect for the standard ages 6-12 trains starter set. Based on these, I suspect we'll be getting three sets: An updated commuter/passenger train with pantographs, tiny boarding platform, a scattering of minifigures, and some flex track standing in for straights on the tiny oval track. A larger, more expensive cargo train, with a truck/forklift/crane, bits of cargo to move on/off the train, and three minifigures working in the freight yard, one of whom drives the train. And, given the large price of the 'confidential' set, I'm hoping that's a new creator expert train. The fun part comes when we try to guess what real-life train it will be based on.

Maybe the train is remaining the same with regards to complexity and size, but they're including much more track? Maybe more than the one switched siding?

I like this a lot - about how much would you say each unit of a full 'car' cost? Are all of the parts available for reasonable prices in large quantities?

It may be worth putting a small amount of thermal grease/compound on the side of the LM317 that is pressed against the heatsink. Even if the device will operate up to 90C, it certainly won't be happy about constantly being run on the ragged edge, and should last longer the cooler it operates. EDIT: It probably doesn't run that hot in general use, but it never hurts.

I finally have a 3d printed piece of track that attaches to Lego bricks! This is the fifth print for this part, so so far have I've spent between 12 and 15 hours on printing. The next step is to set up the flanges and such that allows each track piece to connect to other ones.

I got myself the Monoprice Maker Select V2 - it has a build volume of 200x200x180mm (X, Y, Z respectively), has a heated build plate, and can handle either PLA or ABS. I've never used ABS as it can be tricky to print, especially when you tend to have strong drafts in the area (like my space). I've added a Z-brace to the tower to eliminate back-and-forth motion on the Z axis, which would decrease the quality of prints I can get out of it: My print material of choice is PLA, as it's easier to print and less prone to warping than ABS. In my slicer I have my printer set to 200C and 55C for the extruder and heated bed, respectively. I also use a .2mm layer height with a .3mm initial layer (this helps to take up any uneven spots in the print surface). After I've loaded the output from Cura onto a microSD, I wiped down the print bed with a paper towel to get rid of any dust that may have settled since I last used the printer. After a short preheat for both the heated bed and the extruder, we're off to the races. Here's an in-progress shot: Turns out it's somewhat difficult to get a good shot because the subject is moving back and forth! I let the print bed cool for a bit before I attempt to remove the part. Usually for small pieces I can remove them immediately, but large parts cool slower and I don't want to remove them too early for fear of warping. I managed to coax the part off the bed and leave behind just about all of the supports. The last one that stuck to the part popped off without any tools whatsoever. Then we have the final product! In the second image you can clearly see the difference in surface finish between portions of the model that sat directly on the print bed, and portions that were built on top of supports. I've also got some sort of lighter gray splotches on the bottom, which I've not seen before - maybe it's because I didn't wait long enough for the part to cool? I'm not sure. The next step for this model is to add studs, the clip-on connectors, the rail end cutouts, and the empty spaces on the underside of the ties to allow for connecting this to real Lego parts.

This summer I acquired a 3D printer, and it only just recently crossed my mind that I could make parts that I've been wanting - even those that don't exist yet. This will be the thread I throw all that into. For the first post, here's my first version of the standard straight track: First, I started off by drawing the track profile, using the dimensions I found on the L-gauge wiki: http://l-gauge.org/wiki/index.php?title=Track_Geometry I used Autodesk Fusion 360 for the modelling portion (it's free to students, makers, hobbyists, and businesses making less than 100k USD a year!). Then, I extrude the profile out by 128mm to get the 'blank' for a piece of straight track: I then make another drawing on the top of the base which represents the ties present on the Lego track: Finally, I take every other section of the blank and extrude them downwards to the bottom of the blank, this time using a 'cut' operation instead of a 'new body' operation: I now have something that looks quite a bit like a piece of Lego track! It's obviously missing studs, the snap-together connectors, and the cutouts on the ends of the rails. However, it will do for a first print test. I then export from Fusion 360 as a .STL and load that into my slicing program of choice, Cura. I'm looking at the model in the layer view after applying my 'strong' settings - this lets me see the model layer-by-layer and I can see how it should look. I can also see a cross-section by using the slider in the upper right: Here we're seeing the interior of the rails, but not the ties. Here we can see inside the ties, as well as the supports - these are temporary structures that will be removed once the print is completed. They hold up the overhangs in the model that may otherwise sag or distort excessively - I'll need to change the support orientation before I commit to a print for better results. Unfortunately, it's too late at night for me to kick off a print - I know the time estimate given is somewhat of an underestimate, so one of these very basic track pieces will actually take a bit over three hours instead of the two and a half that's given by my slicer. I'll be doing that tomorrow.

If they were to re-release the Santa Fe, I'd like to see it reworked to be more in line with the more recent trains. I've seen it in person, and it's actually quite huge. I've also never really been a fan of how they attempted the nose on it.

I'm sure there's various complex processes that take an input of carbon feedstock (wheat, in this example) and can turn them into simple hydrocarbons. If the process is fancy enough, I bet you can get all of the component materials for ABS plastic from wheat! I'd think that using an algae-based process would be cheaper and easier though, since the algae do a good portion of the work for you by producing an oil straightaway, as opposed to synthesizing the oil from a carbon feedstock (wheat).

I've got my workspace cleaned off and have the long straight for this layout mostly completed. I'm just missing an abundance of 1x2 tiles to finish off the ties for this section of track. It's seven baseplates long - however, the actual layout will add two more baseplates to either end from the curves. I've had to give up the table for Easter dinner, unfortunately!

Maybe you could attach metal foil to the magnets on the trains themselves - you could at least do automatic power connections between cars that way, assuming you left enough loose wire to let the magnets swing freely. There's also pogo pins - fill up a 1x1 Technic brick with some hot glue to locate them, and you could have matching contacts on the other coupler that the pointy bit fits into.

The stickers are what really sets these apart from the rest. Nice work.

Well, good luck with the Kickstarter! I suppose there's a reason college students don't go into business ventures such as this nearly as often as other age groups.

Cable management will be of great importance for this setup. I can't recommend anything specifically, but McMaster-Carr has a wide selection of sleeving for you to choose from. Personally, I'd probably go with some abrasion-resistant (braided) stuff since you're presumably going to moving stuff around until you get everything just right. https://www.mcmaster.com/#standard-cable-sleeving/=16hwme3 Also, keep in mind that the Arduino used here can only handle 200mA maximum being drawn or sunk on the digital IO pins. I found this information here: https://forum.arduino.cc/index.php?topic=121675.0 . If you're driving more than a few of those signals at any given time you'll need to give them their own power supply so you don't cause damage to the controller. Looks good otherwise!

At this point in Trains I wouldn't bother getting into 9V if you haven't already got some. It's ridiculously expensive and parts are only going to get rarer - think $40 for a working used 9V train motor and double that for a NIB one!

I have had this exact problem - same pump, same set too. From that set as well my large hand pump has developed issues to the point of squealing horribly when depressed and taking a very long time to return to the neutral position. I've not had issues with any of the other parts from the Education pneumatics set!

Well, I never said it'd be reliable, to be fair. Nice PCB as well. For my purposes I'll probably stick with some sort of servo shield or breakout, but I was planning to do that anyway.

I don't know as much as you, since you're teaching on the subject, but it is very possible, apparently: http://electronics.stackexchange.com/questions/108689/how-can-the-arduino-uno-support-up-to-12-servos-if-it-only-has-6-digital-pwm-pin It may not be very efficient but certainly doable!

It's what the library can handle on the Uno - and apparently the Mega can do 48! As for the reset, that's why you'd use a servo shield or breakout board with its own separate power supply. I'd go for a maximum of two driven off the Uno directly, personally.

Apparently I am - so then you could easily run 10+ switch tracks from the one controller, if you aren't using any sensors. The cost would only be another $8 added on from the four servo motors left over in the previous example. At that point it'd be prudent to use a separate power supply, but I know you can get servo breakout boards that handle that for you.

Wires don't matter that much when you're building everything on MILS - I've got plenty of space underneath to hide wires, and small hills should do the job for the various control boards.

I finally have good pictures of the demonstrator model for my take on a cheap no-modification-required switch track motor. Have a look! The key that makes this work is that the servo acts on a slider, which pushes on the little spring-loaded switch point piece, rather than forcing the lever mechanism back and forth. As such, it takes very little force to change the switch from open to closed and vice versa. I'm using two of the 1x1x1 corner panels to trap the servo horn so that it pushes the slider back and forth, while a 2x2 corner tile pushes the point piece backwards and forwards. The actual switch lever needs to be in the 'open' position to allow the point piece to move back and forth properly; otherwise, the switch will stay closed even when the servo releases the point piece. I'm using an Arduino Uno, but you could use any Arduino or compatible clone as long as you get the pins hooked up right. It's a lucky coincidence that the servo is the size it is; two of the 1x2x3 panels form a nice enclosure that keeps it from moving about too much. It's important to get the older style that don't have the reinforcing ridges on the edges, as otherwise it won't fit. I used a small piece of paper folded on itself a couple of times to keep the servo wedged in tightly. I imagine you could use some of those 1x2 bricks with the vertical groove in them to help hide the servo cabling, but I didn't bother since this is only a demonstrator. Here's a better view of the setup without the track in the way. My servos came with a pack of three differently-shaped horns to put on them - I'm using the shortest one available to me (mine was 19.5mm long with six small holes in it and was the only one with one 'arm' on it). I also have not permanently attached it with the screws that also came in the package, mainly for the purposes of testing. Lastly, here's a picture of the support structure I built up to keep everything in place. I also made an LDD file of the structure as well as the slider mechanism and servo holder so that you can build your own! http://bricksafe.com/files/Phoxtane/digital-model-files/servoswitchtrack.lxf The hard part of this built is not the mechanism, but setting up the servo as well as the Arduino controller. If anyone is interested, I can do a more in-depth post on how these servos work and how to use them, but the basics go something like this: Attach the servo to the Arduino using the diagram on this page: https://www.arduino.cc/en/Tutorial/Sweep Test your servo to make sure it's working using the example code on that page (the servo should slowly move back and forth between its endpoints) Center the servo at 90 degrees - http://www.allbot.eu/build/allbot-arduino/centering-a-servo/ - this puts the servo at a known position for use in our mechanism Place the small one-arm servo horn onto the servo spline so that it's pointing across the servo body, not away from it. This allows the servo to reach the little pocket we've built and actuate the slider. This is the tricky part; you have to play around with the Arduino code to calibrate your servo for its switch track. These servos are mass-produced as cheaply as possible, so the actual physical position of the horn at the 0 and 180 degree endpoints will vary somewhat from unit to unit. For my servo, the two positions the servo should move to for a closed and an open switch are about 83 degrees and 113 degrees, respectively. The corner tile should barely touch the point piece when open, and should keep the point piece tight against the outside track piece without the servo struggling or forcing itself out of position. I made some minor improvements to this code for my demonstrator - the servo doesn't sweep between positions, but jumps between them, so it's faster to actuate. I also have the Arduino disconnecting the servo in between movements so it doesn't 'hum' while waiting to move to the next position. General improvements to this model would include building the mechanism out of DBG and black for the servo holder, as well as tidying up the wiring to the servo. The servo horns stand out quite a bit color-wise, but since they're nylon, they could easily be dyed black to match the servo housing, and the silver-colored screws that come with the servo horns could be touched up with some paint or nail polish to turn them black as well. The only downside to this mechanism is that you can't run a train backwards through the straight part of the switch when it's closed, since the point piece can't move out of the way. Since this is already being controlled by a microcontroller, it wouldn't be difficult at all to add some sort of sensor that would open the switch when a train is approaching it from the wrong side. As for overall cost, beyond the price for the pieces needed to build this barebones mechanism (I had all of the pieces in my collection): I bought a ten-pack of these servos for $2 apiece, and if you don't already have one, a small Arduino starter kit can be found online for $25. The Arduino Uno has six analog pins, so it can potentially control up to six servos at once. If you're starting out from scratch, the total cost for six motorized switches would end up being around $37 - which is much cheaper than the ~$125 it would take to build this out of genuine Lego parts (one battery box, six M-motors, three IR receivers, three IR remotes), and it doesn't take any PF channels.