Hacking with LEGO Bricks

Hacking with LEGO Bricks NOT for the LEGO Purist!Graphic images involved! Turn back now!( LEGO is a trademark of the LEGO companies) ( I am NOT affiliated with the LEGO companies )

Confessing my sins (and tips) I have used… • Cyanoacrylate (“Super-glue”) • Hot Glue • Xacto Micro-saw • Dremel moto-tool • SOLDER! • Use Non-LEGO elements!!

Graphic Image Desktop

Got non-LEGO scrap parts? • A use for non-LEGO bricks and plates! • Hold your precious LEGO while you cut, saw, glue and solder them! • You don’t want towaste your LEGO • You don’t care if you damage thenon-LEGO bits!

Start simple, and practice • Cutting my first green 2x2 tiles into a pair of 1x2 tiles for a roof project was tough, but I learned from it; • Practice on non-LEGO parts first! • Use non-LEGO parts as a saw guide • Hide the “cut side” under other parts • Use a micro-saw to minimize loss/gaps

Making Adapter Tracks • Have you ever needed a 1/2 straight? • When you are nesting loops oftrack, that 5-inchstraight track isa big shift, when you need 8 studs

Two straights, two adapters • Sacrifice two regular straight tracks, and you get a 1/2-track and a 1-1/2 track • Cut the tracks at the 1/4 to 3/4 point • This puts the junction on a 2x8 “tie” • The split tie is how you align the parts • You can do this with curves and switch track as well, but you need to be careful

Align your track parts! • There will be a gap from the saw to fill • Use non-LEGO to align the parts • Now solder the railhead parts • Short, quicksoldering! • Copper foil?

Add some Copper Foil Tape • Cut and lift the railhead • Align the track • Carefully add foil • Anchor the railhead • Hot-glue rail in place

Stiffen your track joints • LEGO braces thejoints of their track • You should also brace your joints! • AFTER soldering. • If you don’t, your joints may bend underpressure while assembling them…

Smooth out the solder joint • Trains and cars bumping over a bad joint will derail a train and stop your fun • You can either sand it, or cut it flat! • Inside thegauge, andtop of rail,get the work

Was it worth it? • I have these parts on my shelf railroad • I think my club benefited from this effort on some of our public displays. For me, it was.

Track Power Extensions • You cannot get sufficient power across a long distance using the normal LEGO-supplied power extension cables. • Wire gauge is too small for long haul… • Adding train motors adds more load… • Adding more cars, (or causing a motor to “stall”) adds more load. • LEGO designed this for safety!

Why I made my decisions • PNLTC Guinness 2000 layout • Hard to get LEGO 1-meter power cords • They didn’t perform well daisy-chained • The Far End of our layout was 30’ off! • Trains slowed as they got to the far end • Trains sped up as they came back… • We wanted consistent train speed

Debugging a big display… • Hot days/rooms will aggravate the thermal safety devices in Track Power Controllers and in Train Motors! • Thin wires loose more power over a given distance than larger wires. • This holds true for the railhead! You lose more power as you go farther from the power feed points! You need more power!

To splice, or not to splice? • Splicing thicker wire is less work, but is also less efficient. • But, how much power do you need? • Soldering to the rail is easy enough • Soldering to the 2x2 power brick will require some grinding as well! • But it will be WORTH THE EFFORT! • Try 18-gauge wire. Maybe speaker wire?

Opening the 2x2 Power Brick • Use two fine, flat screwdrivers • Two tabs near the cord • Two more on the other end • Approach from the bottom • Be very slow and gentle… • You should wind up with twopieces in the end… --->

Preparing the power brick • I use a small router bit in myDremel tool,to widen the trough that supports the wire. • Be careful to preserve the tabs • You can dig down a bit… • Finally, carefully solder in between the studs like this • Polarity is going to matter…

Soldering to the Railhead • Pick an area near a wire pass-through gap on the bottom edge of the track • Prepare your wire (cut and strip it) • Only one wire goes under the track… • Rough the area on the “outside”edge • Scratch with a scribe, or light steel wool • “Tin” the spot first, before you add wires • Only heat the outside edge, not the top

Railhead Clues • Find the wire pass-through • Wires solder to the “outside edge”, below the top of the railhead so trains won’t derail • A dab of hot glue holds the wire • Only one wire needs to crossfor a track power connection • (Only the white wire here…)

What else can I hack? • Why tie up TrackPower Controllers topower many models? • Make an adjustable-voltage power brick! • Add a 2x2 power brick(now you’ve done it!) • Stack a few modelson this same power

What about Mindstorms Stuff? • I’ve only hacked with the RCX bricks. • I’ve seen some interesting sensors. • I wanted to trigger train automation. • I tried optical sensors, but they are bulky,take up space

Hide-A-Train Idea • I originally heard this at the set-up session for a Vancouver LTC display • Mix a Hogwarts train with freight train • Paced to leave the platform after the freight, and follow around the loop • Diverted to a hidden siding, to wait a random number of freight-loops & return

What would you need? • Automated switch points (2) • Only divert from the main line to the siding! • Switches allow re-entry from the siding! • Isolated track power • Gradual power to start the train • Some type of sensors to say it is safe • Sensors to say Hogwarts is parked • A random-loop counter (Mindstorms)

Magnetic Reed Switches • Two contacts enter the reed from opposite sides, meeting in the middle. • The reed works when opposites attract. • One contact must be North, one South • Where are the poles on your magnets? • Test your idea with a reed switch! • Which axis works the best?

Testing the magnet axis issue • When trains are coupledthe reed switch shouldbe in-line with the track • But, the first and last couplers usually pivot 90 degrees!(The reed cannot sense them!)

What is the best way? • I built a fixture to try all three axis’ • Adjustablepositioning • Lights ifthe switchis tripped • Here’s the best axisto sense train couplers

Building a Reed Switch sensor • All it takes to build a basic switch • LEGO 2x2 brickpower connector(cut a cable?) • a pair of wires • small reed switch(no polarity) • A housing to keepthe reed safe

Solder the reed switch • Don’t clip the leads of theswitch until you are done • Keep the cable leadsshort, and solder themclose to the reed body • Test the switch with a meter, or an RCX • If it works, THEN you can clip the leads

Build a safe enclosure • The switch will fit inbetween the studs • You need to trim 2studs for the wires! • I use a thin router bit in the Dremel, but I’ve also used an Xacto hobby knife too. • Test-fit the switch before you proceed!

Make the tiles to cover it… • Left: remove one edge of the tile, and part of the inside surface • Right: remove one edge, the center stud, part of the inside surface, and notch other edge

Uses for the Reed Switches • Robot cows -> • Level crossing • Train pacing(block control) • Use a few in parallel, if it works • Use a resistor plate to save inputs

Test-fit the tile covers • First try the tile that protects the cable and the reed. • Make adjustments as may be needed • Check the fit of the second tile • The reed it just a little taller than the space under the tiles, so you may need to grind the inside-edge of the tiles for a good fit • Seal with hot glue, or CA

Track Power Isolation • Useful for “Block Control” of tracks • Controlled by handor by Mindstorms! • Original train pacing project developed by Tony Pratkanis, using all-LEGO part for a BayLUG public display

How Block Isolation works • Start with a normal loop of track,powered by a speed controller. • Now, electrically isolate one sectionof track from the loop (the red track) • When the train motor gets here, itstops because there is no power. • Add a switch, so you can apply theloop power when you want it to go…

Step 1: Miniaturization! • I replaced the LEGO switchand track power connectorswith a pair of Reed Relays • I would drive them with anRCX, or a 9-volt battery box • The reed relay is a reed switchwith a wire coil wrapped aroundthe reed switch.

I built it onto a straight track • I used the micro-saw to make a gap • Hot glue to tack down the railhead • Set the relays backfrom the track, andkept the profile low,below the trains…

Step 2: Make it simple! • Short structure • Self contained • To isolate the block, just addpower. • Fail-Safe • No power? No isolation!

Step 3: Make it reliable! • I soldered to the outside ofthe railhead (away from theflanges of the rail wheels) • I made sure the railhead was smooth and flat, so trains would not derail • I used a reed switch sensor to detect the passing trains instead of optical…

Why is there only one cut? • I made one block power switch track.(The isolated section is to the right) • The other track simply has a micro-gap

But how big is a Block? • The white building hides the RCX • The red tiles indicate the block limits

Track Cleaning Tools • Even a Kleenex is a light abrasive… • You will eventually wear off the metalon the railhead if you clean your track • But track should be cleaned once in a while to preserve it’s service lifetime!

L-Gauge Track Cleaning Cars • Centerline was first, Aztec was second. • Aztec bought Centerline, retired both!

RCX Level Crossing Program • Basic flow iswaiting for apassing trainto get near the crossing • Start lights • Lower gate • Wait for train

Two of theprocess flows arepretty busy,moving thegates! • Two othersdo nothing!

Thank you for attending! • I’ve very glad that you came to BbtB • Thanks for attending my talk • You can reach me at ; zonker@baylug.org

Hacking with LEGO Bricks