TECHNIC BUILDER’S GUIDE - No Starch Press · THE UNOFFICIAL LEGO ® TECHNIC BUILDER’S GUIDE ... LEGO Technic builder, a guest blogger for the official LEGO Technic blog, and a

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THE UNOFFICIAL LEGO® TECHNIC BUILDER’S GUIDEPaweł “Sariel” Kmiec

INSPIRATIONAL MODELS, COMPREHENSIVE BUILDING ADVICE, AND BUILDING INSTRUCTIONS FOR OVER 40 MECHANISMS

WHAT WILL YOU BUILD?™

The LEGO® Technic system opens a new realm of building possibilities. Using motors, gears, pneumatics, pulleys, linkages, and more, you can design LEGO models that really move.

The Unofficial LEGO Technic Builder’s Guide is filled with building tips for creating strong yet elegant machines and mechanisms with the Technic system. Author Paweł “Sariel” Kmiec will teach you the foundations of LEGO Technic build-ing, from simple machines to advanced mechanics, even explaining how to create realistic to-scale models. Sariel, a world-renowned LEGO Technic expert, offers unique insight into mechanical principles like torque, power translation, and gear ratios, all using Technic bricks. You’ll learn how to:

Create sturdy connections that can withstand serious stress

Re-create specialized LEGO pieces like casings and u-joints, and build solutions like Schmidt and Oldham couplings, when no standard piece will do

Build custom differentials, suspensions, transmissions, and steering systems

Pick the right motor for the job—and transform its proper-ties to suit your needs

Combine studfull and studless building styles for a stun-ning look

Create remote-controlled vehicles, lighting systems, motorized compressors, and pneumatic engines

This beautifully illustrated, full-color book will inspire you with ideas for building amazing machines like tanks with suspended treads, supercars, cranes, bulldozers, and much more. Your Technic adventure starts now!

about the author

Paweł “Sariel” Kmiec (http://sariel.pl/ ) is a prolific blogger and Technic model builder. He is YouTube’s most popular LEGO Technic builder, a guest blogger for the official LEGO Technic blog, and a 2012 LEGO Ambassador.

326 Index

nOte Italicized page numbers refer to illustrations.

Numbers

2L axle, 322-speed transmissions

linear heavy-duty, 254, 262–264orbital, 255ratchet, 256, 267RC motor, 255, 264–265synchronized, 254

3L axle, 32, 333-speed linear transmission, 256, 268–2694×4 (four-by-four), 7, 474-bar linkage, 69–704L axle, 32, 334-speed transmissions, 257–258, 270–2714WD (four-wheel drive), 74.5 volt motors, 1635L axle, 325-speed linear transmission, 2585.5L axle with stop, 336L axle, 326L cylinder, 1077L axle, 328L axle, 32, 338-tooth gear, 49, 589 volt motors, 163–1709L axle, 3210L axle, 3210-speed synchronized transmission,

259, 271–27512L axle, 3212-tooth gear, 5014-tooth gear, 5016/24-tooth differential gear, 5316L axle, 3216-tooth gear, 50–5124-tooth gear, 52, 53, 5832L axle, 3236-tooth gear, 5340-tooth gear, 53, 1201969 Dodge Charger, 295

2838 motor, 164–1658041 set, 1518043 Motorized Excavator set, 258048 Buggy set, 258070 Super Car set, 24, 348262 Quad-Bike set, 258263 Snow Groomer set, 258265 Crane Truck set, 708275 set, 2428285 Crane Truck set, 258288 Crawler Crane set, 1548296 set, 2978421 Mobile Crane set, 258422 set, 2998436 Truck set, 308448 Super Street Sensation set, 248460 Pneumatic Crane Truck set, 718466 4×4 Off-Roader set, 248480 Space Shuttle set, 248485 Control Center II set, 3028850 Jeep set, 248855 Prop Plane set, 3038865 set, 1978880 set, 19743362 motor, 16547154 motor, 16653983 turbine, 31971427 motor, 165

A

AAA battery box, 174AA battery box, 174Ackermann steering geometry, 195–198actuators. See linear actuatorsadapter plugs, 186adders, 277–280aging of LEGO pieces, 159–160air deflectors, 296–297air pressure, 112aircraft, 302–305airtanks, 111

and automated pressure switch, 123non-LEGO, 112

all-wheel drive (AWD), 7

arches, 34arctangent (inverse tangent), 202arms of levers, 67automated pressure switch, 123–124autovalve, 120–122AWD (all-wheel drive), 7axle joiner, 252axle joint, hose connector with, 110axle pins, 11

in linear clutches, 83, 84with towball, 12

axles, 31–34categories of, 32convergence of, 199–202with differential lock, 81driven, 203driven and suspended, 209–224

pendular suspension with turntables, 210–213

portal axles (geared hubs), 213–217flexible, 23, 32, 34holes for, 10independent, 227–229independent steered, 226–227modified, 33pendular portal

heavy duty, 230–235with worm gear, 236–240

pendular steered, 225standard, 32with stops, 33structural reinforcement with, 31supporting, 140–144transferring drive with, 31

B

back iron, 49backlash, 5

with 8-tooth gear, 49avoiding, using pneumatics, 47between driving ring and gear, 253and delay in motion, 5from pendular axle with worm gear, 236

index

The Unofficial LEGO Technic Builder's Guide©2012, Paweł “Sariel” Kmieć

Index 327

ball joint, 38–39balloon tires, 317balls, 55batteries, 174–175battery boxes, 171, 174beams, 12–14

aligning bricks with, 13connecting to bricks, 27–28in eccentric mechanisms, 85height-to-width ratio for, 13orientation independent of, 13reinforcing parts using, 138, 141versatility of, 13

bevel gears, 48blueprints, 307–314

dimensions in, 309–314finding online, 307–308using photos instead of, 308

BMR-2 personnel carrier, 322body frames, 151–153Boeing CH-47 Chinook helicopter, 303bogies, 246–247booms, on cranes, 49, 69–71, 154brackets

for cylinders, 110–111for linear actuators, 184

bricks, 9–10aligning with beams, 13connecting to beams, 27–28height of, 9height-to-width ratio for, 13holes in, 10with lights, 91Technic vs. regular, 18with two plates, 19

Brown truss, 155–156buggies, 8, 25, 297builder showcase, 135bushes, 35–38

connecting modules using, 37half, 35–37with long pin, 37–38regular, 37

C

cab-over-engine trucks, 296–298cams, 124, 130Cardan joints. See universal joints

cars, 295–2961969 Dodge Charger, 2958070 Super Car set, 24, 348448 Super Street Sensation set, 24Dodge Viper, 296, 311Ford GT40, 23, 26Pagani Zonda, 296, 307

casings, reinforcingdifferential, 144–148, 203worm gear, 149–150

catapult, 83catch, transmission changeover, 80,

252–253center of gravity, 7center of turning radius, 199chains, 57–59changeover catch, 80, 252–253channel selector, 173chassis, 151–153Chebyshev linkage, 73chromed pieces, 320circular elements, 316–319clearance from ground, 7, 8, 205clutches, 83–84, 185colors, 319–320compressors, 113, 115–119. See also

autovalveconnector pieces, 321, 322constant ground clearance, 205continuous rotary motion, 89continuously variable transmissions (CVTs),

260, 276control module, 103convergence of axles, 199–202counterjib, 158–159coupling motors, 277–280couplings, 87–88cranes

8285 Crane Truck set, 258288 Crawler Crane set, 1548421 Mobile Crane set, 258460 Pneumatic Crane Truck set, 71body frame of, 153booms on, 49, 69–71, 154levers on, 71Liebherr LTM1200 mobile telescopic

crane, 310string and pulley systems on, 61–62tower cranes, 154, 158–159

crank mechanisms. See eccentric mechanisms

cruciform, defined, 38C-shaped frames, 144curb-to-curb turning radius, 6custom mechanical solutions. See

mechanical solutions, customcustom-chroming, 320CVTs (continuously variable transmissions),

260, 276cylinders, 103

6L cylinder, 107bracket for, 110–111large, 107in New LEGO pneumatic system, 104,

105, 108in Old LEGO pneumatic system, 103,

104, 107in pneumatic engines, 124–134

single-cylinder, 125–127two-cylinder, 128–134

small, 108

D

dead gears, 251dead spots, in pneumatic engines, 124delay in motion, and backlash, 5Demag H135 model, 324dependent suspension, 204details, 320–323differential casings, 144–148, 203differential gears, 53–54differential locks, 78–82differential mechanism, 44, 77–78differential pulley system, 63–65dimensions, in blueprints, 309–314distribution block, 103, 104, 106distribution transmissions, 260–276Dodge Charger, 295Dodge Tomahawk concept motorcycle, 300Dodge Viper, 296, 311double tackle, 64double-axle turntable transmission,

96–100double-beveled gears, 50, 51, 251–252double-wishbone independent suspension,

206–207drifting, tires for, 4


328 Index

drivetransferring to linear actuator, 184, 185transmitting through turntable, 96–100

driveline, 6driven and suspended axles, 209–224


portal axles (geared hubs), 213–217driven axles, 203driver gears, 44–45, 48driveshaft, 6drivetrain, 6driving rings, 252–254

e

E motor, Power Functions, 167eccentric mechanisms, 84–85efficiency, 5

of gears, 46of pneumatic engines, 130and size/weight of parts, 5

effort, of levers, 67European trucks, 296–298even and odd width, 30excavator, 25extendable driveshaft section, 6extension driving rings, 253, 254extension wires, 186–187

F

fantails, 303flashing lights, 91–92flexible axles, 23, 32, 34floating axle (trailing arm) suspension, 209,

222–224, 248–249flotation, 244FLU (fundamental LEGO unit), 9fluids, in pneumatic systems, 113flywheels, in pneumatic engines, 125follower gear, 44, 48Ford GT40, 23, 26form vs. function, 295–305

aircraft, 302–305cars, 295–296motorcycles, 299tracked vehicles, 299–301trucks, 296–299

four-by-four (4×4), 7, 47four-wheel drive (4WD), 7

frames, 151–153friction, 4friction pin, 11front loader, 70front-wheel drive (FWD), 7fulcrums

of levers, 67–69of suspension systems, 204

function. See form vs. functionfundamental LEGO unit (FLU), 9FWD (front-wheel drive), 7

G

gear ratios, 45–46, 58–59in transmissions, 251when using adders, 279

gearboxes, 143, 149geared hubs (portal axles), 213–217, 318gearing down, 43, 46, 48–49gearing up, 43, 46gears, 43–56

acceleration of, 46backlash of, 47controlling rotational direction, 47–48efficiency of, 46hard-coupling Power Functions

switches with, 92–93reduction of, 46reinforcing

differential casings, 144–148perpendicular gears, 142, 143by supporting axles, 140–144where to reinforce, 138–140worm gear casings, 149–150

transforming speed or torque with, 43in transmissions

dead, 251double-beveled gears, 251–252engaging of, 251–253reverse gear, 254

types of. See also worm gears8-tooth, 49, 5812-tooth, 5014-tooth, 5016-tooth, 5016-tooth with clutch, 50–5120-tooth, 5124-tooth, 52, 5824-tooth with clutch, 52

24-tooth with crown, 5536-tooth, 5340-tooth, 53differential, 53–54double-bevel 12-tooth, 50double-bevel 20-tooth, 51driver, 44–45follower, 44Hailfire Droid wheel, 55idler, 44–45, 59knob wheel, 55obsolete, 56planet, 278single-bevel 20-tooth, 51single-bevel 20-tooth with

pin hole, 51spider, 278turntables, 54–55

used with chains, 58wear of, 160

Geneva mechanisms, 89–90GIMP application, 310gravity

center of, 7and ratchets, 83

grease, 4grip, defined, 4ground clearance, 7, 8, 205gun tackle, 63gyn tackle, 64

H

Hagglunds BV 206 personnel carrier, 300Hailfire Droid wheel gear, 55half bush

smooth, with cutout, 37thickness of, 60toothed, 35–36toothed, with cutout, 36variants of, 35

half pins, 11, 12half studs, 14–15half-track truck, 301hard plastic tracks, 242–244hard-coupling motors, 277, 280height, of bricks and plates, 9height-to-width ratio, 13helicopters, 302–305high torque, joints for, 38


Index 329

hockey spring, 195Hoeken’s linkage, 73holes in bricks, 10hoses

connecting, 110non-LEGO, 112pneumatic, 108–109splitting, 110use of term, 109

hubs, 305Humvee, 26, 312hydraulic system, turning pneumatic

system into, 113

i

idler gears, 44–45, 59independent axle, 226–229independent suspension, 220–221

defined, 204double-wishbone, 206–207

input axle, 44interacting gears, 45intermittent rotary motion, 89inverse tangent (arctangent), 202inversely proportional, speed and

torque as, 44

J

Jeep Wrangler Rubicon, 297jib, 158–159joints, universal. See universal jointsjumper plates, 15

K

Kenworth Road Train model, 18knob wheels, 55, 203knobs

hard-coupling with, 280wear of, 160

L

L motor, Power Functions, 168large cylinder, 107LEDs, 91–92, 187–188LEGO pneumatic engine (LPE), 124–134Leopard 2A4 tank, 301, 323levers, 67–71

classes of, 68–69effort of, 67

fulcrums of, 67–69law of the lever, 67and linkages, 69–71load of, 67, 70mechanical advantage of, 72parallel, 70, 71remotes with, 179–180

Liebherr LTM1200 mobile telescopic crane, 310

Liebherr R944C, 243liftarms, 12lights

flashing, 91–92reverse, 90–91turn signals, 92–95

linear (sequential) transmissions, 252linear actuators, 183–186

flawed, 184–185large, 183–185vs. pneumatics, 185–186production code on, 184–185small, 185transferring drive to, 184, 185

linear clutches, 83–84linear motion, converting rotary motion to,

71–72linear speed, defined, 3linkages, 71–76

Chebyshev linkage, 73Hoeken’s linkage, 73and levers, 69–71pantograph, 73Peaucellier–Lipkin cell, 74rocking motion of, 71, 74Sarrus linkage, 74–75scissor linkage, 75–76Scott-Russell linkage, 75Watt’s linkage, 76

live axle. See floating axle suspensionload

of levers, 67, 70rotating under large loads, 55

load-bearing structures, 151–159rails, chassis, and body frames, 151–153trusses, 154–159

Brown truss, 155–156choosing, 157–159triangular Warren truss, 156–157Warren truss, 156

locking mechanisms, 82–83

long pins, 11, 12longitudinal subtractor, 282–287longnose trucks, 296–298LPE (LEGO pneumatic engine), 124–134L-shaped beams, 143luff tackle, 63

M

M (Medium) motor, Power Functions, 28, 168

Maltese cross mechanisms. See Geneva mechanisms

MAN TGS truck, 298manometer, 112maximum steering angle, 6mechanical advantage, 61–62

levers, 67, 72pulley systems

differential pulley system, 64–65power pulley system, 65–66simple pulley system, 62–63

mechanical power, defined, 3mechanical solutions, custom, 77–101

differential, 77–78differential locks, 78–82double-axle turntable transmission,

96–100eccentric mechanisms, 84–85flashing lights, 91–92Geneva mechanisms, 89–90linear clutches, 83–84Oldham couplings, 87–88ratchets, 82–83reverse lights, 90–91Schmidt couplings, 88Scotch yokes, 85–86stepper motors, 88–89turn signals, 92–95universal joint, 101

mechanics, vs. pneumatics, 47Medium (M) motor, Power Functions,

28, 168microleaks, 103Micromotor, 166–167Micromotor pulley, 59, 65mineral oil, 113misaligned pieces, 27MOCs (My Own Creations), 17Model Team approach, 26


330 Index

modeling process, 315–324circular elements, 316–319colors, 319–320details, 320–323odd angles, 321–322size considerations, 315–316wheels, 316–319

modified axles, 32, 33module, 9Monster Truck model, 17, 207motorcycles, 299, 300motorized compressors, 115–119motorized valves, 119–120motors, 163–170

2838, 164–16543362, 16547154, 16671427, 165complexity of, 316controlling

manually, 171–172remotely, 172–174

coupling with adders, 277–280Micromotor, 166–167NXT motor, 167Power Functions E motor, 167Power Functions L motor, 168Power Functions Medium (M) motor, 168Power Functions Servo motor, 169Power Functions XL motor, 169RC motor, 170stepper, 88–89

mudguards, 317My Own Creations (MOCs), 17

N

N•cm (Newton centimeters), 3new LEGO pieces, vs. old, 159–160Newton centimeters (N•cm), 3Newton’s law of action and reaction, 138nonlinear (regular) transmissions, 252nonrigid connections, 21number:number ratio, weight distribution, 7NXT motor, 167

o

obsolete gears, 56odd angles, 321–322old LEGO pieces vs. new, 159–160

Oldham couplings, 87–88old-type gears, 48one-way valve, 104output axle, 44overdrive, 46

P

Pagani Zonda, 296, 307Paint application, 310pantograph, 73parallel levers, 70, 71pawls, 82–83Peaucellier–Lipkin cell, 74pendular axles

portal, 230–235steered, 225with worm gear, 236–240

pendular suspension, 208–209stabilized, 211–214stabilized with portal axle, 214–217with turntables, 210–213

perpendicular gears, reinforcing, 142, 143personnel carriers

BMR-2, 322Hagglunds BV 206, 300RG-35 4×4 MRAP vehicle, 26, 214

Peterbilt truck, 298, 313photographs, using instead of

blueprints, 308pin holes, 10pins

axle, 11, 12, 83, 84friction, 11half, 11, 12long, 11, 12overview, 10–12specialized, 11–12three-quarter, 11, 14–15with towball, 12using to connect bricks and beams, 27

planar trusses, 154planes, 302planet gears, 278plates

disadvantage of using, 20height of, 9reinforcing parts using, 141

plugsadapter, 186stackable, 171

pneumatic devices, 115–136. See also pneumatic system

automated pressure switch, 123–124autovalve, 120–122builder showcase, 135motorized compressors, 115–119motorized valves, 119–120pneumatic engines, 124–134

overview, 124–125single-cylinder, 125–127two-cylinder, 128–134

water pressure pump, 135–136pneumatic system, 103–113. See also

pneumatic devicesavoiding backlash using, 47vs. linear actuators, 185–186microleaks in, 103modifying, 112–113

non-LEGO airtanks, 112non-LEGO hoses, 112pneumatic suspensions, 113removing springs to create motorized

compressors, 113turning pneumatic system into

hydraulic, 113New system, 104–105Old system, 103–104parts of, 105–112

6L cylinder, 107airtank, 111cylinder bracket, 110–111distribution block, 106hose connector with axle joint, 110large cylinder, 107, 108manometer, 112pneumatic pump, 103, 104, 105–106pneumatic tubes and hoses, 108–109small cylinder, 108T-piece, 109–110valve with studs, 106–107

PTO (power take-off), 110points. See fulcrumspoints of reference, 309portal axles (geared hubs), 213–217, 318power, 3Power Functions system, 171–188

extension wires, 186–187IR receiver, 28LED lights, 91–92, 187–188linear actuators, 183–186


Index 331

motors, 163–164controlling, 171–174E motor, 167L motor, 168Medium (M) motor, 168Servo motor, 169XL motor, 169

power supplies, 172–175receiver, 175–176remotes, 176–177

controlling, 172–174modifying, 177–182

switches, 28, 90, 92power pulley system, 65–66power supply, 173power take-off (PTO), 110powertrain, 6pressure generator, 103pressure switch, automated, 123–124production code, on linear actuators,

184–185propellers, 302, 303PTO (power take-off), 110pulleys, 59–61

vs. chains, 60in Micromotor, 167ratios between, 59–60rubber bands used with, 60slippage, 60string and pulley systems, 61–66


pumps, pneumatic, 105–106in motorized compressors, 115–116in New system, 104in Old system, 103

pushrods, 84

R

rack gear, 193rack-and-pinion gearset, 191racks, driving with worm gear, 49radius, turning, 6–7, 199rails, 151–153ratchets, 82–83RC motor, 170reach stacker, 7rear-wheel drive (RWD), 7

receivers, 172–176receiving mechanism, 6rechargeable battery, 175red pieces, strength of, 160regular (nonlinear) transmissions, 252regular LEGO bricks, 18reinforcement, 137–160. See also load-

bearing structureschoosing strongest pieces, 159–160defined, 19of differential casings, 144–148right way to reinforce, 140–144where to reinforce, 138–140why things fall apart, 137–140of worm gear casings, 149–150

remotes, 176–177with central steering wheel, 181–183modifying, 177–182multiple, using simultaneously, 174with sideways lever, 179with steering wheel, 178using many receivers with single

remote, 173resistance, and surfaces, 4–5return rollers, 245return-to-center steering, 194–195reverse gear, in transmissions, 254reverse lights, 90–91RG-35 4×4 MRAP vehicle, 26, 26, 214ride height, 8rigid connections

vs. nonrigid connection, 21between perpendicular beams, 22using single axle, 21

ripple, of motorized compressors, 115road wheels, 245, 249–250rocking compressor, 116–117, 118rocking motion

converting rotary motion to, 84–85converting to linear motion, 71of linkages, 71, 74

rolling resistance, 4–5rotary motion

continuous, converting into intermittent, 89

converting to linear motion, 71–72converting to rocking motion, 84–85

rotational direction of gears, controlling, 47–48

rotational speed, defined, 3

rotors, 303–305RPM (rotations per minute), 3rubber bands

used for self-centering steering, 195used with CVTs, 260used with pulleys, 60

rubber tracks, 241RWD (rear-wheel drive), 7

S

Sarrus linkage, 74–75scaling, 307–314

and blueprints, 307–309and points of reference, 309

Schmidt couplings, 88scissor linkage, 75–76Scotch yokes, 85–86Scott-Russell linkage, 75seams, weak, 138sequential (linear) transmissions, 252Servo motor, Power Functions, 169sets, Technic, 24–26shock absorbers, 209, 211

alternative to, 248–249flexible axles as, 34for road wheels in a track, 247Tatra-type suspension stabilized with,

217–220trailing arms suspension with, 247used with chains, 58

side gears (spider gears), 278sidecars, 299sideways lever, remotes with, 179–180Sikorsky MH-53 Pave Low helicopter,

303, 313single-bevel gears, 50, 51single-cylinder pneumatic engines, 125–127size considerations, 315–316size of parts, and efficiency, 5sliders, 130sliding worm gear, 120slippage

of 24-tooth gear with clutch, 52and differentials, 78, 80in pulley system, 60

small cylinder, 108smooth half bush, with cutout, 37snow groomer, 25soft axles. See flexible axles


332 Index

solid tracks. See hard plastic tracksspace trusses, 154specialized pins, 11–12speed

and mechanical advantage, 61–62traction, 3transforming using gears, 43

speed control remote, 176–177, 181–182spider gears (side gears), 278spindles, 191splitting hoses, 110sprocket wheels, 243, 244–245, 250sprung suspension systems, 205stabilized suspension

pendular, 211–217Tatra-type, 217–220

stackable plugs, 171standard axles, 32steering geometry, 195–198, 317steering lock, 6steering systems, wheeled, 178, 181,

191–202convergence of axles, 199–202return-to-center steering, 194–195steering geometry, 195–198, 317

stepper motors, 88–89stopping vehicles, 177string and pulley systems, 61–66


stringers. See railsstructural reinforcement. See reinforcementstud measurement, defined, 9studfull vs. studless building, 17–30

aligning studless pieces with studfull, 13combining styles, 23–30

matching widths, 28–30methods for connecting bricks and

beams, 27–28Technic sets, 24–26

overview, 17–18studfull, 18–20studless, 19, 20–23, 29, 144studless transverse subcontractor,

291–292studs

half studs, 14–15valve with, 106–107

subtractors, 280–292longitudinal subtractor, 282–287reasons for using, 281–282transverse subtractor, 288–292

surfacesand friction, 4and resistance, 4–5

suspension systems, 246–249. See also wheeled suspension systems

bogies, 246–247pneumatic, 113trailing arm suspensions, 247–249

SUVs, 7, 2968466 4×4 Off-Roader, 248850 Jeep, 24

switchesautomated pressure, 123–124Power Functions, 28, 90, 92, 172

synchronized transmissions, 251–252, 261

t

T-72M tank, 301, 320, 321tanks, 299–301

barrels of, 320, 321British Churchill, 245guns of, 323Leopard 2A4, 301, 323road wheels on, 245Sherman, 246Soviet, 245, 250suspension system, 244T-72M, 301, 320, 321turning radius of, 6using wedge belt wheels with tires, 250

Tatra-type suspension, 207–208, 217–220Tchebycheff ’s linkage, 73Technic sets, 24–26threaded axles, 33threefold purchase, 64three-quarter pins, 11, 14–15tie rods, 193–194, 196–197timers, in battery boxes, 174, 175tires. See also wheels

size of, 317traction, 4

toothed half bushes, 35–36top mast, 159torque. See also axles; chains; gears; pulleys

and coupling motors, 277–280

and extension driving ring, 253and knob wheels, 55and mechanical advantage, 61–62overview, 3summing with adders, 277–279

torque ratio, 45torsion bars, 248–249Tow Truck 2 model, 153, 316tower cranes, 154, 158–159T-pieces, 109–110tracked vehicles. See also chains; tanks

favoring form or function, 299–301hard plastic tracks, 242–244with road wheels, 249–250rubber tracks, 241speed control remote for, 181–182tracked wheel systems, 244–246using subtractors with, 280–281and weight distribution, 7

traction, 4trailing arm (floating axle) suspension, 209,

222–224, 248–249transmission changeover catch, 80,

252–253transmission driving rings, 51, 259transmissions, 251–276. See also gears

2-speedlinear heavy-duty, 254, 262–264orbital, 255ratchet, 256, 267RC motor, 255, 264–265synchronized, 254

3-speed, 256, 268–2694-speed, 257–258, 270–2715-speed, 25810-speed, 259, 271–275changeover catch, 252–253combining, 254continuously variable (CVTs), 260, 276distribution transmissions, 260–276double-axle turntable, 96–100driving rings, 252–254regular (nonlinear), 252sequential (linear), 252synchronized, 251–252, 261

transverse subtractor, 288–292tread hubs, 241triangular Warren truss, 156–157


Index 333

trucks, 296–2998436 Truck set, 30half-track, 301Kenworth Road Train model, 18MAN TGS, 298Monster Truck model, 17Peterbilt, 298, 313Tow Truck 2 model, 153, 316

trusses, 154–159Brown truss, 155–156choosing, 157–159triangular Warren truss, 156–157Warren truss, 156

tubes, pneumatic, 108–109turn signals, 92–95turning radius, 6–7, 199turntable transmission, 96–100turntables, 54–55two-cylinder pneumatic engines, 128–134

u

universal joints, 38–39, 101alternative to, 87and high torque, 38length of, 38making sturdy, 101

unsprung suspension systems, 205US trucks, 296–298

V

valvesmotorized, 119–120in New LEGO pneumatic system, 104with no studs, 107in Old LEGO pneumatic system, 103, 104with studs, 106–107

voltage, 3

W

wall-to-wall turning radius, 6Warren truss, 156water pressure pump, 135–136Watt’s linkage, 72, 76wear of LEGO pieces, 159–160

wedge belt wheel, 59at center of hub, 305in differential pulley system, 63in pneumatic engines, 124thickness of, 60use with tracked vehicles, 249–250

weight distribution, 7weight of parts, and efficiency, 5wheelbarrow, 69wheeled steering systems, 178, 181,

191–202Ackermann steering geometry, 195–198convergence of axles, 199–202return-to-center steering, 194–195

wheeled suspension systems, 203–240dependent suspension, defined, 204driven and suspended axles, 209–224


portal axles (geared hubs), 213–217driven axles, 203floating axle (trailing arm) suspension,

209, 222–224, 248–249ground clearance, 205independent suspension, 220–221

defined, 204double-wishbone, 206–207

pendular suspension, 208–209stabilized pendular suspension,

211–214stabilized pendular suspension with

portal axle, 214–217sprung/unsprung, 205Tatra-type suspension, 207–208,

217–220wheels

knob wheels, 55, 203and modeling process, 316–319road wheels, 245, 249–250sprocket wheels, 243, 244–245, 250wedge belt wheels, 59

at center of hub, 305in differential pulley system, 63in pneumatic engines, 124thickness of, 60use with tracked vehicles, 249–250

Windows Paint application, 310wings, 302worm gears, 48–49

backlash with, 47boom-extending mechanism with, 49as driver gear, 48driving racks with, 49gearing down with, 48, 49to lock mechanisms, 82pendular portal axle with, 236–240reinforcing casings of, 149–150sliding, 120in valve-switching mechanism, 120wear of, 160

Y

yellow pieces, strength of, 160yokes

defined, 38Scotch, 85–86

Z

zero, turning radius of, 6


Documents

TECHNIC BUILDER’S GUIDE - No Starch Press · THE UNOFFICIAL LEGO ® TECHNIC BUILDER’S GUIDE ... LEGO Technic builder, a guest blogger for the official LEGO Technic blog, and a