pitsco Tetrix Max User manual

39132 V0909

TETRIXTM by Pitsco
Creator’s Guide
Developed and written by PJ Graham, Paul Uttley, and Tony Allen.
Graphics by Todd McGeorge, Ben Gaddy, and Paul Uttley.
©2008-2009 Pitsco, Inc., P.O. Box 1708, Pittsburg, KS 66762
All rights reserved. This product and related documentation are protected by copyright and are distributed
under licenses restricting their use, copying, and distribution. No part of the product or related documenta-
tion may be reproduced in any form by any means without prior written authorization of Pitsco, Inc.
All other product names mentioned herein might be the trademarks of their respective owners.
On the Cover
Roaming over a simulation of frozen tundra with the aurora borealis lighting the sky, the robot on the cover
is built from one TETRIX Base Set, a DC motor controller, and an R/C unit. This robot features a double-decker
design so that some of the electronics and batteries are not exposed.
Ro-botica Global S.L.
C/ Hercegovina 22, Bajos
08006 Barcelona (Spain)
Tel: [phone]
[email protected]
http://ro-botica.com

Table of Contents
Materials Included ..............................................................................................4
Tools and Materials Not Included ...............................................................................4
Construction Tips ...............................................................................................5
Safety ...........................................................................................................5
A – Building a Basic Chassis with Indirect Drive .................................................................6
Chassis .....................................................................................................6
Motor Mounts and Drive Wheels ............................................................................6
Motors and Gears ...........................................................................................7
Back Wheels ................................................................................................8
Direct Drive Alternative .....................................................................................8
B – Servos and Pivots............................................................................................9
Single-Servo Mount.........................................................................................9
Single Servo with Pivot Attachment .........................................................................9
Double-Servo Mount and Pivot.............................................................................10
Pivot with Structural Elements..............................................................................11
C – Tubes .......................................................................................................13
Attaching Tubes ...........................................................................................13
D – Grippers ....................................................................................................14
One-Motor Gripper ........................................................................................14
Two-Motor Gripper ........................................................................................15
E – Advanced Construction Techniques ........................................................................17
F – Using the R/C ...............................................................................................18
G – Using the LEGO® NXT Intelligent Brick .....................................................................20
Connecting the NXT Components ..........................................................................20
Connecting the NXT to TETRIX Elements ....................................................................21
Additional Items Available for Purchase .......................................................................23

4 TETRIX by Pitsco 39132 V0909
• 2 single-servo motor brackets
• 8 at brackets
• 12 L brackets
• 2 servo joint pivot brackets with included hardware
• 1 dual-servo motor bracket
• 4 – 32 mm channels
• 2 – 96 mm channels
• 2 – 160 mm channels
• 4 – 288 mm channels
• 2 – 288 mm at bars
• 2 – 144 mm angles
• 2 – 288 mm angles
• 2 – 64 x 192 mm at building plates
• 2 – 80 mm tubes
• 2 – 145 mm tubes
• 2 – 220 mm tubes
• 6 tube reinforcers
• 6 tube clamps
• 6 set screw axle hubs*
• 2 motor hubs*
• 2 servos with horns
• 2 servo extensions
• 1 servo Y connector
• 2 DC drive motors
• 2 DC motor power cables
• 1 on/o switch
• 4 – 3" wheels
• 2 – 3" omniwheels
• 2 – 80-tooth gears
• 2 – 40-tooth gears
• 6 – 100 mm axles
• 2 motor mounts with included hardware
• 2 gear hub spacers with included hardware
• 12 bronze bushings
• 6 axle set collars
• 200 kep nuts
• 50 – 3/8" button head cap screws (BHCS)
• 100 – 1/2" socket head cap screws (SHCS)
• 100 – 5/16" socket head cap screws (SHCS)
• 12 – 1/8" axle spacers
• 6 – 3/8" axle spacers
• 12 – 1" stand-o posts
• 12 – 2" stand-o posts
• Hex key pack (7/64", 3/32", 1/16", and 5/64")
• 12 – 11" zip ties
• Blue storage bin with sorting tray
Tools and Materials Not Included
Note: The TETRIX system enables you to create your own robot design, and you can build a robot with just the base
set. However, additional parts and tools can be added. Many of the optional items below are available at www.shop.
pitsco.com or www.LEGOeducation.us.
Required
• Remote control (R/C) or LEGO® NXT Intelligent Brick with Hard-Point Connectors and various Technic beams*
• 8 AA batteries
• DC motor speed controller with 8-cell battery holder (34244)
• Extra small (#3) athead screwdriver
• Small Phillips screwdriver
Optional
• 416 mm channels (39069)
• 120-tooth gears (39085)
• Drill or drill press with bits for metal
• Hacksaw or band saw with metal-cutting blade
• Tubing cutters (34724)
• Multi nut pliers (39130)
• Hook-and-loop fastener (such as Velcro) (51974)
• Rubber bands
• Synthetic lubricant (20821)
*A robot can be operated with an R/C. Another option is the LEGO® NXT Intelligent Brick. The NXT is attached with
Hard-Point Connectors and Technic beams, which are sold separately.
Materials Included
For pictures of the TETRIXTM parts, see the top card in the TETRIX Base Set bin lid. Note: Additional pieces of all the
parts below can be purchased separately at www.shop.pitsco.com.
TETRIX Tip:
Visit the Blog
To learn tips and new ways
to use the TETRIX Robotic
Design System, visit the
TETRIX blog at http://
community.pitsco.com/
blogs/tetrix/default.aspx.
At this online community,
see posts from TETRIX
robotics experts.

TETRIX by Pitsco 39132 V0909 5
Construction Tips
Aligning to the holes – The patented hole pattern on the TETRIX structural pieces enables you to attach pieces
together at an angle, not just horizontally and vertically from each other. For example, you can attach a piece at 45°
(Figure A).
Tightening screws – The TETRIX hole pattern is on all sides of the
structural pieces – making it easy to tighten the screws with the hex
key by simply putting the wrench through the other side as shown at
right.
The screws in the TETRIX system are fastened with kep nuts, which
feature a toothed side. This toothed side should face toward the
screw so the teeth can grab onto the metal, which helps it hold
better.
Selecting screws – There are two sizes of socket head cap screws
(SHCS) in the base set: 1/2"and 5/16". As a rule, use the 1/2"screws
for joining two structural elements together. Use the shorter 5/16"
screws to attach tube clamps to structural pieces or when there isn’t
much clearance on the inside of parts.
The 3/8" button head cap screws (BHCS) are useful when the SHCSs might stick out too far from the body and rub
against a moving part, such as a gear. Use BHCSs to attach servos to servo brackets.
Tightening tube clamps – For maximum clamping grip, tighten the clamp screws in stages. First, snug the set screw
on the clamp – but not too tight. Then, attach the clamp to the structural element with four screws and tighten them
partway. Finish tightening the set screw, and then nish tightening the four other screws. This will keep the clamp in
the proper shape for attaching to structural elements while ensuring proper grip on axles and tubes.
Tightening the set screw axle hubs – When tightening these hubs, be sure to tighten the set screw – using the 3/32"
hex key – against the at side of the axle.
Safety
• To avoid possible injury, keep your ngers clear of
metal gears and other pinch points while they are
moving (Figure B).
• Never pick up the robot when it is moving.
• Be sure power is o when the robot is not in operation.
• Do not operate the robot in wet environments.
Figure A
Pinch point
Figure B

6 TETRIX by Pitsco 39132 V0909
A – Building a Basic Chassis with Indirect Drive
The chassis constructed in this section is a basic
rectangular chassis with four wheels and two drive
motors. This provides basic construction information.
You can use dierent channel pieces, have three
wheels instead of four, or otherwise change this
chassis to t your design.
Chassis
1) Set two 288 mm channel pieces side by side with
the open end of the U-shape facing down. Set
two more 288 mm channel pieces across the rst
two, but with the open end of the U facing in
toward each other (Figure A1).
2) Align the holes of the top channels to the holes of the bottom channels where
you’d like them to be (in the model pictured, the top channels are fastened at the
four large holes from each end to create a bumper). At each corner, drop
two SHCSs down through the two small holes on either side of the large hole
(Figure A2).
3) Thread the kep nuts on the end of the screws. Using the 7/64"hex wrench,
tighten the screws.
4) Repeat Steps 2-3 for the other three corners.
Motor Mounts and Drive Wheels
In this model, the motors are not directly driving
the wheels but instead are turning gears that will
connect with gears on the wheels. A direct-drive
setup is covered on page 8.
1) Set one motor mount along the top of one
bottom piece of channel. Determine where you
want the motor to rest – be sure to allow space
for the wheel and the gears. Note that the motor
mount holes align with the smaller holes on the
channel and that you can use any two parallel
holes in the circle (Figures A3 and A4).
2) Using the 1-1/2"screws that come with the
mount, bolt down the unclamping end. Bolt
the other side, but do not tighten it all the way
(Figure A5).
3) Place a gear hub spacer on the center hole of a
wheel and line up their holes. Thread a 1-1/4"
screw that comes with the hub through a small
hole on the other side of the wheel (Figure A6).
Figure A1
Figure A2
Figure A3 Figure A4
Figure A5 Figure A6

TETRIX by Pitsco 39132 V0909 7
4) Drop an 80-tooth gear over the screw end,
followed by a set screw axle hub (Figure A7).
Thread the screw through all four parts. Repeat
this with the other three screws.
5) Slide an axle about 1/4"in the hub and hold it
while tightening the screw using the 3/32"hex
key (Figure A8). Be sure tighten to it against the
at side of the axle. Do not overtighten.
6) Insert the bushings in the hole where you want
to place the axle – there will be one on each side
(Figure A9). Push the end of the axle into the axle
hole.
7) To lock the axle in place, put an axle set collar
over the end and push it against the bushing
(Figure A10). Turn the collar until the screw is
facing the at side of the axle. Use the 1/16"hex
wrench to secure it to the axle.
8) Repeat Steps 1-7 for the other side of the chassis.
Motors and Gears
1) Attach a 40-tooth gear to a motor hub using four 1/2" SHCSs (Figure A11). If you
think the screw heads might rub against other parts, you can use BHCSs instead.
2) Take a DC motor and place it through the back of the motor mount so the motor
shaft points toward the wheel.
3) Take the gear assembly and slide it on the motor shaft with the gear facing out.
Adjust the motor until its gearbox is centered in the motor mount. Slide the gear
assembly on the motor shaft until the 40-tooth gear is aligned with the 80-tooth
gear (Figure A12). Tighten the hub screw with a 3/32"hex wrench.
4) Turn the motor until the 40-tooth gear meshes with the 80-tooth gear (Figure
A12). Tighten the clamping end of the motor mount with the 7/64"hex wrench.
5) Repeat Steps 1-4 for the other side of the chassis.
Figure A7 Figure A8
Figure A11
Figure A9
Figure A12
Figure A10

8 TETRIX by Pitsco 39132 V0909
Back Wheels
1) Slide an axle into a set screw
axle hub until it is ush with the
at side of the hub. Tighten the
set screw using the 3/32"hex
key (Figure A13). Place the set
screw axle hub on the wheel
and align the holes so the set
screw faces the at side of the
axle. Use 1/2" SHCSs to fasten
the wheel to the set screw axle
hub.
2) Insert two bronze bushings in the hole where you want to place the axle – there will be one on each side. Push the
end of the axle into the axle hole. Lock the axle in place by placing an axle set collar over the end and pushing it
against the bushing (Figure A14). Turn the collar until the screw is facing the at side of the axle. Use the 1/16"hex
wrench to secure it to the axle.
3) Repeat Steps 1-2 for the other side.
Direct Drive Alternative
With direct drive, small wheels
need to be mounted under the
chassis. Be sure to plan for this when
constructing the chassis so the
channel pieces are oriented with the
open part or one of the two sides
facing up (the model shown uses
L brackets to construct such a
chassis).
1) Set a motor mount on one
bottom piece of channel.
Determine where you want the
motor to rest (Figure A15). Note
that the motor mount holes align
with the smaller holes on the
channel.
2) Using the 1-1/2"screws that
come with the mount, bolt down
the unclamping end. Bolt the
other side, but do not tighten it
all the way.
3) Slide a motor hub over a DC motor shaft; tighten the hub’s screw. Slide the motor into the motor mount with the
shaft and hub facing out. Adjust the motor until the gearbox is centered in the motor mount and the motor shaft
is at the bottom of the mount (Figure A16). Tighten the clamping end of the motor mount.
4) Attach the wheel to the hub with four 1/2" SHCSs (Figure A17). Flip over the chassis (Figure A18).
5) Repeat Steps 1-4 for the other side.
Figure A14
Figure A13
Figure A15
Figure A17
Figure A16
Figure A18

TETRIX by Pitsco 39132 V0909 9
B – Servos and Pivots
Servos can be used in many dierent ways – one is to create robot parts that pivot.
This section covers how to mount a basic servo and several ways to create a pivot.
However, you should explore other ways to create a pivot as needed for your design.
Note: All the servos come with a plastic servo horn on them. Remove these plastic
horns and replace them with the metal servo horns that come with the kit. The plastic
horns can be disposed of or used with robotics and electronics other than TETRIX.
Single-Servo Mount
1) Determine where on the chassis you want to
place the servo. Using 1/2" SHCSs and kep nuts,
attach the single-servo motor bracket to the
chassis – note that the side with one long piece
standing up is where the back of the servo faces
(Figure B1).
2) Slide the servo into the bracket. The anged
sides on the front of the servo should go on
the outside of the two prongs of the bracket
(Figure B2). Using 3/8" BHCSs and kep nuts,
attach the servo to the mount.
3) At this point, it is possible to attach other pieces
– such as channels, angles, and at bars – directly
to the servo horn (Figure B3). However, using a
pivot bracket will make a stronger pivot (see sec-
tion below).
Single Servo with Pivot Attachment
1) Remove the servo
horn. Place the
horn’s at side to
the inside of one
end of a joint pivot
bracket. Using
four 5/16" SHCSs,
attach the horn to
the pivot bracket
and secure it with
kep nuts (Figure
B4). The kep nuts
should be on the
outside of the bracket. Set aside the servo horn screw.
TETRIX Tip: Servos
When determining the
placement of servos for
pivots, always check the
servo’s range of motion.
The TETRIX servos can pivot
180°.
Figure B1 Figure B2
Figure B3
Figure B4
TETRIX Tip: Pivot Bearing
This diagram illustrates how to put a pivot
bearing into a pivot and servo bracket.

10 TETRIX by Pitsco 39132 V0909
2) Find the pivot bearing, screw, nut, and washer
that comes with the pivot bracket. Place the bear-
ing ange-side down on a at surface. Place the
side of the pivot bracket opposite the horn over
the bearing and align the bracket hole to it (Figure
B5a). Press down rmly to pop the bearing into
the bracket hole (Figure B5b).
3) Place the bearing screw through the bearing from
the outside of the pivot bracket. Insert the screw
into the back of the motor bracket (Figure B6).
Secure the pieces together with the washer and
nut – but do not overtighten.
4) Place the servo into the motor bracket,
stretching the unattached side of the pivot
bracket so the horn ts into the
servo’s motor shaft. Secure the
servo to the motor bracket with
3/8" BHCSs (Figure B7).
5) Adjust the servo’s range of mo-
tion as needed (see TETRIX Tip
on this page). Thread the servo
horn screw through the pivot
bracket and horn and secure to
the servo.
Double-Servo Mount
and Pivot
1) Determine where on the chas-
sis you want to place the servos.
Using 1/2" SHCSs and kep nuts,
attach the double-servo motor
bracket to the chassis
(Figure B8).
2) Remove servo horns from two
servos. Attach these to a joint
pivot bracket – each with two
5/16" SHCSs and kep nuts –
so one is on the inside of the
bracket and the other is on the
outside and opposite end
(Figure B9).
Figure B6 Figure B7
Figure B8 Figure B9
Figure B5a Figure B5b
TETRIX Tip: Range of Motion
To adjust a servo’s range of motion, you must rst nd its mechanical stop.
Push the bracket or structural element attached to the servo until it won’t
go any further – this is the mechanical stop. Without moving the servo mo-
tor shaft, detach the bracket or element and position it where you want it to
stop. Reattach it to the servo, taking care not to move the servo motor shaft.
Secure the bracket or element to the servo with the servo horn screw.

TETRIX by Pitsco 39132 V0909 11
3) Place one servo
into the double-
servo motor
bracket so it
faces into the
bracket (Figure
B10). Secure
the servo in the
bracket with
four 3/8" BHCSs
and kep nuts.
4) Place the pivot
bracket so the horn on the outside of the pivot bracket connects
with the servo on the motor bracket (Figure B11). Secure the
servo horn to the servo with the servo horn screw.
5) This is a good time to set the servos’ range of motion and to
center them together. Attach the two servos to the Y connector,
and then attach the connector to the remote control. Power up
the remote control and the servos’shafts will be centered to the
same position. Note: This step is very important when servos are
linked together mechanically – it ensures that they do not work
against each other.
6) Place the second servo so it faces out of the motor bracket and is parallel to the
other servo (Figure B12). Use four 3/8" BHCSs and kep nuts to secure the second
servo to the bracket.
7) Using the other servo horn screw, secure the second servo to the other side of the
bracket.
Pivot with Structural Elements
Strong pivots can be achieved using structural elements such as channels and axles. This section shows one way to
make such a pivot.
1) Determine where you need to place the pivot. This will be the
center of this pivot conguration. Count over three large holes to
one side of the center. With two 5/16" SHCSs, attach two stand-
o posts on top of the chassis so they are parallel to each other
(Figure B13). Whether you use 1"or 2" stand-o posts depends
on how tall you want the pivot to be.
2) Now, count three large holes to the other side of the center.
Attach two more stand-o posts of the same height as those in
Step 1. They should be in holes parallel to the rst pair of posts.
Figure B10 Figure B11
Figure B12
TETRIX Tip:
Y connector
The Y connector can be
used whenever you need
two servos to work in
tandem.
Figure B13
Center hole

12 TETRIX by Pitsco 39132 V0909
3) Mount a single-servo motor bracket on top of
one set of stand-o posts with two SHCSs – make
sure the bracket is attached so the servo faces the
center. Remove the horn from the servo. Place
the servo into the bracket so the servo shaft is
centered with the channel piece on which the
bracket is mounted. Secure the servo with four
SHCSs and kep nuts (Figure B14).
4) Using 1/2" SHCSs, attach a set screw axle hub to
the outside of a 32 mm channel piece (Figure
B15a), but do not tighten them all the way. Insert
an axle into the hub so it is ush with the outside
of the hub. Turn the axle so the set screw faces the
axle’s at side and tighten the set screw.
Note: Take care not to push down on this piece as
it is connected to the servo.
5) Attach any structural element – such as a tube
– to the top of the 32 mm channel piece at this
time. On the side opposite the set screw axle hub,
attach the servo horn to the outside of the 32 mm
channel piece with four 3/8" BHCSs and kep nuts
(Figure B15b). Attach the side with the horn to the
servo on the bracket and
secure with the servo
screw (Figure B16).
6) Find the second piece of
channel you want to use.
Another 32 mm piece is
good if you don’t want it
to extend over either side
of the chassis channel
(Figure B17). Alternative-
ly, a longer piece can be
used to reach the other
side of the chassis and
be another part of the
construction (Figure B18).
7) After nding the piece you want, place a bronze bushing into a
large hole where you intend to place the axle.
8) Push this side onto the axle. Before pushing it out the other
side, place an axle set collar on the axle. Then, push the piece
until the channel piece holes line up with the two stand-o
posts beneath it. Use two 5/16" SHCSs to attach the
channel to the posts. Push the set collar against the bushing
and tighten the screw (Figure B19).
Figure B19
Figure B18
Figure B15a
Figure B16
Figure B17
Figure B14
Figure B15b

TETRIX by Pitsco 39132 V0909 13
C – Tubes
Tubes can be used many ways. They make a strong
and lightweight lever arm. Tubes can be part of the
structural body of the robot; for example, connect-
ing two sides of a chassis. Or, they can be used as an
extension. You can attach them directly to a servo
horn or a gear to tube ends.
When more strength is needed for a tube and you
must tighten the tube clamp really tight, the tube
can become bent. To avoid this, insert a tube rein-
forcer into the end of the tube being clamped and
then tighten the clamp. The reinforcer will prevent
the tube from being bent.
Try attaching a sensor or a gripper or another end
eector on the end of a tube – run any wires inside
the tube to hide them and keep your robot design
looking clean.
Attaching Tubes
1) Insert a tube into a tube clamp (Figure C1). Insert
a 5/16" SHCS on the unthreaded side of the
clamp. Be sure not to overtighten this or you
might bend the tube end.
2) To attach a tube to a structural
element such as a channel, align
the element’s holes with the
clamp holes. Insert 5/16" SHCSs
from the underside of the ele-
ment and tighten (Figure C2).
3) To attach the tube to a servo,
align the clamp holes with the
servo horn holes and secure
them with 5/16" SHCSs (Figures
C3 and C4).
4) To attach the tube to a gear,
attach a tube clamp to the other
end of the tube and secure that
end to the gear with screws
(Figures C5 and C6).
TETRIX Tip: Gears and Ratios
By attaching one end of a tube to a servo and the other to
a gear, the gear will have the same rotation as the servo
(servos in the base set come with 180° rotation). But you
can mesh a dierent-size gear to the gear on the tube
to create a dierent rotation. For example, attaching an
80-tooth gear to the tube and meshing it with a 40-tooth
gear will provide a 2:1 ratio – and the 40-tooth gear will
have a 360° rotation.
Figure C1 Figure C2
Figure C3 Figure C4
Figure C5 Figure C6

14 TETRIX by Pitsco 39132 V0909
D – Grippers
One-Motor Gripper
1) Determine where you want your gripper to be placed. Also determine what kind of structural element you will use
to make the arm of the gripper (the model shown uses a tube).
2) Align one side of a at bracket to
the back of a single-servo motor
bracket. Hold those together
and attach whatever structural
element you are using – shown
here is a tubing clamp. Connect
these three together with four
1/2" SHCSs (Figure D1).
3) Making sure the servo shaft is in
line with the structural element,
place the servo in the motor
bracket and secure it with four
3/8" BHCSs and kep nuts
(Figure D2).
4) Using four screws and kep nuts,
attach an L bracket to the other
end of the at bracket (Figure
D3). One side of the L bracket
should extend from the top of
the at bracket. Now, attach
another at bracket straight out
from the top of the L bracket
(Figure D4).
5) Take two more at brackets and
connect them with screws to
make a 90° angle. Remove the
servo’s horn. Using four 5/16"
SHCSs and kep nuts, attach the
horn to one of the at brackets
so it will be the one on top after
attaching it to the servo
(Figure D5).
6) Check the servo’s range and adjust it if necessary. Attach the horn to the servo with the servo horn screw
(Figure D6).
Figure D1 Figure D2
Figure D3 Figure D4
Figure D5 Figure D6

TETRIX by Pitsco 39132 V0909 15
Two-Motor Gripper
This gripper was designed for two servos to be joined by a Y connector and to be run on the same channel. Because
this makes the two servos move in the same direction (both left or right, rather than toward or away from each other),
the pivot brackets that make up the gripper arms need to be oset and facing the opposite direction. Grippers with
servos running on dierent channels can be designed dierently.
1) Attach a servo horn – on the inside – to one side
of a pivot bracket with four screws and kep nuts
(Figure D7). Repeat this with a second servo horn
and pivot bracket.
2) Place a pivot bearing ange-side down on a at
surface. Place the side of the pivot bracket
opposite the horn over the bearing and align the
bracket hole to it. Press down rmly to pop the
bearing into the bracket hole. Set aside the pivot
bearings’screws, nuts, and washers until Step 5.
3) Connect two channel pieces (the model shown
uses 96 mm channels, but dierent sizes can be
used depending on how high you need the
gripper to be) side by side with at least four
SHCSs and kep nuts – two on each end
(Figure D8).
4) To each side of the connected channel pieces,
attach one single-servo motor bracket. The two
should be directly across from each other, but
one should be facing up and the other facing
down.
5) Thread the bearing screw through the bearing
from the outside of the pivot bracket. Insert the
screw into the back of one motor bracket (Figure
D9). Secure the pieces together with the washer
and nut and tighten the screw – but do not over-
tighten. Repeat this with the other motor bracket,
keeping in mind that the servos will face in op-
posite directions (Figure D10).
6) Connect the two servos with the Y connector.
Attach the Y connector to the remote control
system and power it up. This will synchronize the
centering of the two servos. Leave the remote
control powered up.
Figure D8
Figure D10
Figure D9
Figure D7

16 TETRIX by Pitsco 39132 V0909
7) Place the servos into the brack-
ets with the servo motor shafts
facing toward the servo horn on
the bracket. Secure each servo
to the motor bracket with 3/8"
BHCSs. With the servos still
connected to the powered R/C
system, attach the pivot brack-
ets to each servo where you
want them – you will have to
stretch the end with the horn
over the servo (Figure D11).
Power down the R/C and detach
the Y connector from it. Secure
the servo to the horn with the
servo screw.
8) To the end of each pivot bracket, attach a 32 mm
channel with the open side facing away from the
bracket (Figure D12).
9) On the top of each side of one 32 mm channel
piece, attach a at bracket at a 45° angle toward
the open side of the connected channel pieces
(gripper arm) (Figure D13). Repeat this on the
other 32 mm channel piece, but place the at
brackets on the underside of the 32 mm channel
ends – this will compensate for the dierence in
height. Be sure to angle the at brackets toward
the other side of the gripper.
Figure D11 Figure D12
Figure D13

TETRIX by Pitsco 39132 V0909 17
E – Advanced Construction Techniques
The TETRIX Robotic Design System is intended to be used as it comes – the structural elements come in a variety of
shapes and sizes to provide building exibility. However, advanced robot builders can go a step further and customize
the metal structural elements by cutting them to dierent lengths and angles and by drilling – or even bending.
Caution: Do not cut or drill any TETRIX parts without the consent of your teacher or project leader. If they intend to
use the system for several classes or teams, they may not want parts altered.
Cutting Metal Parts
All the aluminum structural pieces in the TETRIX Design System – such as channels, angles, or at bars – can be cut
using a hacksaw or band saw with a metal-cutting blade. If you do cut any metal pieces, you should smooth o any
burrs with sandpaper or a le.
Cutting Tubes
1) Using a marker or pen, make a line on the tube where you wish
to cut it.
2) Adjust the wheel of a tubing cutter so the tube can t into the
cutter. With the tube tted into the curved side, line up the mark
on the tube to the small wheel blade in the cutter (Figure E1).
Adjust the wheel so the cutter is snug – but not too tight – on the
tube.
3) Twist the cutter around the tube several times. Tighten the wheel
a little and twist the cutter several times. Continue to do this until
the tube is cut in two pieces (Figure E2). This could take ve to 10
times.
4) If needed, use sandpaper to smooth o any burrs where you cut
the tube.
Safety
If cutting or drilling metal parts, be sure to use proper safety gear –
such as safety goggles and gloves – for the machinery you are using.
Be sure to use any safety instructions or physical guards that come
with the tools you are using.
Figure E2
Figure E1

18 TETRIX by Pitsco 39132 V0909
F – Using the R/C
Several R/C units will work with
the TETRIX system. Shown in this
section is the Futaba T6EX (Pitsco
product 34243). The instructions
below are general, and you should
refer to your R/C’s instructions for
more information.
Note: The way you connect your
robot and R/C unit will vary
depending on the function and
design of your robot. Below is a basic
setup for a robot with two drive wheels
and a two-motor gripper run on one Y connector.
1) If needed, add structural plates on which to place
the electronics.
2) Determine where you want to place the
electronics. The R/C receiver and its battery pack
should be placed near each other; the DC motor
controller should be close to the receiver as well.
3) Using the Velcro-like fasteners, zip ties,
and screws that come with the electrical
components, attach them to the robot body
(Figure F1). The DC motor controller can be
attached with screws, but you might have to use
just two screws or angle the controller to align
to the holes on the body. Items attached in the
model include the receiver, receiver battery pack,
on/o switch, DC motor controller, and the DC
motor and controller battery pack (Figure F2).
4) Make sure the on/o switch is turned to the O
position. Insert the batteries into the battery
holder.
5) Connect the two folded metal ends of the DC
motor power cables to the posts of one DC
motor (Figure F3). Repeat with the other cables
and motor. Insert the free ends of the cables for
one motor to the DC motor controller where it
is labeled M1A and M1B (Figure F4). Tighten the
screws down onto the cables. Insert the other
motor’s cable ends into the controller where it is
labeled M2A and M2B and tighten the screws.
6) Insert the free end of the Y connector on the gripper servos to the receiver’s Channel 3.
TETRIX Tip: Wires
Wires from servos and
other electrical compo-
nents can get messy and
tangled. To keep things
cleaned up, you can secure
wires out of the way with
zip ties or rubber bands.
FigureF1
Figure F2
Figure F3 Figure F4

TETRIX by Pitsco 39132 V0909 19
7) Insert the free end of the on/o switch into the
controller where it is labeled B+ and tighten the
screw (Figure F5).
8) Insert the black wire from the battery holder into
the controller where it is labeled B- and tighten
the screw (Figure F6).
9) Plug the red wire from the battery holder into the
back of the on/o switch.
10) Locate the three-strand wires connected to the DC motor
controller. Plug in the free end of the wires labeled CH1 and CH2
into the receiver slots for Channels 1 and 2, respectively (Figure
F7). The wire labeled Flip is not used here and can be tucked out
of the way.
11) On the DC motor controller, ip the switches so 1, 2, and 3 are
ipped up (on) and 4, 5, and 6 are ipped down (o) (Figure F8).
12) If your robot needs anything else connected to the receiver,
connect it at this time.
13) Turn on the R/C hand set, and plug in the wire from the receiver
battery pack into the receiver (Figure F9) – an LED light should
come on. Turn the on/o switch to the On position. Now, you
can use the right steering control to move the robot forward,
backward, and side-to-side. The left steering control will open and
shut the grippers.
14) At this time, test the robot and make sure the gears and wheels
turn smoothly. If not, you can loosen the motor mount screw and
turn the motors until the gears mesh better. Retighten the screw
and test the robot again.
Also, if a motor is running
backward, you can correct this
either by switching the ends
of the DC motor power cables
on the motor terminals or by
switching the red and black
ends of the motor power cables
where they attach to the DC
motor controller (either M1A
and B or M2A and B).
Figure F7
Figure F8
Figure F9
Figure F5 Figure F6
TETRIX Tip: R/C
Programming
Some radio systems –
including the Futaba T6EX
– have programmable
features. Depending on
your robot design, these
options may need to be
programmed to achieve
desired motor operation,
such as motor reversing,
mixing, and so forth.

20 TETRIX by Pitsco 39132 V0909
G – Using the LEGO® NXT Intelligent Brick
To create an autonomous TETRIX robot, you can use the LEGO® NXT Intelligent Brick. The Hard-Point Connectors to
enable this are available at www.LEGOeducation.us. You will also need the HiTechnic Servo Controller, HiTechnic DC
Motor Controller, 10-cell battery pack, and enough Studless Technic Beams, Angle Beams, and Long Connector Pegs to
attach the NXT elements to a TETRIX robot design.
Figure G1
DC Motor
HiTechnic DC
Motor
Controller
HiTechnic
Servo
Controller
10-cell
battery
pack
NXT
Intelligent
Brick
Servo
On/o switch
Connecting the NXT Components
Figure G1 shows the connections described in this section. The red numbers correspond with the steps below.
1) Connect the NXT Intelligent Brick to the bottom connection on the HiTechnic DC Motor Controller.
2) From the top connection of the HiTechnic DC Motor Controller, connect it to the HiTechnic Servo Controller’s
bottom connection.
3) One or two DC motors can be connected to the HiTechnic DC Motor Controller where it is labeled Motor 1-, 1+,
2-, and 2+. The black wire from a motor goes into the negative position, and the red wire goes into the positive
position. After inserting each wire, tighten the screw on top of the control box to hold the wire in place. Loosen
the screw rst if you need to remove the wire.
1
2
54
3
6
78