Simulating Tread Systems in Creo Elements/Pro 5.0

Upon starting Creo, go to: File New Assembly.
File
New
Creo opening window
Assembly

In Assembly, turn off datum planes, coordinate systems, and 3D annotation
display by clicking on each of their icons in the upper right hand corner.
Datum Plane Icon “ON”
Initial Assembly window Modified Assembly window
3D Annotation Display
Icon “ON”
Coordinate Systems Icon
“ON”
Datum Plane Icon
“OFF”
3D Annotation Display
Icon “OFF”
Coordinate Systems Icon
“OFF”

Press the Assembly icon on the right-hand side. Then, right click on
2011_FTC_KOP Set Working Directory.
Working
Directory where
2011_FTC_KOP
components will
now be found
2011_FTC_KOP
Set Working Directory
Assembly Icon

Press the assembly icon and go to: Working Directory Tetrix_Kit_FTC. Then,
open the 416 mm channel (downloaded at beginning of power-point).
Working Directory
Channel-416mm.prt
Tetrix_Kit_FTC
Open 416 mm Channel

Set the 416 mm channel from the Automatic constraint type to the Default constraint type. The
Default constraint positions the part’s coordinate system and the assembly’s coordinate system so
that they are relative to one another.
Constraint Options
416 mm Channel on
Automatic Constraint
416 mm Channel on
Default Constraint
No other constraint
options – part is ready
to go!
Click on the green check
to move on

Press the assembly icon, and go to: Working Directory Tetrix_Kit_FTC
dc_motor_mount_2011.prt
dc_motor_mount_2011.prt
Open DC motor mount

Constrain the DC motor mount to the 416 mm channel using the Mate and Insert
constraints.
Using Mate constraint
Assembly: Surface of 416
mm Channel
Part: Bottom Surface of
DC motor mount
Using Insert constraint
Assembly: Small hole of 416
mm Channel
Part: Long Hole
DC motor mount

Bring out dc_motor_mount_2011.prt and constrain it to DC motor mount by using
the Pin connection set: 1. Axis Alignment, 2. Translation, 3. Rotation Axis.
Axis Alignment
Rotation Axis
Translation

Bring out tetrix_tt_idler_wheel_2011.prt and constrain it to DC motor by again
using the Pin connection set: 1. Axis Alignment, 2. Translation, 3. Rotation Axis.
Axis Alignment Translation
Rotation Axis

Bring out three axle_d-shaft_2011.prt and constrain each of them to different area of the channel
by again using the Pin connection set: 1. Axis Alignment, 2. Translation, 3. Rotation Axis.
Constraining first axle Constraining second axle
Constraining third axle

Bring out three idler wheels and constrain each of them to different areas of
the channel by using the Mate and Insert constraint types.
Constraining first idler wheel Constraining second idler wheel
Constraining third idler wheel

Change Applications from Standard mode to Mechanism mode. (Standard mode is for
creating assemblies; mechanism mode is for defining servo motors and belt tracks.)
Applications
Mechanism (servo, belt)
Standard Mode to Mechanism mode
Standard (assembly)

In Mechanism mode, select Servo Motors icon in order to open the window to define
servo motors for the sprocket and idler wheels.
Locating Servo Motors Icon and opening window
Servo Motors Icon
Servo Motors
definition window

Define the sprocket’s servo motor by selecting the connection axis (arrow) for the sprocket in
the Type box. Then, in the Profile box, change position to velocity and A to equal 360 degrees
per second.
Type Box
Defining the servo motor for the sprocket
Sprocket’s
Connection Axis
Profile Box

Define the servo motors for each idler wheel in the Servo Motor window.
Defining servo motor for first idler wheel Defining servo motor for second idler wheel
Defining servo motor for first idler wheel

Select the Belt icon in order to open the window for creating a belt track around the
sprocket and idler wheels.
Information for setting
up belt track
Locating Belt icon and opening window
Belt Icon

To create the belt track, select the outer rim of the sprocket and then the outer rim
of each of the idler wheels while holding down the ctrl key.
Starting belt track with sprocket and first idler wheel Adding second idler wheel to belt track
Adding third idler wheel to belt track

To make the belt track an assembly part, first right click on Belt1 in the Model Tree,
and then select Make Part.
Turning the belt track into an assembly part

The Component Create window will appear for you to name the part you are making for the belt
track. Then, the Creation Options window will appear for you to select a template for the belt
track. (You can use the default, start_part_mmks.prt, which is already shown.
Default template

In the form of the little spin center, the belt part will be in your grasp. Place the belt part down,
and select the Default constraint to automatically place it over the sprocket and idler wheels.
Constraining the belt part
Belt part represented by
spin center

Change Applications from Mechanism mode to Standard mode in order to get ready to
constrain tread links.
Mechanism mode to Standard mode

Bring out the tt_link_asm_2011.asm and select the Slot connection option, which
features the Point on Line constraint.
First Slot
connection
Initiating Tread Link constraints
Tread link

Under the Point on Line constraint, click on the “Select assembly item(s)” box. Then,
select each of the seven parts of the belt while holding down the Ctrl key.
“Select
assembly
item(s)”
box
Selecting Point on Line assembly items of the first Slot set

Under the Point on Line constraint, click on “Select component item(s)” box. Then,
select the mid-bottom vertex of the tread link as shown below.
“Select
component
item(s)”
box
Selecting Point on Line component item of the first Slot set
Mid-bottom
vertex

Select a second Slot connection option. Again, click on the “Select assembly item(s)” box under
the Point on Line constraint and select the seven parts of the belt while holding down the ctrl
key.
Second Slot
connection
Selecting Point on Line assembly items of the second Slot set

Again, under the Point on Line constraint, click on the “Select component item(s)” box
and select the upper-bottom vertex of the tread link
Selecting Point on Line component item of the second Slot set
Upper-bottom
vertex

Select the green check after completing the first and second Slot connections. Then,
switch from the Standard mode to Mechanism mode
Display in Mechanism mode

Define tread link’s servo motor by selecting the second connection axis (slot) for the
tread link in the Type box. Then, in the Profile box, change position to velocity and
A to equal 360 degrees per second.
Defining the servo motor for the tread link
Tread link’s
connection axis

Click on the Analysis Definition icon in order to open the window for defining how the
movement of the tread link is shown.
Starting the Analysis Definition process
Analysis
Definition Icon

Set up the graphical display for the Analysis Definition by changing the End Time to 1, Frame Rate
to 75, and Minimum Interval to 1/75 or .01333 …. (Also, experiment with different values.) Then,
click on Run to view movement and OK to save.

Select the Playback icon in order to replay the analysis ran before.
Opening the Playback window
Analysis
Definition Icon

Select Save in the Playbacks window and the analysis will be set to save as a .pbk
(mechanism playback) in the Tetrix_Kit_FTC folder.

Select Playback in the Playback window and the Animate window will appear. In the
Animate window, adjust factors including the speed and the animation’s direction.

In the Playback window, select Capture to open the Capture window. In the Capture
window, save the adjusted playback as a .mpg (video) and select OK.

Continue connecting and defining servo motors for the tread links. This may take a
while; however, be patient!!! … all of the hard work will pay off in the end. (Then,
work on the Playback when totally done.)
Tread System for the Bounty Hunters FTC Team