Aim My-Chron 2 User manual

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User Guide
My-Chron 2 Model MCT/K and MCV/K
Introduction
Congratulations on your purchase of a My-Chron 2 from AIM,
the world leader in motor sport electronics. The My-Chron 2
incorporates the most advanced electronic technologies
available. Full understanding of what this product offers begins
with reading this user’s guide.
The My-Chron 2 has extended battery life, which includes a
new auto-off feature. The auto off feature will power down the
My-Chron 2 after 5 minutes of no activity. The My-Chron 2 still
offers a non-volatile memory like the original My-Chron, no
information is lost at power down.
The My-Chron 2 is a small and powerful tool that gives the
driver information useful to evaluate driving performance and
the tuning of the kart. The My-Chron 2 will display RPM, 2
temperatures, wheel speed and lap time. It then records the
maximum values for every lap. The My-Chron 2 has a powerful
data logger built in that records RPM and wheel speed at a
configurable rate, which can be replayed in real time and
manually scrolled. This data can also be downloaded, via the
optional infrared download cable, and analyzed with the
powerful WDRACK software. It also records the time the
engine has operated, and the distance traveled, which is useful
for engine maintenance.
Getting Started
In order to get started using your new My-Chron 2 right away,
follow these simple steps and you’ll be done in less than 5
minutes.
Install the Battery
1. Remove the battery cover located on the junction box.
2. Install 1 alkaline 9V battery and replace cover.
The following instructions refer to the My-Chron keyboard
buttons, a copy of those buttons is below.
Power ON, by pressing the ON button
Configure for First Time Use
1. Press the MENU button 6 times, or until you see
full
Setup
2. Press the CONF button
3. Sampling The first item to configure is the sampling
frequency, this is the rate which the built in data logger
records the speed and RPM information. There are two
choices, x1 is 10Hz (10 times per second) and x2 is
5Hz. The recommended 10Hz will yield 17 minutes of
recording, 5Hz will yield 34 minutes. If these time limits
are exceeded, the My-Chron discards the oldest data
keeping the most recent. You can toggle between these
choices by pressing the CONF button.
4. After choosing the sampling frequency, press the MENU
button to advance to the next menu item.
5. Fahren or Centig The next item to configure is
the temperature unit of measurement. There are two
choices Fahrenheit and Centigrade. You can toggle
between these choices by pressing the CONF button.
6. After choosing the temperature unit, press MENU.
7. Mph or metric The next item to configure is the
speed unit of measurement. There are two choices,
MPH (miles per hour) or metric (kilometers per hour).
You can toggle between these choices by pressing the
CONF button.
8. After choosing the speed unit, press MENU
9. Rpmratio The next item to configure is the RPM
ratio. This is the number of spark pulses per revolution
of the motor. The choices are 1,2,3,4,5,6 and x2. Most
all kart motors have 1 pulse per revolution. You can
toggle between these choices by pressing the CONF
button.
10. After choosing the RPM ratio, press MENU.
11. Limrpm The next item to configure is the maximum
RPM limit. This is a very important parameter. Your
new My-Chron reads the number of signals coming from
the motor, but sometimes the motor sends several extra
signals that may disturb the RPM computation. In order
to avoid this, it is necessary to introduce the maximum
RPM number for your motor. A good number is the
absolute maximum RPM of the motor PLUS 10-15%.
Example, if your motor can turn 15,000 RPM you would
enter 16,500. For My-Chron versions 2.1-2.2 the value
to be entered is divided by 10, for example 12,000
would be entered as 1200, etc. To configure the value,
use the NEXT button to increase the number of the
flashing digit. Toggle to the next digit by pressing the
CONF button.
12. After configuring the RPM limit, press MENU.
13. Wheel The next item to configure is the wheel
circumference. If you have chosen MPH in the units of
speed configuration, this measurement needs to be
measured in inches. If you have chosen metric in the
units of speed configuration, this measurement needs to
be measured in millimeters. To configure the value, use
the NEXT button to increase the number of the flashing
digit. Toggle to the next digit by pressing the CONF
button.
14. After configuring the wheel size, press MENU.
15. Npulses The next item to configure is the number of
pulses per wheel revolution. Using the recommended 1
magnet per wheel for wheel speed, the number of
pulses per wheel revolution is 1. If you are using a
sensor other than the standard magnetic sensor, please
see the instructions that came with the sensor. To
CONF
>>
OFF
ON
VIEW
NEXT
MEM
MENU
<<

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configure the value, use the NEXT button to increase
the number of the flashing digit. Toggle to the next digit
by pressing the CONF button.
16. After configuring the number of pulses, press MENU.
17. LAP_MIN After the My-Chron receives a signal it can
not receive another signal for 008 seconds by default. If
you expect your lap time to be below 8 seconds, you
may lower this value under this parameter. Take
caution when increasing this value. Setting this value to
a number higher than your lap time will cause missed
laps.
18. Flash_1 through Flash_5The next item to
configure is the optional RPM warning LED’s. These
LED’s can be individually configured to come on at a
specified RPM. The most obvious use for this is an F1
style sweeping shift light. This value also is to be
entered is divided by 10, for example 12,000 would be
entered as 1200, etc. To configure the value, use the
NEXT button to increase the number of the flashing
digit. Toggle to the next digit by pressing the CONF
button. Press the MENU button and repeat for each
desired LED.
19. After configuring the RPM Flash, press MENU.
20. Temp_1 and temp_2The last item to configure is
the temperature warning LED’s. These LED’s, one for
each temperature input, can be configured as an alarm.
If the temperature reaches the alarm value you have
configured, the LED will light and continue to blink until
the value goes below that value. To configure these
values, use the NEXT button to increase the number of
the flashing digit. Toggle to the next digit by pressing
the CONF button. Press the MENU button and repeat
for temperature 2.
21. Press the ON/VIEW button to exit the setup and return
to the ready mode. You’re done with the configuration!
Main Menu
In the previous section you did the Full Setup, this section
explains the other menu items and their function. You can
switch from one menu item to the next by pressing the MENU
button.
Light – If you’re My-Chron is equipped with a back light,
pressing the CONF button will turn on/off the light. When the
motor is running, you can turn the light on by pressing the
MENU button only.
TRANSMIT – If you have purchased the optional PC
Loader (infrared download cable), this is how you send data
to the PC. Press the MEM button, and at the prompt, press
the MEM button again to confirm. More detailed instructions
are available with the PC Loader.
TOTAL RUN – The My-Chron keeps a separate timer
for the total time on the motor and total distance traveled,
these numbers are displayed here. The total time
accumulates time a RPM signal is present. The total distance
is accumulated by the wheel travel. Press the MEM button to
display the totals. To clear totals, press MENU, CONF or
MEM, then, at the prompt press MEM to confirm.
CLEAR TESTDATA – This option is to clear the
memory of all test data. This does NOT affect the Total Run.
Press the MEM or CONF button and then press the MEM
button at the prompt.
DAILY SETUP – This is a small menu of items found
in the Full Setup. This is a quick way to change values that
change frequently, such as wheel circumference. Navigate
the menu options just as you did the Full Setup.
MODE – The My-Chron 2 can also be used as the display
for DRACK, a professional data acquisition from AIM. It is
necessary to change the cable on the display and choose
Dash from the mode menu. More detailed instructions are
available with the cable option.
Run Time Operation
When the My-Chron is powered on, it is ready to display and
acquire data. The default display will look like the following:
Fig 2
When you pass the track side beacon, you will see the
following display for approximately 7 seconds:
Fig 3
Where the BE will appear when it is the best lap of the
session up to that lap. T## is the test number and L## is the
lap number. In this example, the 0:32.58 is the lap time.
It is also possible to change between the two views at any
time by pressing the VIEW button.
Tip: Pressing a button for more than one second
will auto-repeat. Pressing VIEW at any time will
return the My-Chron to the ready mode.
TEMP1 TEMP2
Speed RPM/10
°F
MPH
BE 0:32.58
T01 Lo4
°F
MPH

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Data Recall and Analysis
When a test session has concluded, you are ready for data
recall and analysis.
To enter the data review mode, press MEM, which also marks
the test as being ended. The display will first show the best
lap in the session, as in Figure 3. Again, the best lap
indicated by the be to the left of the lap time.
Press the direction keys to move forward or backward through
the lap times. Forward is indicated by >>, backward is
indicated by <<.
To view the maximum channel values for the lap currently on
the display, press the MEM button. You will see the
maximum values for each channel; temp 1, temp 2, speed
and RPM, as in Figure 2.
To view the data logger memory from the display, while
viewing the maximum value screen, press the MEM button.
Immediately you will see the selected lap played back in real
time on the display. The values you will see are speed, RPM
and distance from the beacon. If wheel speed is not present
during the test, as in the MCT/K model, the playback will
display RPM and time. The playback screen is pictured
below.
At the end of the playback, it is possible to scroll through the
recorded data for that lap manually by pressing the direction
keys, forward >> and backward <<.
Installation
You new My-Chron 2 is composed of:
•Display, to be mounted to the steering wheel.
•Junction Box/Data Logger, to be mounted under the
front fairing.
•Infrared Receiver, to be pointed to the beacon set track
side.
•RPM Pickup, an inductive sensor, to be attached directly
to the spark plug wire.
•Temperature Sensor(s), k-type thermocouple to monitor
specific temperatures.
•Wheel Speed Sensor/Magnet, to be mounted to sense
1 wheel speed, typically the front wheel. Standard on
MCV model, optional on MCT model.
•Beacon, or infrared transmitter, to be placed track side to
mark laps.
Display, the display is designed to be mounted directly to the
steering wheel. The notch on the bottom of the display is
designed to slide under the top bolt of the steering wheel
mount. The top of the display has a narrow piece with 2
notches on the side, which you attach to the forward spoke of
the steering wheel with a tie wrap. See photo.
Junction Box/Data Logger, the junction box is designed to
be mounted under the front fairing. We recommend mounting
the box with dual lock Velcro®, not included. The junction
box is where all the input channels connect. See photo.
Infrared Receiver, the receiver must be pointed to the side of
the track where the beacon is placed. The receiver must
have a clear line of sight to the beacon, it will not work
through opaque materials. Race traffic will virtually NEVER
cause a missed lap, the beacon has an extremely powerful
signal which will reflect off anything in its path. The small lens
at the end of the receiver is where the signal is received. The
My-Chron 2 has an approximate 7 second blanking, where it
cannot receive a second signal. We also recommend
mounting the receiver with Velcro, not included, which will
allow you to change for left or right side receiving. See photo.
RPM Pickup, the RPM wire should be routed along the
chassis back to the motor area, secured to the chassis in a
few points with electrical tape or tie wraps (when using tie
wraps, be careful not to cut the wire by over tightening).
CONF
>>
Distance
Speed RPM/10
°F
MPH

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Attach the clip at the end of the RPM wire directly to any part
of the spark plug wire. See photo.
RPM Pick-Up
Temperature Sensor(s), the My-Chron 2 will accept two
temperature inputs and comes with your choice of 1 standard
thermocouple to measure: exhaust gas temperature, cylinder
head temperature or water temperature.
•The exhaust gas thermocouple, or EGT, is designed to
measure the temperature of the exhaust gas. The tip of
the probe is where the measurement is taken, we
recommend 25-50 percent insertion into the exhaust gas
flow. Mounting the probe as close to exhaust port as
possible, check with your motor builder for his
recommendations. The probe is made of a semi-soft
material, which will allow you to bend the probe up to 90°
by hand. This allows you to cleanly route the wire and
helps avoid any accidental breakage from the probe
sticking up. The range of this sensor is 0-1832° F. See
photos.
•The cylinder head thermocouple, or CHT, is designed to
measure the surface temperature of the head. This
washer like thermocouple is intended to replace the
washer of the spark plug. It is possible to use the spark
plug washer in addition to the thermocouple, but this will
increase the cc’s in the combustion chamber slightly.
See photo.
•The water temperature thermocouple has many
installation options. You can tap the head, or if the head
has an elbow for the return line, you can tap the elbow.
AIM offers an optional return line fitting designed for this
specifically for this purpose. This thermocouple can be
also used for oil temperature. The tap size for this probe
is 5.0mm x 0.8 pitch. See photo.
Shown with optional fitting.
Wheel Speed, there are two parts required for wheel speed
sensing. The actual sensor and the magnet attached to the
wheel. We recommend mounting to either front wheel. To
attach the magnet, first clean the inside of the wheel to be
used to ensure that it is free of oil and dirt. Remove the
adhesive back from the Velcro to which the magnet is
attached. Place the magnet near the outer edge of the wheel
and press firmly to ensure good adhesion. The next step is to
attach the wheel speed sensor to the front spindle. The small
bubble at the tip of the sensor opposite the cable side is the
sensing element. This sensing element needs to line up with
the magnet and not be further than 2-5mm from the magnet.
When routing the wheel speed cable, make sure to allow
some slack for the wheel to turn. See photo.
Beacon, the beacon or infrared transmitter is to be placed
near the edge of the track. The height of the beacon should
be near the height of the receiver, a camera tripod works well,
but is not included. The effective range of the beacon is 5-20
meters in the worst conditions. Because the beacon is so
powerful, we recommend placing the beacon on the inside of

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the track, so the signal may not cross the track a second time
(given ideal conditions, the beacon will work well beyond 20
meters). The beacon sends an infrared array of
approximately 17° or a 3:1 field of display. This is to say that
at 3 meters the size of the array is approximately 1 meter.
The beacon can be powered by either 8 AA alkaline batteries
internal, which provide 20-30 hours of use, or from an
external 12V-power supply with the included cable. To install
the internal batteries, remove the 4 screws from the cover of
the beacon, there you will find an 8-battery plastic retainer.
Install the 8 batteries matching the positive and negative
guidelines on the plastic retainer. Using the external power
supply cable will bypass the internal batteries.
Warranty
Understanding that your new My-Chron 2 will be used in
competition, it comes with a full 1-year warranty. The
warranty includes parts, labor and return shipping. Return
shipping will be of the same service it was received, for
example, if it is sent next day air, it will be returned next day
air. We understand you race and need your new My-Chron,
please allow a minimum 1-day to perform the repair. The
warranty covers problems associated to electronic component
failure and product workmanship. The warranty does not
cover problems caused by physical damage, abuse or
misuse.
My-Chron 2 Options
Expand the functionality and power of your new My-Chron 2
with these available options:
Exhaust Gas Temperature Cylinder Head Temperature
Water Temperature Water Temperature Fitting
Infrared Tire Temperature Gearbox Temperature
Blue Back Light Wheel Speed Sensor
PC Loader Cable Colored Display Boxes
My-Chron 2 Contact Information
Notes:
IMPORTANT:
The My-Chron
beacon is a common frequency. Only
one beacon is required per track,
regardless of the number of karts.
Additional beacons will produce split
times.
Manufacturer
Aim s.r.l.
Via Cavalcanti 8, 20063 – Cernusco s/n -MI- ITALY
Tel. [phone]
Fax. [phone]
E-mail [email protected]
North American Distributor and Service Center
AIM Sportsystems
508-C N. Spring Street, Lake Elsinore, CA 92530
Toll Free 1.800.718.9090 (US and Canada)
Phone [phone]
Fax [phone]
E-mail [email protected]
Web www.aimsports.com