Smart Avionics PB-4 User manual

PB-4 Propeller & Rotor Balancer
Hardware Manual
Smart Avionics Ltd.
16/04/2019www.smartavionics.comRevision: 1.6

PB-4 Propeller & Rotor Balancer: Hardware Manual
Revision: 1.6
Publication date 16/04/2019
Copyright © 2003-2019 Smart Avionics Ltd.
Android is a trademark of Google Inc.
iOS is a trademark of Apple Inc.
Dropbox is a trademark of Dropbox inc.
Gyroplane photographs courtesy of Mike Goodrich and Jerôme Prompsy.

Table of Contents
1. Introduction ................................................................................................... 1
1.1. Balancing system overview ............................................................... 1
1.1.1. Wi-Fi network components ..................................................... 1
1.2. Accessing the PB-4 user interface .................................................... 3
1.2.1. Accessing the PB-4 user interface (AP mode) ...................... 3
1.2.2. Accessing the PB-4 user interface (STA mode) .................... 3
1.3. Batteries ............................................................................................. 4
1.4. PB-4 panel .......................................................................................... 5
1.5. Environmental limits .......................................................................... 7
1.6. Operator warning ............................................................................... 7
2. Preparing for Propeller Balancing ................................................................ 9
2.1. Additional items required .................................................................. 9
2.2. Positioning the aircraft ...................................................................... 9
2.3. Mounting the accelerometer ........................................................... 10
2.4. Mounting the tacho sensor ............................................................. 12
2.5. Attaching the reflective tape ........................................................... 14
2.6. Attaching the cables ........................................................................ 15
2.7. Positioning the PB-4 ........................................................................ 16
3. Preparing for Rotor Balancing ................................................................... 17
3.1. Mounting the sensors ...................................................................... 17
3.2. Positioning the PB-4 ........................................................................ 21
3.3. Offline capture button ..................................................................... 22
4. The PB-4 User Interface ............................................................................. 23
4.1. Getting started with the browser based user interface ................. 23
5. Upgrading the PB-4's Firmware ................................................................. 25
5.1. Upgrading the UI firmware .............................................................. 25
5.2. Upgrading the CPU firmware .......................................................... 25
5.3. Upgrading the Wi-Fi firmware ......................................................... 26
A. Battery Charging & Replacement .............................................................. 27
A.1. Replacing the RTC battery .............................................................. 27
B. Specifications ............................................................................................. 29
B.1. Main unit .......................................................................................... 29
B.2. Accelerometer ................................................................................. 29
B.3. Tachometer ...................................................................................... 29
C. EMC Compliance & Safety Information .................................................... 31
D. CE Declaration of Conformity .................................................................... 33
Index ................................................................................................................ 35
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List of Figures
1.1. Wi-Fi roles when PB-4 is in AP mode ....................................................... 2
1.2. Wi-Fi roles when PB-4 is in STA mode ..................................................... 2
1.3. PB-4 panel .................................................................................................. 5
2.1. Accelerometer axes and orientation ...................................................... 10
2.2. Accelerometer mounted on a Rotax 912 gearbox ................................ 11
2.3. Tacho sensor with flexible mounting plate ............................................ 12
2.4. Tacho sensor mounted on cowling ........................................................ 13
2.5. Tacho sensor angle of incidence ........................................................... 14
2.6. Cable taping ............................................................................................. 15
3.1. Standard sensor orientation (top view) ................................................. 18
3.2. Sensors mounted on an ELA rotor head (top view) .............................. 19
3.3. Sensors mounted on an ELA rotor head (side view) ............................. 20
3.4. Sensors mounted on an ELA rotor head (bottom view) ........................ 20
3.5. Sensors mounted on a Magni prerotator drive ...................................... 21
4.1. Initial screen ............................................................................................ 23
A.1. Locating the PB-4 board securing screws ............................................. 28
A.2. Correct orientation of RTC battery ......................................................... 28
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Chapter 1. Introduction
This manual describes the hardware of the Smart Avionics PB-4 product and
how to prepare for balancing a propeller or rotor using the PB-4. The balancing
procedures and the features of the PB-4 software are covered in the user
interface manual (pb4_ui_manual.pdf).
1.1. Balancing system overview
The PB-4 balancing system has these main components:
This is mounted near the hub of the propeller/rotor to
detect the vibration due to imbalance.
Accelerometer
A strip of reflective tape is attached to one propeller/rotor
blade and an optical sensor detects the tape as it passes
Optical
tachometer
and generates the tachometer signal required by the
balancer.
This processes the vibration signal and sends the resulting
data over a Wi-Fi network to be displayed on the user
interface (UI) device.
Digital processor
(CPU)
This provides the means whereby the user can view the
results and interact with the PB-4 using a standard web
User interface
device
browser. The PB-4 may also be used with the Propeller
Balancer Android app.
The PB-4 uses Wi-Fi to communicate with the user interface device which can
be any computer that supports a modern browser and Wi-Fi. Obviously, the
most suitable devices for use in aircraft are lightweight tablets. A 7" format
tablet is a good choice for use while balancing as it is not too bulky but still
has reasonable screen resolution. Later, you can look at the results on a device
with a bigger screen, e.g. a laptop computer. The following text simply calls
the user interface device a tablet.
1.1.1. Wi-Fi network components
The PB-4 uses a Wi-Fi network to communicate. Most commonly, a Wi-Fi
network consists of an access point and one or more stations . The network
traffic to and from the stations is routed through the access point. The PB-4
can operate as either a Wi-Fi station or as a Wi-Fi access point depending on
where you are located at the time.
1.1.1.1. PB-4 is the Access Point
When you are at the airfield doing the balancing, you would not normally have
an access point available. Fortunately, the PB-4 can be the access point (as
well as being a balancer). By starting the PB-4 in AP mode, it will be an access
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point and the tablet will be able to communicate with it directly as shown
below. Note that unless the tablet has some other means of accessing the
internet, it will only be able to talk to the PB-4 in this configuration.
SSID: PB4- XX
PB-4
AP MODE
TABLET
WEB BROWSER
HOST ADDRESS
ALWAYS 172.21.21.1
PB-4 & UI device
communicate via
PB-4's built in AP
Fig 1.1. Wi-Fi roles when PB-4 is in AP mode
1.1.1.2. PB-4 is a station
When you are back indoors, your tablet will most likely be already configured
to use an existing access point at that location. The PB-4 can be started as a
station (STA mode) and it will then use the same access point as the tablet
so they will be able to communicate. In this configuration, your tablet will be
able to access the network (internet, printers, etc.) as normal.
ACCESS
POINT
SSID: YOUR WIFI NAME
PB-4
STA MODE
TABLET
WEB BROWSER
HOST ADDRESS ASSIGNED
BY ACCESS POINT
PB-4 & UI device
communicate
via separate AP
Fig 1.2. Wi-Fi roles when PB-4 is in STA mode
For the PB-4 to be able to talk to the access point, it needs to know the access
point's SSID (Wi-Fi network name) and password. The PB-4 supports Wi-Fi
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Wi-Fi network components

Protected Setup (WPS) which makes setting up the access point credentials
easy. The SSID and password may also be entered into the PB-4 manually if
required.
Note
One way of remembering which mode you need to use is that when
you are "at the AirPort" use AP mode and when you "STAy at home",
use STA mode!
1.2. Accessing the PB-4 user interface
Safari users please note that the PB-4 is not compatible with Safari's “Private
Mode”.
Accessing the PB-4 user interface from your tablet's browser requires the
PB-4 and the tablet to be using the same Wi-Fi network.
1.2.1. Accessing the PB-4 user interface (AP mode)
When the PB-4 is in AP mode, the Wi-Fi network name (SSID) will be PB4-XX
where XX are two letters/digits. You will need to tell your tablet to use that
Wi-Fi network (via its Wi-Fi configuration). At the airfield, the tablet will probably
use the PB-4 Wi-Fi automatically because your normal Wi-Fi is not available.
If not, you will have to tell the tablet to use the PB-4 Wi-Fi manually.
Once the tablet is using the PB-4 network, you can load the user interface
page into the browser. If your tablet supports MDNS, you can simply use
pb4.local as the host name in the browser. Apple devices (mac/ipad/iphone)
and most Linux systems have MDNS, most Windows systems do not. If not,
use the IP address 172.21.21.1. Having accessed the PB-4 user interface
page, just add a bookmark for that page in your browser called something like
"PB-4 AP Mode (at the airfield)".
1.2.2. Accessing the PB-4 user interface (STA mode)
When the PB-4 is in STA mode, the Wi-Fi network name (SSID) will be whatever
you normally use at the current location. The PB-4 will need to be taught that
SSID and the associated password. The PB-4 supports WPS for automatically
obtaining the SSID and password from the access point which is quick and
easy if the access point also supports this feature. Alternatively, you can
manually enter the credentials by starting the PB-4 in AP mode, loading the
user interface into your browser (as described above), connecting to the PB-4
(click on red button) and then going to Menu / Options / PB-4 Configuration
/ Set Access Point Details.
Once the PB-4 is able to connect to the local network, you can load the user
interface page into the tablet's browser. Again, if MDNS is supported by the
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Accessing the PB-4 user interface

tablet, the host name pb4.local can be used. Otherwise, you need to find out
the IP address that has been assigned to the PB-4 by the access point. Follow
these steps:
1. Turn on the PB-4 in STA mode (press the on/off switch until LED 2 goes
green). When you release the switch, LED 2 will go off and then after a few
seconds will flash green slowly if the PB-4 has successfully managed to
log into the access point.
2. Turn the PB-4 off (press switch until the LEDs go out).
3. Turn the PB-4 on again but this time start it in AP mode (press on/off only
until LED 1 comes on).
4. Access the PB-4 user interface page with your browser as described in the
previous section, connect to the PB-4 (click on red button) and then go to
Menu / About. The about box will contain a line that says STA Mode IP
Address: XX.XX.XX.XX. The address that is shown is the IP address that
has been assigned to the PB-4 by the access point, note it down.
Having found out the PB-4's IP address when in STA mode, you can use that
address to access the user interface page and then add a bookmark for that
page in your browser called something like "PB-4 STA Mode (at home)".
1.3. Batteries
The PB-4 is powered by 4 x 1.2V AA NiMH rechargeable batteries. The batteries
are easily accessible via a hatch in the bottom of the PB-4 case. The PB-4
itself cannot charge the batteries, they have to be removed and charged in an
external charger. It is also possible to use non-rechargeable 1.5V AA batteries
in the PB-4.
The PB-4 also contains a CR2032 3V coin cell which provides backup power.
This battery will require replacing every now and then.
See Appendix A for more information on battery charging and replacement.
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Batteries