Smart Avionics PB-4 User manual

PB-4 Propeller & Rotor Balancer
User Interface Manual
Smart Avionics Ltd.
17/07/2019www.smartavionics.comRevision: 2.4

PB-4 Propeller & Rotor Balancer: User Interface Manual
Revision: 2.4
Publication date 17/07/2019
Copyright © 2003-2019 Smart Avionics Ltd.
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iOS is a trademark of Apple Inc.
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Table of Contents
1. Introduction ................................................................................................... 1
1.1. Accessing the PB-4 user interface .................................................... 1
1.1.1. Accessing the PB-4 user interface (AP mode) ...................... 1
1.1.2. Accessing the PB-4 user interface (STA mode) .................... 1
1.2. Initial screen ....................................................................................... 2
1.3. Jobs .................................................................................................... 3
1.4. Menu button ....................................................................................... 4
1.5. Connect button .................................................................................. 4
2. Polar Tab - Propeller Balancing ................................................................... 7
2.1. Polar chart .......................................................................................... 7
2.1.1. Capture button ......................................................................... 9
2.2. Points list ............................................................................................ 9
2.3. Option buttons ................................................................................. 10
2.3.1. Print Polar Chart menu ......................................................... 10
2.3.2. What Next? button ................................................................ 10
2.3.3. Show Waveform button ........................................................ 11
2.3.4. Polar Options button ............................................................. 11
2.4. Point details dialog .......................................................................... 11
3. Polar Tab - Rotor Balancing ....................................................................... 15
3.1. Polar chart ........................................................................................ 15
3.1.1. Capture button ...................................................................... 16
3.2. Points list .......................................................................................... 17
3.3. Option buttons ................................................................................. 18
3.3.1. Print Polar Chart menu ......................................................... 18
3.3.2. What Next? button ................................................................ 18
3.3.3. Show Waveform button ........................................................ 19
3.3.4. Polar Options button ............................................................. 19
3.4. Rotor mode profiles ......................................................................... 20
3.5. Point details dialog .......................................................................... 21
3.6. Rotor balance solution dialog ......................................................... 23
3.7. Edit move line dialog ....................................................................... 24
3.7.1. Defining move line nodes ..................................................... 25
3.8. Changing adjustment settings ........................................................ 26
4. Spectrum Tab ............................................................................................. 29
4.1. Spectrum display ............................................................................. 29
4.1.1. Capture button ...................................................................... 31
4.2. Lines and spectra lists ..................................................................... 31
4.3. Option buttons ................................................................................. 32
4.3.1. Print Spectrum button .......................................................... 32
4.3.2. Spectrum Options button ..................................................... 32
5. Data Tab ...................................................................................................... 35
5.1. Data Options button ........................................................................ 35
6. Options Page .............................................................................................. 37
6.1. Change to another job ..................................................................... 37
6.2. Create a new job .............................................................................. 37
6.3. Rename the current job ................................................................... 38
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6.4. Delete jobs ........................................................................................ 38
6.5. Save / restore PB-4 data ................................................................. 38
6.6. PB-4 configuration ........................................................................... 39
6.6.1. Set access point details ....................................................... 39
6.6.2. PB-4 hardware configuration ............................................... 39
6.6.3. Get / set configuration values .............................................. 40
6.6.4. Firmware upload ................................................................... 41
6.7. Upload UI files .................................................................................. 41
6.8. Set PB-4 IP address ......................................................................... 42
7. Propeller Balancing .................................................................................... 43
7.1. Minimising other sources of vibration ............................................ 43
7.2. Propeller mass imbalance .............................................................. 43
7.3. Static propeller balancing ............................................................... 43
7.4. Dynamic propeller balancing .......................................................... 44
7.5. Taking a vibration reading ............................................................... 45
7.6. Balancing procedure ........................................................................ 46
7.7. After balancing ................................................................................. 48
7.8. Troubleshooting ............................................................................... 48
7.8.1. The displayed RPM is erratic or wrong ................................ 48
7.8.2. The current polar point position varies widely .................... 48
7.8.3. Adding weight does not reduce the vibration level ............. 49
8. Rotor Balancing .......................................................................................... 51
8.1. Causes of rotor vibration ................................................................. 51
8.2. Rotor adjustments ........................................................................... 52
8.3. Balancing procedure ........................................................................ 53
8.3.1. Measuring the effect of adjustments .................................. 54
8.3.2. Creating move lines .............................................................. 55
8.3.3. Obtaining the balance solution ............................................ 55
9. Two Plane Balancing .................................................................................. 57
9.1. Two plane balancing method .......................................................... 57
9.1.1. Measurement and correction planes ................................... 57
9.2. Two plane balancing dialog ............................................................ 58
9.3. Balancing procedures ...................................................................... 59
9.3.1. Single accelerometer procedure .......................................... 60
9.3.2. Dual accelerometer procedure ............................................. 60
A. PB-4 Configuration Values ........................................................................ 63
B. User Interface Configuration ..................................................................... 65
B.1. Editing rotor profiles ........................................................................ 66
B.2. Editing other values ......................................................................... 67
Index ................................................................................................................ 69
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PB-4 Propeller & Rotor Balancer

List of Figures
1.1. Initial screen ............................................................................................... 3
2.1. Polar tab - propeller balancing (with options visible) .............................. 7
2.2. Polar chart - propeller balancing .............................................................. 8
2.3. Points List Header - Propeller Mode ........................................................ 9
2.4. Set Weight Amounts And Positions Dialog ........................................... 10
2.5. Point details dialog - propeller mode ..................................................... 12
3.1. Polar tab - rotor balancing (with options visible) .................................. 15
3.2. Polar chart - rotor balancing ................................................................... 16
3.3. Points List Header - Rotor Mode ............................................................ 17
3.4. Span Adjustment Dialog ......................................................................... 18
3.5. Add Move Line Menu .............................................................................. 19
3.6. Standard accelerometer orientation (top view) ..................................... 21
3.7. Point details dialog - rotor mode ............................................................ 22
3.8. Rotor balance solution dialog ................................................................. 23
3.9. Edit move line dialog ............................................................................... 24
3.10. Span Adjustment Settings .................................................................... 26
4.1. Spectrum tab (with options visible) ....................................................... 29
4.2. Rotor spectrum with line info box .......................................................... 30
5.1. Data tab (with options visible) ................................................................ 35
6.1. Options page (when connected to PB-4) ............................................... 37
6.2. Accelerometer orientation during calibration ........................................ 40
7.1. Sine wave ................................................................................................. 44
8.1. Rotor spectrum with large × 2 peak ....................................................... 51
8.2. Rotor Adjustments .................................................................................. 53
9.1. Two plane balancing an object supported at both ends ....................... 58
9.2. Two plane balancing an overhung object .............................................. 58
9.3. Two plane balancing dialog .................................................................... 59
B.1. UI configuration dialog ........................................................................... 65
B.2. Example profile configuration ................................................................ 66
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Chapter 1. Introduction
This manual describes the PB-4's browser based user interface and how to
use it to balance a propeller or rotor. Please refer to the PB-4 Hardware Manual
(pb4_hw_manual.pdf) for information regarding the PB-4 hardware and how
it is installed prior to carrying out a balancing job.
For simplicity, this manual refers to the user interface as a tablet but it could
be any device that supports a modern web browser and it talks about “clicking”
buttons. Obviously, if the device has a touch screen then you will be “touching”
or “tapping” rather than clicking.
This manual describes the PB-4 user interface software version 2 upwards.
Note
In depth tutorials that cover propeller and rotor balancing using the
PB-4 are available on the Smart Avionics website.
1.1. 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.
1.1.1. 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)".
1.1.2. 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
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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
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)".
1.2. Initial screen
When you load the PB-4 user interface into your browser, after showing the
splash screen for a few seconds it will show an initial screen, like Fig 1.1
This shows a polar chart and a list of captured points (both empty as no points
have been captured yet). At the top of the screen, are the Menu and Connect
buttons and the name of the current job.
Most of the screen is used to display the PB-4 data. At the top of the region
are three tabs (Polar,Spectrum &Data) which you use to select the data you
wish to see.
The polar tab shows a polar chart, a list of captured points and
some buttons. For a detailed description of using the polar tab
Polar
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Initial screen

see Chapter 2 (propeller balancing) and Chapter 3 (rotor
balancing).
The spectrum tab shows a spectral display, a list of captured
spectra, a list of spectral lines and some buttons. See Chapter 4
for a detailed description of the spectrum tab.
Spectrum
The data tab shows an area that displays the current vibration
data (RPM, IPS, DEG) as text and some buttons. See Chapter 5
for a detailed description of the data tab.
Data
Fig 1.1. Initial screen
The PB-4 user interface is "responsive" - the layout changes depending on the
resolution and orientation of the user interface's screen. It should be usable
on many different user interface devices. For in-cockpit use, a 7" form factor
tablet is ideal. For lower resolution devices, you may find that changing the
orientation to landscape is beneficial.
1.3. Jobs
The PB-4 supports the notion of a "job".
• A job is simply a named collection of data (points and spectra) associated
with a single balancing job.
• There is always a current job . The name of the current job is displayed
alongside the connect button. When data is captured, it will be stored in the
current job.
• Each job is named and may be loaded into the user interface to become
the current job. The points and spectra captured for that job can then be
viewed.
• When new, the PB-4 contains a single job, called "default".
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Jobs

• Jobs can be created, deleted and renamed.
• The default job is always available. If you delete it, it is recreated.
• All of the job data is stored on an SD card in the PB-4.
• Jobs can be exported and imported so you can share job data with other
PB-4 operators and also view the job using the PB-4 online viewer.
1.4. Menu button
Clicking the menu button pops up a menu with these items:
Options Clicking this will toggle the visibility of the options
page. When the options page is being displayed,
to return to the tabs page you can either click
Menu / Options again or press the browser's back
button.
Two Plane Balancing Opens the two plane balancing dialog.
Fullscreen If your browser supports displaying a web page
fullscreen, clicking this will toggle fullscreen
mode. To exit fullscreen mode, either click Menu
/ Fullscreen again or press the Esc key (if your
device has a keyboard!)
Help Clicking this will display a simple web page with
links to the PB-4 documentation.
About Clicking this will display the About dialog. Some
of the information in the dialog is only available
when the PB-4 is connected.
1.5. Connect button
The connect button toggles the user interface - PB-4 connection state. The
current state is indicated by the colour of the button:
When the button is red, the user interface is not connected to the
PB-4. The browser can display the data for the current job that has
red
already been captured but no new data can be displayed or another
job viewed until the connection has been made to the PB-4.
When the button is green, the user interface is connected to the
PB-4 and the text on the button is updated with the PB-4's battery
green
capacity remaininga. New data can be displayed and other jobs
can be accessed via the options page.
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Menu button

The button is orange while the connection to the PB-4 is being
established and also when the battery is down to the last 20-30
orange
minutes of run time to remind you that you will need to change the
batteries soonb.
aThe battery capacity remaining is estimated from the time the PB-4 has been running since the
batteries were last changed. It assumes the batteries were fully charged to their rated capacity
when they were installed.
bThis low battery warning is based on the battery voltage and is an accurate indication that the
batteries are almost flat.
If the browser page is reloaded from the PB-4 while connected or the browser
is closed, the connection will be dropped.
The PB-4 will turn itself off automatically after 30 minutes of not being
connected.
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Connect button

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Chapter 2. Polar Tab - Propeller Balancing
The polar tab shows the polar chart we use when balancing. Some features
of this tab differ depending on whether we are balancing a propeller or a rotor.
Here we see the polar tab displaying the results of a propeller balancing job.
Fig 2.1. Polar tab - propeller balancing (with options visible)
2.1. Polar chart
The polar chart shows the points that were captured during the balancing
process. The chart may be panned and zoomed1. If the PB-4 is connected and
the Update checkbox is checked, the chart will be updated in real-time to show
the current balance condition.
The current point is simply the most recent point sent from the PB-4 when the
display is being updated in real-time or the point that has been selected in the
points list when the display is not being updated in real-time.
Each point is plotted as a circle2, the colour coding of the plotted points are:
Captured point.White
Start point.Blue
The current point.Yellow
1Pinch-zooming is supported for touch screens and mouse-wheel zooming for laptops, etc.
2Other symbols (square, triangle and rhombus) are available. By default, X and X2 axis points are plotted as
circles and Y and Y2 axis points are plotted as squares.
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Fig 2.2. Polar chart - propeller balancing
The chart shows some text in yellow boxes that describes the current point:
The top-left box contains the tacho channel name (A or B) and the current
point's propeller RPM.
The top-right box contains the accelerometer channel name (X, Y, X2 or Y2)
and the current point's IPS and DEG values.
The bottom-right box contains the date & time the current point was measured.
The bottom-left box is only visible if there is a start point defined for the axis.
It shows a “solution”, i.e. what adjustment needs to be made to the balance
weight to improve the balance. The adjustment has the form ANGLE ×SCALE.
ANGLE is signed; a positive value means move the weight forward (in the
direction of propeller rotation) that many degrees and a negative value means
move the weight backward (opposite to the direction of propeller rotation).
SCALE is a multiplier that specifies the required change in weight; e.g. a value
of 1.2 means increase the weight by 20%, a value of 0.5 means halve the
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Polar chart

weight. So in the chart above, the solution is saying move the weight backwards
5° and keep the amount the same.
2.1.1. Capture button
Below the polar chart is the Capture button. Clicking on this will capture the
next polar point produced by the PB-4. All axes (X, Y and also X2, Y2 if the
second accelerometer is in use) are captured together irrespective of which
axis is currently being displayed.
2.2. Points list
To the right of the polar chart are the Update check box, the points visibility
menu and the points list.
• The Update checkbox controls whether the polar chart is automatically
updated to show the latest polar point(s) returned by the PB-4 when it is
connected. If not checked, the last displayed data is preserved. So if you
want to pause the display, un-check this checkbox.
• The points visibility menu controls which points are displayed in the points
list and the polar chart. The choices are:
All All points will be displayed. Also, the point index number column
is highlighted and clicking on a point's index number will toggle
its hidden state.
Visible All points that have not been hidden will be displayed.
Best Only the “best” point from each group of points is displayed.
The points are grouped by similar capture time and RPM. If
there are less than 3 points in the group, the point with the
lowest IPS value is considered to be the best. When a group
contains 3 or more points, the best point is the point that is
closest to the average position of all the points in the group.
• The points list header row contains two column headers (WT1 and WT2)
that show the current weight configuration.
Fig 2.3. Points List Header - Propeller Mode
The weight configuration values have the form AMOUNT @SITE where
AMOUNT is a number ≥ 0 and SITE is a value from 1 to the number of weight
sites being used for the current job (see later). Clicking on those values
opens the Set Weight Amounts And Positions dialog. In there are input
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Capture button

fields into which you enter the current weight configuration as separate
numbers. The weight amounts and positions you specify will be assigned
to the polar points that are subsequently captured. The weight amounts
can be in conventional weight units (e.g. grams or ounces!) or simply
numbers of washers.
Fig 2.4. Set Weight Amounts And Positions Dialog
• The points list contains one row for each point that has been captured. The
points are listed in reverse capture order, the most recently captured point
being at the top of the list. Clicking on the Time header reverses the order
of the list.
Each row in the list shows the data for a single point (time of capture, RPM,
IPS, DEG, the amounts and locations of the balance weights that were
present when that point was captured and the point's notes).
Groups of points with similar capture times and RPM values are separated
by a black line.
Clicking on a row will make the selected point the current point and it will
be displayed with a yellow background. Clicking that row again will display
the point details dialog for the selected point.
2.3. Option buttons
To the right of the points list are a drop down menu and some buttons:
2.3.1. Print Polar Chart menu
This gives you the choice of either printing just the chart or the chart and a
table of points. It will create a new page in your browser which you can then
print using the normal browser print page facility (e.g. type Ctrl-P).
2.3.2. What Next? button
Clicking this will open a dialog that suggests your next action. When you are
doing your first propeller balances, you may find this useful.
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Option buttons

2.3.3. Show Waveform button
Clicking this will open a dialog that shows the current acceleration waveform.
2.3.4. Polar Options button
Clicking this will toggle the display of the polar options box, the options in the
box are:
• The Propeller/Rotor Mode button pops up a menu that let's you choose the
polar mode for the current job.
• Drop down menu, Axis 1 lets you choose the axis to be displayed in the
points list and polar chart.
• The Point Smoothing text input box is used to specify the number of
readings that are averaged together to produce a single polar point. A low
value will allow more variation in the polar points and the display will react
more quickly to input changes (i.e. changes of RPM). A large value will tend
to smooth out variations in the polar points but will make the display slower
to react to input changes so you will need to wait longer for the point to
settle in the averaged position. The value should be between 1 and 50, the
default is 15.
• The Weight Sites text input box is used to specify the number of locations
that balance weights may be attached to. For a typical propeller balancing
job, this would be the number of fasteners that hold the spinner to its
backplate. It cannot be less than 3.
• The PSRU Ratio text input box is used to enter the ratio of the engine to
propeller step down gearbox. If your engine has a PSRU and you know the
ratio, enter it here as a single number (i.e 2.43 rather than 2.43:1). If you
don't know the ratio or the engine doesn't have a PSRU, enter 1. When
applicable, using a value other than 1 allows the software to calculate the
engine RPM from the propeller RPM and this information can be used to
help identify the source of peaks that may occur in the spectral display.
2.4. Point details dialog
This dialog displays the detailed information for the selected point along with
some text input boxes and buttons as shown in Fig 2.5. To open this dialog
simply click the selected point's row in the point list a second time. The buttons
are:
• The Hide This Point button will make the current point “invisible”, i.e. it will
not be displayed in the points list or shown on the polar chart unless the
point visibility menu is set to All. When a point has been hidden, this button
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Show Waveform button

becomes the Show This Point button and clicking on it will make the point
visible again.
• The Use As Start Point button designates the current point to be the start
point . A start point is simply a point that was captured before any balance
weights were attached, it represents the propeller balance starting condition.
Once a point has been chosen as the start point, the button becomes the
Don't Use As Start Point button and clicking on it makes the current point
no longer to be considered the start point.
• If the point was captured with acceleration data (see the With Waveform
Data option in Chapter 5), the Show/Hide Waveform button will be visible
and clicking that will toggle the display of the waveform.
Fig 2.5. Point details dialog - propeller mode
The text input boxes are:
• The Notes text input box is used to enter any notes that you wish to record
for the point.
• Two rows contain text input boxes that are used to alter the amount and
location (site number) of the balance weights that were present when this
point was captured.
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Point details dialog

Note
The weight configuration should be set before the points are
captured by clicking in the WT1 or WT2 columns of the polar point
list header as described in Section 2.2. If that is done, the weight
configuration is copied into points as they are captured. However,
if you forget to enter that information before capturing the points
or you need to change the values for some reason then this
information can be edited in the point details dialog.
Below the weight configuration are instructions as to how the current weight
configuration should be changed to improve the balance. The new weight
amounts displayed are shown rounded to the nearest integer and also as
(more) exact values.
The Set Configuration To This Solution and Set Configuration To Exact
Solution buttons are a convenient way of updating the current configuration
to the recommended values. They just save you some clicking and typing,
you still have to make the actual changes to the weight configuration on
the aircraft!
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Point details dialog

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