Fona MyCrown Mill User manual

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Service Manual

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MyCrown Mill
Contents
1General information.................................................................................................. 5
1.1 General information....................................................................................... 6
1.2 Additional information.................................................................................... 7
2Description of the service software .......................................................................... 9
2.1 General information....................................................................................... 10
2.2 Basic structure of test dialogs ....................................................................... 12
2.3 Individual Test Points .................................................................................... 17
2.3.1 Serial Communication ...................................................................... 17
2.3.2 Media supply .................................................................................... 18
2.3.2.1 Media supply ..................................................................... 18
2.3.3 Light Barriers, Door Switch, Temperature Sensor and Motor Stop
Positions
19
2.3.4 Stepping motor test .......................................................................... 22
2.3.5 Stepping motors - Single step .......................................................... 23
2.3.6 Stepping motor - Step response ...................................................... 24
2.3.7 DC motors 'Load/Run-in' .................................................................. 25
2.3.8 DC motors 'Touch'............................................................................ 26
2.3.9 DC motors 'Speed' ........................................................................... 27
2.3.10 Force sensors / stepping motors: Rigidity ........................................ 28
2.3.11 Continuous load ............................................................................... 29
2.3.12 Milling Unit Info................................................................................. 30
3Troubleshooting........................................................................................................ 32
3.1 Force measurement errors............................................................................ 33
3.2 Stepping motor does not move ..................................................................... 34
3.3 Spindle motor does not lock.......................................................................... 35
3.4 Milling chamber door switch.......................................................................... 36
3.5 Unit switches off ............................................................................................ 37
3.6 Edges break off, holes or wide stripes in restoration .................................... 39
3.7 Insufficient air pressure ................................................................................. 41
3.8 Stepping motor cannot be controlled ............................................................ 42
3.9 Faulty water pressure.................................................................................... 43
3.10 Unit cannot find starting position ................................................................... 45
3.11 Unit cannot be turned on............................................................................... 46
3.12 Touch errors.................................................................................................. 47
3.13 Service life of the milling and grinding machine is too short ......................... 48

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3.14 Milling unit not addressable.......................................................................... 49
3.15 LAN communication problems ..................................................................... 50
3.16 WLAN connection occasionally interrupted.................................................. 52
3.17 WLAN communication problems .................................................................. 53
4Repair...................................................................................................................... 54
4.1 Removing/attaching covers.......................................................................... 56
4.2 Replacing the (DC) spindle motors .............................................................. 58
4.2.1 DC motor, single.............................................................................. 58
4.2.1.1 Removal ........................................................................... 58
4.2.1.2 Installation ........................................................................ 59
4.2.2 Testing and adjusting the spindle motor(s) ..................................... 62
4.3 Replacing the controller board / microcontroller module .............................. 63
4.4 Replacing the milling chamber lighting......................................................... 66
4.5 Replacing stepping motors........................................................................... 67
4.5.1 BR stepping motor........................................................................... 68
4.5.2 GR / MR stepping motor.................................................................. 69
4.5.3 Linear stepping motor...................................................................... 70
4.5.3.1 Removing the stepping motor........................................... 70
4.5.3.2 Installing the stepping motor............................................. 74
4.6 Replacing the milling machine...................................................................... 77
4.6.1 Removing the milling machine ........................................................ 77
4.6.2 Installing the milling machine .......................................................... 79
4.7 Replacing the tank switch (if present) .......................................................... 81
4.7.1 Preparations .................................................................................... 81
4.7.2 Removing the chassis insert ........................................................... 81
4.7.3 Installing the chassis insert ............................................................. 83
4.7.4 Final work ........................................................................................ 84
4.8 Replacing the suction connection................................................................. 84
4.8.1 Preparations .................................................................................... 84
4.8.2 Removing the chassis insert ........................................................... 84
4.8.3 Replacing the suction connection.................................................... 84
4.8.4 Installing the chassis insert ............................................................. 85
4.8.5 Final work ........................................................................................ 85
4.9 Replacing the light barrier ............................................................................ 85
4.10 Replacing the air pump ................................................................................ 86
4.11 Replacing the pressure switch ..................................................................... 87
4.11.1 Water pressure switch..................................................................... 87
4.11.2 Air pressure switch .......................................................................... 88
4.12 Replacing the fan unit................................................................................... 89

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4.13 Replacing the water pump ............................................................................ 90
4.13.1 Removing the water pump ............................................................... 90
4.13.2 Attaching the water pump ................................................................ 91
4.14 Replacing the display .................................................................................... 92
4.15 Adjusting the plunger pin............................................................................... 93
4.15.1 G-axis and M-axis plunger pin ......................................................... 93
4.16 Replacing the set screw ................................................................................ 94
4.17 Replace the distributor board for the milling motors...................................... 95
5Using the cleaning set .............................................................................................. 96
5.1 Cleaning the manual block clamp ................................................................. 97
5.2 Milling instruments without chuck.................................................................. 97

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1General information
Contents
1.1 General information...................................................................................... 6
1.2 Additional information................................................................................... 7

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MyCrown Mill
1.1. General information
Nominal line voltage ranges The MyCrown Mill milling unit operates in the following nominal line
voltage ranges:
● 100V - 230VAC; 50 / 60 Hz
Wireless phone interference with
medical electrical equipment
ESD warning label
ESD protective measures
ESD protective measures include:
● Procedures for preventing electrostatic charge build-up (e.g. air
conditioning, air moistening, conductive floor coverings and non-
synthetic clothing)
● Discharging the electrostatic charges of your own body on the frame
of the UNIT, the protective ground wire or large metallic objects
● Connecting yourself to ground using a wrist band.
Measurements Always switch off the device before connecting the measuring instrument.
Select the correct current/voltage type and adjust the measuring range to
match the expected readings.
Perform continuity tests only on devices which are switched off.
NOTICE
To ensure safe operation of medical electrical equipment, the use of
mobile wireless phones in practice or hospital environments is
prohibited.
CAUTION
Risk of injury or damage to components from electrostatic discharge
For electrical components labeled with an ESD warning label, observe
the following instructions.
➢Apply the ESD protective measures.
➢Do not touch connector pins or sockets without applying ESD
protective measures first.
➢Do not establish any connections between these connectors without
applying ESD protective measures first.

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Replacing parts
Switch the device off and disconnect the power plug before replacing
parts.
The item numbers for ordering spare parts are in FONA.
Before replacing the boards, observe the ESD protective measures.
Disposal Observe the information on disposal in the relevant operating
instructions.
Installation site Observe the information on the installation site in the relevant operating
instructions.
1.2. Additional information
In addition, you also require:
Wiring diagrams MyCrown Mill
Order No.: “66 18 974”
Operating Instructions MyCrown Mill
Order No.: 66 11 748
Tools
● Allen key angled, size (mm) 1.27 (0.05”); 1.3;6
● Open-end wrench, size (mm) 6;10
● TORX screwdriver, size 6; 8; 10; 20
● Phillips screwdriver, size 1
● Blade screwdriver, insulated, sizes 2 and 3
● Box wrench: 6mm; 7mm
● Universal tongs
● Flat tongs
● Torque wrench 1.1 Nm
● Feeler gauge 0.1mm
WARNING
Potentially lethal shock hazard when working near the power supply unit
Disconnect from the line power supply.
Check for zero potential.

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Auxiliary tools & equipment
● Digital Multimeter, Accuracy Class 1
● Soldering tool for repairing cables
● Side cutting pliers
● Cable ties
● Teflon tape
● Loctite 221
● Calibration set (supplied with unit)
● Step Bur 12 SandCyl. Pointed Bur 12 S
● Torque wrench for changing the milling instruments
(order no: 61 19 346)
● Fuses (recommended):
F1 (2 pcs) T5H250V Order No.: 20 33 111

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2Description of the service software
Contents
2.1 General information....................................................................................... 10
2.2 Basic structure of test dialogs ....................................................................... 12
2.3 Individual Test Points .................................................................................... 17
2.3.1 Serial Communication ...................................................................... 17
2.3.2 Media supply .................................................................................... 18
2.3.2.1 Media supply ..................................................................... 18
2.3.3 Light Barriers, Door Switch, Temperature Sensor and Motor Stop
Positions
19
2.3.4 Stepping motor test .......................................................................... 22
2.3.5 Stepping motors - Single step .......................................................... 23
2.3.6 Stepping motor - Step response ...................................................... 24
2.3.7 DC motors 'Load/Run-in' .................................................................. 25
2.3.8 DC motors 'Touch'............................................................................ 26
2.3.9 DC motors 'Speed' ........................................................................... 27
2.3.10 Force sensors / stepping motors: Rigidity ........................................ 28
2.3.11 Continuous load ............................................................................... 29
2.3.12 Milling Unit Info................................................................................. 30

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MyCrown Mill
2.1. General information
Test requirements Requirement for all tests:
● PC / acquisition unit is switched on and ready for operation.
● PC/ acquisition unit and milling unit are connected to each other
(network cable, wireless or WLAN).
● The door of the milling chamber must remain closed as long as any
motors or the water pump are running. If the door of the milling
chamber is opened during the test, all motors and the water pump will
switch off immediately (same function as pressing the
"STOP"
button).
● When operating the water pump, the tools (grinder or miller) must be
installed.
● When operating the water pump, the air pump must always be
running alongside it in order to protect the DC motors from water,
e.g., the air pump is started first. If the air pressure switch detects no
air pressure, an error message will appear and the test cannot be
performed.
● To operate the suction system, if the machine configuration permits
it, the suction system must be connected to the milling unit (interface
cable and suction hose) and switched to “Auto”.
Service software log file The Service software generates a log file for all tests performed. This log
file is located in the folder on delivery.
C:\Program Files\FONA Dental\MyCrown Design
1.0.x\Bin\Service\Service\Protocols
The protocol is called:
Test file_XXXXXXXXXXXX_YYYYYYYY_ZZZZZZ.xml or
Test file_XXXXXXXXXXXX_YYYYYYYY_ZZZZZZ.html
The “X” here denotes the serial no. of the milling unit, “Y” denotes the
date, and “Z” the time the protocol was generated.
Each time the service software is started, a confirmation query appears
asking whether this file (if it already exists) should be deleted. If
"No" (do
not delete) is selected, the tests subsequently performed will be
appended to the ones previously saved. Each test is labeled with a
starting and ending date. The test file can be viewed with the editor at any
time. If the user quits a test without saving it, he will be asked if he really
wants to quit without saving. If
"Yes" (Quit without saving) is then
selected, the data just measured will be lost.
Assessment scores There are three different scores which can be assigned to test results:
● Passed fully (
"Passed fully" , green label)
● Passed (
"Passed" , yellow label)
● Not passed (
"Not passed" , red label)
The area which passed may be irrelevant for a specific test. In that case,
n/a (not applicable) will be written to the log file for this area.

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Grinding chamber
Grinding chamber
NOTICE
Assessment scores
Passed fully: If all test results are scored
"Passed fully" , flawless
operation of the system is possible.
Passed: If the test results are scored
"Passed" , uncritical changes have
occurred.
Not passed: If the test results are scored
"Not passed" , you must find
and eliminate the cause.
NOTICE
Keep the cover closed
If the milling unit housing is left open, the temperature switch on the
controller board may cut out after a short time (T>90°C). The cooling fan
can work properly only with the cover closed.
A Instrument set C Ceramic block
B Motor mount D Workpiece spindle

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2.2. Basic structure of test dialogs
Password The service software test dialogs are protected by a password to prevent
manipulations by unauthorized users.
The password has four digits. It changes daily and is generated from the
system date of the computer according to the following scheme:
Example: 02/28/2007 becomes 2082
The dialog for setting the system time can be called up in all Windows
operating systems by double-clicking the time displayed in the systray.
NOTICE
Do not share your password formula!
The Service functions may be used only by authorized service
engineers who have been trained by FONA Dental.
Password number Generated from
1 2. number of the current month
2 1. number of the current month
3 2. number of the current day
4 1. number of the current day
NOTICE
Do not disclose the password scheme
Do not disclose the password creation scheme to others.
Before entering the password, always determine the date as
inconspicuously as possible.
Since the password is always valid for one single day only, it can be
passed on to the user in exceptional cases, e.g. to provide immediate
telephone support.
NOTICE
Password input errors
If the commands are not enabled after you enter the password, check
the following:
- correct entry of the password,
- the system date set on the computer.

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Opening the service software 1. Call the service menu as follows:
Programs\FONA Dental\MyCrown Design
x.x\Tools\Service Software
The Service Login dialog box then opens for entering the
password:
2. Enter the password and confirm with the
"Yes" button.
Selecting a device
Log file If a log file with the name of the milling unit you have selected already
exists, you will be asked if you want to delete this file.
● If you click on the
"Yes" button:
The old file is deleted and a new log file is created.
● If you click on the
"No" button:
The old file is not deleted and the details of the new test run are
attached.
NOTICE
Selecting the milling unit
If no data link is present between the milling unit and the acquisition unit
/ the PC or multiple milling units are connected, the
"Select unit" window
opens.
➢Establish a data link if necessary.
➢Click on the
"Add automatically" button.
The acquisition unit / PC installs the milling unit.
➢Select the relevant milling unit and confirm with the "OK" button.

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Test selection dialog box
In the
"Test selection" dialog you can
● select a test for the entire milling unit (
"Total test" ) or
● select an individual test.
Through confirmation with the
"OK" button, the corresponding test dialog
opens.

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Example: Total test
Total test

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A Number of test runs completed since the last time the Start button was actuated.
B Progress bar for test currently being run.
C Check boxes for selecting (activating/deactivating) the tests available in this test dialog.
D Check box for selecting the options possible in this test dialog.
E Number of test results since the last start:
● Passed fully
● Passed
● Not passed
F With the
"Start" button, the test run is started with the settings selected. The test run is repeated until it is
cancelled using the
"Stop" button. The test run counter is then reset to 0. After starting, the test run can only
be paused with
"Stop" . No other inputs are possible during the test run.
G With the
"Stop" button, the test is broken off as quickly as possible. The test in progress at the time of
cancellation is not counted. All inputs are now possible again.
H Store the available data in the log file with the
"Save" button. The data are appended to the previously existing
log file (if the current test run has not yet been saved). If no data is available, a message appears to this effect
(confirm with
"OK" ). Once a test run has been saved to the log file, a new test run must be started before
selecting the save function again.
IWith
"Back" , you can exit the test dialog and return to the service dialog. If any data exist and have not yet
been saved, you will be asked whether or not the test data should be saved.
J Result:
● No color: No measurement available yet.
● green: Test passed fully.
● yellow: Test passed.
● red: Test not passed.

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2.3. Individual Test Points
2.3.1 Serial Communication
The test is primarily used to measure the speed and quality of data
transmission. This is especially important if the system is not operated via
the network cable (LAN) but rather via other types of connections such as
e.g. WLAN (AdHoc, Infrastructure.
The transmission time between the beginning of transmission and the
end of reception is calculated for a specific record on the PC. A test run
comprises one complete transmission in both directions.
The values measured are then saved to the log file (refer to "General
information“).
Serial communication
Typical values
1 Result of last test run 3 Average measured
transmission time
2 Minimum measured
transmission time
4 Maximum measured
transmission time
Time
LAN 200 - 400 ms
WLAN 300 - 600 ms

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2.3.2 Media supply
2.3.2.1 Media supply
Purpose of Test: To check the media supply (air, water, fan) for proper functioning and test
the pressure switches and the function of the pump.
Procedure The pumps and the fan are switched on by nominal select control
depending on selection. The motor currents and the condition of the
pressure switches are registered. The points of time when the pressure
detectors respond are measured. After approx. 5 seconds the pumps are
switched off and the time required until the pressure switch responds is
measured and evaluated.
Save Save stores the measured values to the log file under the heading of
Media supply.
Media supply
Deviations of measurements Deviations may occur:
● During the first test run (if any air is still in the water circuit)
● If the amount of water in the water tank is insufficient
● After filling the water tank.

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2.3.3 Light Barriers, Door Switch, Temperature Sensor and
Motor Stop Positions
Purpose of Test: This test is used to evaluate the safe functioning of the light barriers and
check the door switch, the temperature sensor and the motor stop
positions.
Light barrier When the end position is located, the slot of the gear is measured via the
width and height at which the stepping motor positions are registered with
the flanks.
The light barriers to be tested can be selected in all variations. If no light
barrier is selected, the Start button is not active. Default setting: All light
barriers selected.
Switch - light barrier
Door switch The current state of the door switch can be checked via a status bar
display.
Door switch
Control keys The current state of the control keys can be checked via a status bar
display.

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Switches - Control keys
Display / Illumination The selected pattern is shown on the display as a display test.
The "Illumination" button tests all colors of the milling chamber
illumination:
● white (milling, default color)
● blue (not assigned to any function)
● green (operation completed)
● red (error / Stop button pressed)
Switches - Display / Illumination