iOptron HEM27 User manual

iOptron®HEM27TM Hybrid Stain Wave GoTo Equatorial Mount
Instruction Manual
Product HEM27 and HEM27EC

2
Read the Quick Setup Guide (QSG) BEFORE setup and operate the mount! Read the full online
Instruction Manual for details.
Please hold the mount/scope when disengaging the gear switch. Any worm system damage due to
improper operation will not be covered by iOptron’s limited warranty.
If you have any questions please contact us at [email protected]m
WARNING!
NEVER USE A TELESCOPE TO LOOK AT THE SUN WITHOUT A PROPER FILTER!
Looking at or near the Sun will cause instant and irreversible damage to your eye.
Children should always have adult supervision while observing.

3
Table of Content
Table of Content.................................................................................................................................................3
1. HEM27 Overview ..........................................................................................................................................5
2. HEM27 Terms................................................................................................................................................6
2.1. Parts List..................................................................................................................................................6
2.2. Identification of Parts ..............................................................................................................................7
2.3. HEM27 Port.............................................................................................................................................7
2.4. Go2Nova®8409 Hand Controller ...........................................................................................................8
2.4.1. Key Description................................................................................................................................9
2.4.2. The LCD Screen...............................................................................................................................9
2.5. Install and Check the Hand controller Battery ......................................................................................10
2.6. Bench Testing the Mount ......................................................................................................................11
3. HEM27 Mount Assembly.............................................................................................................................12
4. Getting Started..............................................................................................................................................20
4.1. Setup the Mount and Polar Alignment..................................................................................................20
4.2. Manual Operation of the Mount............................................................................................................20
4.3. Initial Star Alignment............................................................................................................................20
4.4. Go to an Object......................................................................................................................................20
4.5. Star Identifying Function.......................................................................................................................21
4.6. Power-Down Memorization..................................................................................................................21
4.7. Install iOptron iGuider ..........................................................................................................................21
4.8. Turn Off the Mount...............................................................................................................................21
5. Complete Functions of Go2Nova®8409 Hand Controller...........................................................................22
5.1. Slew to an Object...................................................................................................................................22
5.1.1. Solar System...................................................................................................................................22
5.1.2. Deep Sky Objects...........................................................................................................................22
5.1.3. Stars:...............................................................................................................................................22
5.1.4. Constellations.................................................................................................................................22
5.1.5. Comets............................................................................................................................................22
5.1.6. Asteroids.........................................................................................................................................22
5.1.7. User Objects ...................................................................................................................................23
5.1.8. Enter R.A. DEC..............................................................................................................................23
5.2. Sync to Target........................................................................................................................................23
5.3. Alignment..............................................................................................................................................23
5.3.1. Pole Star Position ...........................................................................................................................23
5.3.2. One Star Alignment........................................................................................................................23
5.3.3. Two Star Polar Align......................................................................................................................24
5.3.4. Three Star Align .............................................................................................................................24
5.3.5. Polar Iterate Align ..........................................................................................................................24
5.3.6. Solar System Align.........................................................................................................................24
5.3.7. Display Model Error.......................................................................................................................24
5.3.8. Clear Alignment Data.....................................................................................................................25
5.4. Settings ..................................................................................................................................................25
5.4.1. Set Time and Site............................................................................................................................25
5.4.2. Set Beep..........................................................................................................................................25
5.4.3. Set Display......................................................................................................................................25
5.4.4. Set Maximum Slew Rate................................................................................................................25
5.4.5. Set Guiding Rate.............................................................................................................................25
5.4.6. Set Parking Position .......................................................................................................................26

4
5.4.7. Set Tracking Rate...........................................................................................................................26
5.4.8. Meridian Treatment........................................................................................................................26
5.4.9. Set Altitude Limit...........................................................................................................................26
5.4.10. Wi-Fi Option ................................................................................................................................26
5.4.11. Set RA Guiding (HEM27EC Only)..............................................................................................27
5.4.12. Language ......................................................................................................................................27
5.4.13. Enable CW Up Position................................................................................................................27
5.5. PEC Option............................................................................................................................................27
5.5.1. PEC Playback.................................................................................................................................27
5.5.2. Record PEC....................................................................................................................................27
5.5.3. PEC Data Integrity .........................................................................................................................27
5.6. Edit User Objects...................................................................................................................................28
5.6.1. Enter a New Comet ........................................................................................................................28
5.6.2. Enter Other Objects or Observation List........................................................................................28
5.7. Firmware Information ...........................................................................................................................29
5.8. Zero Position .........................................................................................................................................29
5.8.1. Goto Zero Position .........................................................................................................................29
5.8.2. Set Zero Position ............................................................................................................................29
5.8.3. Search Zero Pos..............................................................................................................................29
6. Maintenance and Servicing ..........................................................................................................................30
6.1. Maintenance ..........................................................................................................................................30
6.2. iOptron Customer Service.....................................................................................................................30
6.3. Product End of Life Disposal Instructions ............................................................................................30
6.4. Battery Replacement and Disposal Instructions....................................................................................30
Appendix A. Technical Specifications.............................................................................................................31
Appendix B. Go2Nova®8409 HC MENU STRUCTURE ..............................................................................33
Appendix C. Gear Switch Meshing Adjustment..............................................................................................36
Appendix D. Firmware Upgrade......................................................................................................................39
Appendix E. Computer Control an HEM27 Mount .........................................................................................40
Appendix F. Go2Nova®Star List.....................................................................................................................41
IOPTRON TWO YEAR TELESCOPE, MOUNT, AND CONTROLLER WARRANTY.............................50
Ver. 1.0 2022.06
iOptron reserves the rights to revise this instruction without notice. Actual color/contents/design/function may differ from those described in this
instruction.

5
1. HEM27 Overview
Introducing the HEM27 and the HEM27EC, iOptron’s revolutionary hybrid strain wave drive mounts.
These light weight, high payload tiny titans will deliver an astronomy experience like never before. Imagine
a mount head weighing in at 8.15lbs with a payload capability 29.74lbs, without needing a cumbersome
counterweight or shaft. Applying iOptron’s multi decade experience creating precision mounts, the HEM27
brings this vision to reality.
Utilizing state of the art strain wave drive technology for the RA movement in tandem with backlash-
free DEC worm/belt drive design, the HEM27s deliver unparalleled weight to payload efficiency. Its black
anodized all metal CNC machined body is not only appealing to the eye, it’s a rugged platform that will
perform at the highest level for many years to come. Unique features such as an electronic friction break
and power down memory allow the mount safely stop and resume a GoTo slew or continue tracking even
after an abrupt power loss (No need to realign and start from the beginning).
The HEM27EC features a high precision RA axis encoder that delivers incredible tracking accuracy,
enough that many will choose to image “sans” guiding.
The iOptron HEM27 mount uses the Go2Nova®8409 hand controller to navigate the night sky. This
incredible technology helps observers find celestial objects with the aid of the mount's 212,000+ object
database!
A HEM27 mount can be controlled by a computer, either via ASCOM/Commander for a Windows PC
or a third party INDI driver for MacOS software; a SmartPhone/Tablet via iOptron Commander Lite or an
App like SkySafari; or a Raspberry Pi device via INDI driver.
Features:
Advanced strain wave drive technology
Payload capacity of 13.5 kg (29.7 lbs) with the mount weight of 3.7 kg (8.15 lbs)
CNC machined
Unique friction brake to safely stop movement during a planned or unplanned power interruption
360 second gear period
High precision encoder with real time PEC (RPEC) for HEM27EC
Go2Nova® hand controller with ~212,000 object database
iPolar electronic polar scope for easy and accurate polar alignment (for HEM27A and HEM27EC)
Cable management system, no hanging exterior cables to moving parts
Accept Vixen or Losmandy-D style dovetail bar
Built in zero position search and locator
Power down position and location memory
Integrated ST-4 autoguiding port
Built-in Wi-Fi (via hand controller)
USB port for firmware upgrade and computer control
Soft carrying case
Two year warranty
Optional carbon fiber tripod #3061
Optional iGuiderTM autoguiding system #3360
Optional counterweight shaft (#8456SL) and counterweight (#3006-10)
Optional MiniPier extension #8040 or #8040-8

6
2. HEM27 Terms
2.1. Parts List1
SHIPPING CONTENTS
Your new HEM27 mount comes in one shipping box:
iOptron®HEM27 mount (#HEM27)
iOptron®HEM27 mount head with iPolar (#HEM27A), or
iOptron®HEM27 mount head with high precision encoder and iPolar (#HEM27EC)
Go2Nova®8409 Hand Controller with USB port
Internal iPolarTM electronic polar scope (HEM27A or HEM27EC)
AC adapter 100V-240V, 12V/5A DC output, 5525 plug (for indoor use only)
1X coiled control Cable (6P6C RJ11 to RJ11, straight wired)
USB cable for mount
MiniUSB cable for iPolar
EVA case
OPTIONAL PARTS
Carbon fiber tripod (#8061)
iGuider 1 mini autoguiding system (#3360)
MiniPier extension #8040 or #8040-8
Counterweight shaft (#8456SL) and counterweight (#3006-10)
ONLINE RESOURCES (click on the “Support” menu at www.iOptron.com)
Quick Start Guide
Instructional manual
Tips for set up
Hand controller and mount firmware upgrades (check online for latest version)
iOptron ASCOM driver and computer control
Reviews and feedback from other customers
Accessories
1US market only. Actual contents, design and function may vary.

7
2.2. Identification of Parts
Figure 1.HEM27 mount assembly
2.3. HEM27 Port
On the Mount:
Figure 2. Ports on a HEM27 mount
DEC Gear Switch
iPolar Cover
CW Shaft Thread Hole
DEC Axis
AZI Adjust. Screws
Dovetail Saddle
ALT Locking Screws
RA Axis/Polar Axis
ALT Adjust. Screw
AZI Locking Screws
Carbon Fiber Tripod
(Optional)

8
DC 12V IN: DC power socket to power the mount (5.5mmX2.5mm/5525, center positive)
I/O: Power switch
iPolar: iPolar miniUSB port
HBX (Hand Box): For connecting to an 8409 Hand Controller
ST-4: ST-4 compatible autoguiding port. The wiring is shown in Figure 3
Figure 3. ST-4 Compatible Guiding Port Wiring
DC 12 OUT (on top of the mount body): DC power output socket (5.5mmX2.1mm/5521, center
positive). Maximum current 4A, combined with DC 12V output from dovetail saddle.
USB INPUT: USB pass through to the USB port on dovetail saddle.
On Dovetail Saddle:
Figure 4. Port on dovetail saddle
DC12V 3A 5521: DC power output socket (5.5mmX2.1mm/5521, center positive). Maximum
current 3A
USB: USB-A port connect to mount body.
2.4. Go2Nova®8409 Hand Controller
The Go2Nova®8409 hand controller (HC) shown in Figure 5 is the standard controller used on the
HEM27 mount. It has a large LCD screen, function, direction, and number keys on the front; and an HBX (6-
pin) and a USB port at the bottom.

9
Figure 5. Go2Nova®8409 hand controller
2.4.1. Key Description
MENU Key: Press “MENU” to enter the Main Menu.
BACK Key: Move back to the previous screen, or end/cancel current operation, such as slewing.
ENTER Key: Confirm an input, go to the next menu, select a choice, or slew the telescope to a
selected object.
Arrow (▲▼◄►) Keys: The arrow keys are used to control the movement of DEC and R.A. axes.
Press and hold ▲(DEC+),▼(DEC-) buttons to move a telescope along the DEC direction,
◄(R.A.+), ►(R.A.-) to move a telescope along the R.A. direction. They are also used to browse
the menu or move the cursor while in the menu. Press and holding an arrow key for a fast
scrolling.
Number Keys: Input numerical values. Also used to adjust speeds (1: 1X; 2: 2X; 3: 8X; 4: 16X; 5:
64X; 6: 128X; 7: 256X; 8: 512X; 9: MAX)
Help (?) Key: Identify and display bright stars or objects that the telescope is pointing to.
0 Key: Stop the mount during GOTO. Also toggling between starting and stopping tracking.
HBX (Handbox) port: connect the HC to the HEM27 mount using a 6P6C RJ11 cable.
USB port: connect the HC to a computer for firmware upgrade and computer control.
2.4.2. The LCD Screen
The 8409 HC has a large 4-line, 21-character per line LCD screen. The user interface is simple and
easy to learn. When the mount first turned on, an initial information screen will be displayed as shown in
Figure 6, after company logo displayed. It displays the Zero Position, current date and time.
Figure 6. 8409 Initial Information Screen
HBX
Port
USB
Port
RA+
RA-
DEC-
DEC+

10
The LCD screen will switch to the information screen, as indicated in Figure 7, with pressing any
button.
Figure 7. 8409 HC LCD Information Screen
1. Target Name/Mount Position: displays the name of the target that telescope is currently pointed to or
the current mount position.
An object name, such as “Mercury” or “Andromeda Galaxy”: Name of the Star or celestial object
that the mount is currently slewing to, GOTO or tracking;
User Position: The mount is point to a user defined position, which could be a real sky object or
just simply due to press an arrow key;
Zero Position: Mount is at Zero Position. When set the mount at Zero Position physically, the
hand controller should display the same.
2. GPS Status: Indicates if there is GPS or GPS is connected to the satellite. HEM27 does not have a
GPS. The GPS status will be always OFF.
3. Right Ascension: Right Ascension of the telescope, or R.A.
4. Declination: Declination of the telescope, or DEC.
5. Azimuth: Azimuth of the telescope (north is 0º, east 90º, south 180º, and west 270º).
6. Altitude: Altitude of the telescope (degrees vertical from the local horizon - zenith is 90º).
7. Mount Status: Display current operation status of the mount.
Stop: mount is not moving;
Slew: mount is moving with an arrow key is pressed;
GoTo: mount is slewing to a celestial object using “Select and Slew”;
8. Slew speed: It has 9 speeds: 1X, 2X, 8X, 16X, 64X, 128X, 256X, 512X, MAX(1440X, or 6°/sec).
9. Current Time: display local time in a format of HH:MM:SS.
2.5. Install and Check the Hand controller Battery
The hand controller uses a CR2032 button battery to keep the Real Time Clock running. The HC is
shipped without battery installed due to shipping restrictions. Open the HC back cover with a good, size 1
(4mm) Phillips Screw Driver. With battery + sign facing up, slide the battery under two small metal hooks on
the positive side first. Then push the battery down to make a good contact. Make sure that two spring
contacts on the negative side are underneath the battery. If none of the metal pins in battery holder can be
seen after battery installed, the battery is not installed properly.
Target Name
Right Ascension
Mount Status
Azimuth
Altitude
Declination
N/S Hemisphere
GPS Status
Slew Speed
Current Time

11
Figure 8. Install a CR2032 battery
If the hand controller can’t display the correct date and time, most likely the battery is installed
wrong, or power is low and needs be replaced.
2.6. Bench Testing the Mount
Plug in the power and hand controller and turn the power on. Now you can bench test the mount
manually.

12
3. HEM27 Mount Assembly
NOTE: The HEM27 mount is a precision astronomical instrument. It is highly recommended that you
read the entire manual and become familiar with the nomenclature and function of all components
before starting the assembly.
Step 1. Set up tripod
The mount has a 102mm base. Thread the Alignment Peg onto the tripod head, on top of a tripod
leg or between two legs depending on the latitude. Insert the Accessory Tray through the center rod and
secure the setup by tightening Locking Knob from underneath.
Figure 9. HEM27 tripod top : LiteRoc tripod (left) and Carbon fiber tripod (right)
Step 2. Attach mount head
Remove the mount from the package. Retract the 2x Azimuth (Azi) Adjustment Screws from both
sides to leave ample space for the alignment peg to be fitted in between the 2x Azi Adjust. Screws. Remove
the 2x Azi Locking Screws from the mount base and insert them into the opening next. Secure the mount
head by tightening the Azi Locking Screws into the M6 holes on the tripod. An Allen wrench is stored in the
EQ base if needed.
Figure 10. Attach the mount
Level the mount by adjusting the tripod legs. Use the build-in Bubble Level Indicator or an external
leveler for this purpose.
Azi. Locking Screw
Allen wrench
Azi. Adj. Screw

13
Step 3. Adjust latitude
Without any payload, slightly loosen the 4x Latitude Locking Screws. Use the Latitude Adjustment
Knob to set the correct latitude value, as displayed in the Latitude Mark Window. Insert the Allen wrench
into the Latitude Adjustment Knob for more turning torque.
Figure 11. Adjust latitude
Two latitude ranges, 15~41° and 39~65°, can be set up for the mount head. To change the latitude
range from one to the other, both the Latitude Position Bolt and the Latitude Locking Screws need to be
moved to the correct locations.
To switch the latitude range:
Loosen the Latitude Locking Screws just enough to adjust the latitude setting to between 39~41°.
Tighten Latitude Locking Screws.
Unthread and pull out the Position Bolt. Remove and do not lose the two black sleaves. Insert
the Position Bolt to a new latitude position with one black sleave on.
Adjust the Latitude Adjustment Knob while holding the brass eyebolt until it lines up with the
Position Bolt. Insert another black tube and secure the Latitude Position Bolt.
Move the Latitude Locking Screws (one on each side) to the new locations revealed.
Lat. Lock Screw
Lat. Mark
Lat. Adj. Knob
Position Bolt
Eyebolt
Lat. Lock Screw

14
Step 4. Install telescope
HEM27 accepts a Vixen or a Losmandy-D dovetail mounting plate. The default is Vixen-type one.
Release the dovetail Saddle Locking Lever and slide the telescope dovetail plate into the saddle with Gear
Switch disengaged. Make sure that the arrow sign on the saddle is pointing forward. Tighten the Saddle
Locking Lever. Pull the lever and turn it to the position that the lever is parallel to the saddle to prevent it
interfering with the DEC unit during mount GOTO and tracking.
Figure 12. Dovetail saddle locking lever
If you have a scope using a Losmandy dovetail plate, please follow the following steps to convert
dovetail saddle from Vixen-type to Losmandy-type.
(1) Loosen the two socket screws (red circled), move the fixed block outward. Then tighten the
screws.
Figure 13. Convert dovetail saddle to accept a Losmandy-D plate (1)
(2) Remove the two blue circled screws and pull the dovetail saddle locking block from the saddle.
(3) Release the four screws (yellow circled in Figure 13) to separate the saddle from the mount. Flip
the dovetail saddle locking block and secure it onto the saddle from bottom of the dovetail saddle
(blue squares in Figure 14)
Locking Lever

15
Figure 14. Convert dovetail saddle to accept a Losmandy-D plate (2)
(4) Put the dovetail saddle back and retighten the four yellow circled screws.
Here is a dovetail saddle that can receive a Losmandy-D dovetail bar.
Figure 15. Dovetail saddle for Loasmandy bar
Step 5. Connect cables
Connect the Go2Nova® 8409 Hand Controller to the HBX port on the mount back. Plug in a 12V DC
power supply to the DC12V IN socket.
Figure 16. DC power and HBX ports

16
Step 6. Balance payload
No RA balance is needed for a HEM27 mount.
Turn the mount power on. Press number 9 to change the slew speed to max. Press ◄ or ► button
to slew the telescope to one side of the mount. Hold the telescope and disengage DEC Gear Switch to
check the balance. Release dovetail saddle locking lever and move the scope back and forth to adjust the
position. Tighten the dovetail saddle locking lever and engage the gear switch after balancing completed.
Figure 17 Balance the mount in DEC
Return the mount to Zero Position after balancing and engage DEC gear switch.
If a counterweight is needed for higher payload, please thread in the CW shaft into the CW shaft
mounting hole. Slide the CW up and lock the CW. Put CW shaft safety screw on. Move the CW to the
bottom of the CW shaft.
Figure 18 Engage DEC gear switch

17
Figure 19 HEM27 with optional CW shaft and a 5kg CW
STEP 7. Set Zero Position
The Set Zero Position command registers the current position as zero position. So before
registering, the mount should be physically set at Zero Position either manually or slewed by hand
controller. The Zero Position is defined as the telescope being on top of the mount head and pointing to the
North Pole (in northern hemisphere), with CW shaft mounting hole pointing to the ground. To register, press
MENU=>Zero Position =>Set Zero Position. Press ENTER to confirm.
STEP 8. Set hand controller
HEM27 mount does not equipped with a GPS receiver. Hence one need to manually enter the GPS
location or sync it from the App
To set up the controller, turn the mount power ON. Press MENU=> “Settings”:
Press ENTER and select “Set Time and Site”
Press ENTER. A time and site information screen will be displayed:
2020-10-01 12:01:36
UTC -300 Minute(s)
W071d08m50s DST: N
N42d30m32s Northern
Set Time and Site
Set Beep
Set Display
Set Guiding Rate
Select and Slew
Sync. to Target
Alignment
Settings

18
Set Local Time
Use the ◄or ► key to move the cursor _ and use the number keys to change the numbers. Use the
▲or ▼button to toggle between “Y” and “N” for Daylight Saving Time, or “+” and “-“ for UTC (Coordinated
Universal Time) setting. Hold the arrow key to fast forward or rewind the cursor.
In order to make the hand controller reflect your correct local time, time zone information has to
be entered. Press the ◄or ► key, move the cursor to the third line “UTC -300 Minute(s)” to set the time
zone information (add or subtract 60 minutes per time zone). For example:
Boston is “UTC -300 minutes”
Los Angeles is “UTC -480 minutes”
Rome is “UTC +60 minutes”
Beijing is “UTC +480 minutes”
Sydney is “UTC +600 minutes”
All the time zones in North America are “UTC –”, as shown in the following table, so ensure the
display shows “UTC -” instead of “UTC +” if in North or South America.
Time Zone
Hawaii
Alaska
Pacific
Mountain
Central
Eastern
Hour behind UT
-10
-9
-8
-7
-6
-5
Enter UTC
-600
-540
-480
-420
-360
-300
To adjust minutes, move the cursor to each digit and use the number keys to input the number
directly. Use ▲ or ▼ key to toggle between “+” and “-”. When the time information entered is correct, press
ENTER and go back to the previous screen. Note that fractional time zones can be entered.
Do not manually add or subtract an hour from displayed time to reflect Daylight Saving Time (DST).
Instead please select “Y” for DST when daylight saving time begins.
For other parts of the world you can find your “time zone” information from internet.
Set Observation Site Coordinate
The third and fourth lines display the longitude and latitude coordinates, respectively. The longitude
and latitude coordinates will be automatically updated when the GPS picks up satellite signals. “W/E”
means western/eastern hemisphere; “N/S” means northern/southern hemisphere; “d” means degree; “m”
means minute; and “s” means second.
Press ◄or ► key to move the cursor and using ▲ or ▼ key to toggle between “W” and “E”, “N” and
“S”, using number key to change the numbers. It is always a good idea to do your home work to get the
GPS coordinates before traveling to a new observation site.
The site coordinates information can be found from your smart phone, GPS receiver or via the
internet. Site information in decimal format can be converted into d:m:s format by multiplying the decimal
numbers by 60. For example, N47.53 can be changed to N47º31'48”: 47.53º = 47º +0.53º,
0.53º=0.53x60'=31.8', 0.8'=0.8x60"=48". Therefore, 47.53º=47º31'48" or 47d31m48s.
Select N/S Hemisphere
The northern/southern hemisphere will be determined by your latitude coordinate, with one
exception. If you are near the equator (within +/- 10°), you can choose your own N/S setting.
If the polar axis is aligned to the North Celestial Pole, then set the mount to Northern Hemisphere. If
the polar axis is pointing to the South Celestial Pole, set the mount to Southern Hemisphere. Press the ◄ or
► key to move the cursor and use the ▲or ▼key to toggle between “Northern Hemisphere” and “Southern
Hemisphere”.
2020-10-01 12:01:36
UTC -300 Minute(s)
W071d08m50s DST: N
N42d30m32s Northern
Daylight Saving Time

19
The site information is stored inside the hand controller’s memory chip. If you are not traveling to
another observation site, they do not need to be changed.
Check the Hand Controller Battery
There is a real time clock in hand controller. If hand controller lost its date and time, please check
the battery.
STEP 9. Perform polar alignment
BrightStar Polar Alignment
If you mount does not have an iPolar installed, or the pole star is not in sight, you may use two bright
stars with Polar Iterate Align to perform a coarse polar alignment.
(1) Level the mount and set it to the Zero Position. Align the telescope to the R.A. axis of the mount.
If a finder scope is used, adjust it to be parallel to the telescope optical axis.
(2) Use the HC (MENU => “Alignment” => “Polar Iterate Align”) to display the azimuth and altitude
position of several bright stars near the meridian. Select one that is visible at a high altitude as
Alignment Star A. Follow the HC instruction to move Alignment Star A to the center of the
eyepiece using a combination of the Latitude Adjustment Knob and the “◄” or “►” buttons.
Press ENTER to confirm when the star is centered. Next, select a bright star that is close to the
horizon as Alignment Star B. Center it using the Azimuth Adjustment Knob and the “◄” or “►”
button (the “▲” and “▼” buttons are not used here). Press ENTER to confirm the settings.
(3) The telescope will now slew back to Alignment Star A. Repeat the steps above. The iteration can
be stopped when it is determined that the alignment error has been minimized. Press the BACK
button to exit the alignment procedure.
NOTE: It is highly recommended to use an eyepiece with an illuminated crosshair for accurate centering.
NOTE: The movement of the alignment star in your eyepiece may not be perpendicular depending on its
location in the sky.
iPolar Polar Alignment
For a HEM27 with an iPolar, refer to iPolar Operation Manual from iOptron’s website to perform the
polar alignment, or steps briefly outlined below:
Download and install iPolar Software (first time use);
Connect a miniUSB cable between the iPolar and a computer USB port;
Click Connect and start polar alignment by following on screen instructions.
Figure 20. USB port on an iPolar electronic polar scope

20
4. Getting Started
In order to experience the full GOTO capability of GOTONOVA®technology it is very important to set
up the mount correctly before observation.
4.1. Setup the Mount and Polar Alignment
Assemble your HEM27 mount according to Section 3. Mount an OTA and accessories, and balance
the mount in DEC. Turn the mount power switch on. Check the date and site info. Perform polar alignment.
Always check if the mount is at the Zero Position when the mount is powered on, i.e. with the
counterweight shaft mounting hole or CW shaft pointing to ground, OTA at the highest position with its axis
parallel to the RA axis and the telescope pointing to the Celestial Pole. Check the hand controller diplay to
see if the Zero Position is displayed. If not, press MENU => “Zero Position” => “Set Zero Position”to
register the Zero position in hand controller. Or perform Searching Zero Position to set the Zero position.
4.2. Manual Operation of the Mount
You may observe astronomical objects using the arrow keys of a Go2Nova®hand controller.
Flip the I/O switch on the telescope mount to turn on the mount. Use ►,◄,▼ or ▲ buttons to point
the telescope to the desired object. Use the number keys to change the slewing speed. Then press 0 button
to start tracking. Press 0button again to stop the tracking.
4.3. Initial Star Alignment
Perform a simple one star alignment/synchronization after set up the hand controller to correct any
pointing discrepancy of the Zero Position and to improve the GOTO accuracy.
To perform “One Star Align,” press MENU=>“Alignment”=>“One Star Align”=>ENTER. The
screen will display a list of bright objects for you to select from. Select an object using ▲ or ▼ key. Then
press ENTER. After the mount slews to the target, use the arrow keys to center it in your eyepiece. Then
press ENTER. (More align details in 5.4)
An alternate way is to perform “Sync to Target.”Press MENU=>“Select and Slew”=>ENTER.
Browse over the catalogs and select an object. Press ENTER. After the mount slews to the star, press
MENU=>“Sync. To Target”, follow the on-screen instruction to center the star and press ENTER. You may
need to use the number keys to change the slewing speed to make the centering procedure easier.
4.4. Go to an Object
After performing these set-ups the mount is ready to GOTO and track objects. One of the most
common objects is the Moon.
To slew to an Object, such as Moon, press MENU=>“Select and Slew”=>“Solar
System”=>Moon=>ENTER. The telescope will automatically slew to the Moon and lock on it. It will
automatically begin to track once it locks on. If the Moon is not centered in your eyepiece, use the arrow
keys to center the Moon. You may use “Sync to Target”to improve the tracking.
You may also select other bright celestial objects to start with, such as Jupiter or Saturn.