iAFS3 - Uncategorized iOptron - Free user manual and instructions

Product Type	Electronic Inline Automatic Focuser
Model	iAFS3 (3")
Dimensions	94 × 133 × 108 mm
Weight	1062 g
Clear Aperture	68 mm
Maximum Payload	6 kg
Drawtube Travel	30 mm
Focusing Resolution	0.6 µm
Drive Train	Stepper motor with belt reduction
Power Supply	5V USB via Type-C port
Communication Ports	2× USB 2.0 Type-C
Computer Control	Yes (ASCOM and INDI compatible)
Automatic Focusing	Yes
Motorized Focusing Button	Yes
Manual Focusing	Yes, with mechanical override (powered or unpowered)
Temperature Sensor	Built-in
Camera Angle Adjustment	Yes, via grub screws
Zero Backlash	Yes, due to iLock™ technology
Position Memorization	Yes, during power off
Position Over-Run Protection	Yes
Warranty	One year limited
Included Accessories	Visual back (2"), USB-C cable
Compatible Telescope Adapters	Optional: M68×1 (camera), M117×1 (telescope) and more

Frequently Asked Questions - iAFS3 iOptron

How do I connect the iAFS3 to my telescope?

First select a proper telescope adapter (e.g., P-FA30-M1170 for GSO RC10-16). Back out the three position screws and locking screw on the focuser body, insert the adapter, then thread the position screws back in a quarter turn. Finally, tighten the locking screw after adjusting the focuser angle.

Can I use the iAFS3 manually without power?

Yes. You can turn the Manual Focusing Knob to adjust focus even when the device is not powered. The focuser position is maintained mechanically due to iLock™ technology.

How do I control the iAFS3 from a computer?

Install the USB-Serial PL2303 VCP driver and the iOptron Focuser ASCOM Driver. Connect the focuser via USB-C to your PC, then launch the iOptron Standalone Focuser software. Select the correct COM port (auto-detection available) to control the focuser.

What is the purpose of the built-in temperature sensor?

The temperature sensor monitors ambient temperature and can be used to compensate for focus drift due to thermal changes. The temperature reading is displayed in the control software.

Does the iAFS3 support ASCOM and INDI?

Yes, it is ASCOM and INDI compatible. You can connect it to imaging software (e.g., N.I.N.A., Ekos) by selecting "iOptron Standalone Focuser" from the ASCOM focuser menu.

How do I attach a camera to the iAFS3?

You can thread the included visual back (2") directly onto the focuser camera end. Alternatively, use an optional camera adapter like P-FA30-CA (M68×1). Fine angle adjustment is possible via three grub screws.

What is the maximum payload for the iAFS3?

The maximum payload is 6 kg (13.2 lbs), suitable for most medium to heavy imaging setups.

How do I clean the iAFS3?

Use a soft, dry cloth to wipe the exterior. Avoid solvents. Keep the drawtube clean and lubricated only if specified by iOptron. Do not disassemble internal components.

Can I firmware upgrade the iAFS3?

Yes, firmware upgrades are performed via one of the dual USB-C ports. Download the latest firmware from the iOptron website and follow the provided instructions.

What does the iLock™ technology do?

iLock™ passively locks the focuser position when movement stops, using a lead worm mechanism. This prevents focus shift even when the telescope angle changes or heavy payloads are attached.

USER MANUAL iAFS3 iOptron

Electronic Inline Automatic Focuser With iLock™ Technology

Instruction Manual

Feb 2025, Version 1.0

iOptron reserves the rights to revise this instruction without notice. Actual color/contents/design may differ from those described in this instruction.

Introducing the most versatile inline auto focuser: the iOptron iAFS ^TM focuser with iLock ^TM technology! Utilizing a lead worm movement is the key to the iAFS focusers patented design; this method passively locks it at the exact position when movement is stopped, maintaining focus for most any sized payload even as the instrument angle is changed. The iAFS incorporates three movement control modes, USB (computer control), on board directional buttons (for powered manual adjustments) and a manual focus wheel to override the motorized adjustment. Other features include a built-in temperature sensor, dual USB-C ports, solid all metal body, fingerprint resistant surface, 0.6 micron resolution, and position limiters to prevent over runs. It comes standard with a 2 inch visual back, and optional telescope adapters to fit various OTAs are available. The iAFS focusers will be available as the iAFS2 two inch model and the iAFS3 three inch version.

Features:

• High precision stepper motor with position over-run protection
  • Built-in temperature sensor
• Built-in CAA
• Quiet, smooth operation
• Compact and lightweight
• Zero backlash
• Dual USB-C port for computer connection and firmware upgrade
  • ASCOM and INDI compatible
• Manual adjustment (powered or unpowered)
• Position memorizing during power off
• Compatible with most OTAs with proper adapter

Package includes:

• 1X FA20 iAFS2 2" auto focuser w/ 2" visual back or 1X FA30 iAFS3 3" auto focuser w/ 2" visual back
• USB-C cable

Accessories:

P-FA20-CA iAFS2 camera adapter M48X0.75
P-FA20-M0800 iAFS2 telescope adapter Askar/65PHQ and other M80X1
P-FA20-M0835 iAFS2 telescope adapter Celestron/C11 and other M83.5X1.5
P-FA20-M0900 iAFS2 telescope adapter GSO/RC6, RC8 and other M90X1
P-FA30-CA iAFS3 camera adapter M68X1
P-FA30-M1170 iAFS3 telescope adapter GSO/RC10,12,14,16 and other M117X1

Others are coming.....

iAFS Parts

Attach Focuser to Scope

1. Select a proper telescope adapter, such as FA20-M0900 for RC6 telescope.

Close-up of a black plastic cap with ridged edge and flared rim (no text or symbols visible)

1. Install telescope adapter. First, back out three (3X) Position Screws and the Locking Screw on the iAFS body.

Next, insert OTA Adapter (FA20-M0900 shown) into the focuser body.

Close-up of a hand holding a black optical instrument with a red arrow pointing to the lens (no visible text or symbols)

Thirdly, thread 3 Position Screws all the way in, then back out a quarter turn or so. The OTA adapter can be rotated freely but can not be pulled out from the focuser body.

Close-up of a black cylindrical device with a red arrow pointing to a small component, no visible text or symbols.

1. Thread the focuser onto the OTA (RC6 is shown here). Turn the adapter ring to secure the iAFS onto the scope.

Close-up of a black IAFS 2 mechanical device with red arrows indicating rotation and adjustment (no text or symbols on the device itself)

1. Tighten the Locking Screw to lock the focuser. Release the Locking Screw to adjust the focuser angle. Finally tighten three Position Screws after angle adjustment.

Attach Camera Adapter

1. If a visual back is used, thread it onto the focuser camera end.

1. If an optional camera ring (P-FA20-CA or P-FA30-CA) is used, thread it onto the focuser camera end.

Close-up of a black IAFS 2 optical sensor module with no visible text or symbols on the device itself.

There are three grub screws for fine angle adjustment between the focuser and an accessory, such as a filter wheel. A thread conversion adapter may be needed.

Close-up of a black camera lens with orange circular button and directional arrows, next to a digital camera (no text or symbols on the lens itself)

Adjust iAFS

1. Connect to a 5V power source via USB port, such as a SmartPhone charger.
2. Press arrow button to move the focuser forward or backward.
3. Short press the button for fine adjustment.
4. Turn the Manual Focusing Knob to adjust the focus, powered on not powered.

Connect to a Computer

1. Download and install USB-Serial PL2303 VCP driver
2. Download and install the iOptron Focuser ASCOM Driver Installer from iAFS product page and install it.
   https://www.ioptron.com/v/ASCOM/iOptron_Focuser_ASCOM_DriverInstaller.exe

1. Connect any one of the focuser USB2.0 port to a PC USB port using included USB-C cable. The focuser will get the power from the USB port.

2. Click iOptron Standalone Focuser icon located on your computer desktop to launch the focuser.

1. Connect the focuser by either "Auto Detection" or select a COM port. Click OK.

1. After the focuser is connected and a control interface is launched, you now can control the focuser.

Set how many steps you want the focuser to move in Nudge Steps, here is 100 steps. Press +100 or -100 button to manually move the focuser forward or backward.

You also can set up the Maximum Steps by click on Change button.

The other functions are self-explained.

1. When using an imaging software, choose "iOptron Standalone Focuser" from Image Software ASCOM Focuser setup menu to connect the iAFS to the Imaging Software.