Direct-drive structure
The strain wave reducer is driven directly by a servo motor. The drive train avoids belt slippage, missed steps and gear backlash for smooth operation with near-zero backlash.
ToupTek Astro
New release
ATLAS SH20
Strain wave drive equatorial mount
20–30 kg capacity · precise tracking · quiet operation
Switch modes with one tap
ATLAS SH20
Compact, powerful and versatile
Product images and overviewShow
ATLAS SH20 Strain Wave Drive Equatorial Mount
- Drive system
- Brushless DC motor (BLDC) + direct-drive strain wave reducer (100:1)
- Operating mode
- Equatorial (EQ) / Alt-Azimuth (AZ)
- Encoder
- Dual-axis 18-bit motor-side absolute magnetic encoders
- Periodic error (PE)
- Peak-to-peak ≤ 30 arcseconds
- Azimuth adjustment range
- ±6°
- Latitude adjustment range
- 0°–90° (dual-range scales: 0–60° / 30–90°)
- Mount weight
- 5.1 kg
- Counterweight shaft thread
- M12 × 1.75 mm
- Payload capacity
- 20–30 kg
- Connectivity
- USB-C / 2.4 GHz Wi-Fi / BLE 5
- Operating temperature
- −20°C to +40°C
Why choose the ATLAS SH20?
7 key advantages
Drive design
Servo direct drive
with strain wave reduction
BLDC servo motors and motor-side encoders
High-precision brushless servo motors work with dual-axis 18-bit motor-side encoders for faster high-frequency guiding response and more accurate positioning, with stable motion at both low and high speeds.
No belt adjustment
With no belt tensioning or aging to manage, the drive system needs no transmission adjustment during long-term use.
Quiet drive
The direct-drive structure and carefully tuned control algorithms keep operation virtually silent.
Factory PE report
Each mount includes an individual periodic-error test report, with periodic error of ±15 arcseconds.
Adjustable slew speeds and load modes
10 selectable speeds from 0.25×–1440× cover fine movement for visual observing and fast slewing to targets. Switch between Light / Medium / Heavy load modes as needed.
An in-house control system
with broad platform support
In-house hardware and software
Custom control hardware, drivers, firmware and apps form an integrated, expandable system.
Native client apps
Native PC, Android and iOS clients make mount control straightforward.
Open software ecosystem
Supports ASCOM and INDI and integrates with StellaVita for imaging.
Multiple connection options
Choose from USB-C / 2.4 GHz Wi-Fi / BLE 5 connection options.
Dedicated hand controller
The MHC has an 8-direction joystick, a LOCK switch, programmable buttons, a Wi-Fi hotspot and a coiled cable.
Lightweight and powerful
5.1 kgMount weight
20–30 kgPayload at 20 cm
The lightweight mount head weighs only 5.1 kg. It carries 20 kg @ 20 cm without counterweights and up to 30 kg @ 20 cm with counterweights, to support large-aperture, long-focal-length telescopes and complete astrophotography setups.
Multiple layers of protection
RA-axis brake engages on power loss
A mechanical brake on the RA axis engages automatically if power is lost, helping prevent the telescope from dropping or tipping.
Adjustable software limits
Altitude and meridian limits can be configured in software to help avoid equipment collisions.
Dual-axis mechanical home sensors
Encoders work with FRAM and mechanical home sensors to retain coordinates in real time through a power loss, and support hardware-level zero-position calibration in abnormal operating conditions.
Real-time collision monitoring
Both axes are monitored for load changes. When collision protection is triggered, the mount automatically reverses slightly and locks the main axis.
Electrical protection
Built-in overcurrent and overvoltage protection responds automatically to abnormal power conditions.
Park position lock
All motion commands are disabled after parking, making equipment installation and removal safer.
Audible alerts
The mount beeps when a command is acknowledged. Adjustable volume makes it easier to operate at night without repeatedly checking the display.
All-metal CNC-machined body
with a refined finish
All-metal CNC-machined body
Precision-machined from high-strength aluminum alloy, the mount is lighter without compromising quality and built for durability.
Fine matte anodized finish
The finely textured surface is wear-resistant and helps resist fingerprints.
Versatile silver-gray finish
The understated silver-gray finish continues the ToupTek Astro family look and pairs easily with other equipment.
Easy-grip adjustment knob
The larger knurled hand knob has rounded edges for a comfortable grip. It is easy to operate with gloves for winter adjustments.
Wide operating temperature range
Designed to operate from −20°C to +40°C, for use in both winter and summer observing locations.
*Heavy-load mode is recommended at low temperatures.
Dual AZ/EQ modes
Switch with one tap, no restart needed
Switch operating modes from the hand controller or app without restarting the mount.
EQ equatorial mode
For deep-sky astrophotography, long-duration accurate tracking, no field rotation and stable guiding.
AZ alt-azimuth mode
For visual observing, quick sky surveys, electronically assisted astronomy (EAA) and solar-system imaging, with intuitive operation.
Convenience built in
Power for your setup
DC IN 12 V: a 12 V, 5 A regulated power supply is recommended; use a field battery or AC adapter. DC OUT 12 V: supplies up to 5 A to accessories such as a camera, guide camera, dew heater or astronomy controller, helping simplify cable routing.
Dual-standard dovetail saddle
Compatible with narrow Vixen and wide Losmandy dovetails for direct mounting of widely used telescope tubes.
Standard counterweight connection
The standard M12 × 1.75 mm counterweight shaft thread lets you balance the setup with counterweights and increase payload capacity.
Two status indicators
The BT Bluetooth light and SYS system status light make power-on, tracking, parking and homing status easy to check.
Dual-range latitude adjustment
0°–90° (dual-range scales: 0–60° / 30–90°) with low- and high-latitude scale ranges covers the full range of observing latitudes.
Magnetic hex-key storage
The included hex keys store magnetically and can be used to install or remove equipment, or as extensions for extra leverage when tightening. They remain easy to handle outdoors in winter despite temperature-related expansion and contraction.
Structure and port guide
Package contents
- Mount head
- Hand controller
- Hand-controller cable
- USB cable
- Hex keys
- Periodic-error test report
- Quick-start guide
Specifications
| Item | Specification |
|---|---|
| Mount type | Strain wave drive equatorial mount |
| Operating mode | Equatorial (EQ) / Alt-Azimuth (AZ) |
| Drive system | Brushless DC motor (BLDC) + direct-drive strain wave reducer (100:1) |
| RA-axis drive | Brushless DC motor (BLDC) + size-20 strain wave reducer (100:1) + brake |
| DEC-axis drive | Brushless DC motor (BLDC) + size-17 strain wave reducer (100:1) |
| Motor encoder resolution | 18-bit |
| Periodic error (PE) | Peak-to-peak ≤ 30 arcseconds |
| PE period | 432 s |
| Maximum slew rate | 6°/s |
| Software slew-speed settings | 0.25×, 0.5×, 1×, 2×, 4×, 8×, 20×, 60×, 720×, 1440× |
| Hand-controller speed presets | 10× / 720× |
| Payload capacity | Maximum 30 kg @ 20 cm. No counterweight is needed when total OTA-side payload is no more than 20 kg; for payload above 20 kg, calculate and install counterweights according to Section 8.7 of the product manual. |
| Mount weight | 5.1 kg |
| Latitude adjustment range | 0°–90° (dual-range scales: 0–60° / 30–90°) |
| Azimuth adjustment range | ±6° |
| Saddle | Dual-standard Losmandy / Vixen dovetail (wide and narrow) |
| Counterweight shaft thread | M12 × 1.75 mm |
| Power input | 5.5 × 2.1 mm DC barrel jack, center-positive (12 V DC; power supply rated current 3–7 A, 5 A recommended; maximum device input current 5 A) |
| Power output (DC OUT) | 12 V, maximum 5 A; output always on |
| Software compatibility | ASCOM, INDI, native StellaVita support |
| Communication | USB / Wi-Fi / Bluetooth |
| Firmware upgrade | SH: upgrade via computer (USB / Wi-Fi) or mobile app (Wi-Fi). MHC: Wi-Fi upgrade only. |
| Home position | Mechanical zero position located by dual-axis Home sensors |
| Power-off brake | RA axis |
| Park function | Supported |
| Operating temperature | −20°C to +40°C |
| Safety protection functions | Software limits, stall detection, overcurrent protection |
| Warranty | 2-year limited warranty |