Heli-Max 1SQ

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Rear view of the 1SQ with motors operating
Front view of the 1SQ with motors at rest
The RTF version of the 1SQ comes with the accessories shown including transmitter batteries
With the canopy removed, the motherboard is clearly visible. Visible as well is the binding button at the upper left of the board
The optional Ram Models lighting kit specifically designed for the 1SQ
1SQ fitted with the same lighting kit. The high-intensity headlights and flashing red and green taillights aid with orientation under all normal flying conditions and allow the model to be flown at night

The Heli-Max 1SQ is an ultra-micro, palm-sized indoor/outdoor quadcopter introduced in October 2012 by Heli-Max, a division of Hobbico of Champaign, Illinois USA.

Available in both RTF and transmitter-ready Tx-R versions, the 1SQ comes with a 250mAh lithium polymer battery, spare rotor blades, a phillips head jeweler's screwdriver and a USB-powered charger. The charger, which resembles a USB thumb drive, has an LED charging status light. The LED glows a steady red to indicate that the battery is being charged and blinks slowly when the charge is complete. A rapidly flashing LED indicates a charging error, generally due to a bad battery pack. The packs, specifically designed for the 1SQ and available under part number HMXP1009, retail for less than US$7 each. Great care must be taken if an aftermarket battery is used. If the polarity is reversed, it will cause the immediate and catastrophic failure of a tantalum capacitor near the power leads on the motherboard.

Stickers on the front of the RTF version's 2.4 GHz transmitter indicate that it may be used in either Mode 1 or Mode 2 operation. Mode 2 is the as-shipped default. Although no mention is made in the manual as to how to switch modes, it is easily done by removing the four screws which hold the stick and trim tab cluster, removing the cluster, rotating it 180 degrees and reinstalling it with the Mode 1 sticker facing upward. The LCD display will show "MODE 1" as well. The RTF version comes with four AA-cell alkaline batteries for the transmitter. Although there is a rubber plug on the lower left side of the transmitter marked "RX CHG," there is no provision for an external charger used with rechargeable batteries.

The Heli-Max HMXE2123 "Battery Plug Adapter w/JST Plug" will adapt the JST-PH-2P plug on the stock battery to a standard male JST plug for use with a JST-equipped lithium polymer battery charger or other models with a standard JST plug.

The 1SQ uses Hobbico's SLT protocol, meaning that the transmitter will bind with other SLT receivers, such as those under the Tactic brand. The transmitter-ready version may be used with an existing four-channel Tactic receiver or, via the Tactic AnyLink adapter, used with a Spektrum, Futaba, Hitec, JR or Graupner aircraft transmitter.

Although similar to the Walkera QR Ladybird, the 1SQ is in fact based on the Nine Eagles Alien.

Flight characteristics

Stability comes from the Heli-Max TAGS three-axis gyro system, allowing it to be flown precisely in an indoor environment. The RTF version has a transmitter with a dual control rate setting, allowing the 1SQ to be flown in either a docile or aggressive mode of flight. While exceedingly stable, especially for such a small model, control input is highly responsive and forward flight rather fast. This responsiveness results in outdoor flight characteristics able to counteract winds of up to 5 MPH (8km/h). A poster on the RCGroups.com discussion board linked below reported success in 10 MPH (16km/h) wind conditions.

Flight rates

High and low control rates are selected by pressing the right stick - or the left stick in Mode 1 - before or during flight. The LCD display in front of the transmitter registers between 0 - 100% throttle. Moving the throttle stick to register between 30 and 40 while pressing the right stick prior to flight adjusts the responsiveness of the controls to the user's preference. The transmitter will emit a series of high-pitched beeps during this procedure and the model will not respond to throttle input. Default is 38 with the low rate approximately 75 percent of the high rate. This cannot be adjusted independently. Setting the rates to 75 and above will allow the 1SQ to do flips, but great caution should be taken to avoid crash damage to the model since the controls will be extremely sensitive at such settings.

Maintenance and repair

Very little maintenance is required in order to maintain the 1SQ in flying condition. The most common problem after a crash is the shifting of a motor within its cradle or propeller along the shaft, causing the propeller to jam. The motors are easily pushed back into place. If a propeller becomes pressed too far down on the shaft, the propeller is simply pulled upward. Distance between the bottom of the propeller and the top of the motor may be gauged with the blade of a razor knife such as an X-Acto #11.

Should a motor's shaft become bent or should a motor fail, it is replaced as a unit with its radial and mount. The motor to be replaced is unplugged from the board and the screw holding the radial loosened just enough to allow it to slide out of the frame. The procedure is reversed for the installation of the new motor and boom.

It should be noted that the right front and left rear booms are designed for clockwise rotation while the left front and right rear are designed for counterclockwise rotation. They are sold as pairs under part numbers HMXE2177 and HMXE2178 respectively.

Lighting kit

In May 2013, Heli-Max released a custom-fitted LED lighting kit from Ram Models Incorporated of Round Lake Beach, Illinois and distributed via Hobbico. The American-made kit, sold under part number RAM 191 and which retails for US$14.95, weighs .705 ounces (2g) and consists of two high-intensity white headlights and flashing red and green taillights/navigation lights. Installation is plug-and-play, although final installation techniques are left up to the modeler. The instruction sheet jokingly suggests using bubble gum as a means to attach the LEDs to the frame.

Though specifically designed for the 1SQ/Alien, it will work with other similarly sized models which utilize a 3.7V battery with the same JST connector. The low weight and low current draw of the kit do not inhibit performance.


  • Length including blades: 5.7" (145mm)
  • Width including blades: 5.7" (145mm)
  • Blade length: 2.16" (55mm)
  • Height: 1.37" (35mm)
  • Flying weight: 1.1 oz (31.2g)
  • Construction: Carbon fiber arms, polycarbonate body shell, composite frame, plastic motor mounts and plastic propellers
  • Radio system: Heli-Max TX410 2.4GHz transmitter with digital trims and LCD status display featuring battery charge; throttle setting in percentage of application; mode; dual rate and trim settings. Onboard electronics combine the receiver, speed controls and three-axis gyro
  • Battery: Heli-Max 1S 250mAh lithium polymer with JST connector
  • Minimum skill level: Beginner
  • Operator age: 14+
  • Catalog numbers (RTF/Tx-R): HMXE0834/HMXE0835
  • Requirements: RTF requires nothing more to operate; Tx-R requires a radio fitted with either the Hobbico SLT or AnyLink adapter systems

External links and references