Copter 6025-1

The is a tiny tiny coaxial aluminium frame helicopter with a gyro and infrared controller. A small vertically mounted tail rotor is used to provide fast forward and backward elevation.

• Back to main helicopter page
• RCGroups 6025-1 w/gyro thread
• RCGroups Sanhuan 6025-1 thread

Specifications

• Motor: 2 solid motors for coaxial, 1 tail motor for elevation
• Remote: Infrared, 3-band switch, 3 channels, yaw trim-dial, integrated charger, 6x AA batteries
  • Controls: Elevator (for/aft), yaw (rotate), throttle (lift)
  • No spring on throttle stick
  • Gyro: Rate mode for coaxial yaw stability
• Battery: 60 mAh 3.7V (1-Cell) 2.1 grams Lithium-Polymer
  • Charging connection on bottom next to power-switch
  • Charging: 15-20 minutes
  • To disengage charging mode, move throttle stick up and down after disconnecting
  • Runtime: approx. 3-4 minutes
• Soft cut-off on low battery
• Weight: 16.3 grams
• Dimensions: 113x22x60mm (LxWxH)
• Main rotor diameter: 110mm

Sanhuan documents:

• Sanhuan Copter 6025-1 Mini-X product page - Store page
• Sanhuan Copter 6025-1 operation manual
• Sanhuan Copter 6020/6020-1/6023-1 operation manual
• Related: Rexx Nano manual - de, en, fr, nl languages

Setup

• For the first 5 flights, only run the battery down to 50%, 1.5 minute flighttime, it will help lengthen the life of the LiPo
• If it swings or wobbles when in hover, try to fasten one or both blades (upper/lower)
• Let the motors cool off after a flight, 5-10 minutes
• Check the tail rotor for plastic residue left from the manufacturing
• To enter forward flight mode, remove the tail fin, boom support, and skids, I think this is how it should fly by default! Weight: 15.1 grams
  • Optionally, bend the skid support screw-tabs down to raise the body above the on/off-switch sticking out. Note that the tabs will now catch most of the force on a crash and will eventually break off. Aluminium doesn't bend much.
• When on crash course, immediately push/kill the throttle to avoid unnecessary motor and blade wear
• If necessary, only use silicone oil to lubricate the shaft, tri-flow is petroleum based and will weaken plastics
• At all cost prevent added oil from reaching and entering the motors, the performance will degrade substantially
• Its metal frame and general good design allows for an amazing amount of improper handling and crashing without much or any damage at all, 1.5m free-fall no problem
• If the copter unexpectedly loses power and the controller LEDs begin to blink when throttle stick is at full, recharge the controller batteries
• Also, power loss can happen if the infra-red signals cannot be reflected/bounce of walls, i.e. in large rooms or outdoors
• To change the infrared band/channel (thanks to Raleigh [1]):
  1. Select the channel (A, B, C) on the controller
  2. Turn on the copter
  3. Turn on the transmitter
  4. Move the throttle stick all the way up then down
  5. Your copter is now on the new channel
• If a rattling or flickering noise start to develop, it's likely the lower-part of inner coaxial main shaft grinding against each other, add a small dot of silicone oil (I used 3000cSt) between the two gears to prevent this, make sure no excess oil reaches the smaller gear/motor

Possible tweaks

• Mount small E-flite battery between the skids
  • Replace battery with higher capacity E-flite battery [2]
• Removable battery with connector
  • Unsolder from circuit and use small connectors [3] [4] [5]
• Improve cooling of the motors
  • Metal fins, funnel, thermal grease
• Replace metal screws with nylon
• Use higher quality LiPo batteries
• Connect batteries in parallel for double capacity
  • E-flite BMCX/MSR 110mAh 1S 3.7V 3.4 grams [6]
  • OUTRAGE NRG15 3.7V 130mAH 15C [7]
  • ZIPPY 70mAh 20C 1S 1.5 grams [8]
  • ZIPPY 100mAh 20C 1S 3.0 grams [9]
  • ZIPPY Flightmax 138mAh-V2 1S 10C 3.7 grams [10]
• Balance weight and flight performance
• Disable LED lights
• Swap controller trim-pot polarization
• Program a better controller
• Different size flybar weights
• Swap the left and right control stick [11]
  • For Throttle and Yaw on left and Elevation on right

Battery

Standard battery

The standard battery is a 3.7V 60 mAh 2.1 grams Lithium-Polymer cell. From my tests, the standard controller charger does a good job packing power. Comparing it against a dedicated Bantam BC6, it supplied the same power/cut-off, 59-62 mAh. The controller seems to charge at a rate of 0.2-0.3 mA. An ideal charging rate would be 1C, or 0.06A.

Doing a stationary test on two different copters and averaging the results, I found the following battery drain:

• Power-on standby: 0.02A
• Minimum driving throttle: 0.3A
• Full throttle: 0.71A
• Both motor stalled: 1.4A
• Going right: 0.57 (decreases 0.14A)
• Going left: 0.75 (increases 0.04A)
• Forward and backward tail motor: 0.15A
• Full throttle and forward 0.85A

The stall amperage suggests that the standard cell is capable of 20C, i.e. 20 times the discharge rate of the cell's capacity, how fast it can supply the electrons.

• 

  Charging at 0.1A using the Bantam BC6, exactly 61 mAh

• 

  Discharging at 0.5A using the BC6, 55 mAh

• 

  Discharging at 1.0A using the BC6, 28 mAh

As the graph shows, the supply voltage drops considerably when the load increases. Thus it's important to minimize any unnecessary load and mechanical resistance.

Upgrade 70 mAh battery

This is the supplied replacement battery for the 6025-1 copter. It's a 3.7V 70 mAh 2.2 grams Lithium-Polymer battery. It comes packaged with one wire insulated with tape, preventing short-circuiting. Optimal storage voltage for LiPo batteries is 3.7V (fully charged 4.2V, depleted 3.0V), it came with 3.8V and 40 mAh pre-charged, which is ideal.

• 

  After 5 half-cycles for conditioning, full capacity hold 65 mAh

• 

  Discharging at 0.5A using the BC6, 59 mAh

• 

  Discharging at 1.0A using the BC6, 50 mAh

• 

  Factory charge, 40 mAh

Now that it's given that this is only a 65 mAh (avg. of 3 charges) battery, ideally, this hould give ~8% more flight time or 15-45 seconds.

Flight times

This is a list of recorded flight times. Setting: continuous flight, general hovering, forward flight, up/down, until throttle is at maximum and battery can't supply the power needed to provide enough lift.

• Red, 60 mAh, new white-top replacement motors, lubricated, usb-charged, 16.5 grams:
  • Flight #1: 3m28s
  • Flight #2: 3m35s
  • Flight #3: 3m52s
• Yellow, 60 mAh, no fins, no tail support, no skids, front heavy aka. forward flight mode, no tail motor use, only rattling lubricated, usb-charged, 15.0 grams:
  • Flight #1: 5m37s
  • Flight #2: 4m55s
  • Flight #3: 5m01s

Spare parts

List of spare parts and accessories for the 6025-1:

• Copter MINIX Heli 6025 70mAh Lipo Battery [12] [13]
• Copter MINIX Heli 6025 Landing Skid [14]
• Copter MINIX Heli 6025 Tail Main Blade Set [15] [16]
• Copter MINIX 6025 Tail Rotor Blades [17] [18]
• Copter Mini X 6025-1 Motor [19]
• Copter Mini X 6025-1 Tail Boom w/ Tail Motor [20]

Accessories:

• Copter V-MAX/MAX-Z 6020 USB Cable [21]
• RC Pro X Aluminium Box for SanHuan Copter Mini X 6025-1 [22]
• 3DPro AluSafe Portable Aluminium Case for Walkera 4#3A/B, CB100 [23] - little bigger, no pre-fit

These suppliers offer original 6025 spare parts:

• rc711.com - 6025-1 spare parts
• rc-fever.com - 6025-1 spare parts
• okhobbu.hk - good prices
• precisionmicrodrives.com - motors
• yessuprise.com - 6025-1 spare parts

Similar mini helicopers

• Nine Eagles Free Spirit Micro 210A [24]
• E-flite Blade mSR [25]
• SanHuan Copter 6023-1 [26] [27]
• E-flite Blade mCX [28] [29]
• Nine Eagles Solo [30] - Revell Proto CX (rebranded) [31] [32]
• Sanhuan Copter 6023-1 [33]
  • Sanhuan Coper 6020-1 [34] - dash one denotes gyro version [35]

References

• Sanhuan Copter 6025-1 Mini-X product page
• SanHuan Copter 6025-1 RTF
• 6025-1 Coaxial Helicopter w/Gyro - rcgroups.com
• 2010 NEW! Copter MINIX Super Mini 3ch Metal Infrared RC Helicopter w/ Gyro, pictures
• Anybody else seen this, 150 mah micro battery by eflite
• Nine Eagles SOLO/Free Spirit mods