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Knife 200/240 - building guide

Scarab Knife 200/240 Build Guide 


the Scarab Knife 200/240 has been called the easiest and fastest build of any mini-quad by the first pilots flying them - it does requires soldering skill and good PC skills to check RC Tx setup, such as Taranis, when connected by USB to a PC/Mac to check RC = 1095/1500/1905 uSecs in the CHROME CleanFLight UI - ability to use hand tools - understanding of how Loctite is used on threads of critical screws and grub screws  (and also how to heat screws with a soldering iron tip to soften Loctite - then remove grub screws without damaging the heads)

RISK - New users must understand RISK in hobby FPV aviation DIY - as the builder you will become the manufacturer and legally responsible for the conduct of the aircraft  - see T&C link bottom of all pages to for a better understanding of RISK in RC drones - don't expose yourself to risks

Tools used / required - all tools below are Excluded 

  1. Hakko FX888 temperature controlled soldering iron ; or similar
  2. Amtech 223 flux paste for soldering correctly
  3. Wire strippers
  4. Wire cutters
  5. small long nose pliers
  6. Hex tool 2mm
  7. Hex Tool 1.57mm pro tool
  8. Phillips #1
  9. Diamond file round "O" tip
  10. Diamond file flat
  11. 20mm standoff (included in kit) - this tool used to wind the shorter 6mm standoffs into place
  12. Loctite - blue
  13. micro USB cable
  14. 8mm spanner for engine/prop tightening - T-Bar is best
  15. 12mm spanner for GoPro nut
  16. 5.5 socket for nylon nuts - optional


Assemble stages overview

  1. Soldering stage - ESC and mini Andromeda connections
  2. Assembly phase 
  3. Install FPV antenna - mount FPV Tx and Camera
  4. CleanFlight UI install
  5. RC setup - bind Rx
  6. Mount RC Rx and set antenna at 45° on zipties - secure with heatshrink
  7. RC setup - calibrate your RC Taranis Tx to 1095/1500/1905 and set modes - set failsafe condition and check
  8. Motor directions setup in BLHeli - via CleanFlight UI
  9. Motor check - any descending motor speeds up
  10. Learn Arming / Disarming using sticks 
  11. Wear eye protection - then install props
  12. fit props - Tethered testing (hand maiden) in ACRO mode
  13. Hover test - 1 min land and check all screws tight
  14. Maiden flight in area of soft long grass
  15. Hover endurance testing and timing
  16. Temperature check on all components
  17. FPV range check
  18. normal ops commence 



  1. The perfect workbench is clean and well lit and well ventilated for soldering - and if anything falls to the floor - you should be able to find it - ie not outside over the lawn grass
  2. STATIC can and will damage electronics - wear cotton clothes and ground your hand before picking up any PCB like the flight controller
  3. A cheapo soldering iron can be leaking voltage thru the tip - please just get a Hakko iron
  4. DO NOT open all the sealed packs at the start - only snip open pack compartments as needed - as the packs are logically grouped
  5. Take a minute to go back to the product website pages and review notes, warnings and PHOTOS
  6. Dull down the sharp edges of all carbon plates using diamond files  - it is important to do this to prevent accidental cuts and damage to wires insulation - skipping this step can result in RISK of serious electrical short circuit if the carbon cuts any wires insulation - caution - carbon dust must NOT be inhaled or swallowed - do this task outside in a well-ventilated area. be sure to smooth the camera mount plate rear side and both sides of the gell balls holes in the camera mount and upper (larger plate)
  7. Insert the 4 white gel balls into the upper plate - push and rotate the balls - do NOT use sharp tools - then assemble the camera plate + GoPro pivot + red washer and with loctite - then carefully push the gell balls thru the 4 holes - one by one - to attach the camera plate to the upper frame plate - Place the entire top plate (combined with gel balls and camera plate) to one side now. 
  8. Install the 2 booms to the lower plate using 8 screws - M3*8
  9. Install the 4 x 6mm black nylon standoffs to the upper side of the lower plate - nuts on bottom side

Scarab Knife - Carbon airframe assembly


Soldering Phase 

connection diagram for naze32 AIR32 Knife 200/240 wiring
For FrSky X4R Rx follow the wiring diagram above (includes A2 Telemetry)

For all other Rx 6Ch such as Spektrum or Futaba or Hitec use this wiring diagram


  1. Warning - DO NOT attach other devices to the Knife 200 5v D bus - especially Buzzers or LMA which have a high risk of RFI and may conflict causing ESC sync issues, overloading of the 5v Regulator etc resulting in RPM issues and crash - at your own risk ....  If you loose your model ALWAYS use Taranis RSSi function to find it - or fit a LOC8TOR device which is far superior to any LMA
  2. C Install the Black XT60 to the mini-Andromeda - then soldering - apply heat rapidly with a large tip iron - do not overheat the PCB by holding a small iron too long ; or using a small tip with a low heat capacity will cause the XT60 to be overcooked slowly - large tip - short fast solder join with Amtech 223 flux - make sure to set the XT60 outward slightly - tilted out by 5° is best
  3. Install the single red 5v wire to the 4.5v + position - (it is NOT necessary to connect a GND wire to 4.5v  - only the red wire) then the connector side (gold) is then inserted into ESC #1 centre vacant hole slot to power the AIR flight controller 
  4. lay all four ESC out on the lower frame (above photo) to accurately estimate wires lengths -  trim wires from motors and ESC - solder ESC red/black to Andromeda - at this point the andromeda is NOT connected yet to the frame (see below)
  5. On the 4 motors cut away the GBC and strip the wires - prepare/expose the ESC by using small scissors to neatly cut away the top out edge of the clear heatshrink - desolder the existing wires - NOTE - be very careful not to disturb the small resistors sitting between the 3 wires on the CarbonBee ESC - tip = by default swap over 2 wires on the back-left and front-right motors 3-phase - as diagonal motors rotate opposite in pairsSoldering the ESC & motors to the PDB 
  6. Install all the ESC in place using the thermal heatpads - tie down the ESC with a ZIP tie - the ESC must be tied at the FRONT of the booms
  7. Install motors with 2 screws each  M2*6 - use Loctite - this includes checking your Grub screws and applying a very small amount of Loctite if necessary
  8. Route the REAR ESC controller wires under the position where the mini-andromeda will be located
  9. Install the FPV Tx onto the bottom of the long 1mm mount plate so the switches line up with the slot - be sure to use the heat-transfer pad to draw heat to the deck - secure with a zip tie at the detent groove position
  10. Install 4 x 15mm posts for the rear tray, 15mm shiny aluminium - and 2 posts for the front RC Rx tray - see photos (below)
  11. Connect the 1177 camera using the short orange FPV wire (4 pins side to cam ; 3 pins side to front of mini-andromeda) - NOTE - at MWC we found that the 1177 camera should be covered with COPPER tape - wrapped - to shield RFI from leaking out of the Camera to the Rx receiver - copper shield tape is sold here - use the tape supplied in the kit initially
  12. Connect the FPV TX using the short yellow FPV wire (yellow 4 pins side plugs into the FPV Tx) - NOTE - the 200mw FPV TX antenna mount can be easily reinforced by adding additional solder to BOTH sides of the antenna mount - hold the iron long enough to allow the solder to flow thru the PCB hles - be sure to use AMTECH 223 flux paste
  13. lock the two mid-trays in place using M2 screws assembly of Knife 200/240 installed electronics
  14. Install the 6 RED 25mm standoffs using M3 screws
  15. mini-andromeda - Use the white nylon 20mm standoff as a tool to screw down the 2nd layer of short 6mm black standoffs (to remove the tool grip the black standoff with the tip of your needle nose pliers) - the mini andromeda is now firmly installed (blue LED to front - Black XT60 to left side - make sure nothing from andromeda shorts to the CF below !
  16. Bind your RC Rx - For X4R hold down the F/S button while powering it with 5v - in conjuction with Taranis BIND activations - see our Taranis page for details
  17. Prepare the PARIS Sirius™ AIR Hero•32 Rc connector - the neatest solution is to solder the SBus connector direct to the X4R - see photo - allow enough length in the wires to rotate the X4R 90° sideways (we also cut off all RC pins as they are not needed) - apply Velcro to the lower side of the X4R and the Rx mount tray 
  18. For the latest 2017 Andromeda90a-OSD - the pins on the AIR3 are not used - so the air3 ESC inputs are soldered directly to the AIR3


    or for other builds with Andromeda50a - see below
  19. connecting the FrSky X4R to the Naze32 AIR32 autopilot Knife 200/240
  20. Ensure the 1177 camera - sitting on the special SLOT - can tilt back fully and is not blocked by the Rx
  21. If you have an (optional) VLVSS cell-by-cell voltage telemetry you can fit it to the top of the FPV deck to provide in-flight voltage via Taranis X4R A2 port now
  22. Mount the Flight controller PARIS Sirius AIR Hero•32 with pins facing forwards - apply the 4 x Phillips nylons screws
  23. Connect the 4 motor ESC control wires - M1 wire will have the RED 4.5v wire inserted into the centre
  24. Route the RC antenna out to 2 long zip ties - set at 45° downward - then lock the antenna in place using the heatshrink tubes supplied, and a lighter or heat source to shrink them
  25. Double check all wires are correct polarity - last chance - all RED wires must be connected to + ; nothing shorted to GND 
  26. Feed the FPV tx thru the top deck hole (MAKE SURE THE FPV ANTENNA DOES NOT SHORT TO THE CARBON FRAME - use heatshrink or tape to insulate the antenna base in the area around where it passes thru the carbon upper plate - NO PART of the FPV Tx can touch the carbon frame) - then Connect the FPV Tx antenna to prevent meltdown (if the antenna is not fitted and the Tx powered up -  the FPV Tx will overheat and be permanently damaged unless the Tx antenna can dissipate the power) - for long periods of bench testing make sure a fan is blowing over the Quad - NOTE Do NOT over tighten the FPV Tx as you may sheer off the mounting - use a small "nip" and Loctite OPTIONAL (not included) purchase the extension cable HERE and Nimbin antenna (not included) - then side mount the bubble antenna "Wing" , this will also allow you to mount a larger/longer battery 
  27. FPV Tx - Antenna re-inforcement - the FPV Tx antenna can be re-inforced by adding addition solder/flux to the GND mount - Be sure not use tools/wrenches as excess torque will strip the antenna off the PCB of the FPV VTx - even when re-inforced - in a crash it is important that crash forces only effect the flex wire - not impact the FPV Tx itself
  28. for maintenance access - undo top 6xM3 screws
    PROPS ARE OFF - not fitted
  29. Connect the main LiPo  XT60 - check blue LED face forwards and Red backwards - the inner LEDs should be tilted UP and outwards ; the outer LEDs face straight back - NEVER connect or disconnect ESC plugs when powered up - always power down first !! Live ESC connections if you make a mistake can damage the Flight controller - don't RISK it - power down each time.
  30. Connect the Hero•32 to CleanFlight 1.1.0 or later - to set up your Tx - the process involves looking at the CF Chrome UI on your PC whilst confirming all Channels are correct direction for Mode 2 - and centres are 1500 exactly (Sbus) ; and the range/travel is 1095->1905 for all channels ; then check mode switches are working and note well switch positions for ACRO ; Horizon ; LEVEL and AirMode if used
  31. You do not need to do anything to the AIR Hero•32 itself
  32. Quit CleanFlight and launch the BLHeli 14.3.01 or later App - select CleanFLight as the interface - you can now test all motors are correct and confirm motor directions - You do NOT need to change any settings in BLHEli - they are correct for the 3100kv motors - you only need change motor directions and confirm engine numbers - Quit BLHeli
  33. re-launch CF and familiarise yourself with arming and disarming without props fitted - see sticks cheat sheet for Hero•32
  34. Motors will spin at arm - and you can verify that all motors are responding to tilt - any motr going down must speed up
  35. Wear eye protection - commercial safety impact glasses are best - Props can cut!
  36. Install props  (only use tapered HQ 4*4.5 props supplied - other props can overload the system temps)
  37. Hand maiden is a form of tethered power / response checking - either hold the quad firmly by the center - or mount/tether it on a large block of foam so you can see it moving slightly when tied down 
  38. We prefer to grip the Quad tight and hold it away from the body - away from fingers and eyes - check the props cannot reach  fingers - then -> Power up ; select ACRO ; and ARM - at low throttle check gyro responses.  Disarm and power down
  39. Disconnect the FPV antenna and feed it thru the upper deck - then reconnect it to FPV Tx - we always secure FPV SMA connectors with a drop of Loctite - the reason the FPV is mounted lower is that in a crash the antenna will "flex" and the FPV Tx remains less exposed to impact
  40. You can now close the Top-Deck - using 6*M3x6 screws ; the 1177 camera should fit perfectly (tilted up) - ensure nothing is shorting to the top deck
  41. For any future USB connections or tuning you only have to undo 6 M3 screws -pivot the deck around the FPV antenna - connect USB - make all changes and save - then close up again
  42. The battery requires a combination of Velcro on the lower side - and the strap ; the strap is effect in the rear position or the centre position - see photos
  43. Hover test - 1 min land and check all screws tight
  44. Maiden flight in area of soft long grass
  45. Hover endurance testing and timing - establish a safe flight time - then subtract 2 mins
  46. Temperature check on all components - ESC and motors
  47. FPV range check
  48. normal ops commence - most pilots are cautious with their first battery then go wild and crash on the 2nd battery - gradually expand your skills - it does not happen in 1 battery
  49. Carry tools and regularly check bolts are firm - tight 
  50. Always avoid take off and landing in dust or dirt - it is just poor airmanship !
  51. Don't Fly closer than 30m to another person
  52. Noise can get you / other pilots banned from large areas of public land - if anybody complains - avoid conflict, thanks them for their comments,  ask them if there is a better side of the park/time to share the space and fly and move elsewhere - avoid conflict 
  53. After the first few flights check all screws are nipped tight - regular pre-flight checks and post flight checks are important

 scarab-knife-200-lower side - Antenna setup

Alternate Assembly options

Option 1 - build with Titanium screws M3 from MWC - optional part - to save weight

Option 2 - build with booms fitted to the TOP deck 

Option 3 - build with booms fitted to top deck and motors facing down - pusher props

Option 4 - fit a 2nd Pico-camera for landing - facing forward / down and operated by switch ( a race camera faces up but can be difficult to land as you have no vision downward in the hover) - an advanced technique for landing is to fly to the LZ aggressively and apply hard yaw - at the moment of inertia (just before Quad flies off again -) cut power to land

Option 5 - fit a FrSky FBVS-01 - see photo below for this option = access the mini-Andromeda and connect the input to any ESC 16.8v ; then purchase a 4 pin wire HERE and move the wires Red/Blue as shown in photo below





Camera tilt notes - by grinding the slot bigger/deeper at 45° you can set the 1177 camera to a shallow angle  - use a flat diamond file - this is OPTIONAL and not required - only for noobs who wont be ready for a heavy tilted CAM

  1. In the photo below you can see the FPV camera and the Yi camera are at the same angle
  2. RC Rx at 45° out to the side - notice the RC antenna go down and the FPV Tx is vertical in forward race angle flight



NOTES for Yi - when flying a heavy payload such as Yi HAD camera - limit full power to 10 secs to control heat in motors - DO NOT USE BULLNOSE props - use only the supplied HQ 4x4.5 tapered props for the 2203 motors.

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