Posts Tagged ‘mod’

Review: MicroHeli Trex 700 MOD 1.0 Gear Conversion

June 28th, 2009 No comments

The ultimate main gear upgrade to strength the Trex 700 drive train.

Trex 700 Main Gear Mesh Continued…

June 23rd, 2009 No comments

When I first built the Trex 700 one of the many issues I found was the main gear moves several mm up and down (in addition to all the meshing issues).
I simply put it down to poor manufacturing tolerance and accepted it, but as it turns out this movement up and down is due to poor assembly of the “main oneway bearing assembly”.

After seeing several gears strip at the field in the weekend, this up and down main gear play was debated and someone (Peter – EMHC) explained how they removed it.

This is just another weak link in the chain that is the Trex700 drive train, which can be completely corrected, this is how.

Bearing Alignment Before Adjustment (NOT flush with the top of bearing housing)

Mainbearing Trex 700 - Before

Bearing Alignment After Adjustment (now flush with top of the bearing housing)
Mainbearing Trex 700 - After
Steps to correct bearing alignment:

  1. Take the main gear out and remove the auto-rotation gear
  2. Remove the one-way sleeve, unscrew the oneway bearing housing, now remove the one-way sprag bearing
  3. Get a 15mm or similar socket (from a socket set) and a hammer, use the socket and hammer to reposition the bearing flush with the top of the oneway bearing housing.
  4. Re-shim the main shaft at the collar if required.
  5. Done

Trex 700 Gear Mesh Mod

June 11th, 2009 No comments

Gear mesh on the 700 is very important as the main gear has a 0.7 mod (fine gear mesh normally found on 50 size heli’s). In order to mesh the gears correctly you need to adjust the main gear to pinon gear gap and also auto rotation gear to tail gear gap. This can be achieved by grinding down the nubs on the clutch block and plastic tail case (see photos). In addition you will need to replace the screws with standard non-specialty button head screws and use the specialty washers from the Trex 600. This will need to be done for clutch block, plastic tail case and engine blocks. This will give you enough play to adjust the mesh.

Upgraded Metal Clutch Block with Grounded Metal Nubs

Trex700 Clutch Block Mod

Tail Case with Ground Plastic Nubs
Trex700 Tail Case Mod

Lipo Glow Igniter Mod

June 10th, 2009 No comments

What do do with your old Align 2n1 Regulator
…because if the controller ribon breaks the regulator fails off

This creation gives you a glow igniter which is fast to charge, has an auto off, battery status, indicates a when glow power is being supplied and when the circuit is connected. Also it has a standard RC connector for a regulated 6v power supply. In my case it’s handy for powering the bluetooth adapter for my Spartan DS760 gyro, but it could really be used for anything, especially during setup.

1xPlastic box (old Align box)
1xAlign 2n1 Regulator
1xGlow extension
1×7.2v2S lipo

Lipo Glow Igniter

OS91 Cline Carb Modification

June 7th, 2009 4 comments

This mod gives you regulated fuel delivery for any attitude and/or through out an entire tank.

Where to get the mod done, email or call James, details at:

The company that make the regulator (square thing attached to the carb):

Note that this mod also works well with the OS 91HZ

OS91 Carb with cline regulator attached and internal carb mod #1

OS91 Carb mod #1

OS91 Carb with cline regulator attached and internal carb mod #1

OS91 Carb mod #2

Tapped Backplate mod for pressure

OS91 Backplate Mod