Good to see some more 'supersized' T500's
A couple notes: I started with a Gaui FES head (aluminum) on mine, along with a Gaui X5 flybar main shaft/custom one-way bearing hub for added main rotor height. The Gaui FES head hub has a somewhat poor fit on the main shaft. Going with the aftermarket/clone CNC Heli hub linked in Cap's post makes for a better fit (and less vibes too). Note that you need to order the shims Cap linked also as the damper setup is different than Gaui if you are going to use this hub.
The Hobbyking 30x25mm 850kv motor that they sell for maybe $16.00 isnt the best deal...lots of vibes coming out of that (even after you remove the 'fan' portion of it, as that is very visibly drilled off-center). IMO is better to spend more $ initally on a better quality motor to get the headspeeds down to .30 size levels. Currently I'm using a Scorp 3026 880kv motor...lots quieter and smoother than the screechy and vibey HK motor.
Other than these two items...pretty smooth conversion. Really cuts down the weight on these .30 size scalers...my .30 Funkey Jetranger weighs in at 6lbs running a 6S 3000mah battery
. The mechanics themselves better match the scale also...I was using Trex before on my .30 scaler...overkill IMO, lol.
Here's some test hop videos of my stretch (somewhat noisy as these videos were shot with that HK motor on board)...