I wanted to buy a couple skyangel/jpower 50mm jets and install all of my own electronics. I was hoping to fly them stock if possible, however, I want to leave myself open to upgrading to bigger batteries and fans. Can I run a 40A ESC on the stock motor so that I can easily upgrade motor and battery if I want? Or should I just start them off with bigger motors and take it easy on the throttle to start?

You can certainly run the stock motor on a 40A ESC if you wish.
Note though, the stock motor/ESC are pretty good and the simplest power upgrade is simply using 4S instead of the stock 3S battery. Around about 1000mah 4S works fairly well but depends on the model in question.
If you do use stock components make sure you 'balance' the rotor and ensure that the motor is centred within the mount. These last two points are the most important aspects to get your jet running well.

Originally Posted by Slaanesh

You can certainly run the stock motor on a 40A ESC if you wish.
Note though, the stock motor/ESC are pretty good and the simplest power upgrade is simply using 4S instead of the stock 3S battery. Around about 1000mah 4S works fairly well but depends on the model in question.
If you do use stock components make sure you 'balance' the rotor and ensure that the motor is centred within the mount. These last two points are the most important aspects to get your jet running well.

Perfect...you hit every piece of advice I was going to mention.

Thought people would like to see following figures recorded on my vertical thrust rig and Wattmeter readings :

Model : T45 50mm EDF Skyangel ARF from Hobby King
Motor : Stock as supplied fitted 4200Kv
DF : 50mm 5 plain blade fan as fitted stock
ESC : 20A as stock

The model is stated to use a 850mAh 3S 20C LiPo and nearest and others have been used in tests ...

Batt ID.... mAh.... ... ..C rating.... Amps.... Watts.... Thrust grams
001 ....... 800.... 3S .. 20C....... 16A ..... 170W .... 255 gr
002 ....... 800.... 3S .. 20C....... 15A ..... 160W .... 245 gr
003 .......1300... 3S .. 25C....... 18A ..... 220W .... 330 gr
004 .......1300... 3S .. 25C....... 16A ..... 170W .... 275 gr
--D .......1800... 3S .. 25C....... 18A ..... 210W .... 340 gr
--G .......1800... 3S .. 25C....... 18A ..... 220W .... 345 gr

Battery D was used for flight tests and Doppler speed checks on video gives 85km/hr straight level and over 90km/hr in shallow dive.

I did connect a 2100mAh 3S 35C pack out of interest to see if C rating could improve performance ... as the Wattmeter went over 21A, 240W - I cut the power before ESC or Motor suffered. There was obviously more power available from the stock set-up.

Tests will be made later with 4S 20C pack as I believe keeping amps in the sub 20A band is advised. But having extra V on tap ... we should see an increase in thrust and consequently more speed. The intention is to push the model to break the 100km/hr mark but with stock as far as possible, apart from LiPo and possibly changing fan to 6 blade .. but shroud, model, motor, ESC will remain.

Anybody else experimented similarly ? Any results to pass on ?

I'm interested in grouping up with other 50mm EDF owners to maximise the adrenaline on these machines !

(copy / paste from another thread on this forum I made)

Note - My T45 needed no balancing or work on EDF at all ... all was good out of box !

I have now also fitted Stinger 64 landing gear from Hobby King (~$6 incl. nose wheel servo) ... tips it fwd on CoG but reducing battery to 1300 3S puts her back again ... AUW is about 500grams now ...