Micro cyclic servos for Stretch

[DoubleCH]

My TGY-S306G-HVs are holding up fine. They are definitely not as torquey as the Align D510Ms that got replaced but the Align's were much slower so power-wise the TGYs are not far behind so you still really need good BEC for those power-hungry TGY/KSTs. For my setup with narrow-chord rearward-CG 470mm blades they are good enough. I haven't tried them with my 430mm Revolution blades (wider-chord) which I know require more servo force. I can't say for the G380 and X3. Many of them are set up with crazy power and HS and I don't know the dynamics of the blades to be used. IIRC, my friend is running KST215 on this X3 with 360 blades. Flies fine but I need to confirm if they're indeed the KSTs.

[DoubleCH]

My friend is indeed running KST 215s in his X3. Remember these micro-size servos are like mini servo guts packed into a micro-size housing. The motor is so big the housing needs cutouts to fit the motor. SImilar story with the BK micro-size servos.
http://www.bkservo.com/?page_id=38

On another note, my HobbyKing US West warehouse package finally arrived today (delay probably from the new Oregon location). They have big spring sale until tomorrow. I saved about $40 this order! I've got some goodies for my Protos.


These won't be as powerful as my Wild Scorpion 45C 3500 or Thunder Power 70C 2250 but they should be better than my Turnigy 20C 2650. Only $31 (20% off).


YEP 20A BEC 12S capable! Only $11 if you use my buddy code below: (reg $14)
http://www.hobbyking.com/hobbyking/s...1-10BCA0056483


Wattmeter to see how my Castle BEC has been doing. It will log min V max A and graph the entire flight. $13 (reg $16).




As I found out today, my TGY-S306G-HV plus Savox 1290MG pulled 3.91A max at 6V.


That means my CC10A BEC (continuous at least 5A) is good enough. I don't know if I really need to change to the YEP20A which sounds way overkill! Look at the size difference.

[DoubleCH]

Back from spring break and I finally had time to break-in the batteries. Pack IR came down from 21mOhm (3.5 mOhm/cell) brand new at storage charge to 17mOhm (<3.0 mOhm/cell which is not bad at all for 3000mAh cells) after 1 break-in flight which I took very easy just flying lazy-8 in different orientations at 2300HS for 4min10sec and came down with 3.92V resting voltage. Looking good!

[DoubleCH]

Since weather hasn't been cooperating, I did some controlled discharge cycles with the lipos using my charger's external discharge function at 7A (1 pack at a time) down to 25% of that (1.75A) at storage voltage. Each pack pulled around 1400mAh (from 4.18V charge). These are the 2nd discharges ever with each pack. At the end of the cycle (storage voltage), the packs warm up to 23C (from 18C room temp) and IR came down to 7-9mOhm per pack! That means cell IR is close to 1mOhm!

[DoubleCH]

I've already put 17 flights in each Nanotech 3000s within a week. I don't do control discharge any more so the 7-9mOhm IR number is not comparable. But under the same condition: finish flying around 3.80V per cell and let lipo settle in 18-20C room temp for at least 2 hours and check IR, numbers still stay at 18mOhm per pack (3mOhm per cell) just like right after broken-in. No sign of puffing (same for the Turnigy 20C 2650 from Sept 2014). For comparison I took a retired pack (far right) to show puffing (this pack from January 2014 with 140+ flights and lots of abuse with running temp up to 60C in the summer).


Here's a recorded flight, 4 mins moderate flying (not exactly my normal style and sorry for the repetitive moves as I was testing out the governor/cyclic aggression re-tuning by comparing different "banks"), pack temp 38degC (19degC ambient), 3.80V (using fast charge to 4.18V).

My Stretched Protos Re-Tuning Governor/Cyclic Agressiveness (4 min 46 sec)

[stoni11111]

Hello DoubleCH,
could you please tell me what blades you are using ?
I am also considering about yousing the TGY 306 servos on a streched protos...

Thanks in advance

Robert

[DoubleCH]

I've actually tried other blade setups and the TGY-S306G-HV cope with OK. The key is to NOT rely on stock YGE internal BEC. Make sure you have a "good" BEC that can actually handle continuous 5A+ (not just the spec says so) and run at least 6V. My Castle Creation 10A (peak) BEC (the small blue one not the BEC Pro) works fine set to 6.1V running the TGYs and full size Savox 1290MG tail servo. I had a 20A YEP BEC ready but no need.