Gabe's Darkside Stryker Build

[19000rpm]

[Gabe]

Doppler analysis results came back from Mopar at the Darkside. My Stryker hit 134 mph +/- 2 mph.

[19000rpm]

Not that there's a contest or anything but it'll be interesting to see whether your Stryker of Kent's Fun Jet ends up being the fastest.

[Gabe]

I'm interested as well!

I gotta get the speed props on there first

[akent]

Sounds like fun!
I have a big ole Castle Ice ESC that came in! But it has a recall so is on it's way back to Castle. When it gets here, I have several sizes of APC pylon racer props to play with!

I'm running close to 2kw now.
Kent

[Gabe]

Ditto here, just under 1900 watts one second after the peak amp spike. I think you would take me as the Fun Jets have less drag at high speeds.

I tried the 7x7 sport prop today and I wasn't a fan. Probably because I was fighting 10-15 mph winds and I just couldn't get a good speed run. I didn't even bother setting up the camera for a doppler run.

I did notice the LVC kicked in a minute early - actually about two or three minutes earlier than I expected - but a minute before my timer went off. The speed prop must be sucking more amps and voltage. I'll download the data and have a look see.

[Gabe]

My 2650 6S Turnigy's just took a crap on me. 4 rounds of flights on the Darkside Stryker and they won't balance. Oh well, got my Thunder Power 3250 45c's sittin here. Jut waiting for the balance board to get here.

[Gabe]

Tool the Darkside Stryker out yesterday for a spin - its been at least four months since I've flown it. Both batteries sputtered after takeoff when the throttle hit 100% - like an LVC. I bench tested all my 6S's that I use with her and only one acted normal, the Turnigy 2650 25C. The other one was the same Turnigy 2650 25C and both Nano Tech 2650 25-50C's sputtered as well.

I'm wondering if not discharging them for storage ruined them?

I sent my ICE logs to Gryphon over at RC Universe to look at. I should know tonight or tomorrow.

Any thoughts?

[19000rpm]

It would seem odd that the batteries would die in that period of time. The fact you are getting sputtering on most of them would lead me to think you might have a wiring issue or ESC issue.

[Gabe]

I still haven't talked to Gryphon, but I'm pretty sure it's the batteries. It's too consistent between the three that always sputter and the one that doesn't. It's always the same three. They're all Turnigy so I can expect that they would fail. I've burned through 3 of the 2650 20C batteries with the 500 heli and the scorpion motor. They really don't seem that reliable- but I knew that when I bought them

[19000rpm]

I've heard that the turnigys fail on a regular basis. Too bad.

You might try Sky Lipos from Hobbypartz. They're pretty cheap, you don't have to wait weeks for them, shipping is either $4.95, or free, and the best part is; they have been very reliable in my experience.

My Sky Lipos usually balance at 4.20-4.19 across the board even after 50 cycles. I'm using Sky Lipos ranging from 1000mAh 3S to 4000mAh 6S and 20C-40C. I try not to overdrain them in use, but I don't storage discharge the lipos either. A good buy, IMHO.

[Gabe]

Thanks! I may try that.

I still have the brand new TP batteries I bought just for this project that I've never used. They were supposed to push me into the 140 mph range. They're a little bigger and I'm nervous to hollow out the battery bay any more.

[19000rpm]

Yeah, less foam and more weight. You might want to put some light weight glass in or around the battery compartment. 1/2 - 3/4 oz. + Minwax polycrylic. Lightweight and strong.

140mph.

[akent]

I have had a number of Turnigy's fail.
Usually they fail by becoming really puffed and then they lose capacity.

I have had several fail with cells that won't push out power. They all balanced fine, but when you pull power from them, one cell would drop very quickly. My guess is that this is what is happening with your LVC batteries, Gabe. If you didn't pull considerable power from those batteries, however, they would work, albeit with reduced flying time.

The best batteries lately for me have been the Nano-Tech 65C-130C !! Yes, they are that high in C rating!
I'm pulling 100 amps from a 3300 6s in my Revolver. After maybe 50 flights, these batteries still run cool and the flight times are the same! I also run 2700 4s in my Electric Formula 1 racers. These are AWESOME batteries.
Kent

[akent]

Oh, and Lipos get angry if you store them fully charged for extended periods.

I used to keep everything fully charged all the time. I have noticed that my batteries are now lasting far longer than they used to.

Now, I charge the night before I fly, and take the still charged batteries and reduce them to the storage voltage if I'm not going to fly them that week.

But it could be that the newer batteries are just built better than before.

Several folks are flying Sky lipos at the field here now. They are working well.
Kent