Gabe's Darkside Stryker Build

[Gabe]

Talked to my darksiders and they suggested running a bench test just to make sure everything checked out. The Phoenix ICE 100amp ESC has full data logging.

I did a few runups on the 3000mah 30C 4S Zippy I'm using for the maiden and here are some cool numbers:

Max volts per cell: 4.0
Amps: 83 (motor rated at 90amps)
Max Watts: 1,200 (1199.8 watts)
Max RPMs: 15,717

Just for fun I hooked up the 6S with the same prop. I got lucky I didn't fry the motor and esc. I only did a 2 second runup so I skated by without any damage:

Amps: 163 (100amp ESC)
Watts: 3560

He he he...

I'm getting prop recommendations from the darksiders for the 6S in the next few days.

Kent, you were right. They recommended tossing it between 1/2 and 3/4 throttle. At that wattage, it shouldn't be an issue.

[Gabe]

Hard times in Stryker Land:


I think the COG was too far aft on this maiden. I avoided the torque roll by giving about 10 clicks right aileron and also bought myself some time on the launch with 10 clicks of up elevator. I thought at first that may have been the issue, but the plane was completely uncontrollable on the pitch axis. Funny, it balance perfectly on the finger holes with the battery in it. Seems like the electronics are all ok with the exception of the 3000mah 30C 4S Zippy, and one HS-85MG servo.



Back to the drawing board. Wish I had taken a video to show you guys.

[Gabe]

Fixed her!

I took Gryphon's advice and shoved two, 5" long CF spars through the fuse and through the chunk of foam that I recovered, hot glued it all together and then stuck a new nose on the end. I also dug out a channel for a large Allan wrench (hex wrench) in the nose which will serve to keep her nose heavy. Even with the wrench and the 4S I have to shove the battery all the way forward to get her to dip on the nose from the front of the finger slots. With the 6S in the bay, she dips HARD with the fingers in the front. When I switch over to the 6S I can just remove the wrench (er...ah....weight).

Here's some pics. She ain't pretty, but she'll fly - just waiting on the new HS-85MG servo to arrive.

[19000rpm]

That sure sounds like a CG issue. Good luck with the next round.

[akent]

Bummer news, Gabe!

Oh man, I sure wish you lived closer. I would make you a deal that you could not refuse for my Stryker and all it's parts.
I am hopelessly hooked on the Funjet now.

Best,
Kent

[Gabe]

She will fly again, I just need a new servo now. I gotta say though, for the split second when I gunned the throttle after the launch, the bird just disappeared - it was like a rocket! I've never used a 1200 watt plane before.

Its like a drug!

[akent]

Now that is cool!
Yep, horsepower and speed is very addictive!

[Gabe]

Ok, I decided to start with a brand new fuse, just for safety's sake. Got the cf tubes and the balsa ailerons on the plane. I found some seriously stiff balsa for the ailerons. I had to sift through the selection but I found some with a lot of grain in it.

They've got 6 evenly spaced CA hinges on each aileron. I also bought some Z-poxy epoxy for the glass job. I decided to try something stronger. This will also get "painted" on the top of the plane for added strength.

I should be able to get the electronics installed next week when I get back.

[19000rpm]

I think it was a wise idea getting a new fuse

The upgrades for the elevons and epoxy paint ought to make for a very solid airframe.

[Gabe]

Update:

Glassed the bottom with MinWax as usual (don't tell Mopar or Gryphon on RCuniverse ). I was just tired of doing all the frame work and then chancing it if I screwed up the epoxy job. So instead, I have a coat of Z-Poxy on glass on the vertical stabs to see how it works. Its really thick and seems like it will be significantly stronger. But its a little harder to work with.

Servos are in. I'm glassing the other side of the stabs tonight and doing the electronics tomorrow. IF all goes good I should be able to maiden late tomorrow or Sunday.

I'll be sure to have the COG right this go round.

[19000rpm]

Sounds good Gabe. It's all a process of crashing and learning when you're in new territory.

[Gabe]

Unfortunate - but true. I even hit another snag last night when installing the vertical stabs. I guess they crush a little when they are stock - well, when they are glassed, they don't. I pulled up the fin slots on the trailing edge when trying to push the front of the stab into the slots. I had already epoxied everything when I noticed. I'll need to file them flush and then coat them with epoxy or maybe even a layer of glass to be safe.

Funny, 5 minutes before that happened, I was just telling the wife that this (version 4.0) was the best and cleanest looking Stryker I had made...

[Gabe]

************MAIDEN SUCCESS!!!****************
* *
********************************************

Flew the first flight for about 3 minutes with two WOT passes. Te second flight was 4 minutes with 4 WOT passes. She flies great! Rolls a little to the left due to the fin slot being pushed up (I think). I'll file it down tonight.

Here's what I'm running:

-Mega 16/40/2.5RC with full heat sink
-Phoenix ICE 100 Lite
-7x5E Prop
-6S 2650mah 20-30C Turnigy Battery (still waiting for the Thunder Power batteries to arrive).

I totaled everything from the ICE log and averaged all the numbers based on one second after the peak amp reading (this is a true reading of the numbers after the prop unloads):


Amps: 86
Watts: 1883
Temp: 152
RPMs: 24436

She comes in really fast on the landing - probably about 20+ MPH and takes about 100 yards to glide in at that speed. I'm going to lay a thin coat of epoxy over the top of the plane tonight to stiffen it up. Here's some pics:

With the battery cover off:


Note the servo extension I used from the AR7000 receiver in the wing so that I can easily unplug the ESC for data downloads:




Bottom of Version 4.0. Only 4 CF tubes in this one with a full fiberglass bottom. Gorilla tape on the leading edges:


Shot of the electronics bay. The yellow things are drywall anchors. The cover is screwed on with 8 screws so its not going anywhere. Note Gary's mount on the tail:


Post maiden flights - on the trunk of my car. I hit the wings with two shots of orange spray paint for visibility:


ICE log for data purposes:
i149.photobucket.com/albums/s60/gabetuft/Mobile%20Uploads/DarksideStrykerRebuild091120107x5Eprop6S2650MAIDEN.jpg

[19000rpm]

Congrats Gabe. The data is staggering.

[Gabe]

Took some vids. I'll post it over in the video section. I botched the doppler analysis though. I was flying way too high and not long enough at WOT to get a good reading. I was at about 100-150' in the air and Mopar suggested 5' off the deck for the best analysis, 3 seconds before the camera and keeping it WOT 3 seconds past.

Looks like I have some work to do.

Initial doppler has it at 125mph though (I can do better).