88" Extreme-Flight Yak Electrified Build

[Captain Carlton]

Mark,

Yah...the reason I went with the power box is due to all the bad press about low voltage conditions and Skektrum RXs. Anyway...to save weight I did upgrade the main landing gear to Carbon fiber.

Langing Gear (Original Metal): 12.8 oz
Landing Gear (CF Upgrade): 7.2oz
5.6oz saved.

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So I guess the operative question is...at max power....with the APC 24x12...how many amps are you pulling. Are we at the motor's maximum?

- Richard

[ben_beyer]

Here's what I suggest you do for that. Go with an A123 or Iron Corps pack from Fromeco. Get the new Spektrum RX that has the high amp connection on it. Cut off the high amp connection and solder on a Deans connector. Or you could leave it on and make an adapter. Since you have to take off the hatch to plug in the batteries to the ESC, just plug your battery directly into the RX through this connection.

[Captain Carlton]

Ben,

Yep...my next Giant Scale Plane...I'm looking at the High Amp Spekrum. I had pulled the trigger on the JR 921 and Power box before I found out about the new Spekrum offering.

[aviti]

	Quote: Originally Posted by Captain Carlton
	Ben, Yep...my next Giant Scale Plane...I'm looking at the High Amp Spekrum. I had pulled the trigger on the JR 921 and Power box before I found out about the new Spekrum offering.

You still don't need a Powerbox with the 921. If you need some piece of mind for low voltage issues, make sure your 921 has the "quick connect" upgraded firmware. If you are running just on Rx battery, you can run heavy gauge wiring to your reg then dual outputs from the reg to the receiver. Save the Powerbox for another project and save several more ounces on your plane.

[Captain Carlton]

Tony and All...

Thanks for being patient with me. I have lots of experience with Electric 3D planes from 15 oz to 7 lbs....but I'm like a Pig on ice skates with the Giant Scale stuff. I have the PowerExpander Sport Plus. So I guess that is a power box with a built in regulator? It does weigh a couple of ounces. The idea of having servos that overload an RX is a new concept for me. I do like Spektrum's High Power integrated unit. Very sexy.

For Batteries...I am starting off with two 2S-2000Mah thunder power batteries for redundancy. I might down size these two 1300mah packs...and save some more weight. I just need to runs some tests first...etc These packs are lighter than the A123 packs. But since I have strong Kung-Fu with Lipo packs...these are easy for me to deal with. :-)

- Richard

[Captain Carlton]

Tony and Mark...on the EF Yak 88"...the wing tube seems to fit really tight...tighter than other planes I have seen. What do you use to loosen this up a bit? - Richard

[JagerBomb]

The tube will loosen after a couple of flights. I'm using a single Flightpower 1600 2S battery for the receiver

Mark

[Dsp Dave]

Flightpower 2s 2p 1600 for me, with that pack you can get 8-10 flights easy!

[aviti]

In looking at the Powerexpander Sport Plus on their website, it appears the regulator only limits the voltage going to the receiver, not the servos. Give Smart-fly a call to verify. If it were me, I'd just run one of those 2000 Lipos with 16 gauge wire into a regulator, then 2 leads out of the regulator into your receiver.

[ben_beyer]

For the PE Sport Plus, you will need a regulator. But a Fromeco or Smart Fly standard regulator with 2 outputs will do the job. Or, since this will be electric, just get a couple of the 1200 maH Iron Corps packs and plug them directly into the RX to turn it on.

[Captain Carlton]

Ha! My Power System Works....Now I must balance my Plane and Fly it!!!!! Way too exciting!!! Like flying a Helicopter for the first time....!!!

[JagerBomb]

	Quote: Originally Posted by Captain Carlton
	Mark, So I guess the operative question is...at max power....with the APC 24x12...how many amps are you pulling. Are we at the motor's maximum? - Richard

I flew again thursday and saw a 90 amp peak at 4 minutes into the flight. I beleive the 24X12E will be as much as I can handle at this point. I talked to Animal and he said don't sweat it the Hacker will handle it. Now that the batteries are breaking in and the weather is warming I'm starting to see some great performance. I was at Buder Park thursday and the guys were shocked at the size of the plane and the performance it had. I'm very happy with my setup.

Mark

ps I'm working on a new video camera

[Captain Carlton]

Mark and All...

Well I guess this makes Yak #3 that was built on this thread. I have never flown a Giant Scale plane. All I can say is "WOW"!

The electric power really eliminates alot of variables from the equation. My ship came out at 18.0 lbs, most due to the upgrade of the CR Landing Gear. I pushed by A60-18 fairly hard, and it was warming up. Not hot by any stretch, but warm enough that I am somewhat concerned how things will go in 100 degree heat. It was 60 degrees today.

Hovering at 70% power with the APC 24x12. I would like to see a hover at 50% personally. But this is plenty good for IMAC.

It might be a useful discussion to see if Steve Neu has a power system, for this plane at a similar weight, but with cooler operation and another 500 watts of power. My Neu batteries... two 6S-5000 ...are totally loafing and are hardly warm. Seems...we could do more with these packs.

[JagerBomb]

Congrats Captain!

Unless your batteries are already broken in you will see an increase in power around the 5th flight on the pack. What settings are you using on the speed control? If you get a chance shoot the motor with a temp gun. As I recall, as long as it's under 160 degrees you should be fine. where did you get your landing gear? Please let me know how they hold up.

Mark

[Captain Carlton]

Mark....a HUGE THANKS to you and Dave for paving the way for me with this Thread. Like any good modeler, I took all the best parts of your builds, and tried to improve. I came out 0.6 lbs lighter (due to the landing gear upgrade). I build the internals pretty much identical to your...especially, the air scoop and the foam flooring holders for the battery. I mimicked yours identically. :-)

Landing Gear and Tires: I bought CF Landing gear from http://www.graphtechrc.com. I broke the landing gear on the 2nd flight, but it was my fault. I had installed light spongy foam 4" wheels for this plane (to save weight). They are not beefy enough and can't handle the weight. I need LIGHT...but strong wheels...so I need a recommendation there. Anyway, I operate from a very short field. 20 feet wide 150 feet long. This Yak can operate from this field pretty well. One of my landings...I was too hot, and I could have let it roll off in the grass, but I did what I have done with smaller planes...snap the rudder hard over and slide the plane sideways. Well it worked, but the foam wheels dug in to the runway, and the plane started hopping. Then I heard a crack. Being stupid. I taxied back and took off. On the next landing, the gear failed...and I slid off the runway. Note to self...don't slide giant scale planes sideways. :-)

Power System: I am going to order new V3 of the Eagle Tree FDR, so I can chart the action. I am using the default program for the Spin 99, Outrunner mode. There are several settings I don't understand at all (that don't exist with small ESCs). The Hacker manuals suck dead bunnies through a straw, so thats no help. I think the acceleration of one second may be too slow for me. I am also going to get a Heat Gun device. I have never had one, but I really need it now.

TO Save Weight... I also dropped the wheel fairings and spats. If someone wants mine, just send me your mailing address. They need a loving home. :-)

So I am ordering replacement CF Landing Gear. I need to find better tires. Very Light, but stronger. The foam ones get flat spots with 18 lbs weight. :-) This is what I have now. These are great...but not for this plane. http://www3.towerhobbies.com/cgi-bin...?&I=LXB930&P=7

- Richard