pappy35

These are looking beter and better by the minute!!!

[link=http://www.sincityjets.com/batteries/a123info.html]A123_Battery_Info[/link]

Delrin

Pappy. It's a 200 lb digital scale used to weigh gravel samples at a concrete testing lab. I weighed it 12 times to make sure I wasn't subtracting weight while balancing on its spinner. 13.4 lbs was the average.
Aluminum landing gear was 10 oz. Carbon gear from Graphtec are 5 oz.
Aluminum tube was 6 oz. Carbon PBG tube from Desert Aircraft is 3 oz. Tube and gear is 1/2 lb right there.
Aluminum spinner was 5 oz. PT Carbon spinner from Troy Built Models is 2.5 oz.

Delrin

These batteries will make Lipo's obsolete, or come way down in price.

No regulators needed.

60C discharge rate (120+ amps from 2300mAh)

Inexpensive ($20 pack if you make them yourself)

10 Amp charge rate (5C). Fully charged in 10 minutes

Will deliver rated voltage for 95% of discarge curve.

Safe like NiCd/NiMh. Can be charged right in vehicle (aircraft, heli, car)

1000+ cycles

2 cell (2300) pack weighs less than 6 oz
2 cell (1100) pack weighs 2.9 oz

I can go on and on. My servos love them. You can easily tell the difference between them and a 5 cell NiCd.

Delrin

Updates: I decided to go with a redundant A123 2300mAh for the receiver and an 1100mAh VPX pack (smaller A123 from Black & Decker) for the ignition. The giant scale guys talked me out of it. I've attached my wiring diagram. The old setup is first and the new one with the VPX pack is 2nd

The B&D VPX pack is wired, wrapped and installed. Man this site is great! Couldn't have been easier. I think the B&D VPX's have to be the easiest A123's to go from the store to rx pack that you can make on your own? It literally took about 10 min to have it ready to install, and that's never converting one before. 2.9 oz with cardboard, shrink and wiring.

The manual for the Fuji states their ignition uses 188 mAH. With a 1000 usable from the VPX, that's about 5 hours. Plus the charge time is so quick. I am running it through the Castle BEC at the default 5.1 volts. I only get 4.9 volts at the end of the connection, but the Fuji runs great. I called and asked Great Planes what the max voltage their ignition could handle and "through the operator", they stated 4.8v. I haven't found anyone trying more so I'll use the Castle BEC for now. I need to get the Castle Link so I can turn it up to 5.4v. The card is the only way to program it. Maybe pick one up at the WRAM show?

I tested the system last night. I had to move the throttle servo off the firewall and back to the front receiver tray. The Fuji fired right up but my throttle servo was jumping all over. Scared the wife pretty good as she was holding it for me! It's ready for the next test. "Honey, you ready?"

Brian

OK: Throttle servo moved to the front receiver tray and it works like a charm.....

Delrin

Success! Maiden flight yesterday. 3 flights without a hitch, only 1 tank of fuel. Kept bringing her in to check her out. Good thing too. I found a missing servo horn screw that vibrated out on the elevator.

CG is perfect. I'm right on the wing tube empty--5-5/8" back. Nose points down a little with full tank of fuel. Floats in on final like a dream. Didn't have the nerve to try the 3D rates on the first session with her. We've been flying of the ice on a local lake. Used the snowblower to make a 50' x 150' runway in to the prevailing winds. Sweet!

Brian

wind junkie

My Feedback: (1)

Good job Brian. You've got a sweet bird there.

Let me know when you guys go out again.
Joe

Delrin

Thanks Joe. Flew 3 flights again yesterday afternoon (Monday). Took it way up and tried the 3D rates. Wow! Very quick and not used to it at all. Hovers at about 1/2 - 2/3 stick. Sounds awesome. Rain today, but that usually makes the lake smoother once it refreezes. We'll keep you posted.

Brian

Delrin

Ok. Finally got most of the graphics done. Installed the Graphtec landing gear and TBM CF Spinner & Prop. Only thing missing is the carbon tail wheel assy. and I'm completing that today. Here are a few pics.

Brian

FLYMIKE

bump

Delrin

Here's the lake in all her glory! Different runway conditions. Glare ice to windblown snow to snowblown runway.....

Added some sponsor graphics to the yak too.....

wind junkie

My Feedback: (1)

Aw shucks. Wish I could have been there.

No green carpet this time I see.

Delrin

We'll be out there again. The snow in the sunny pics has all melted. By Wednesday morning, it will be a sheet of glass again. Epic conditions ensue.

The green carpet is for special guests!

pappy35

Hey Delrin. Where did you get those graphics?!? They look awesome and I'd love to get a set for my Yak.

Delrin

I make them. I can make you a set for a very reasonable price. Let me know.

Brian

pappy35

Delrin, sent you a PM.

AL T

MIXMASTER

My Feedback: (15)

Beautiful plane! I wouldnt want to fly it for a while, just look at it! You're no wus flying in those conditions too, I consider myself a hero if I fly when its 35 deg. & sunny, I stay home if the waters frozen. My friend let me maiden his Yak & one other flight, I was impressed with it, he had trouble with smooth landings, kept bouncing it, I told him you barely need any input to land it, it lands like its on auto-pilot.

Delrin

Thanks for the kind words.

The wind makes all the difference with the comfort factor. The temperature during the sunny pics (glare ice pics and the 8 inches of snow pics) is only 20 degrees! It's comfortable with handwarmers and fingerless gloves. When the wind picks up, it's raw and miserable. The pic of the Yak with the dogs was so miserable after I got set up and started, I had to pack it in after 2 flights. Brrrr.......

I have 8 individual flights on her now. She didn't bounce at all with the stock main gear as it was lower and the angle of attack on her tailwheel was less. The new Graphtec carbon gear is about 1.5 inches taller and when landing on the glare ice that day, she did bounce. I imagine landing on grass will help somewhat with the increased friction and in keeping the tailwheel up longer until she slows down. I have a taller carbon tailwheel but didn't install it because in was 0.4 oz heavier than the modified stock wire tailwheel ( I removed it from the rudder keeper and soldered control horns on and attached springs from the rudder horns). AUW is exactly 13.0 lbs, with the Fuju 43 EI. I'm extremely happy with the flight performance and I am still getting used to her. I've only tried the 3D rates once, way up high.....

Brian

pappy35

13lbs!?! What did you do? Fill it with Helium? Mine is 15.3lbs with all the stock gear and a Brillelli 46GT. How did you attach the horizontal stab? I thought that was, literally, the only thing fundamentally bad in the design with a weak gear mount a distant second. Mine flies great at that weight so I'm not too concerned, more surprised at the variability from one to the other. What did you use to weigh it?

Delrin

Pappy,

I attached the horizontal stab with plenty of 30 minute epoxy. It seems solid enough. Some from this thread and elsewhere cut the bottom monokote triangle under the stab to really get at it while gluing. I didn't do this, but used the epoxy liberally. Landing gear is a weak spot but I'm not concerned with it except for a dead stick event.

It's a 200 lb digital scale used to weigh gravel samples at a concrete testing lab. I weighed it at least a dozen times to make sure I wasn't subtracting weight while balancing on its spinner. It would have been 12lbs 14 ounces if I stuck with the original single battery for rx and ignition. FG forum talked me out of the single A123 so I used a B&D VPX pack at 2.9 oz.

Brian

pappy35

So it's the helium then.

Delrin

Sunday brought us awesome weather on the ice. Sunny and 36F. We just got back from the WRAM show and were itching to fly. We made our largest runway yet. It had to be 250' x 50' and we finally had the prevailing winds out of the west. It makes for a nice long approach. It was en "electric" day for me so no GP Yak or Fury Extreme. I did bring the T-Rex 600, the Typhoon and the Trojan. In hindsight, I should have brought the Yak. It was an epic day. We even broke out the Green Carpet.....

Here are some pics:

pooks31

Hi Vince is your website still up? I cant seem to get to your Yak build page.

Tesla1856

Pooks,

It's still there and working for me. Let me know if you still can't access it and I will call my host.

I still haven't maidend my Yak54 yet, but will this spring (hopefully).

I had to swap transmitters and reprogram. The GraphTech CF gear install turned out good I think. Not much left other than adding nose weight and the final balancing.

pooks31

Hi Vince

The website seems to be fine now. Weird - maybe a glitch at my end. Best of luck with the maiden. I got mine about months ago and started the build today (in other words I've opened the box!!).

twort

My Feedback: (1)

I am using an os 1.60 and cut out the hole for the Pitts muffler. how much area should I remove for cooling. This will be the only hole since the engine fits completely inside the cowl.