Spaceman Spiff

My Feedback: (1)

Hi all, just got a great new toy, CG 330 with Webra 61. 4.5 pounds, CG around 5 inces from LE. Good performance, does tight KE loops, but pitches to the belly something terrible.

Anyone else having this problem? Does GC affect coupling? anyone tried messing with the shape of the rudder to fix it?

hroachen

Mine pitches very strongly to the belly with big rudder inputs, but with small inputs it's pretty neutral. It'll hold a knife edge from horizon to horizon with very little rudder input, but a knife edge loop gets exciting when I crank the rudder in coming down the back half.

4.5 lbs with a 61? Mine's a little over 5 lbs with an Irvine 53. Next time I buy an ARF I'm gonna weigh all the boxes at the shop and buy the lightest one.

D

Spaceman Spiff

My Feedback: (1)

Haven't tried small rudder inputs.

I used light radio gear HS 225 MG's and Hs 81 and small NIMH. If i remember corectly, the Webra is only 20 OZ. Didn't really affect the weight much, ballanced without lead or moving anything around. It runs pretty good and strong but i don't think it is all that much better than the Irvine 53. The 53 is still my favorite engine.

hroachen

I'm not happy yet with my 53, maybe I just got a dog... It's powerful, but the transition has a stumbling hesitation that makes entering a low hover pretty exciting. I've tried to clean up the transition with the low end needle, but when I go in enough to get a clean transition it sags lean at 1/3 throttle while hovering.

I've tried both 10% Omega and 5% Powermaster, it's pretty much the same story with either.

I noticed that I can't kill the engine on low trim, even with the barrel fully closed. I've pulled the carb and used some Permatex RTV to seal around the pinch bar, barrel stop screw, and o-ring areas, I'm hoping that I'll be able to get it to run better and be able to kill it with low trim, but if it doesn't come around pretty soon I'm gonna replace it.

D

hroachen

My servos are kinda on the heavy side, they're JR 8411SA's, (and a micro on the throttle) they're around two ounces each. I could shave a couple of ounces off the plane by going to lighter servos, but I still wouldn't get it down to 4.5, even going to 225's.

D

daren

My Feedback: (4)

i have the same problem. but mine pitches and rolls with just a slight rudder input . my omp knife edges with only rudder input no mixing.

hroachen

daren,

That's great to hear... my OMP Edge kit arrived today, I'm going to start building tomorrow. I'm really looking forward to this.

D

daren

My Feedback: (4)

you will love omp edge. theres nothing like it. go to *************.com and watch the video of a guy flying it.

Spaceman Spiff

My Feedback: (1)

I was just looking at the OMP plans ( next project) The fuse is proportioned differently, but maybe the key difference between the OMP and the Extreem 330 is the stab sits lower on the fuse?

I have the 53 on a Top cap (also with the light gear) weighs just over 4.5 pounds. The vertical performance isn't like a rocket, but pretty solid.

ChuckAuger

My Feedback: (12)

That is JRozman here (used to be V1VRV2). He's something else!! If you look down on the list you'll see Gary Seeloff's name. He is another 3D stud of massive proportions, can't wait to see his video.

For those of us fortunate enough to make the Houston ProBro, we got to see both of these guys flying all weekend, even at the same time, etc. A great 3D demo about every 15 minutes LOL.

Spaceman Spiff

My Feedback: (1)

Well, i took the plunge, and chopped up my new toy.

After several minutes of scratching my head, just decided to try moving the stab down an inch.

Started by carving out the area below the stab with an exacto. A little sloppy, but it works. Fortunatly by the time i was ready to seperate the stab from the top i found a better way. I just took a hacksaw blade and carefully sawed from the back of the stab to the front. Pretty easy so far.

Spaceman Spiff

My Feedback: (1)

Glued in some balsa to form a new shelf to glue to on the bottom, made a block to fill the gap on top. The control horn will have to be switched around to the top of the elevator. Looking forward to trying it out on Saturday.

hroachen

I can't wait to hear how it works out. I've gone the program mix route for mine... I'm mixing some up elevator in with rudder, but the elevator doesn't start coming in until I'm past about a quarter of the rudder throw. Gonna try it as soon as the weather allows.

D

CaMike

Spaceman,

Don't forget to use your servo reversing when you move the control horn to the top of the elevator...

Spaceman Spiff

My Feedback: (1)

Finnally got to test the stab modification today. Still pitches to the belly a littel, but a lot less than it did last week. Tempted to move it down some more. There is a large hole between the vertical and rudder. If i fill it it will probably help keep the pressure above the stab a littel higher and reduce the pitching a little more?

jon595

My Feedback: (2)

I've noticed on mine that when I got the CG correct it no longer wanted to tuck to the belly. I took all the mixing out and it is pretty neutral. Just wants to barely climb when inverted (have to give it just a little back pressure on elevator to get it to go straight and level). It will knife edge loop with only small corrections. I also dialed in more right thrust. Engine is Saito 56 with APC 12x6, JR DS811 servos on flight surfaces with HS225 on throttle. When the tank is almost empty it is a pain to land if windy (this is the only negative).

Have fun,
Jon

Spaceman Spiff

My Feedback: (1)

Thanks Jon,

I'll add a little weight to the tail and try again. Do you know how far back your CG is?

jon595

My Feedback: (2)

5 3/8" from the LE (measured where the fuse meets the wing LE), or about 1 1/4" behind the spar. You can tell it's tail heavy when it is going slow, but I"m satisfied with it there.

Good luck,
Jon