OldFart1

No cowl (I did set it in place, minor change), but did have the spinner and prop. Motor is spaced per the instructions. DA-50 is supposed to be even lighter than the ZDZ...I'm clueless.

Buddy of mine is getting a CG machine, I'll wait to fly it until I've checked balance with that. maybe my calibrated fingers on the CG marks are the problem

arobatx

...lift it with a dowel under the carrying handle, and check your balance. About 1" forward of the rear mounting hole for the handle is pretty good, with wings removed. Resist the urge to assemble the wings on the fuse, and re-check. If you are balanced using the handle method, there is something incorrect about where and how you are lifting the wings to balance that way afterwards.

OldFart1

Did that Chad - used a big heavy pipe between two tables. Marked the carrying handle 1" forward of the rear cabane hole.

As far as rechecking assembled, marked the bottom of the top wing 6-3/8" back from the flat portion of the leading edge - picked up by that point.

OldFart1

Well, I didn't have any great revelations in the middle of the night on this. Thought I did - I actually woke up about 0130 this morning convinced that I had somehow installed the cabane brackets "backwards" - so you guessed it - I got up, booted the PC and checked - nope

Managed to amuse Oscar the Wonderwienerdog, who (in his mind anyway) rightfully assumed that I had gotten up for the sole purpose of taking him for a walk (he didn't have any ideas either - I asked)

REALLY hoping I'm just picking it up wrong to check "assembled".....

Uncas

My Feedback: (1)

I would definately put the cowl on - they are kinda heavy. It looks like you have more electronics in the fuse than I did and I did not have a pilot figure. Just lookin for differences.

arobatx

I put a converted G62 (just over 4 lbs) in mine, standard locations for all servos, tank, rx, switches....the 2700mah 5 cell rx pack went in the tail, mounted just in front of the leading edge of the stab. 15.9lbs, I balanced it once, using the handle method, flew it for 2 years, never changed it, or checked it another way. It was just right for my flying style.

twn

My engine is mounted about 3/8" forward of where the book says. Just move your engine forward untill your cg is right and toss that extra weight. Im running a dl50 and their mounts are just about 2 3/4" so I added some cherry blocks to the firewall to get the engine forward. Also it is ok to have the cg 1/8 aft. I have mine there and it flies great. The extra tail weight is probably in your pilot. Something else you could do is switch to a pull-pull rudder. That would remove 60 gramms (servo) from the tail.

arobatx

Problem is, he balances using the handle method, then when using the wing-on method, he's off and must add weight. There is something wrong here.

OldFart1

Chad hit the nail on the head. CG is CG, it's a point (or a range) irrespective of weight, engine type, etc. It shouldn't make a difference whether I use the "handle method" or the "traditional" method - both should (and do, based on rereading this thread) arrive at the same conclusion. The handle method is just a lot more convienient

I'll see what putting it on a CG machine tells me, plus I'll have a second set of eyes tonight to look at it.

bubbagates

My Feedback: (32)

Jeff,

The handle method works well. I understand the need to try it both ways but after doing two the exact same way I had the follwoing results IN FLIGHT, where it matters most using the handle.

I pulled a 45 degree upright climb, rolled inverted, got the plane back onto the 45 degree line and let go of the sticks, the nose slowly dropped to level in about 5 to 7 seconds which, for me is perfect. I do all IMAC planes like this, I get the CG close to mid-range of what the manufacturer says, then go fly it. Since I pretty much do all IMAC style flying, slightly nose heavy works best for me for spins and snaps

OldFart1

I'm just curious (and a bit worried) why I don't get even close results with the two methods. Once the plane is maidened, I'll feel a lot more comfortable - but I definately don't want to maiden the plane if it really is 18 oz tailheavy

OldFart1

Something else I noticed in my (one of many) re-reads of this thread - my cowl only has one side of the "cheeks" opened. Issue or not?

Uncas

My Feedback: (1)

That is correct. I presume it is for a 1.60 glo engine. I cut the other side open so I could get to the choke.

codfish

It could be the way you are doing the balance with the wings on. How far off is it? I found it rather difficult to balance with the wings only because you have to hold a 17 lb weight exactly at a single point. I did, however, after trial and error get the balance to come out correct depending on how i placed my fingers. How far appart are your fingers? I balanced mine with the wings on and both fingers right next to the center rib. that is my fingers were only an inch apart. then there is the issue of how you are viewing the balance. if you are doing it alone your view will be substantially different with wings on and off balances. I know i worried about this, but the plane flew just fine.

OldFart1

Problem solved!!

As many (or all) of you suspected, it hinged around "how and where" I picked the plane up (and having another two pairs of eyes and hands last night didn't hurt either) What I did was to transfer the 6-3/8" mark to the top of the top wing, and extend it laterally out to the wingtips (all on that blue painters tape). My buddy and I then picked the plane up by the bottom of the top wing at those marks - voila!, we're real nose heavy. Removed the lead, back to neutral/slightly down CG. I'll maiden it this way, then probably move the RX battery back to the plate I put in the fuse when I decide to shift the CG aft.

Whew!!!

JIMESTES

My Feedback: (8)

I need a fuel tank for the gp 160 ultimate I got it used and it came with out one I am putting a dle 55 in it and just wondering what fuel tank mounts easiest in to the fuse with out huge mods
thanks later Jim

vertical grimmace

My Feedback: (1)

Use a bennett built 16 oz. The bennetts are the best design out there. no stopper.

bubbagates

My Feedback: (32)

Glad you got it sorted out

corry

Aerobob, have you talked to anyone who has tried an Evolution 45 engine on the GP Ultimate? They seem to be lightweight and strong. Thanks, Jim

clarkj

My Feedback: (26)

put my 180 saito on today and stuck the cowl, spinner, batt. etc etc. and mine balances perfect without the rudder servo installed using the handle method. so im gonna get it finished and check with the wings on berfore i mount the rudder servo. just wandering why its balancing so good with only the 180 on it?????

slopoke

My Feedback: (16)

Clarkj That sounds about right. When you add the rudder servo to the tail It will require more in the nose. Will take less if you use a Pull-pull system.

Should be light though.

Good flying

Roger

clarkj

My Feedback: (26)

have you weighed yours roger? and if this 180 doesnt perform like i want it to i'm gonna buy a 220 or fg36

slopoke

My Feedback: (16)

Jeff
Mine weighs slightly more than 14 lbs.

A friend has one with a ys 170 that weighs about the same.

The YS is a perfect engine on the plane. He does everything with it. Too pricy for me though.

Roger

clarkj

My Feedback: (26)

mine weighs 13lbs 1 oz

slopoke

My Feedback: (16)

Hey that should fly great!!

Let me know when you fly it.

We have had so much rain this week I don't know if the field will be dry enough to fly on today or not.


Roger