Caelus Balance & CG Assitance Help
 

Howdy,
My Caelus V2 is completed (sorry I do not have a scale to weigh it all) and I understand the balance point is 1/2" behind the trailing edge of the wing tube from what Mike at F3A and many here have stated. In order for the plane to balance I need to move the battery well forward of any other one I've seen or heard of, very strange.

Fuselage is set at Zero,
Wings set at one degree positive
Stab is set at zero
T can is set one degree positive.

In order to maintain level flight it requires several clicks of up elevator, 14 clicks or 2.5 - 3.0 degrees of deflection to maintain level flight. When I roll to inverted it requires plenty of down elevator to maintain level flight. From reading the NSRCA trimming chart it appears to be nose heavy but this is contradictory from what I've read and been told.

Any advice on this would be helpful.

http://www.rcuniverse.com/forum/atta...mentid=2168099http://www.rcuniverse.com/forum/atta...mentid=2168100http://www.rcuniverse.com/forum/atta...mentid=2168101

I have a version 1, but my batteries are way back compared to yours. My balance point is about 210mm from the wing leading edge, or about 3/4 to 1 inch behind the wing tube. I still need a touch of down elevator when inverted.

I guess the V1 was heavier than V2 and the balance point is incorrect as stated in the manual. I tried moving the battery back and it was a handful to land, indicative of a tail heavy plane.

Then it is nose heavy.

Just out of curiosity, have you checked the down thrust angle?
Also, how much do those Revolectrix packs weigh?

I concur with the other posts that your setup is nose heavy. Here's something else to try... you have a +1.0 on the Tcan. Mine was set at 0.2, others have used 0.3. I believe that the more incidence you have on the Tcan the greater nose down pitch to the airplane resulting in the need for more up elevator to trim for level flight. Any lifting force you place on an airplane BEHIND the center of lift always pitches the nose down. I think that the 1.0 on the wings is fine as well as the 0 for the stabs. I also think that the batteries need to be further aft. I completely understand that the V1 and V2 are different, but your plane is doing exactly what mine did on the maiden flight. My solution was changing the Tcan and moving the batteries aft to be inline with the wing adjusters.

The batteries are 521 grams each x 2.
I took the plane up high, cut off the power and pointed nose straight down, half way down the plane tucked toward the canopy. Performed that test twice with the same results.

I do have a bit of an issue with right thrust, that much I do know and I'm working on that this weekend.

Ok, I will move the batteries back this evening and try it again. As for the Tcan, its a pretty simple fix to set it at zero or close to it.

I fully agree with what you guys are writing, it's just troubling that it does not follow all the information I've been gathering. I had one of my fellow club members pick up the plane at the recommended CG and he agreed "its tail heavy".

Perhaps fly it without the Tcan then sort out the plane?

I'm certain you guys are 100 percent correct and it IS nose heavy.

Update...
1st flight, I removed the 1.0 oz. lead in the nose and flew it, a little better,
2nd flight, moved the batteries back 1/2" inch and flew it, getting better.
3rd flight, moved the batteries back 1", better, much better.
Landings from 1st to 3rd flight - VAST improvement, not nearly as much elevator needed to maintain a smooth glide.

Took the plane home and measured the CG, it's 1.25" behind the trailing edge of the wing tube.

Thank you for the advice fellas, it really helped, a bunch!

Before and after photos
http://www.rcuniverse.com/forum/atta...mentid=2168282 http://www.rcuniverse.com/forum/atta...mentid=2168283

I'm sure you meant the wing tube.

Yes I did, I just corrected the omission