Integral CG question
 

Hi

I'm at the balance stage of assembling my Integral and here is my delima.

The manual says the CG is 205mm from the leading edge, which is aft of the wing tube. To get it to balance there, the batteries have to be way back, almost over the wing tube, which dosn't seem correct to me.

If I balance at the middle of the wing tube (which is about 180+/- mm) the batteries end up in a "normal position" over the landing gear, "normal" being described as observations at the field.

Jarvis, Woodie, Steve, or anyone, please give me guidance.

Thanks,
Randy

RE: Integral CG question
 

Yep, that CofG in the manual was Jason Shulman's setting which was aggressive to say the least and I think he moved this forward later on. A setting of 165mm rings a bell for me but it was a while back since I set it. There is a thread in this forum (the Integral build thread) that works through a bunch of CofG settings, Chad Northeast had his dialled in pretty well and I think mine was the same as his.
For what it is worth the other think many people changed (including me) was wing incidence, the factory set was 0 degrees, I installed a set of wing adjusters and ended up at +0.7 degrees, very happy with this set up.

RE: Integral CG question
 

Thanks,
That's just about what I thought. At least I have a place to start, without the danger of an out of control maiden flight.

RE: Integral CG question
 

I set my CG at 1/8 inch behind the leading edge of the wing tube. Been flying there ever since. No problems.

RE: Integral CG question
 

Hi Randy,
I built and competed with three different Integrals. I found the CG to be best at the leading edge of the wing tube or slightly rearward of that (approximately 1/8"). I would suggest raising the wing incidence from where it's at (slightly negative) to 1/2 degree positive. It also has over 2 degrees down thrust and I changed that to 1/2 degree down. Finally, a liitle more right thrust (about 1/2 to 1 degree) will eliminate the drift to the left at the top of tall verticals. I realize that's a bit of work, but it's well worth it. Just placing the CG where I suggested without the other adjustments will get you started on the right track. Making all the adjustments will result in an awesome flying plane. BTW, I left the stab as it came and called that 0 degrees. All the other adjustments are referenced to that. Hope this helps!

Verne Koester

RE: Integral CG question
 

Hi Randy,
Sounds like a good starting point is just at the edge of the wing tube. Do you have wing adjusters? If not I can show you how to put them in. I should be at the field Saturday.

Steve

RE: Integral CG question
 

Hi Steve

I'm ready to maiden today, just need to cut in the cooling holes in the bottom and go over everything one more time.

No, I don't have wing adjusters in it, my flying ability is not there yet, so no hurry on them.

Thanks everyone for the help

Randy

RE: Integral CG question
 

Randy,

Regardless of your flying level, the better you can make the plane fly the better. Honestly at lower flying levels it is even more critical as it makes less work for the pilot. If guys who have flown them for years are recommending them, then after you maiden I would definitely look at making the changes others have suggested as a better flying plane will make you a better pilot regardless of skill level,

Arch

RE: Integral CG question
 

I agree with the recommendations to add incidence adjusters to the Integral. It flies well at the factory settings, I flew it that way for a year. When I got trying to eliminate the mixing for knife edge, etc, I added adjusters and the plane felt much better at all speeds. It isn't hard, there is even an article on how to do it in the Kfactor about 2 years ago. If you can't find it, let me know and I can probably find the article for you. It only takes a couple hours to complete the task.

Woodie

RE: Integral CG question
 

I received a PM from someone who explained that Verne from post #5 is Andrews caller and mentor...well, that's good enough for me, wing adjusters it is.

Thanks everyone
Randy

RE: Integral CG question
 

Hey Don, which K-Factor was that?

RE: Integral CG question
 

Jarvis, it was May 2010 edition of the KFactor

Woodie

RE: Integral CG question
 

Before I say anything, I want to preface it by saying you'll have a better flying plane by taking the steps I suggested. Having said that, it's only fair to tell you that Andrew flew a "box stock" Integral to 7th or 8th place in his first F3A World's in Argentina in 2007. Jason also flew a stock Integral to 4th that year.

Jason later flew one of mine with all the tweaks I suggested and said it was the most locked on Integral he ever flew.

I'd start with the CG at the LE of the wing tube or slightly aft of that. I'd do the wing adjusters next and raise the LE of the wing at least 1/2 degree (remember, it's slightly negative in the stock configuration). Then you can do whatever it takes to remove about 1-1/2 degrees of downthrust and add some right thrust while you're at it.

BTW, I USED to be Andrew's coach and mentor. It's pretty much the other way around now, though I still call for him....

Verne Koester

RE: Integral CG question
 

My "box stock" Integral flew great today, only did one flight, I always take a plane home after one flight and check all the nuts and bolts to make sure nothing has worked loose. But maybe that's overkill since electric's have very little vibration.

Verne, you are spot on, at the top of one hammerhead, it went left a little, so I will be doing the changes you suggested

But for now, I want to get some flights because District 7 championships are next weekend and I want to fly the Integral there. I MAY be able to take home 2nd place in my first year of Pattern.

Here's a picture of it, I used trim sheets for the color schemes to see what will work the best for my vision limitations. I can't see the "easter egg pastels" on most planes.

Again, thanks for everyone's help
Randy

RE: Integral CG question
 

Congrats Randy. I think you'll see a big difference over the Wind.

RE: Integral CG question
 

Thanks Steve, that's what I'm hoping for, a plane I don't have to fight.

If you are there Saturday as you said, I want you to fly it and give me some suggestions.

RE: Integral CG question
 

I can certainly vouch for how well Verne's Integral flies.

I spent all last year trying to make my Integral fly as well as his Integral.

Brenner ...