boneman_66

Hi all,

This is a follow-up to my earlier post on another thread. I recently had a bad experience on my maiden flight which ended in a crash. I had the CG at approximately the beginning of the range recommended in the manual (5 1/4 - 5 3/4) and felt like the plane was too unstable to fly, nevermind trim out etc. The company has said that they originally rec'd a CG of 4 1/4 - 4 3/4 but moved it back an inch based on experiences of owners.

My question to you all is:

1) Where is your CG? and

2) Do you think rec'ing a range of 5 1/4 - 5 3/4 for a maiden flight is aggressive?


I don't doubt that some people have their CG at 5 1/4+ - I just wonder if they would be better off rec'ing something like 4 1/4 - 5 3/4 so people can work out all the kinks and get used to it before the CG is on the verge of unflyable.

I'm also not one to blame others for my faults - I just want to understand what went wrong and to see if I have a reasonable basis for a complaint.

Thanks in advance for your help,

Boneman

flyboone

My Feedback: (3)

Current cg is a little behind 5". Started at 4 1/2 and it flew great at that. I do think the NEW recommended range is extreme.

Jason

stdun

I started at 4 1/4 but now it's at 5 1/4. In either case the plane has flown well. I think how aggressive you are with a new plane depends on your skill level. My step-son did things on a maiden flight with his Pizazz that I still don't do.

Jaco

I flew mine at 5 3/4". Landings with a empty tank could be a handful but it flew stable enough.

rc3ddriscoll

My Feedback: (3)

Started at the 5 1/4 recommended range and hovering was unstable.

I added weight to the rear to get it to about 5 1/2 and it hovers better. I'm thinking about moving it back a little more.

It flies good where it is and gets a little touchy with the tank empty - but I enjoy it.

After flying a PBF, it's ROCK solid ;-)

Maudib

My Feedback: (51)

I did the review here on RCU...

I put my CG at the rearmost location... 5 3/4" from the leading edge at the fuse (NOT the wingtips) and it rocks...

My maiden flight ran all the fuel out and deadsticked...

floated like a sweety and landed without incident...

(The video on the review IS the maiden flight)

Hovered great, spun awesome.... just an absolute awesome plane... I've found "my profile" of choice.

Have you checked your lateral balance? What servo and engine did you have on it?

Maybe your battery came loose and went to the aft of the wing?

Is it possible some surface was reversed or you were getting a radio hit? Mine is SOOOOOo stable atht he rearmost CG that I can't believe another one just like it was horrible...

deletemenow

I started out at 5 1/2 also and have since removed some nose weight so I am not sure where it is now.

hroachen

I started mine at 5 3/4", and the plane was a handful on the initial flights. I was going to add some noseweight, but before I did I noticed one wing panel was warped, as well as both ailerons. I really should have spotted it during the assembly, but I didn't.

I straighened the warps with the covering iron, and then the plane flew very nicely at 5 3/4.

D

bholden

Mine is around 5-1/4"...... only made 2 short test flights so far and I thought that it flew great.

Maudib

My Feedback: (51)

I had a warped aileron too... from covering... but it really wasn't enough to hurt the flight charateristics...

Twisted it and ut the heat gun to it... straight now...


Kepp in mind as the balance goes back the elevator becomes more sensitive...

You mau find decreasing throws and leaving the rearward CG more desirable...

rajul

My Feedback: (58)

Mordib, what are your throws at now ? Thx

bentgear

Any plane of this type is going to be a handfull if you start out with large throws and don't have the experience to use very small stick inputs. If you are using the recommended throws out of the manual and its squirley then something bad is wrong with the plane or I hate to say it, the pilot. My high rates are set up at 45+ degrees, but a lot of time is spent on low rates that are about half that amount.
Ed M.

bentgear

Need to add that my CG is set so that it flys handoff upright or inverted. Have no idea where that is at in inches from the wing leading edge. The aileron position, as with most planes, changes the flying characteristics greatly. Mine is set so the ailerons at neutral follow the shape of the lower part of the wing.
Ed M.

rajul

My Feedback: (58)

Shouldn't it be better if the aileron follows the centerline of the rib ? Comments ?

rc3ddriscoll

My Feedback: (3)

Not necessarily.

I added slight up on both ailerons to control in hovers and harriers. Helped a little, but changed the flying.

I use no elevator input in inverted flight.

stdun

Changed the flying how?

rc3ddriscoll

My Feedback: (3)

Really just affected the trimming. If I'm not mistaken - I needed tp trim in a little down elevator. I just did it yesterday and don't really remember without checking the plane downstairs.

It was a fairly windy day yesterday and for some reason it helped a little to not balloon in the wind.

bholden

my ailerons are set up to follow the contour of the bottom of the wing. from the side they look like they are slightly towards spoilers but it made it a lot more stable.

rajul

My Feedback: (58)

You mean flaps ?

rc3ddriscoll

My Feedback: (3)

Sounds like we noticed the same thing. I actually read in RCU that this trim can help wing rock which is why I tried it to begin with.

Looking at the wing tips from the side, the ailerons are both set a little UP (opposite of flaps). Essentially following the bottom of the wing.

rajul

My Feedback: (58)

Thanks for the clarification.

bentgear

rajul, I think setting the neutral point on the ailerons up just a little takes a little lift off the wing, everything else being the same.
It would also add a little lift when inverted.

After doing basic flight trim on the plane, and getting the cg close I start adjusting the aileron neutral position. I use a JR 8103 radio but many others will do the same thing if they allow you to set up flapperons and have a flap setting knob. During different flights I will slightly lower or raise both ailerons using the knob till I get the plane flying like I like it. Then I measure that setting return the knob to zero and adjust the control linkage.

Ed M.

rajul

My Feedback: (58)

Thanks for the suggestion bentgear ! I'm experimenting with my 4*60 in exactly the same way you described. The ailerons in a slight spoiler position tends to remove some float during landings. So many "killer apps" in the 9C.........

bholden

no.... I mean spoilers...... flaps are down , spoilers are up.... what I was trying to say is that the ailerons look like they are up.... actually they are up a little.

driscoll, it helps for harriers and hovering I'm sure..... I haven't had a chance to get mine back up again...... I need to make time. I did some harrier stuff on the maiden flight and just a little hovering high up...... I'm sure that I still need to work out a few kinks and also need to fly it some more to get the feel for the plane...... I've been flying a Magic. BIG difference......

alex

rc3ddriscoll

My Feedback: (3)

Alex - each time I'm up with mine - I learn the plane can do more than I can. I really have only been flying this plane recently.

Magic is better or worse?