RE: Mini 3d
 

It sure sounds nose heavy to me. Move the CG back about 1/4 of an inch. This should only help. If it does, creep back 1/8 of an inch at a time until you like it.

I have read about Mini 3Ds with the CG at ONE INCH BEHIND the spar that fly well. It seems like the plane is pretty forgiving of the rear CG. The metric directions translate to a CG at 3.3 inches to 4 inches from the leading edge of the wing.

Where are you guys at?

If the CG looks OK, I'd look at thrust angles. At 1/2 power, fly straight and level. Go full power instantly. Did the plane pitch down? If so, that's a problem too. Shim the front engine mount lugs up just a touch. Do the same experiment starting from inverted. Did the plane pitch then? If it does not pitch down then I'd go back to the CG.

Also remember, floating is tough on a plane with drag like this one. Yes, it may fly with low airspeed, but the drag will kill what little speed it has in a hurry. You still want the nose down until just before touchdown, if you're deadstick.

RE: Mini 3d
 

Tailtwister-
Thanks for the help! I'll move it back a little and try that. I'm still not sure what to think about deadstick flight on this one. it was basically uncontrollable...... maybe moving the cg back will help..... I had no elevator control until it was moving pretty fast. then it was too much .... I was lucky that I was over some grass! Thanks again for the information.

alex

RE: Mini 3d
 

I was able to test fly mine a few days ago. I didn't have a deadstick but the plane flew great...lots of fun. My CG is at four inches which I think equates to about one inch behind the spar. It felt right on the money. I got four flights in and never had a problem gliding in, but then there would have been a little bit of power on at idle.

I was able to accurately measure a takeoff run because the wheels left the ground just as they contacted some snow. I was using an asphalt walkway. It took exactly 45 feet to accomplish (OS 15 CVA, 9x4 prop), a lot farther than I expected. As mentioned a couple times above, there's not much incidence with the ground so I'm going to try it next time with some 2 1/4" wheels...even though they've added a half ounce. I now understand why I haven't noticed any takeoffs in the Mini3D videos I've seen :eek:. Has anyone hand-launched this thing by themselves yet? It's not easy to grab with one hand. I haven't attempted that yet, but maybe my new wheels will solve the problem. Still, I was able to takeoff everytime (again, on asphalt).

I think it was Going Vert who mentioned having a lack of power with the OS 15 CVA. I'm using 15% nitro and it started off a little challanged (2 lbs 1-1/2oz). But it gained some strength by the fourth flight as it was continuing to break in. I could pull out of a hover and go vertical, but not with much authority. I'm going to try some prop changes for grins (8x4) and allow the engine to break in some more.

I'll deal with these couple of problems without too much worry because this plane is FUN to fly. I couldn't believe how nice it handles...I like it! Oh well, now I probably have to wait another month for a decent Ohio winter day [:o].

Chuck

RE: Mini 3d
 

it took me about 50 ft to lift off........ I was very surprised. I also think that I will go to a larger wheel......

RE: Mini 3d
 

Just ordered mine today, Cant Wait... any comments on upgraded hardware needed.

RE: Mini 3d
 

Well I'm hoping the larger wheels will help with some grass takeoffs too. I figured out that I'm getting close to a half degree of added incidence, but I won't be able to test it very soon.

FYI, I picked up a set of Dave Brown Lite Flite 2 1/4" wheels at the LHS. Together they weigh 0.8 ozs and the originals weighed 0.3 ozs (pretty darn light!). There may be some lighter foam wheels out there but these don't seem too bad (I may consider drilling some holes between the "spokes" later). I haven't checked what this does to my CG yet but I'll wait until I switch to a lighter prop. I really did like the CG at 4" and I'll make sure it's there again.

You can see the bit of incidence increase in the photo.

Chuck
(after previewing my picture I see that the image is slightly tilted...look at the edge of the computer table, but it's too late for me to correct that)

RE: Mini 3d
 

I just checked my CG, its 4 1/2" from L.E. or approx. 1 3/4-1 7/8 aft of main spar. It really performs well, and is great floater at idle, haven't had a dead stick yet. I'm running a Norvel 15 with a APC 8x4, I sure that dead stick WONT be a problem.

I plan on getting some larger park flyer wheels.

Mark

RE: Mini 3d
 

The video is impressive!

All Thumbs, looking at the pic you posted, it almost looks like the horizontal stablizer is low in the front-high in the back, when eyeballing it to the wing chord line. Not the elevator, the stabilizer itself looks like it should be higher in the front.

Could this contributing to the ground roll issue? Does it pop-up on take-off when it does leave the ground?

Sweet looking plane, how does it hover???

RE: Mini 3d
 

Regarding CG - I'm 1" behind the spar. All Thumbs, you are right, I do have the power problem. I'm going to switch over to 30% heli fuel. That's what Chris was flying in the video. I'm currently running 10% and it barely hovers at 100%.

RE: Mini 3d
 

Doyou rekon i could get one of theese over to england?

RE: Mini 3d
 

I'd like some better wheels too. Anybody know where to get some 3 inchers that are only 1/2 an inch wide? I fly from grass, and this plane won't get off of the ground with these tiny wheels.

RE: Mini 3d
 

No, the stab is level. I took a good look at the picture (especially the unshrunk original) and noticed that I was slightly below the stab when I took it. The stab leading edge sweeps back a little and that's causing the illusion....sorry. I only have four takeoffs in the books so I can't be the final word on performance, but the plane does not "pop" off the ground...it comes off pretty level. I didn't notice any bad habits other than it seemed to want to hug the ground for a long while. After learning about this type of problem for float plane setups, I'm convinced the problem belongs to a low incidence between wing and ground (but that's untested so far).

I'm still new to hovering...but this plane was making me look good. It's very stable.

RE: Mini 3d
 

I just put some Dave Brown 2 1/4 lite electra wheels (skinny) on, it did improve the take off roll issue. I also had a couple of dead sticks today. With my CG @ 4 1/2" from L.E. it dead sticks just fine.:D

Mark

RE: Mini 3d
 

my plane with a .25la, 4 hs 81's, 1 gws naro servo, a 600 mah battery and a regular reciever came in at 1000grams or about 2lbs. 4oz
is this too much? will 100 grams really make a difference? The only thing I can change is the battery to either a lithium or a smaller capacity. Would this also effect the takeoff

RE: Mini 3d
 

FNG, where you taking off from grass or pavement? I had the skinny wheels in my hand but then thought they might not work good in the grass and went with the foam. I can't experiment anymore without being able to fly the thing. Do you think the improvement you got in incidence is good enough?

Thanks,
Chuck

RE: Mini 3d
 

All Thumbs, I had the same problem with a Knife. You could get the thing up to a hundred miles an hour and it just would not rotate. I would feed, and feed in up elevator and finally it took off with the trajectory of a rocket. I had a very long tail wheel wire on it and there was just not enough positive angle of attack. Went to a pair of Crazy Legs which were taller and that cured it.

Tom

RE: Mini 3d
 

Dave Brown makes Lectra Lite wheels that are a half inch wide, but the largest dia. is two and a quarter @ .32 oz. ea.

Tom

RE: Mini 3d
 

Thanks Tom. Hobbytown labled the wheels I got as Lectra-Lite but the package says "Lite Flite" so I didn't realize there was a difference. Now looking at the back of the package shows there is, doh! That may be my best choice, and I might get them when I stockpile enough needs to place another order to Tower. That'll save me about a fifth of an ounce, and I'll take it. In the meantime, should a good day arrive I'll still see how the ones I have will do. Thanks again for pointing that out.

Chuck

RE: Mini 3d
 

Sure, just as soon as we can get some of those Capiche 140's over here... ;)

RE: Mini 3d
 

Chuck, mine are the Lectra-Lite 1/2" wide foam wheels, I didn't weigh them because I picked them up on the way to the field and installed at the field. With these 2 1/4" wheels and flaperon mixing on it is now much more acceptable. However, you may consider going to an even larger wheel. Oh, I'm flying off of pavment.

Mark

RE: Mini 3d
 

er, well, can we et em out over here first[8D]

Its the same with my flip. If the plane has 2 wing servos (one for eash wing half) you could add in flap with th elevator. This gives th ewing higher lift so it takes off easy. Loking at all thubs pic it looks like the wing masks the tail andit sits very flat which will contribute towards the long take off run

RE: Mini 3d
 

Oh yeah, the thing sits very, very flat. It's a thin line to almost having a negative incidence once the tail raises. Everyone with the plane likely knows what the issue is. If I had it to do over again I'd buy some music wire and just make some gear that was an inch higher and be done with it. But it sounds as if the bigger wheels might do the trick and make it better for grass besides. If that's not satisfactory I may be dremelling out some epoxy on the gear mount :D. It looks like it's going to finally be another good flying day in Ohio tomorrow. I believe I'll be starting out the New Year with this plane in the air. (Mental note to self: Don't drink too much!)

Chuck

RE: Mini 3d
 

I'm with you Thumbs, taller mains is the answer. I'm just starting mine so I will probably bend some new mains about an inch longer.

Tom

RE: Mini 3d
 

Here is my flight report from today - weather was great! 40 and little wind.

I got three flights in w/ my new 30% cool power fuel. The plane can do everything in the book, except pull out of a hover w/ authority. I'm thinking about switching back to the zinger 9x4w. Has anyone put a tuned pipe on their .15 OS?

I am totally amazed w/ this bird in a harrier. It is rock solid. In fact, it really didn't want to come down. At idle and a little wind, it just sits there. To get it to drop I had to do them down wind. I didn't try a KE spin but I'm sure it'll do one. Blender was great. Flat spin was easy. I just wish this thing had a little more power...

RE: Mini 3d
 

I rarely feel otherwise...[:o]

I hope the 25LA pulls it well. I do not expect a rocket from vertical, but a reasonable pull from vertical would be nice. I want the 10x3 to work out, otherwise a 9x4 is on stand by. Either way, Wildcat 20/20 is the juice.

They can't all have 2:1, but why not?