NutBall Scratch Build

earthsciteach

Moderator
Moderator
Oliver - It flies like a nut ball! LOL

Looks to me like you need to move the cg forward and reduce the control throws. Also, you may need to shim the motor so it has a bit of down thrust. But, don't do them all at once!

Start with the cg and see how it flies. Then dial down the throws and see if you are more comfy with it. Finally, if it climbs like a rocket when you add throttle, put some down thrust in the motor.

Congrats on your first flight! Hey, it was airborne! Don't feel discouraged - your maiden was better than many I've seen!
 

MrClean

Well-known member
CG too far aft. I really don't like the nutball for a trainer, there are better in my opinion. It does build easy and you done good there. Then I think you've got way too much throw. So everything Earthsciteach just said. Heck, I'd say its a succesful maiden. Most I've seen with no flying experience do a figure 9 to self destruction.

Find your cg as it is now, move it forward a bit. Fly again. It shouldn't immeadiatly drop it's tail if the control surfaces are neutral (flat across the top). I know that Josh likes to say "I have my dual rates set at 30 and 60%" or something like that but that doesn't really tell us much. What hole out is he on the servo, how tall are his control horns. 60 percent on one setup will produce half an inch of movement at the tip of the control surface in one setup, 1 inch on another. Look for up deflection of half an inch from neutral, dial it down to there with your transmitter. Launch with the proper cg and it should fly level. Looks like you're solid on roll so at least they're set right. If you can get it to fly away from you without holding much up on the stick then you're close. Giving full up should put your nose up like it did in this video. If it does so slower then you're controls are probably a bit more comfortable. Rolling should also not be lightning fast. again, half inch maximum should produce controllable rates.
Try to imagine yourself IN a cockpit on the plane. When you start coming back at yourself roll will appear backwards but if you are 'in the cockpit' you'll see it's normal and just your perspective. Gentle circles right and then left and then figure eights both ways this will clear you of the 'in the cockpit' weirdness and then we can work on more active flying.

You're close. Maybe take advantage of the swappable feature and build the FT Flyer for some primary flight instruction? But set up correctly this is a stable, easy flying platform.

It ain't as easy as it looks, but it's not impossible. You did well recovering from tail heavy tail dropping. When you don't have to fight that the rest will be more manageable. And it happens to all of us. My Baby Bixler is tail heavy. Found out New Years day when I threw it and then had to fly with down stick to keep it going forward. Not as comfortable a test flight as I'd like BUT I've had worse.
 

Oliver

Junior Member
Thank you very much for your help Earthsciteach and Mr clean
I have managed to glue it back together and i moved the battery right to the front under the landing gear (previously it was just behind) and she fly's without any down pressure on the elevator.
Im it seems to stall alot, even when I get it pointing forwardit barely moves it just sort of floats down :( Im using the stock blue wonder outrunner, a 2s 500mah turnigy battery, A 25A speed controller and these props as the ones recommended weren't in stock. Ive also tried cutting down a spare one and balancing it, its even worse!
As for the expos im not sure i can change them as im using a cheap hobbyking transmitter :(
I think im going to give the FT flyer ago, sems like a fun plane to build!
 

Bolvon72

Senior Member
Mentor
Oliver, It just dawned on me, you said you used magnets to secure the pod at the rear. That could be your CG problem right there. Try to pull those off and go for the lightest means of securing it to the rear.

Mr Clean is absolutely correct, the FT Flyer is a much nicer flying plane, and very easy to build. I threw one together last night in a half hour (already had the plans ready to go) for my father to crash this weekend when I visit. I find it much easier to control than the nutball.

You were doing great fighting the unbalance of the plane in your vid and I wish you the best in getting up and staying up. I look forward to a successful maiden video from you real soon.
 

MrClean

Well-known member
It doesn't seem right that a power combo that had you hanging on the prop pre crash to not have enough to motivate you now that your CG is correct. Is the motor spinning up like it did before or did it suffer in the crash?

Which blue wonder do you have? I'd like to look up that stats. But an 11x7 prop sounds a little on the too large a load side. On any down time have a browse at Josh and Josh as they discuss prop selection and take the test.

Even on a tight budget, all is not lost. Foam is a dollar a sheet. motors are generally under 10 and props are cheaper still. you may have to order them and that will take a while to get them in BUT You could swap stuff out to a DIG that was posted just yesterday and play learn to fly while waiting. Where this guy uses carbon fiber you could use a cheap dowel rod. Won't be as strong so don't throw it as hard.
 
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Oliver

Junior Member
It doesn't seem right that a power combo that had you hanging on the prop pre crash to not have enough to motivate you now that your CG is correct. Is the motor spinning up like it did before or did it suffer in the crash?

Which blue wonder do you have? I'd like to look up that stats. But an 11x7 prop sounds a little on the too large a load side. On any down time have a browse at Josh and Josh as they discuss prop selection and take the test.

Even on a tight budget, all is not lost. Foam is a dollar a sheet. motors are generally under 10 and props are cheaper still. you may have to order them and that will take a while to get them in BUT You could swap stuff out to a DIG that was posted just yesterday and play learn to fly while waiting. Where this guy uses carbon fiber you could use a cheap dowel rod. Won't be as strong so don't throw it as hard.

The motor seems ok, im using this one It might be my flying but it just seems incredibly slow compared to the flitetest video. Unfortunately foam board here in the UK runs at about £13 (Just over $20!!!!!!!!!) How ever i managed to find a sheet on sale for £5 so I stocked up with a few sheets :)
I was originally thinking about building the old fogey after this, would it be a better idea to build the FT flyer first?
Thanks again for taking the time to reply!
 

Bolvon72

Senior Member
Mentor
The Hextronik 1300kv just carries these smaller swappables with a 2s and a 9x5 but, looking back at the review, it seemed about accurate. I personally don't like the motor myself. I use it if for first time flyers so I don't get mud caked in the ones I do like.

Flying these little swappables for myself I like the Suppo motors.

As for building the Fogey, I love that plane, but the Hextronik is too anemic on it. I think it is a great starter plane in terms of handling and joy of flying, but you would need a 3s to get it going well with that motor.

I would say build them all and play around to see whats good or not, but I having lived outside the US quite a bit, I understand having to hunt for the stuff that we can buy by the stack over here. The Flyer is a one sheet project compared to the two sheet Fogey which may also include a need for a new battery or motor. Some pros and cons for you there.
 

MrClean

Well-known member
ok, theres your problem. any hobby shops around? you'v got 3 inches more diameter and twice the pitch. makes a good helicopter rotor but a bad high spedd thrust producer. probably over currenting your speed control too.

20 bucks a sheet? better be a 4 x 8 sheet of foam core. Yes, the ft would be better. one handed holding grand baby typing
 

Oliver

Junior Member
Haha its A1 size, its a complete rip off!
Theres one a couple of miles from me ill probably pop down there tomorrow. What sizes do you recommend buying? Ill probably buy a couple to try them out.
 

MrClean

Well-known member
8 x 3.8 is listed on the page you have. That would probably make it happier. The page also says to use a 3 cell on it which would give you quite a bit more rpm.

I know it hasn't been posted much here, but there is quite a bit of similarity between foam board and cardboard. They DO have cardboard over there in England don't they?

And of course, my ultimate fix to your problem is to recommend immigration to the Good ole USA. Hey, you'll probably test higher then the average kid here though we generally like people that can speak English.

Anyways, an 8x4 or 7x6 ish prop would probably be a good size for your motor.
 

Oliver

Junior Member
Thanks I was going to go today but its started snowing so ill have to wait :( We do have cardboard (like the stuff boxes are made from?) but its extremely heavy so its probably a no go. Ive always wanted to live in the US, maybe some day!
 

Bolvon72

Senior Member
Mentor
Well, I went from the 17 inch to 20 so, as I sat around last night I decided to grab a couple of sheets of Adam's and build a 30 inch. I put the pod on the top upside down because I have some lighting plans for it on the bottom. I used the Blender NTM 28-26A with a 2s 1800 right to the front to balance. I gave it more control surface than it needed as it turns out, but that just means it's there if I need it when I start adding weight. I put on some BBQ skewers for support JIC.

nutball black2.jpg nutball black.jpg

Now I just have to talk my disassociated teenage daughter into standing in a field with Dad to video it.
 

cyasa

Junior Member
I am another newbie , This is going to be my first build , I currently live in New Zealand.
I can get hold of the following foam cheap.
Resilient polystyrene memory core that "bounces back" after cutting & resists denting. Ultra smooth surface perfect for mounting without ripples, bumps or dips. White outer & core.
Its 5mm can i use this??
Thanks
Gary
 

CrashRecovery

I'm a care bear...Really?
Mentor
Ok what's the trick to get these things to fly right? I can't seem to keep it in the air?
 
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MrClean

Well-known member
A dialed in, handed to ya Nutball is an ok trainer. It has the tendency to not be dialed in for beginners when built by beginners, and instead is ready for the most capable hands. If the CG is correct and the throws minimized, a Nutball will fly sedately. If the CG is too far back or the throws are too large or both it will turn around in the space of it's own diameter, in any direction or all three at once, which is amazing but a little skeery if you just wanted to go straight out 20 feet.

Check your CG, maybe put it half an inch forward of plans. Dial down your throws, whatever you have now HALVE IT. now see if you can fly it. If you can trim it for level forward flight, make a gentle turn by using 1/4 or almost half rudder stick and pulling full up with full throttle will barely make a loop but more often a figure 9 if you do it close to the ground, you have it tuned for training.

If it is more active, you need to dial it down some more.
 

CrashRecovery

I'm a care bear...Really?
Mentor
Only thing I can do right now is move the rod where it connects on the servo arm. Should it be farther out or more in on the arm? The other problem is I still haven't gotten the 9x so I'm using the controler and receiver from the big foamy thing I bought. There is no dialing down on the remote