Flight Troubles?

[jander14indoor]

Start by reading backwards in these note strings and last years archive. No one way to get there so all we can give are pointers.

First, pick a plan.
Many designs on the web work, some need modifying to this years rules, some don't. The Finny-09 by Bill Gowen works VERY well and still fits this years rules I think. It is in the Yahoo group Indoor_Contruction in the files section. You'll have to join the group to see it.
This one is available on the national SO website, not perfect, but certainly capable of 2 min flights. http://soinc.org/sites/default/files/up ... ans2.0.pdf
This is an older plane that flew well, modified to fit this years rules with similar proportions and it will work. http://www.rivard.org/aeromodeling/freeflight.html
Note, all of above assumes you built the plane to max allowed dimensions under the rules and minimum weight.
Most of these plans are missing a key element, the detailed bill of materials that tells what each part should weigh to hit the minimum 7 gm before you build the plane.
What plans have you tried that don't work?

Second gather materials. Refer to the bill of materials to make sure you pick light enough wood to build a 7 gm plane. Random selection just won't work. Note, SO planes do NOT need exotically light wood. None of my demos uses less than 6 lb/ft3 density and most is above 8 lb/ft3. But you do need to select for weight.

Build carefully. Use jigs and fixtures to make everything come out as intended. Again, see the archives for hints and tips. And the National SO page for the Wright Stuff event, http://soinc.org/wright_stuff_b lots of tips there.

Fly, fly, fly.

Jeff Anderson
Livonia, MI

[andrewwski]

I used these instructions to build my first WS plane about 5 years ago:

http://web.archive.org/web/200806190448 ... ws/ws.html

The original webpage seems to be gone, but thanks to the Wayback Machine you can still get it.

The instructions are a tad outdated, and there's some things I learned to do differently. Mylar is now allowed, you don't need to use Japanese Tissue (although with WS weight allowances, you can use it just fine. It's easier to work with too). You can probably use 1/16" balsa for ribs instead of 1/32" (much easier to work with). Dihedrals are much easier to create by building and covering the wing as one piece, then cutting the outer spars, elevating the tips, and gluing, rather than this method of angled ribs. A two piece motor stick is much easier than trying to create a tapered one. Most builders will use tubes to attach the wing - although a wing saddle is very useful for a first-time builder, let's you see the ideal position of the wing and how different positions make a difference. The Ikara props eliminate the need to shave another prop down.

They are good instructions for starting out though. I think I got about a minute out of that design my first year, with only about 3 days of trimming. I ended up doing WS at the last minute, had 3 weeks between the time I started building and the competition. I'm pretty sure if I had more time to test it, it would be capable of at least 30-60 seconds more without anything other than simple trimming. That is under the old rules of that year though.

You have to change the dimensions to fit the current specs. They're not perfect instructions. But they are a good starting point.

[blue cobra]

ok then, any way so can anyone tell me exactly what to do or post some designs that actually work??? because there's some designs on th web,but so far none of them have ever worked and I have to start building tommorrow!!!

Well, your first plane isn't going to be very complicated, so you don't really need a design. If it will help you, of course use one, but it should be pretty simple. Of course I may not be as experienced as some of the others here, but I was in the same place you are just last year, so this is what I reccommend:
1)Wing- Cut out two 40cm sticks out of 1/16 sq. for your leading and trailing edge. Pin the TE down to your building board first, parallel to the edge of your board, if possible. Next, pin down the LE parallel to that at the distance you need for your ribs. I used laser-cut ribs at first, which you can get from Indoor Model Supply. Don't trim them. So now make sure your LE and TE are parallel and squared up and at a good distance, and measure the distance between them. Cut two sticks 1/16 sq. this distance and glue them between your LE and TE at the tips. Next, glue your ribs on (make sure all the Leading Edges are facing the same way). Put two about 1-2mm apart in the middle. Evenly space the rest. Now cover the wing, we've already gone over that part, and induce about a .75 inch dihedral. Add posts, and possibly more supports, and you're done.
Horiz/Vert Stabilizer- I just built this flat, with a peice extending out the front center to rubber band down. Angle the vertical one (the rudder) to induce a turn.
Motor Stick/Tail Boom- I personally used 1/8x1/4 for my motor stick, but a lot of people use 1/8x3/8. The thicker one obviously is stronger. Use 1/8 sq. for the tail boom.

About measuring weights, maybe all my wood just happened to be perfect all year long and I'm about to get struck by lightning twice, but I didn't check, and all my planes came out under 7g. The problem with checking weight of individual parts is that beginners don't know what each part should weigh. Now, weight is very important, but your first plane really doesn't have to be 7.00000g. Maybe your second, but not the first . It definitely should be under 7.5g, though.

Hope I could help!

[goblue007]

I have built an airplane just to get the hang of things untill my kit arrives. The plane curves but doen't climb what can I do to get it to climb and get a good flight?

[jander14indoor]

Well, more details would be useful. Its hard to give help with so few facts.
How much does the plane weigh. How big is it. How much rubber are you using, what kind? How hard are you winding the motor. How long does it circle without climbing. Please describe a flight in detail.

That said, here's the couple of big generic things I've seen over the years preventing good flights.
Plane is just too heavy. Sorry, only solution to that is to build a lighter plane.
Not winding the motor hard enough! Even with a properly built and trimmed plane it takes 1200 plus turns on a 3/32 wide 1.5 gm motor to fly good SO planes to these rules. WIND those motors.
If your plane is light, you are winding the motors hard, and are getting nice level, but not climbing flight, increase the angle of attack by tipping the leading edge of the wing up or trailing edge of the rear stab up. Make small changes.

Get back to us with details for your flights and we can be more helpful.

Jeff Anderson
temporarily in Oakville, ON, Canada
hoping to get home for the holidays to:
Livonia, MI

[goblue007]

I doubt that the plane is to heavy it weight about 6 grams. We were using a .95 rubber band. Th H. Stablizer is 18.5cm and our wing span is 37cm. Our flight was about an 2/3 circle to 3/4. It tried to climb but couldn't. I thought it didn't have enough torque. We are only winding it 40 to 50 times with a 16:1 winder, so thats 640 to about 800. That could very easily be the problem. I then tried it with 960 rotations and it turn way to sharp and fliped over and flew upside down. It was not good we had to chase it as skimmed the ground to save it from wrecking the mylar. What do I do?

[carneyf1d]

what kind of dihedral do you have on the wing?
and what do you mean by 2/3 or 3/4 circle?

[goblue007]

when we launch it it flies alone for the circle

[jcollier]

I doubt that the plane is to heavy it weight about 6 grams. We were using a .95 rubber band. Th H. Stablizer is 18.5cm and our wing span is 37cm. Our flight was about an 2/3 circle to 3/4. It tried to climb but couldn't. I thought it didn't have enough torque. We are only winding it 40 to 50 times with a 16:1 winder, so thats 640 to about 800. That could very easily be the problem. I then tried it with 960 rotations and it turn way to sharp and fliped over and flew upside down. It was not good we had to chase it as skimmed the ground to save it from wrecking the mylar. What do I do?

Sounds like if you wind it harder, it flies worse. If that is true, it could be the motor stick bending. You should be able to raise the leading edge of the wing to get it to lift. If it doesn't lift with .095, it is not because of too little torque. We usually do trim flights with 600 winds, and a good plane will fly for 1:15-1:30 and climb to 15 ft. high or more.

[jander14indoor]

I doubt that the plane is to heavy it weight about 6 grams. We were using a .95 rubber band. Th H. Stablizer is 18.5cm and our wing span is 37cm. Our flight was about an 2/3 circle to 3/4. It tried to climb but couldn't. I thought it didn't have enough torque. We are only winding it 40 to 50 times with a 16:1 winder, so thats 640 to about 800. That could very easily be the problem. I then tried it with 960 rotations and it turn way to sharp and fliped over and flew upside down. It was not good we had to chase it as skimmed the ground to save it from wrecking the mylar. What do I do?

Yep, weight is OK. Assuming conventional configuration it should fly.

Definitely needs more turns, but sudden changes in behavior point to other things being wrong too.

Weak motor stick already mentioned, equally a weak prop hanger. But typically that causes a dive, not a roll over.

Increased torque could have flipped it over with more winds, but you didn't increase that much. Did it fly OK when you went back to less winds? If not, look for something broken. If yes, something is bending.

If the Motor stick is stout enough, try to watch the plane carefully in flight as you increase torque. I once had a plane that would fly great in low sites, but when I increased torque in taller sites to get to the ceiling the thing would roll into the ground. It was almost an on-off behavior, small changes in torque flipped the plane over the edge. Took forever to figure it out till was able to see things right. I had a weak front spar on the tail and above a certain torque (speed) the stab would suddenly twist the LE up on one side, rolling and diving to the ground. A weak front spar on the wing can cause similar things. For this, and other reasons (flutter if you want to look it up), its best to have a slightly stiffer front spar than a rear.

And yes, make sure you have enough dihedral.

Jeff Anderson
Jeff Anderson
temporarily in Oakville, ON, Canada
hoping to get home for the holidays to:
Livonia, MI
Well, more details would be useful. Its hard to give help with so few facts.
How much does the plane weigh. How big is it. How much rubber are you using, what kind? How hard are you winding the motor. How long does it circle without climbing. Please describe a flight in detail.

That said, here's the couple of big generic things I've seen over the years preventing good flights.
Plane is just too heavy. Sorry, only solution to that is to build a lighter plane.
Not winding the motor hard enough! Even with a properly built and trimmed plane it takes 1200 plus turns on a 3/32 wide 1.5 gm motor to fly good SO planes to these rules. WIND those motors.
If your plane is light, you are winding the motors hard, and are getting nice level, but not climbing flight, increase the angle of attack by tipping the leading edge of the wing up or trailing edge of the rear stab up. Make small changes.

Get back to us with details for your flights and we can be more helpful.

Jeff Anderson
still in Oakville, ON, Canada
but looking more like I'll get home for the holidays to:
Livonia, MI