Wright Stuff B

[bob3443]

What size motor are you using? What size and type of prop? How many winds? What's the plane doing (besides just flying). Do you get to the ceiling? How high a flying site? How big a turn. Etc.

i'm using 1/16in. tan 2 super sport rubber, but that doesn't seem 2 making it go up so i folded that in half and now i have 4 strings of rubber going from the front motor hook to the back motor hook(would using 2 strings going from front to back, each string is about 42cm. long be better? the distance from my front to back hook is only about 21.cm should i make it longer?) i'm using about 750 winds on it. i'm using an ikara propeller, trimmed to 20. cm. diameter. yes i get pretty much up to the celling, i would say about 20-25 ft. the diameter of the turn is about 10-15 ft. i'm actually flying in my school's auditourium, because both gyms are taken almost everyday. one time it broke because of hitting the lights hanging from the celling, another by crashing into the chairs. but once it was just flying and it basiclly came straight down, wing broken, didn't crash into anything just flying then comming down. i don't get what you mean by if its doing anything else other than "flying" it takes about 20 seconds going up, i would say maybe 5 circles? then it flies at a constant height for maybe another 20 seconds and then starts it's decent. if you need anymore information about my plane or something just ask also what do you guys mean by trimming it? i don't think i understand it correctly.

i guess the next one i make i'll probably make it a little longer and the distance from the front hook to back hook longer
do you guys make only a motor hook and attach the back stabalizer onto it or do you make a motor hook and then make a tailstick and attache the stabalizer onto the tailstick? i figure if i only use a motor stick i can made the distance longer.

[andrewwski]

You don't want your rubber like that. Yes, you'll increase torque that way, but severely at the expense of winds.

I'd get thicker rubber (closer to 3/32") and put a lot more winds in. You should be getting about twice as many winds, which is going to keep you up a lot longer.

1:00 to 1:20 is great for your first plane. It would medal at most regionals.

[jander14indoor]

Don't sweat making the rubber length match the hook length, its just not important.

Are you using all 1.5 gm of rubber?

Concur with andrewwski, two strands of 1/16th is too thin a motor, not enough torque. Four is too thick, too much torque, not enough winds. Two strands of 3/32 is about right for these planes. You'll pick up a lot of time just by going to the right thickness of rubber and winding harder. 750 turns is very low, when we had two grams I'd typically wind motors 1800 plus turns, so a 1.5 gm motor should take more than a thousand turns.

If you don't have quick access to 3/32 rubber, try three strands of your 1/16 till you can get some, tricky, but doable. And make sure you use 1.5 gm not a specific length.

Trimming, the process of adjusting the plane so it flies the best possible. Best possible in this case means low drag and efficient lift for long flights. Typically this means adjusting the motor size, prop pitch, wing angle of attack, tail angle of attack, stab tilt, wing wash, center of gravity, etc. To organize all those factors you need a process, see http://www.gryffinaero.com/models/ffpag ... 0step.html for one person's approach.

For example, a 10 to 15 foot circle is pretty tight unless you have to compete in a small room. It creates a lot of drag, open out your flight circle by adjusting the stab tilt.

From your description so far, you've built a fine plane, it just need trimming. An experienced flyer could adjust (trim) your plane to fly much longer in a short time. Your job now is to focus on becoming one of those experienced flyers. Thus the recommendation to focus on flying, not building

On the breaking, you shouldn't break very often with normal collisions on a light plane, but a busy room like an auditorium is certainly a hazard. Check carefully where the breaks are occurring, probably a defect in the wood, either it came that way, or you damaged it in building. Or maybe a little too light on the glue. For the next build pay more attention to those things.

You described the flight just fine so far. Sounds like you need small tweaks as discussed for much longer flights quickly.

Jeff Anderson
Livonia, MI

[bob3443]

yes,i'm using 1.5 grams of the rubber, how do i make 3 strands going back and forth? i can't figure out a good way to tie it. if i take out the propeller when trimming it, it changes the weight, so then the plane basicly stalls, then go straight down. 4 strands of 1/16 generally breaks at around 800 winds, i broke alot of rubber so far.

[carneyf1d]

you really want just one loop. buy a thicker rubber size and like 3/32 and you can get around 1500 winds. more winds= more time.

[jander14indoor]

Tie a short loop at each end of the strand, run it back and forth three times, hook one loop over prop hook (or better through your O-ring) and other over your tail hook (or again another O-ring). Certainly NOT ideal, but will let you continue to improve until you get some correct size rubber.

As to trimming without prop, ballast out the weight of the prop. Make sure you maintain overall CG and total mass.

Another alternative (and what most indoor flyers do) is to wind just a few turns (say 100) onto the motor so the prop is just ticking over. No real power. The idea is to test the glide.

Are you lubing your motors? 800 to break for 1.5 gm rubber, four strands is reasonable, so I'm guessing you are. And everybody breaks LOTS of rubber. That's why I buy it by the pound!

Jeff Anderson
Livonia, MI

[killerninja999]

hey my prop is on back order so what is a good angle for my horizontal and vertical stab. (conected). Also would it be better for me to put no angle on my stab. tip (for dihidreal efect)? What is a good design for the vertical stab.? I have 6 cm. wide and 8cm. high with no curvature. Also what would be a good adjustment system for stab. to change angle? I did have an Idea for a trip system for flaps. Thanks for the help.

[dinodude]

Does anyone have any ideas for adjusting the pitch on Ikara propellers? It seems like heating it would work, but I'm afraid I'd melt the prop blade.

[andrewwski]

Ray Harlan had real good instructions in his manual for the kit he sold. They may be on his site (indoorspecialties.com) or on one of the links on the WS page at SOInc.org.

You want to heat the plastic piece between the center and the blade very gently over a candle. Only heat it for a short time, as you do not want the blades to start deforming. Then, take two small pairs of needle nosed pliers - hold one in each hand - and position them at both ends of that piece. Actually, I'd hold the prop over the candle in this fashion. Then very carefully twist that piece. You may have to repeat a few times to reach the desired pitch.

Harlan also had an excellent article on how to build a pitch gauge for free. Should be a link to it on soinc.org.

[noob]

i am sooo good at this one (5th place two times)