Wright Stuff C

[scioly2345]

Any tips on how to get my plane to fly in a tighter circle? It ends up turning in a really wide circle to the point where it’ll hit a wall before turning (even in gyms), so I want to try getting the circle to be smaller

Adjust the rudder? The bigger the angle the tighter the turn will be. You'll have to play around with it because if the circle is too tight the plane might stall into the ground.

Xiangyu

Thanks! Should I adjust the front or back of the rudder? And I’m assuming just slight slight angle changes to see if the size of the circle changes.

[xiangyu]

Any tips on how to get my plane to fly in a tighter circle? It ends up turning in a really wide circle to the point where it’ll hit a wall before turning (even in gyms), so I want to try getting the circle to be smaller

Adjust the rudder? The bigger the angle the tighter the turn will be. You'll have to play around with it because if the circle is too tight the plane might stall into the ground.

Xiangyu

Thanks! Should I adjust the front or back of the rudder? And I’m assuming just slight slight angle changes to see if the size of the circle changes.

I'm not sure your exact design and what exactly you mean by front/back of rudder. Shouldn't the rudder be adjusted as a whole? You certainly don't want to twitst the rudder itself if that's what you mean.

And yes, start with small angles.

Xiangyu

[lechassin]

I was there Sat and saw Luke's flight. It was awesome, and avoided the two big US flags hanging down from the rafters (saw a few planes crash and not recover after hitting those). The stories of 2min both ways are not true. I think Luke finished first in the event overall - across all three classes A, AA, and AAA with only one flight. Here are the results. https://app.avogadro.ws/il/palatine-inv ... s/event/22

You guys are in great shape. That invitational is basically the state meet. It has all the powerhouse teams, Stevenson, New Trier, Nequah Valley, Naperville, etc. plus teams from WI and IN, so finishing first with only 1 flight means you guys are miles ahead of everyone else in Illinois at this point.

That's great to know, thanks for posting that. Knowing why he crashed going left yesterday (incorrect incidence setting) hopefully means he'll do OK moving forward, even as other teams improve. We'll continue working but at least he knows that if he sticks to the plan (ahem... Luke, I'm talking to you) he'll place well.

[Airco2020]

I was there Sat and saw Luke's flight. It was awesome, and avoided the two big US flags hanging down from the rafters (saw a few planes crash and not recover after hitting those). The stories of 2min both ways are not true. I think Luke finished first in the event overall - across all three classes A, AA, and AAA with only one flight. Here are the results. https://app.avogadro.ws/il/palatine-inv ... s/event/22

You guys are in great shape. That invitational is basically the state meet. It has all the powerhouse teams, Stevenson, New Trier, Nequah Valley, Naperville, etc. plus teams from WI and IN, so finishing first with only 1 flight means you guys are miles ahead of everyone else in Illinois at this point.

That's great to know, thanks for posting that. Knowing why he crashed going left yesterday (incorrect incidence setting) hopefully means he'll do OK moving forward, even as other teams improve. We'll continue working but at least he knows that if he sticks to the plan (ahem... Luke, I'm talking to you) he'll place well.

Always a risk/reward trade-off when you launch from close to the ground. No room for a bank and recovery before hitting the ground.

[lechassin]

Energized by some success, we're working on improvements. The plane I built is our test mule and we increased its MS to 19". A 3 gram 38" (broken in) motor stays on till the end, a pleasant surprise. There is a little vibration throughout the run from the extra slack which hopefully isn't too inefficient. We still have 0.2 grams of lead behind the prop so if we're desperate we can remove the lead and lengthen the nose a tad. In the house the plane climbs and cruises well till the end.

To deal with the extra rubber weight we decreased the drag, lowering the decalage to 4mm going left and 3mm going right, and we moved the CG from 29% to 39% to compensate. The tail boom is now a whopping 40 cm so the aft CG seems stable enough. We'll see.

Luke's contest planes both get 1'45" reliably now, launching at 4500 turns/0.3 in.oz. The test plane launches smoothly at a higher 0.4 in.oz, I think because of the lower decalage. At 0.4 in.oz the motor has 5200 turns (20% more), so hopefully we can get past 2 minutes now.

The school is giving me a hard time about sneaking into the gym on Sundays, so there might be a testing delay...

QUESTION: the amount of wing offset I'm using is too small so the test plane still banks some. I recall somewhere that the ideal offset is 10% of wingspan , or 3cm this year. Is that right? It seems like an awful lot. I need to remove and re-glue the wing mounts to adjust, so I'd like to get it in as few tries as possible.

[bjt4888]

Eric,

Wing offset varies quite a bit between typical designs in the AMA and FAI classes. Whatever is necessary to control roll. Also, it is not always desirable to control roll. A little roll in the initial part of the climb is sometimes deliberately trimmed in order to moderate climb rate. This is trick to trim though.

Roll is usually controlled by a combination of wing offset and washin.

Brian T

[lechassin]

I'll get it no matter what, but I'd rather not have to fix a bunch of stuff getting there. I was thinking about 1/2" either way to start?

We want to cruise flat, but we deo like the initial bank when launching left, it does control the climb and small rudder adjustments tweak the initial climb nicely and don't affect cruise radius much. I think the higher velocity air at launch causes this convenient discrepancy.

The rudder also moderates initial climb to the right, but by inducing side slip instead of a bank, also adjustable with the rudder without affecting cruise radius much.

[newflight]

when you guys practice in the gym, is the air ventilation blower on? my gym has that on. it seems the air turbulence impact the plane a lot. I had several flights that seem to fly well for about 40 seconds, then it stalled at very high position (maybe around 25ft). The torque at stalled is already much lower than launch torque since it already flew about 40 seconds. what could be the reason?

[xiangyu]

when you guys practice in the gym, is the air ventilation blower on? my gym has that on. it seems the air turbulence impact the plane a lot. I had several flights that seem to fly well for about 40 seconds, then it stalled at very high position (maybe around 25ft). The torque at stalled is already much lower than launch torque since it already flew about 40 seconds. what could be the reason?

I actually kind of have the same situation sometimes as well. My plane would stall mid air after first initial climb which should've taken care of torque.. It can still keep flying, but it just suddenly goes much slower and drops a little. I've tried to play around with CG and things and that fixes it somewhat, but it will still be there from time to time and I could never get rid of it completely. Now, I have tuned my plane so that this occurs much rarer, but again, occasionally it still happens. Is anyone else experiencing this? Could it be occasional inconsistencies in the rubber?

If you gym has ventilation on, that would probably explain the reason. Could you ask your school to turn it off during your practice? I'm sure they have a way to control it some how.

Xiangyu

[lechassin]

We're in the same boat and we're happy just to get into the gym let alone demand HVAC management. It makes tuning a challenge but I think the best teams will incorporate HVAC into their algorithms. I don't think it's wise to assume that HVAC will create an even playing field. Some teams will be able to quickly shift from conservative to higher performance settings based on not only HVAC, but smaller spaces, different ceilings, etc... For now we're happy to have a decent flying plane, but it is set for lower ceilings, smaller spaces, HVAC, etc... and it will be outclassed in higher, larger, calmer spaces where aggressive setups can thrive. This is where we're concentrating our work now (see above)

You'll never keep a basting vent from affecting the plane, but I think good HVAC tolerance goes hand-in-hand with good recovery from hits: conservative (forward) CG, higher decalage, and maybe even different prop/rubber. If we want maximum flight times we have to move the CG back and lower decalage (drag), but we already know that recovery from hits (and HVAC) will suffer. Ideally we will have logged different setups and will be able to switch back and forth based on the site, but we're not there yet (and we might not get there; our school is being difficult about gym access even when it's empty because of the liability we bring *sarcasm*).