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Old May 29, 2004, 10:10 AM
The Airplane Gremlin
Seared Ice's Avatar
United States, PA, Pittsburgh
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Good thermalling time is an hour or two after the day gets its hottest. That way, the dark areas of the ground have had time to warm up hotter than the surrounding air (best thermalling day is when it gets hot and sun is out early...then the air cools off but the sun stays out...the sun keeps the ground warm but since the air is cooling, more thermals break free of the ground and rise faster).
~John
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Old May 29, 2004, 10:20 AM
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Is humidity a factor?
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Old May 29, 2004, 10:50 AM
The Airplane Gremlin
Seared Ice's Avatar
United States, PA, Pittsburgh
Joined Jun 2003
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The lower the humidity, the more cylindrical and defined a thermal will be (has sharp edges...one second you'll be out and one second you'll be in). The more humidity, the wider and more "mushy" a thermal will be. The thermal will be larger, but weaker proportionally. Sometimes thermals like this are so big, you happen to think there is lift all over your field (there probably is too...until it passes by...when you get mushy sink all over your field...)
~John
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Old May 29, 2004, 11:13 AM
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Thanks, John! Thats about what its been like the past couple times i was able to put my parkflyers up. EXACTLY what it was like. I just put my J3 up and seen it rise over a roof top, but when I flew back over it, the lift wasnt there, niether was sink. I didnt feel a gust of wind that could have made a lil' slope affect on the side of the house, but the winds are 0 to 3mph so far, witch wouldnt have been enough to "slope" it. What do you think it was? I looked on top of the house to see if I coudl see any heat rising off the top, there was, but only a few inches up 'til it disipated....?
Could that have been lift? The plane was about 15ft over the house at the time and about 20ft on the way back over.
Thanks so much
-Jake
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Old May 29, 2004, 11:18 AM
The Airplane Gremlin
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United States, PA, Pittsburgh
Joined Jun 2003
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sounds like a passing thermal...

...or it could have been a bubble breaking free of the roof. You didn't see much heat coming off the roof because it'd just risen up. If you had started a thermal turn as soon as you saw the plane rise, you may have gotten into the bubble and worked it for lift. Bubbles, when big enough, form thermals...thermals feed rising bubbles with more warm air. Once the thermal's been formed, it can sustain itself and does't need the bubble on top to continue rising.

~john
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Old May 29, 2004, 11:36 AM
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I bet thats what its was.
I just got the Cub back down again after riding some lift. It was very minimule and I was flying @ full throttle, but it was still enough lift for me to gain altitude in a tight turn(witch the lil' J3 w/IPS motor cant do by its self-so it had to be lift). But there was also a lot of sink "floatong" around. But today doesnt seem humid, but the lift and sink s acting just like if it was. Last night was cool with lost of fog and this morning was about the same, but without the fog. The sun is VERY hot todat and will make for good thermals!
I hope to catch sme more later.
Thanks for the help, John!
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Old May 29, 2004, 04:55 PM
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You can thrmal anything. Just be careful. Light planes like the slow stick can be caught in strong thermals and be carried up very fast. All of a sudden they are out of sight. Or they can get caught in the thermal wall.

Just don't let them get too high.

Hot, dry with no breeze is the best thermal weather. However you can get thermals any time there is sun. Even on cloudy days. Even at 30 degrees with snow on the ground, bt hot, dry calm arre the best conditions.

I was out flying today in 10 MPH winds with gusts to 20 MPH. I was practicing my ballasting techniques with my Sagitta 600. speced the plane out twice. Once it went up so fast I actually had to bring it down, I was concerned I would lose it.

Popped the spoilers and put the nose down.

Great day. Ballasted to about 15% of the plane's weight.
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Old May 29, 2004, 05:48 PM
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Wow! Thats a lot of ballest! Glad to hear you had a good time. I today was a "boomer day" in terms of weather, but Ive only been able to catch light lift(light compared with my J3!), my firend was having some emotional problems and I had to "talk her down". But shes fine now and all is well. The winds here today have been 0-5or6mph gusts. Great day, but becasue of haveing to spend time with my friend I missed peak thermaling hours. But i'll try tomarrow morning
I'll be sure to be careful! I woudl die if i lost my SS or J3.
thanx
-Jake
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Old May 29, 2004, 08:02 PM
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One thermal was a real "hat sucker" as they say. I wasn't even circling, it just pulled me into the sky right off the end of the launch. Wild!

I was getting so high, approaching spec out, when I bailed out because it had carried me far off the the field, down wind, and I was concerned about getting back against that strong wind. Had to work at it in a series of dives to get up enough speed to fight my way back against the wind.

A real learning experience

Hope you have wonderful weather Sunday!
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Old May 29, 2004, 09:36 PM
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The winds are going to be up too much for the SS and J3, so I'll have to try thermaling with my profile 51 or my Corsair. lol
Cant wait to get that Aspire back up, but i am just not in the mood to work on her anymore
But i'll make myself monday when the winds are goin gto peak @ 20mph(+ gusts ) Non of my planes can handle that...make me wish I had a BL Hotliner,
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Old May 29, 2004, 09:55 PM
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Your Aspire, in sailplane configuration can handle 20 MPH if you ballast it right. I can't say how it would do in e-glider configuration since I have never flown one.

How much does the battery weigh that you use when you have the motor in the plane? Does it sit over the CG of the plane? Remember when you have the motor and the battery in the plane you have dramatically increased the wing loading which means it flies faster and will penetrate wind better.

The Aspire can do it, but are you up to it and do you have enough room? That is a different question. I will tell you that hi-start launches at 20 MPH are monster high! But if the plane is not properly ballasted and balanced, then can have a wicked time trying to control the plane.

It is more the pilot than the plane that is usually the limitation.
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Old May 29, 2004, 10:08 PM
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My aspire has NEVER like teh wind. I tryed FAR formawrd CGs adn Far Aft CGs and none worked. The Battery does sit over the CG ans CG is achived through the positioning of the Rx battery. She does fly better, but WILL NOT gain altitude. IDK y, but it just won't. Im using the recomened battery(6cell D pack- not sure of the wieght) and no other will fit adn still maintain the proper CG.
I do like the launch hights ing higher winds, but the last times ive tryed it, she gets to the top of the launch and just floats in that spot and i have to push her ove, but then the parashute doesnt come off. Witch is what happoned on the second crash.
I do need more balast, but then I would have a MUCH more decreased glide ratio wouldnt I? Yes, I coudl add down trim to speed it up, but that doesnt help the glide ratio much(ive tryed it-and again, with fore adn aft CGs).
I do not mave much room, but enough for the one or 2 8cell AAA batterys im using as ballast.

Im thinking about just doing away with the motor sence I cant upgrade to a 7 cell pack Im just going to build the nose(whats left) around the electronics that go in the nose. I might be able to get a hotliner next year, but I haven't the money to do much sence my car insurance is $2000 a year adn I have no job @ the moment.
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Old May 29, 2004, 10:31 PM
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A 6 cell D pack seems very unusual. The e-aspire pilots at our field are using 7 cell sub C packs. That is what I have for the power pod on my Spirit. D's would be very heavy.

While the 6 cell might be the standard battery for the aspire, I am quite certain that a 7 cell subC pack would be fine. Just check your speed control to see how many cells it is rated for. Probably 8.

Take a look at the motor. It is probably an 8.4 or 9.6V rated Speed 550 or Speed 600.

This is the pack that goes in the Great Planes Spectra which uses the same motor, basically, as the Aspire. This pack would work fine.
http://www2.towerhobbies.com/cgi-bin...?&I=LXBNC4&P=V
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Old May 29, 2004, 10:35 PM
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[QUOTE=Mchone, Jake]My aspire has NEVER like teh wind. I tryed FAR formawrd CGs adn Far Aft CGs and none worked. The Battery does sit over the CG ans CG is achived through the positioning of the Rx battery. She does fly better, but WILL NOT gain altitude.
QUOTE]

Balasting a plane has NOTHING to do with balancing it.

Balancing weight is used to set the CG. Adjusting the CG will not help you much in the wind. Get the plane properlly balanced for normal flight and leave it there. I was flying in 20 MPH winds and I did not move the CG at all. In fact I tried adding 1/4 ounce of nose weight to shift the CG forward a little. The plane did not fly as well.

What I did was add 3, then 4, then 4.5 oz of lead to a box I created right over the CG (right over the launch hooks). This does not change the CG of the plane, it just makes the plane heavier which will allow it to penetrate the wind better by gliding faster.

When you have the motor in your plane, it glides faster than when it is a pure sailplane. However the CG should be in the same spot.

hope that helped. Don't confuse balancing and CG with ballasting. They are different and have different purposes.
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Old May 29, 2004, 11:26 PM
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Quote:
Originally Posted by aeajr
A 6 cell D pack seems very unusual. The e-aspire pilots at our field are using 7 cell sub C packs. That is what I have for the power pod on my Spirit. D's would be very heavy.

While the 6 cell might be the standard battery for the aspire, I am quite certain that a 7 cell subC pack would be fine. Just check your speed control to see how many cells it is rated for. Probably 8.

Take a look at the motor. It is probably an 8.4 or 9.6V rated Speed 550 or Speed 600.

This is the pack that goes in the Great Planes Spectra which uses the same motor, basically, as the Aspire. This pack would work fine.
http://www2.towerhobbies.com/cgi-bin...?&I=LXBNC4&P=V
OH! lol I am sorry, they ARE C batterys.
The motor is a 550 but idk what the Volts are.
I do not have an ESC. the Aspire ARF doesnt need it. I use an extra servo to push a botton to turn on the motor. Its, literaly, all or nothing!
I ahve looked into a pack like that, but when I got the specs on the pack, I woudlnt be able to have a proper CG. It woudl be a tad forward and I do not add weight on any of my planes. I just move the electronics around, but i am un able to im the Aspire becasue of the limited space. Im just stuck with the 6s C's.
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