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The Wattflyer Sailplanes Thermal Duration Contest

Old 09-19-2011, 08:11 AM
  #26  
Larry3215
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Originally Posted by Helinut View Post
Well I have to admit you guys have given me renewed hope. I'm using a 4oz 1500mah battery but I think my problem is the camber/ trim. I've got it flying pretty slow right now. I'll experiment with the set-up next weekend. Thanks!
Yeah, like Nitro said - trimming for the slowest flying speed isnt always best. For sail planes, its almost always a bad thing to do.

Typically, if the model is trimmed for its slowest forward speed it is NOT trimmed for best L/D and will in fact come down faster (have a higher sink rate) than if it is trimmed to fly a little faster.

Every model is different but you want the hands off flying speed to be significantly above stall. You will have to play with it to find whats best for your model at its current weight. The speeds will be different depending on how much camber you have dialed in.

On my sailplanes that have adjustable camber, I have 3 flight modes. Fast cruise for getting out of sink in a hurry, Normal cruise for thermal hunting and slow cruise (max camber) for turning once Im in lift.
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Old 10-03-2011, 05:41 PM
  #27  
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Originally Posted by Larry3215 View Post
Yeah, like Nitro said - trimming for the slowest flying speed isnt always best. For sail planes, its almost always a bad thing to do.

Typically, if the model is trimmed for its slowest forward speed it is NOT trimmed for best L/D and will in fact come down faster (have a higher sink rate) than if it is trimmed to fly a little faster.

Every model is different but you want the hands off flying speed to be significantly above stall. You will have to play with it to find whats best for your model at its current weight. The speeds will be different depending on how much camber you have dialed in.

On my sailplanes that have adjustable camber, I have 3 flight modes. Fast cruise for getting out of sink in a hurry, Normal cruise for thermal hunting and slow cruise (max camber) for turning once Im in lift.
Maybe this is just a case of semantics but...

As I understand it there is a best L/D speed AND a minimum sink speed. They are not the same thing.

From a given height 'minimum sink' speed provides the longest duration in the air timewise. From that same height 'best L/D' gives the most distance traveled but at a higher sink rate. Meaning you go farther but you're on the ground sooner.

Minimum sink is generally a notch or two above stall speed (i.e. slow but not mushing).

Best L/D is normally quite a bit faster. (i.e. cruising not diving).

Obviously the specifics depend on the plane in question.

.......Mike
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Old 10-04-2011, 07:54 AM
  #28  
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You're absolutely correct. I was keeping it simple
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Old 12-12-2011, 05:05 AM
  #29  
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15:05 today with the Radian Pro, not great but my personal best. Hey RT, do I get a half-award?
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Old 12-12-2011, 05:48 PM
  #30  
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You bet, & I will also clap for you with one hand,lol.....jk

Keep at it I know you can get there
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Old 02-07-2012, 02:45 AM
  #31  
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Default still trying...

Just an update.....I switched from a 2200mah to a 1800mah battery in my sonic.What a difference that made! I actually specked out my sonic this time but then I got nervous so I brought it down lower but when I did I lost all my lift.
Crazy how these thermals work.I got 17 minutes this time.Ive noticed the thermals I catch seem to last 10 to 15 minutes then I start coming down.
Oh well will get back at it.
Having fun trying
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Old 02-07-2012, 04:03 AM
  #32  
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Unless its windy, less weight is almost always better

Remember too that thermals move WITH the wind. That means they are constantly drifting down wind. For you to stay in the lift, your sail plane must also move down wind.

When you can do that you will start to stay up longer. You must also remember to bail out soon enough to make it back up wind to reach the field!

Thats why most guys search for lift UP wind first. Then they have longer time to spend in lift before having to bail out.

One other note - the winds up at altitude are often very different than the winds on the ground. Watch birds, clouds, dust devils etc and watch your plane. It may want to drift at 90 degrees to the direction the wind is on the dround and it may be moving MUCH faster. So be careful not to get into trouble when well aloft.
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Old 03-10-2012, 05:29 AM
  #33  
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I have a couple of questions about this contest. Is it still running and when does it stop? Also, if you get a 50 minuet flight, do you get the icon for 30 and 45 minuets, or just the 45 min? There doesn't seem to be very much activity going on now. Is that because it's winter or has everyone stopped?

Ed
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Old 03-10-2012, 07:02 AM
  #34  
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Other than a few short test flights, its been too wintery around here for me to be outside
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Old 03-10-2012, 07:44 AM
  #35  
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It got up to around 62 here today, but the air was dead. Not a thermal to be found.................

Ed
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Old 03-10-2012, 12:02 PM
  #36  
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Still going Mred. We're flexible, if you want one icon we'll take care of you, if you want three, remind me and I'll put all three up!!
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Old 04-08-2012, 06:35 PM
  #37  
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I'm still in. Going for 45 and 60 minutes or beyond with new plane as soon as weather allows.
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Old 05-08-2012, 02:46 AM
  #38  
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Well, finally had a decent day of flying. It seems that there has been nothing but flat air for ever around here, but we finally got a little thermal activity going now that it is getting warmer, or maybe I am just finding them where I couldn't before. Anyway, out of 8 flights yesterday, my best was at 52:38 and I didn't hardly have to work for that one. All the others I had to work at keeping it up, but then I always have been good at finding down air WAY faster then finding up air. Right now I am using my Chrysalis 2M with a 200W motor and a 3S 2200MAh battery. I would love to go to a smaller battery, but I need this one for nose weight to get the CG right. I should have my new glider finished pretty soon and then I can try flying that one and see if there really is a difference in bigger is better. I'll be posting again pretty soon and see if I can FINALLY break 1 hour. For the past 3 years I haven't been able to do it, but I have a feeling that I may finally get that one. I don't think I will ever get that 1 1/2 hour mark.

Ed
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Old 05-08-2012, 05:22 AM
  #39  
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Ed, that's good enough for a 30 minute award! Best of luck on the one hour mark!
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Old 05-08-2012, 05:23 AM
  #40  
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Upps, make that a 45er...
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Old 05-16-2012, 08:00 AM
  #41  
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I finally had all the elements come together at the same time that are necessary for me to get some duration flying done - low to moderate winds, a warm sunny day, my Mirage all trimmed out, my lounge chair, sun hat and a bottle of chilled water

On the first launch I was just going to check trims and didnt go up very hi but I caught strong lift on the way down. After about 30 minutes, I put the Mirage into a steady hands off turning mode and went back to the truck and got out my lounge chair and water and relaxed into the flight.

I could have stayed up much longer but I got a call from my ex-son-in-law and had to land so I could handle his latest bit of immaturity Jerk!

Im still happy with the 60 minutes and 44 seconds



30 minutes



My second launch wasnt as long but was more fun in one way - I spent almost 1/2 the flight at low altitude circling in small light bubbles. Just like flying a super sized DLG! What a hoot!
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Old 05-16-2012, 12:14 PM
  #42  
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Congrats Larry!
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Old 06-24-2012, 11:31 PM
  #43  
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Had another great day with the Mirage - 98 minutes and a max of 2383 ft AGL. I could have stayed up longer but had one too many cups of coffee for breakfast!

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Old 08-01-2012, 02:58 AM
  #44  
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I haven't bailed on this, I'm still working on my 45 minutes. I seem to be stuck at just a bit less for some reason with tons of 35 minute flights . Here's this evening's flight with my Pulsar 3.2 M RES, another effort that fell short.....again
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Old 08-01-2012, 02:59 PM
  #45  
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Don't feel bad. I shot myself in the foot with a really dumb move on my part. I think I finally had 1 hour in the bag, but got turned around and was flying away from myself instead of to me, so I had to use the motor to keep from landing it in the trees. We had some great lift around her Sunday and I really thought I was going to make it until I pulled that stunt. Oh well, there is always next time.

Ed
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Old 08-22-2012, 10:36 PM
  #46  
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May I please have a 45 and 1 hour sticker???

Name- Leadchucker/Warren
Weather: Partly Cloudy, +85*f,58% RH, Wind from 045* <5kts
Glider/plane name and wingspan: Pulsar 3.2 m
Thermal, Hand Launch or Slope: Thermal
Date and Time of flight: 22 Aug 2012 @ 1415
Duration of flight: 1 hour 21 min with 200 meter launch
max. Altitude:2469 ft AGL
Location:South Jersey Golden Eagles Club field, Pole Tavern NJ


Great day with lots of lift, had to dump spoilers three times to keep her in sight, finally set her down to come home for supper.
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Old 08-23-2012, 04:06 AM
  #47  
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Nicely done Leadchucker!

Have you flown any ALES contests with that new plane?
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Old 08-23-2012, 04:24 AM
  #48  
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Thank you Larry. Yes, I've flown two contests, The Big Kahuna of ALES, The Pole Cat and a local one. So-so sucess with goofy teething problems making their mark when I didn't need them. She's pretty much sorted now and is a fine flying machine.


Thank you for the stickers to whoever does the sticker handing out.
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Old 08-23-2012, 11:40 AM
  #49  
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It was me leadchucker, it took more time to figure out how I gave you two 45 minutes and get rid of one of them to actually give the sticker! Congrats on them both!
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Old 02-05-2013, 07:00 AM
  #50  
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I didn't see anything in the rules about using
slope lift. I've stayed up for more than 3 hours
and not thought anything of it.
I think it should be mentioned that slope is not
thermal.
Flier Dwight
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