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Old Aug 08, 2012, 09:39 PM
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As a spectator, I liked the event very much and wish I could have entered, but I couldn't get my sailplane ready in time.

I liked the ability to launch in any direction, but would be careful with this from a safety issue. I think allowing the pilot to pick the launch direction adds gamesmanship, I also think the more speed available, the more gamesmanship the pilot can use during launching . This appeals to me partly because it requires air picking knowledge, partly because it adds a spark to a TD contest and produces other obvious benefits. It is pure TD after the launching is over.

Electric launched sailplanes will add interest to soaring and attract new people, hopefully add new people to Soaring clubs membership roasters. The dumb club will end up pushing out the winch guys in favor of electrics, the smart club will embrace electrics with separate club activities for both interest, just as a smart club does for hand launch and slope. The bad thing that could happen is the human thing of trying to push everyone into electrics. You know ... I like it and therefore you should like it.

I hope clubs start sponsoring electric launched contests with two size classes, 2M and unlimited and no limits on number of controls or motor/battery. The first contest for electric launching that I would hold will be limited at 150M for both size classes.

Thanks to all the LSF guys for their dedication to the hobby.

Ray
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Old Aug 09, 2012, 06:08 AM
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Ray, you are right. Too bad LSF has some members that seem pretty well stuck with only one choice in flying sailplanes in the USA, and that only includes something with a string attached. Hopefully as time moves along the attitudes will change and we can move forward flying TD in a few different launch forms, not just one (and we already do, but they seem to forget that)

Marc
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Old Aug 09, 2012, 11:05 AM
WINS - Winch In Nose Sailplane
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Marc, you are quite correct. They also seem to forget that they, too, have a motor attached to the string. Of course, they could just toss that 3.5M ship up by hand or go back to bungee launching only. But with the advent of altitude limiters, etc., it's an argument that has just flat out run out of steam. The same thing happened years ago in the photography community. Digital photos were deemed "not photographs". We all know how that went. There are so many factors mitigating for the full acceptance of e-powered gliders as gliders that it's only a matter of time until this form factor is fully accepted. For the growth of the sport and the enrichment of the hobby I hope it is sooner rather than later.
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Old Aug 09, 2012, 07:51 PM
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It's OK in America to not be a go along with something new, although, most people find it easier to just be quite than speak out. Hats off to those that are not afraid.

Anyone ever figure out the lurker to poster ratio on RC GRoups ??? get my point ??

Not knowing exactly what is being referenced with the " stuck on one choice " , the part of electric launched sailplanes I don't go along with is the move to allow electrics in the present LSF Achievement Program. Without spending time on rehashing the different responses to the inclusion of electrics into the program, my vision is make a separate Achievement program for electrics. And don't rush into it because electrics are new, electric contest are at the embryo stage. Landings are not necessarily as important to electrics for obvious reasons, launch altitude becomes a new ball park for electrics and these should be defined in a separate LSF achievement program.

Rather than go political, pointing fingers at people, bullying, and destroying what many consider traditional, spend the mental energy on promoting electrics in a positive way.
There will be migration both ways, some first timer electrics will migrate to winch and vise verse. This is all good for the hobby, what is bad in my view, is all the negative talk between fellow rc soaring pilots ABOUT ELECTRIC LAUNCHING VS WINCH LAUNCHING. NEW PEOPLE READING THE NEGATIVE STUFF WILL BE TURNED OFF TO THIS HOBBY. WHAT PART OF NEGATIVE DISCUSSIONS BETWEEN OLD GUYS COULD POSSIBLE ATTRACT NEW, YOUNG PEOPLE TO THIS HOBBY ?????

Many Soaring clubs I'm aware of are struggling with just a handful of active members, this is the real issue. Not how many Radians are sold, but how many new club members have we signed up. What are we doing to reach out to potential new club members is the real issue.

Let's get together on the real issues, not pi-- around the bush on non issues like our fake leaders in Wash.DC. are doing.

At least, lets live and let live, rather than pi-- off folks who grew up in this hobby lugging a winch or stretching a hi-start and like doing it. You definitely will not recruit them to electric by pi--ing them off. There are better ways.

Ray LSF 803
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Old Aug 09, 2012, 08:08 PM
Mesa AZ, it's a dry heat!
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Joined Oct 2004
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ALES ect.

Ray, I agree with your sentiments. I was a 'string launch' guy until a few years ago awhen I went totally electric launch. To me, as I get older, it is so much easier! I love the no fuss practice sessions where I can just go out and launch and fly. If others want to use a winch or hi-start, that's fine with me.

I think an achevement program with different launch heights at diferent levels is a great way to go. I would love to see it set up under the auspices of LSF, but if they are not able to do it then maybe someone else will. I am willing to help.

Randy Brust is doing a great job with the League scores, and that kind of initiative is what is needed.

Iain
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Old Aug 09, 2012, 08:30 PM
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Iain

Thanks for your supportive post, I went to my first electric contest in 1998, drove from Indiana to Pennsylvania to participate. The availability of light weight electric power is the turning point for all of model aviation. Look at the two achievement programs that are stickys on RC Groups, Sportsman and LSF. The Sportsman program was started by one individual and his open style of creating the program tasks has been very successful. Could be done for Electric too.

I'm one of the lucky ones in rc soaring, I have participated in all the ways there are to fly an RC Sailplane. I still lug my winch as well as use a hi-start and fly electric launched sailplanes. It is all good and I love all of it.

Getting mighty hot down there in Arizona ....

Ray
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Old Aug 09, 2012, 09:24 PM
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Quote:
Originally Posted by rev.iain View Post
Ray, I agree with your sentiments. I was a 'string launch' guy until a few years ago....

Iain
I'm just glad that you were Iain! I'm not sure you'd remember it, but way back in the early 90's I brought my 'gentile lady' out to Rodeo Park, where I knew I'd seen guys flying gliders before. Only you were there... you had a winch out... and you patiently helped me learn how to 'tap tap tap' that thing into the air. I'd been using a high start for months at my uncle's farm, so it wasn't the flying that I struggled with as much as the launching. Thanks to you, I was hooked! Never looked back!

Now I'm getting hooked on the non-string version... thanks to your leadership at recent CASL events (SWC over the last few years).

I sincerely appreciate your willingness to be forward thinking, and to encourage others as well.

Skip (the 'other' Skip) in Colorado!
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Old Aug 09, 2012, 10:51 PM
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USA, MN, Rochester
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Quote:
Originally Posted by Ray Hayes View Post
Iain
The Sportsman program was started by one individual and his open style of creating the program tasks has been very successful. Could be done for Electric too.

Ray
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Hi Ray,

Just to clarify a point here, electric launched planes are already allowed to participate in the SSP. Steve Boone has done a fantastic job of starting a soaring program open to both string launch and e-launch sailplanes. He has done it on a shoestring budget and if any of you want a really challenging program to work on you should give it a try.

Wayne
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Old Aug 11, 2012, 12:37 PM
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Dave R. I have to say your Oracle has probable the best color combination for visibility!!
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Old Aug 12, 2012, 05:57 PM
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United States, IN, Fort Wayne
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rev.iain

What would you say the climb ability would be for my 2M Lil Bird with the following equipt.

E-Flite Park 480, 910 Kv

Thunder Power 1350 mAh 3-cell, 25C lipo

E-Flite 30-Amp Pro SB brushless ESC

APC 13 x 7 F folder

Total flying weight is 28 oz

I finally got it in the air today, but did not have a limiter plug in. Previous flights on this Bird were years ago with a geared Speed 400... remember those ???

Ray
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Old Aug 12, 2012, 07:43 PM
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Miamisburg OH
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Without running some numbers through MotoCalc or something similar, you should be a bit better than a Radian with a prop upgrade. Motor, battery and AUW are similar to a Radian but your running a bigger prop and should be between 25 and 30amp, so more like 250 watts compared to the 200 watts in the Radian. Should get you to altitude in less than 25 sec, and the Lil Bird has a better airfoil so you can get upwind farther before you get to 200m or any other altitude that you choose.
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Old Aug 13, 2012, 07:46 AM
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What I have observed is that you need to achieve about 130 watts/pound in order to make the 200M climb in 30 seconds or less. Naturally there are some variatons by aircraft design and pilot skill in holding the optimum climb angle, but 130 is a good target. More will insure success but I would not go less.

Lower kV motors, or high kV with a gear box that would produce under 1500 rpm/V with wider props are better than high kV motors with smaller props. Againk these numbers are approximate, not hard numbers.
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Old Aug 13, 2012, 09:17 AM
WINS - Winch In Nose Sailplane
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USA, NH
Joined Mar 2008
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Ray,

You might be over-propped, but you should get to altitude in a spritely manner. Put a limiter in and time it. Simple. Please report back.
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Old Aug 14, 2012, 06:26 AM
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United States, IN, Fort Wayne
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Quote:
Originally Posted by jaizon View Post
Ray,

You might be over-propped, but you should get to altitude in a spritely manner. Put a limiter in and time it. Simple. Please report back.
Question: Over-Propped ... for the motor/battery sizes ???

Ray
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Old Aug 14, 2012, 08:13 AM
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Found the specs on that motor:
http://www.e-fliterc.com/Products/De...rodID=EFLM1500

Product Specifications
Type: Brushless outrunner
Size: Park flyer
Bearings or Bushings: One 4 x 9 x 4mm Bearing, and One 4 x 10 x 4mm Bearing
Wire Gauge: 16
Recommended Prop Range: 10x7 to 12x6
Voltage: 7.2 to 12
RPM/Volt (Kv): 910
Resistance (Ri): .08 ohms
Idle Current (Io): .85A @8V
Continuous Current: 20A
Maximum Burst Current: 25A (15 sec)
Cells: 6–10 Ni-Cd/Ni-MH or 2–3S Li-Po
Speed Control: 20–35A brushless
Weight: 87 g (3.1 oz)
Overall Diameter: 35mm (1.40 in)
Shaft Diameter: 4mm (.16 in)
Overall Length: 33mm (1.30 in)

I would assume the 12X6 prop is for a 2 cell lipo and the 10X7 is for a 3 cell lipo.

On 13X7 iI would expect a short but exciting life.

Using WebOCalc

An 11X7 will pull about 25 amps, 270 watts and over 40 ounces of thrust. That is right at the burst amperage, 15 seconds. Since you are only running for 30, then shutting down it might be able to take it. You will be able to hover it on the prop till she burns up.

An 11X6 or a 10X8 should put you right about 20-22 amps and about 35 ounces of thrust, which it should be able to tollerate for 30 seconds.

I am running a 10X8 on my Radian. Makes 200 meters in about 28 seconds on a 25C 1500 mah pack. That is a 480 960 kV motor.
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