Ryan Nau

My Feedback: (54)

Im thinking about ordering this setup from Tower Hobbies to try out a sailplane with no motor. I have everything for it besides the kit and hi-start. Does this hi-start get it up to 500' if stretched all the way. Are these easy to use. I never used one. I saw one guy fly off of a high start a few years ago. I will be using a 6v1450nimh reciever battery pack, standard hitec in the rudder, and either an hs 55 or 81 in the elevator, and a 3channel hitec radio and reciever. That should work ok. Anything to know about the Bird of time ARF??
Thanks
Ryan

aeajr

My Feedback: (2)

As to the Dynaflyte HD for the BOT? Should work but I would go for something a little stronger.

I think the www.nesail.com Pinnacle Standard would give you a little more pull in a better package.
http://www.nesail.com/detail.php?productID=875

If you plan to move on to larger or heavier gliders, you might consider the Pinnacle Large which is made for 3M planes.

Two articles for your question - launching system and how to use a hi-start.

The New Glider Pilot's Handbook
by Ed Anderson
www.lisf.org

Welcome to the world of silent flight. If you plan to fly gliders and
sailplanes, whether slope or thermal, powered or pure, this series of articles
may be helpful in getting off to a good start. They are written with the new
glider pilot in mind. I hope you find them useful.

Getting Started in Sailplanes
http://www.rcezine.com/cms/article.php?cat=&id=36

Radio Systems Part 1 - Standard Radios
http://www.rcezine.com/cms/article.php?cat=&id=44

Radio Systems Part 2 - Computer Radios - The right choice for almost everyone
http://www.rcezine.com/cms/article.php?cat=&id=65

Sailplane Launching Systems
http://www.rcezine.com/cms/article.php?cat=&id=55

How to use a Hi-Start
http://www.rcezine.com/cms/article.php?cat=&id=52

Finding Lift
http://www.rcezine.com/cms/article.php?cat=&id=57

How Slope Soaring Works
http://users.iafrica.com/s/st/stevemac/afc/ssoar.html

Sailplanes are Wonderful
http://www.rcezine.com/cms/article.php?cat=&id=18

Plane Locators & Battery Monitors
http://www.rcezine.com/cms/article.php?cat=&id=67

The AMA, the Academy of Model Aeronautics, is an outstanding resource to the
new and experienced flyer. I encourage you to become a member. Here is an
outstanding series of articles published by the AMA that will be really useful
to new pilots, especially new e-glider pilots. It is called, "From the Ground
Up" by Bob Aberle. I highly recommend it.
http://www.modelaircraft.org/mag/FTGU/Part1/index.html

RC Clubs in the United States:
http://www.modelaircraft.org/clubmai...5E31DE4FA6F552

International RC Clubs
http://www.fai.org/fai_members/addresses.asp


Additional Articles and Resources

Colorado Gliders
http://www.coloradogliders.com/tools.htm#articles

How thermals work
http://www.scalesoaring.net/thermals.html

RC Soaring Digest - online magazine
http://www.b2streamlines.com/RCSD.html

Read this next article only if you like to dabble in deeper technical stuff.
This article
is on advanced set-up of a full house sailplane. Definitely not something a
beginner, or even a many experienced sailplane pilot need to do. This is more
for competition pilots, but if you like to look at some of the advanced stuff,

this might be fun. It is a translation, so take your time as you read it.
http://www.gliders.dk/triming_and_se...der_wi_eng.htm

If you have a high speed link, take a look at these videos of beautiful scale
sailplanes being flow off the slopes of Taiwan. Magnificent!
http://www.dwhs.tnc.edu.tw/~andycheng/wmv/200502.wmv
http://myweb.ncku.edu.tw/~n2893166/w...agon_cliff.wmv

BillL

Ryan,
Hi-starts are way cool and they're easy to use. Definately get a heavy duty version if you go with a sailplane of such majestic proportions. The instruction that come with it are real straight forward. Get your center of gravity right first and the tow hook a little aft of that to start with. (helps the plane stay nose up while under the influence of all that potential energy being released.) Maybe go 1/2 or 3/4 of a full stretch at first to get an idea of how the plane reacts. Experiment. 500 foot launches? Could well be, but sometimes numbers just don't tell the story. You will be amazed, whatever the quantitative value is, at how high your Bird is off the ground. Plenty high enough to feed its appetite for lift. The first few flights, though, just get the feel of a few turns and play with the speed range. The elevator is in effect the throttle, put the nose up a little and she'll float like a kite but nose 'er down a bit and don't she go! Best have an idea for your landing approach before launching. Give yourself lots of room. Find somebody that can help you the first few times as your confidence builds. Also, look into potential slope soaring sights in your area. It doesn't take much of a hill if the wind is right and you can fly all day with one toss as long as your batteries hold out. Definately go with the hs-81. The 55 is smaller than prudence dictates. Go for it and good luck,
Bill

aeajr

My Feedback: (2)

Bill, I think you made a type here. The hook is normally forward of the CG. If you are a competiton launcher maybe you put it on the CG or slightly but it is slightly forward on all of my planes.

aeajr

My Feedback: (2)

6 cell is fine. Follow the directions on servos but I would think the HS-55 would be too small for this plane. HS-81 or 85 should be fine.

Ryan Nau

My Feedback: (54)

I think I will get the Pinnacle Hi start instead of the Dynaflite. I did a search and they seem to be better. The large will have more launching power then the standard. Will the large be OK for the stressing of the wing or should I go with the standard for the BOT?? I'm not planning on flying any thing bigger then this glider, maybe a spirit 100 from great planes.
So which would be better, standard or large pinnacle? Does the pinnacle hi starts come with everything you need to launch gliders from the hi start??
Ryan

aeajr

My Feedback: (2)

Pinnacles come complete.

If BOT is the largers and heaviest plane you ever expect to launch off the hi-start then the Pinnacle Standard will be just fine. The BOT is a fairly light 3M plane. The Spirit 100 is probably similar in weight.

However if you get a heavier 3M you will want the large.

Up to you.

Chillybee

My Feedback: (3)

Ryan Nau,

I agree with Aeajr about using the dynaflite heavy duty hi-start. I also have the Pinnacle from NESP for my really large gliders and it's a bit too strong for my Bird of Time. I've been using the HS-55 for the elevator and it's plenty strong. The Bird of Time has the so called aerodynamically balanced flying flying stabilizer which therefore isn't supposed to need much force to move. I've been flying one for almost 3 years and have never had any problems pulling out of vertical dives. But then again, the Bird of Time doesn't exactly break the sound barrier when diving either.

Balsa Steel

My Feedback: (3)

I have the Bird Of Time ARF version and a Dynaflite heavy duty hi-start and in my personal experience, it is barely adequate. Although I've never used the hook farther than the second hole back, I usually don't get more than about 300 feet out of it. I'm sure a more experienced hi-start jockey could move the hook aft and get more, but I would rather opt for a stronger unit from the get go and just not pull it back all the way to afterburner tension.

aeajr

My Feedback: (2)

After further thought on the hi-start, I still think the Pinnacle standard is good for the BOT but I would advise the large, because you know you are going to go up in weight on the next 3M, and there will be a next 3M. Or you will be flying with a friend with a 72 ounce 3M and you can now share the hi-start.

The good thing about hi-starts is you can vary the strength of the pull by how far you stretch it.
In hundreds of launches that I have made and observed off Dynaflite and Pinnacle Large and XL hi-starts I have only seen one plane damaged, and that was yesterday, off my practice up-start, with an old plane. Frankly, I think there was some hidden damage on that one.

Will the Large be too strong? I doubt it! Let me give you the basis of that opinion. I use a fish scale with a 25 pound max weight range. $5

Here are BOT specs:

SPECS: Wingspan: 118" (3000mm)
Wing Area: 1050 sq in (67.73 sq dm)
Weight: 3.75 lbs (1700 g) 60 ounces
Wing Loading: 8.2 oz/sq ft (25 g/sq dm)

Wing loading is higher than my Spirit which is about 7-7.5 oz/sq ft so it should be able to take at least as strong of a launch as the Spirit. ( I also winch the Spirit often. Broke the wing once because I got a little too much pedal and a gust at the same time.)

The rule I have used successfully and which seems to give good results is that you need about 4 times the model's weight in pull from the hi-start to get a reliable launch and 3X is adequate if you have more than 5 mph breeze. 3X gives you a weak launch in calm air but it will get the plane in the air.

My Spirit Select RTF 2M weighs about 2 pounds, so for that plane 6 pounds is adequate and 8 pounds would be good in most conditions. I have verified this with a fish scale. She can take more, but frankly 8 will do.

FYI, I have launched this plane at a measured 13 pounds pull off a Pinnacle XL which is rated for up to 4 meter planes. At 13 pounds I can just about hold it. The wings flex a bit but after hundreds of launches of Spirits, Gentle Ladies, Aspires and similar planes at 10-12 pounds in up to 10 mph winds, we have never damaged a wing. So that would be 6 times the plane's weight at 12 pounds. These represent kits, ARFs and RTFs. The problem with my pinnacle XL is that we hit that pull at 1.5X the the length of the rubber for a pull. So it delivers that energy over a fairly short burst.

Using the Pinnacle Large, which is the standard for 3M planes in our club, I hit about 12 pounds at about 2.25X pull. A 12 pound pull is the pull I am used to using so this is what a launch at, if the hi-start can deliver it. I get a better launch off the large because the energy is delivered over a longer period of time.

The XL is really to strong for the Spirit. However this hi-start will launch my 80 ounce Airtronics Legend with authority at about 20+ pounds pull. Holding that is a challenge but it works. I am tired and stiff at the end of 4-6 hours of of that. Good excercise!

We have several club members that have the Dynaflite Standard and HD hi-starts. They work well for ligher planes. DF Standard I think we could get about a 6 pound pull and on the HD, I believe we measured the max pull we could get, stretching the rubber 3X its length was about 11 pounds. Gives a nice launch on the Spirit. Plenty of power over a longer time. Frankly a very good match for the Spirit.

Based on the specs above, 3 times the BOT would be 12 pounds. So the DF HD would give an weak launch in calm air and would give you an adequate to good launch in 5mph+ breeze. This may be what BALSA Steel is seeing since he rates this combo as barely adequate.


I have never measured the pull on an Pinnacle Standard but I would guess it can probably deliver 14 pounds pull at full pull.

Pull it to 10 pounds and watch the launch.
Pull it to 12 pounds and watch the launch.
Pull it to 14 pounds and watch the launch. I think this is where you will be comfortable for most launches.
She will probably take a 16 pound launch with no problem.

With the Pinnacle Large:

Now, since you have some more pull left on the hi-start, you can get that 70 ounce 3M plane and still have enough pull to launch it but will get a good pull on the BOT. Your friend, whomever that might be, can put their 70+ ounce plane up as well just by pulling back the full 3X length.

Pinnacle standard will be fine, but I would get the large.

Chillybee

My Feedback: (3)

I mostly agree with aeajr. Here's what I've found in the past 3 years of flying my Bird of Time ARF. Using the Dynaflite Heavy Duty, if there is no wind, I take 100 steps and it takes it up great with the hi-start still stretched while the glider is releasing overhead. With any type of wind, I can take as little as 65 steps depending on the actual wind speed. One thing my friends have told me is that my steps are much larger than theirs are so that could be taken into consideration too. But regardless, it seems to be a perfect match for that glider.

As for my Pinnacle XL, that thing is a monster! I've yet to measure the pull but at 55 steps (which is the most I can manage to pull it back and hold onto my Prism glider), I'm quite sure the pull is way over 20 lbs. I say that because of how physically hard it is to lean and pull the thing back and I lift weights daily so I'm no 208 lb weaking...then again, maybe I am! I think I'll connect the tubing to my electronic fish scale to see exactly how strong it is. Anyway, that hi-start easily pulls up my 7.5 lbs X-Calibur composite ship with power to spare. And I don't even throw the plane. Instead I just hold it towards the rear of the fuselage and let it go.

I wouldn't even attempt to use the Pinnacle XL on a Bird of Time but the Pinnacle Large would probably be perfect. As as aeajr says, if you ever decide to move up to a larger glider, then you won't need to buy a new hi-start. The Dynaflite does take my 4.5 lb Prism up but it's on the weak side. The Pinnacle Large would be much better. You don't need a Pinnacle XL unless you're hauling up some really big gliders and like getting a serious work out. I used mine yesterday for 7 hours and it was really brutal in the heat.

aeajr

My Feedback: (2)

Chillybee,

Great post!

100 steps? I am 6'2" so that would be about 280 feet so that would be a full pull for me. I believe 3X is the recommend max so 300 foot pull is as far as you want to go. I don't count steps, I work by feel.

With my Legend on the XL, I hook the plane then put the nose under my left arm and walk. When I think I have reached the limit of my ability to hold the plane with one hand I stop. Since this is a glass fuselage, I can hold it much tighter than the spirit so I can handl more pull. I believe I measured this at 24 pounds on one occasion. Not certain, but I know it was over 20.

You launch a 7.5 pound plane with the XL? Cool! That means my 6.5 pound Ventus 2C 3.6M should go up just fine if I don't have the winch with me. It is not done yet.

I am not a weight lifter ( unless you count what is attached to me). I was thinking of making a launch dolly for the Ventus as the grass by us can get somewhat high and I was not certain I coudl get a good launch by hand. I am going to set up a bridal for launch since it is a scale plane.

Chillybee

My Feedback: (3)

Aejr,

I haven't flown my Legend yet but I plan on soon. The Pinnacle XL will EASILY pull up your Ventus especially with a dolly since the wing tips won't snag the grass. Once the plane got airborne, it would do quite well. The problem is pulling the thing back. I can lean back at more than 30 degrees from veritical and not fall over...at only 55 steps...with a stomach full of food! I can't imagine what it feels like at 100 steps. At the club, we've knicknamed it "The Garden Hose" and for a good reason too. I too have a 4.5 meter Ventus 2cx from NESP which weighs in at about 10lbs. I was thinking about attaching a bridle to it just to get some low test flights. I've done that in the past with my 4 meter Ash-25 but never using the Pinnacle. If I could make some sort of anchored foot release, I'm quite sure it would take up my Ventus high enough to trim it out. So the bottom line is your Pinnacle XL can pull up just about anything you manage to grip without crushing as long as you pull it back far enough.

aeajr

My Feedback: (2)

Funny, my club calls the XL the Big Bear!

One guy just loves it for hi 100" Sagitta 900. He hooks it to the plane, then does one rotation and wraps the line around his waist and walks it back, way back. Then he does a turn to unwind it and he gives it a good throw. I have seen him exceed the winch on these many times with a zoom at the end.

Ryan Nau

In case you think we forgot you, we have not. This discussion gives you some idea of what can and can't be done with hi-starts. I have had guys in the club tell me my Legend can't be launced off a hi-start - gotta have a winch - wrong

You can't do a scale plane off a hi-start - gotta have a winch or a tow plane - wrong

They also told me the XL would rip the wings off the Spirit - Wrong! I broke 'em twice on the winch, but never on the hi-start.

Your BOT can take a strong hi-start launch much better than it can take a winch launch. Why?

In my opinion, it is the pulse - tap tap tap - of the the winch that breaks things. You have to tpa it or you tear the wings off because each tap can far exceed the force we are discussing here.
And because each of those taps can be much stronger than the hi-start pull it gets this flexing going on the wings.

The hi-start has a steady and diminishing pull. I think it is much easier on the wings.

Whatever you get, launch with confidence. Your BOT should be able to take it, and if it doesn't, you get them to replace it!!!!!!!