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Bird of Time - Is Standard Hi-Start OK ?

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Bird of Time - Is Standard Hi-Start OK ?

Old 10-23-2012, 08:52 AM
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BalsaBob
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Default Bird of Time - Is Standard Hi-Start OK ?

Finishing up a Bird of Time (ARF). Is a standard Hi-Start adequate .... or is the heavy duty one a better choice ? Also, which hole for the tow/launch hook seems to work best ?

Thanks. Bob
Old 10-23-2012, 08:54 AM
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l.j.glaab
 
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

I think you would really benefit from the heavy-duty high-start.

Thanks, Josh.
Old 10-23-2012, 03:32 PM
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PeterC
 
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

I have the Heavy duty high start for my BOT and I find it pretty marginal. A headwind sure helps.
Peter
Old 10-23-2012, 04:41 PM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

As for towhook location, usually just slightly in front of the CG works for all sailplanes. I like to take new sailplanes out to the slope and get the CG nailed down before installing the towhook.
Old 10-23-2012, 07:23 PM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

By "slightly" speed means SLIGHTLY! We're talking at most 1/2 inch in front of the balance point at the wing root. And a better option would be 3/8 of an inch. If it seems stable then don't be afraid to move it back another 1/8 or even a hair more.

You'll know when you hit the "sweet spot" when you find you need to hold a touch of down pressure for the first 30 to 40 feet to avoid it slowing down and stalling on the line. The altitude it gets for the rest of the launch makes up for the need for that slight down pressure for the initial portion. And by "slight" I really do mean SLIGHT! We're talking two to three clicks of down trim sort of "slight".

EDIT- And yeah, for a model of the BoT's size you want a heavy duty high start. Wimps need not apply....
Old 10-23-2012, 09:56 PM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

A good way to determine if your high start has enough "umph" for any particular model is to use a digital fishing scale to measure the pull. A good rule of thumb is to be able to have it generate pull that is 3-5 times the weight of the model in question. A model like the ARF BOT I'd tend to go a little light on the pull at first as they have a reputation of having weaker wings than BOTs made fro a kit. It wouldn't do to have your wings fold up during your first launch.

Another thing to keep in mind is to have a high start that will also handle your models weight if you add some ballast. I regularly launch my Paragon with several ounces of ballast added due to the winds being in excess of 10 MPH. I always weigh my models and then pull the high start back so it has the required amount of pull developed for launching.

Jeff
Old 10-24-2012, 02:23 PM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

I assume you're talking about (a)the 118" BoT ARF that weighs 60 oz ready to fly and (b)the "Heavy Duty" high start that Tower Hobbies sells under the Great Planes brand. If that's the case, in the long run, you're going to be buying another high start. TheGP Dynaflite HDHigh Start rubber tubing is sized such that it is best suited for 2 meter birds, give ortake. It will launch the BoT ARF, but not very high, unless you're launching into a decent breeze. If I were you, I'd look at the Hobby Lobby "3 Meter" high start, or the Aerofoam (Hosemonster), also in the 3 meter size. Both of these are sized more appropriately foryour 60 oz bird.
Old 10-26-2012, 07:35 PM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?


ORIGINAL: AMA-69405

I assume you're talking about (a)the 118" BoT ARF that weighs 60 oz ready to fly and (b)the "Heavy Duty" high start that Tower Hobbies sells under the Great Planes brand. If that's the case, in the long run, you're going to be buying another high start. TheGP Dynaflite HDHigh Start rubber tubing is sized such that it is best suited for 2 meter birds, give ortake. It will launch the BoT ARF, but not very high, unless you're launching into a decent breeze. If I were you, I'd look at the Hobby Lobby "3 Meter" high start, or the Aerofoam (Hosemonster), also in the 3 meter size. Both of these are sized more appropriately foryour 60 oz bird.
Iwould agree on all counts. The Dynaflite HD hi-start is comparable to most 2 meter hi-starts. It will likely launch the BOT with a 5 mph breeze, but in calm air it is going to be kinda weak.
Old 10-28-2012, 08:41 AM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?


ORIGINAL: AMA-69405

I assume you're talking about (a)the 118" BoT ARF that weighs 60 oz ready to fly and (b)the "Heavy Duty" high start that Tower Hobbies sells under the Great Planes brand. If that's the case, in the long run, you're going to be buying another high start. TheGP Dynaflite HDHigh Start rubber tubing is sized such that it is best suited for 2 meter birds, give ortake. It will launch the BoT ARF, but not very high, unless you're launching into a decent breeze. If I were you, I'd look at the Hobby Lobby "3 Meter" high start, or the Aerofoam (Hosemonster), also in the 3 meter size. Both of these are sized more appropriately foryour 60 oz bird.
Absolute agreement!!! I've got the Tower 118" BoT (kit) and GP HD highstart - - it's just barely enough to get her up, even in winds around 8-10mph. I appreciate the info on the HL3-meter unit - going to get one myself for next year.

Dave


Old 11-01-2012, 07:01 AM
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Art ARRO
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

Hi Bob,
I noted your inquiry on hi-starts and recommend that you follow the advice for a HD high start version.
An alternate route would to to electify the BOT and follow the nearby thread on this subject for motor/esc/prop and battery setup. The RCSoaring Digest article is very informative.
I fly sailplanes in the off-jet season and have electified most of my fleet. It sure beats shagging the hi-starton every flight and the power is nice for a fly back to your preferred landing zone. Most of my conversions are of 2M sailplanes and the hardest part is cutting off the nose to fit the motor. However, I've designed a power pod mount for some models that I wish to remain as pure gliders. These conversions also work well for winter flying with snow cover, and the motors are kept clear of any scooped up snow on landings. Good luck and keep us informed on all this.

Art ARRO
Old 11-30-2012, 12:20 PM
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Default RE: Bird of Time - Is Standard Hi-Start OK ?

How are you doing with the BOT?

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