While watching videos of my INDORE TLG1, it occured to me that we could make an estimate of the speed at launch.
I looked at the 12 stop action pics in post no 73-75 in the following thread

http://www.rcindia.org/kites-trains-free-flight-and-all-others/for-the-5th-sweepstakes-first-model-k-k-iyer/

Educated guesses:
1. Launch height about 50 ft
2. Flight radius in launch phase about 30 ft (smaller than a control line circle)
3. Climb ends about 180 degrees after launch
4. Estimated climb time about 1 second

From the above it can be calculated that the flight path was about 112 ft till the top, in 1 second.
Since 44ft/sec is 30 mph or 48kmph, it means the launch speed was about
122 kmph!

Maybe we'll never do 1 min unless we reach 100mph/160kmph!

Comments requested from chuck glider veterans.

Maybe there is something to be learnt from this:



If you have reached a height of 112 feet (1344 inches) and you want the model to stay aloft for 60 seconds, then you are asking for a sink rate of 22.4 inches per second, without a thermal helping you. That shouldn't be too difficult, or am I reading you wrong?

edit: I WAS reading you wrong

Sirrrrrrr

Educated guesses:
1. Launch height about 50 ft
2. Flight radius in launch phase about 30 ft (smaller than a control line circle)
3. Climb ends about 180 degrees after launch
4. Estimated climb time about 1 second

From the above it can be calculated that the flight path was about 112 ft till the top, in 1 second.

Guessing about 2ft/sec sink (25 sec from say 50ft)
Why do you think i am paranoid about wing loading being below 3oz?
Or the balsa being under 6oz?
Who do you think invented that pivoting fuselage?

Edit: Buddenbohm's indoor models weigh about 10gms. Mine is 51!

"If you have reached a height of 112 feet (1344 inches) and you want the model to stay aloft for 60 seconds, then you are asking for a sink rate of 22.4 feet per second, without a thermal helping you. That shouldn't be too difficult, or am I reading you wrong?"

Feet/inches??
From 50ft height, need 1 ft/sec for 50 sec duration

Errrrrrrrrrrrrrrrrrr- corrected Sir.

Thanks anyway.
How many would care about TLG launch speed estimates anyway?
Maybe Saikat sir

"I'd ask him what the matter was,
But i know he don't talk...
Oh Mama, can this really be the end..."

Now the bricks lay on Grand Street
Where the neon madmen climb
They all fall there so perfectly
It all seems so well timed
An' here I sit so patiently
Waiting to find out what price
You have to pay to get out of
Going through all these things twice

Dreamt a few days back that my nylon strung 3/4 Fender was crushed during packing.
Thankfully it wasn't.

Now i lie here all so lonely
Knowing only the rate of sink
I'd ask you how to cal cu late
The coeff of lift i think...
Oh Mama...

Cordially inviting you to NorthEast India with RC Aunt on 24th. May. Shillong is the ONLY place in India that celebrates Dylan's birthday, since 1972, with a mega rock concert. Its Dylan all the way.

In this age of RTFs and Quads,
Maybe someone would be interested in the article that inspired this thread:

'From Release to Stick - One Frame at a Time Using high speed video to better understand catapult glider launch dynamics
by Paul Love, San Diego, CA, USA'

https://1f9972a0-a-62cb3a1a-s-sites.googlegroups.com/site/ffqstorage/file-cabinet/FFQ35_PL.pdf?attachauth=ANoY7cq5eQmlsItN95rbPVLa0dQngcIXcAWaM8-pxyDSXdcjEwXUdirVeStTy38R829eWsWUqHzSWpha4ctOLv_zJDPCWBJmki5z9D9Q6J468Lk6rMXb3wx_vuum15MjgvnnGIx4qd1SEF-wrD14vL6YaSFdVTKEW1PW9nrZQYA9W3Hfvwa2BolBEKpb7medUkc3CgS73Sxv6Agxawn61e4s1spXseeOjXZeRxkNBE0SnwI90-_g8Mo%3D&attredirects=1&d=1

No takers for this article?

'From Release to Stick - One Frame at a Time Using high speed video to better understand catapult glider launch dynamics
by Paul Love, San Diego, CA, USA'

It's worth looking at. (Link in last post)

Im closely following this thread though this is a bit confusing,
Agree that the art of aeromodelling is lost and now its become just RC flying.
Its obvious from this threat itself.

Ashok.P

Bump.
No one?

The PDF you mentioned is also referenced here - http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=12247.0
Launch speeds seem to be in the range of 100mph+ for CLGs (suggesting even past 130mph), and one of the posters does refer to an 80mph+ launch for TLG, so 100mph expectation is not a surprise based on the compute.

1 minute of glide or more will, of course, also be determined by glide speed, etc., but you would have already thought of that.