The art and science of recovering close to the launch pad

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Beanboy

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Over the years, I've honed the ol' launch rod angle skill, particularly at club launches, to bring rockets back as close as possible to the launch pad. Includes medium-sized Estes rockets in the 2K+ range. Mix of backsliding via streamer and watching other flights helped with this endeavor.

With that said, looking to launch at smaller fields with my kids who are now interested. The combination of smaller fields, smaller teleport rocket flight profiles (Estes Yankee for example), and fewer data points on what the winds are doing has me interested in getting better at keeping rockets recoverable.

There's obviously lower flights to start the day and ability to time the launch between any wind gusts. Also streamers and no parachutes. Also interested in wind forecasting websites/apps... What are your favorites for ground wind and winds aloft forecasts? Any other tips or tricks that you've found success with?

Thanks!
-B
 
I've observed that smaller/faster rockets tend to follow the "aim" of the rod better than slower/heavier rockets. What I mean is a BT20 or BT50 rocket on a B will maintain its line better than a BT60 rocket on a C. The slower rockets tend to take a horizontal trajectory more often and this gives them a lot of horizontal displacement so they go farther from the pad.
 
Yes, that is due to angle of attach of the wind on the fins causing a correction of the atitude.
The faster a rocket is moving the lower the angle of attach at the same wind speed. Thus less corrective force.

This is called 'weather-cocking' and is the reason for the Safety guidelines of minimum TTW, thrust to weight ( translates to minimum speed off rod) and maximum wind speed.

At our club launch everyone is interested in how the first launch goes. We are mainly looking at what the winds are doing at various altitudes. On windy days we joke as who is launching first to see how far the rocket drifts and in which direction. Ground wind may not be in the direction of the upper winds.
Last launch was interesting as the winds above 200 feet were slower than below. Usually winds aloft are faster.
 
This is called 'weather-cocking' and is the reason for the Safety guidelines of minimum TTW, thrust to weight ( translates to minimum speed off rod) and maximum wind speed.
I understand weathercocking but I've had this happen with little or no wind too.
 
The stability has a lot to do with it, as does fin size, speed and wind speeds.

A marginally stable rocket may fly straight up on one flight and tilt over and go sideways the next. I had one that did that and a couple of ounces of weight in the nose cone eliminated the tilting over.
 
A Jolly Logic Chute Release can get you lower to the ground before your chute opens. Less drift. That is, if it will fit in your rocket. I watch the first rockets too. Or send up a scout.
 
I just underpower everything until I really know the field, know the rocket, and know what flights can be recovered. I’m pretty conservative in my estimates and I always go straight up.
I bought a cheap pocket level after losing my Level 1 rocket due to the launch rod tilted in the direction of the trees :mad: 🤬
 
Over the years, I've honed the ol' launch rod angle skill, particularly at club launches, to bring rockets back as close as possible to the launch pad. Includes medium-sized Estes rockets in the 2K+ range. Mix of backsliding via streamer and watching other flights helped with this endeavor.

With that said, looking to launch at smaller fields with my kids who are now interested. The combination of smaller fields, smaller teleport rocket flight profiles (Estes Yankee for example), and fewer data points on what the winds are doing has me interested in getting better at keeping rockets recoverable.

There's obviously lower flights to start the day and ability to time the launch between any wind gusts. Also streamers and no parachutes. Also interested in wind forecasting websites/apps... What are your favorites for ground wind and winds aloft forecasts? Any other tips or tricks that you've found success with?

Thanks!
-B
Earlier this week I did a test comparing backslider recovery to horizontal spin recovery, more than ten flights each with identical tubes and B4-4 motors, just different fin cans. Winds were at ~4mph at 60 Acres. Every backslider (BSR) landed several hundred feet from the pad, and every HSR landed only about a hundred feet from the pad after making 3 or more spirals on the way down from apogee. Altitude was in the 500'+ range. If interested, there is a big thread on HSR in the Scratch Built forum.
 
I bought a cheap pocket level after losing my Level 1 rocket due to the launch rod tilted in the direction of the trees :mad: 🤬
Smartphones can use the phone's sensors to provide a graphic display of angle. Essentially works like a bubble level, hold the edge of the phone to the surface you're measuring. There are a number of such apps for Android phones and a level can be found on iPhone's Measure app. Some apps let you use the camera to sight the angle.

https://play.google.com/store/search?q=level+tool&c=apps&hl=en_US&gl=US
 
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