Got my first launches in today.....

[Rakk187]

Bought an Estes riptide launch set and finally made it out to see my 4 yr old nephew today.....we went to the athletic fields at his school to launch. First launch was made using an A8-3, the rocket didn't go very high, and the 'chute finally fully deployed about 6 feet off the ground. Then I loaded up a C6-5, repacked the chute.....and let him launch with a little help and supervision. The rocket went HIGH and drifted quite a bit after ejection, under a partial 'chute.....it took some searching, but we finally found it about 300 feet beyond where I though it landed, and about 300 yards from the launch pad. On to the 3rd launch.....again with the C6-5, the rocket immediately hooked right after clearing the launch rod, went probably 200 feet verticallily, and a whole lot of horizontally, partial chute again, and drifted somewhere probably into the next town. 3 launches, 2 recoveries.

A bit of a learning experience, I'll be sure to order some B motors with the next rocket, as they seem like the logical "sweet spot" after using A and C motors. If you think you have enough recovery wadding, add a couple more sheets (that first C motor did melt the chute a little bit with 3 sheets). I'm wondering if a smaller parachute will help with drifting though (less drift, more drop) or maybe ditching the parachute completely for a streamer or two, or possibly even a parachute streamer combo, anybody got any ideas??

 

[OverTheTop]

Glad you had some fun!

I would suggest just flying for the conditions. If there is a stiff cross breeze just wait for a lull or come back another day. As you fly more you can judge the wind better and compensate with launchrod angles somewhat. It takes experience.

Streamers are good for a small rocket, and ones that don't have fins that go back past the end of the rocket body. Those are prone to breaking on faster landings and generally like chutes better. Don't forget you can change chute size based on flight conditions.

We all chastise ourselves for overpowering rockets at some stage .

 

[Rakk187]

I'm kinda concerned about the 3rd and final launch though, the wind was blowing into my back at launch, and literally the moment the rocket cleared the launch road it hooked HARD right, perpendicular to the wind, it barely cleared the roof of the school and continued in a horizontal trajectory, again perpendicular to the wind. It was only after the ejection stage that the wind finally started to take it, with the parachute flapping in the breeze. My brother was acting as a "spotter" downrange, and he last laid eyes on the rocket as it crossed the tree line, into a neighboring farm.

While the worst thing that happened this time was the loss of a brand new rocket, I worry about sending a rocket through the window of a neighboring building. The field we were launching from houses 3 full size soccer fields, so I figured it would be ample space, but when I saw that rocket take an immediate turn on launch I actually let out an audible "oh boy...."

 

[Antares JS]

Are you sure the wind was blowing exactly into your back? How hard was the wind blowing? A rocket turning into the wind is a normal thing. It's why you don't fly when the wind is blowing too hard - a good gust while thrusting can blow a little rocket over 90° as you described.

Was the rocket sliding completely freely along the entire length of the rod when you mounted it to the pad?

Was the rocket damaged at all after the second flight?

 

[Rakk187]

Alright, heres a little visual of my two C6-5 launches. Blue is the launch pad, black dashes are wind direction according to the ribbon on launch rod safety cap. Red is the first C6 launch, yellow is the doomed 3rd and final launch, with a decent estimate of where the rocket may have finally touched down. The rocket immediately banked hard and to my right at launch, it gained some altitude eventually, but at first i thought it was going to center punch the building. Then at apogee/ejection, the wind finally took it over to the neighbors farm (and maybe beyond)

Wind was sustained at 5 mph, with gusts to 15 mph, the remnants of a cold front that had come in the day before.

No visible damage to the rocket prior to final launch, despite burning in on a partial chute, it landed in some waist high grass, giving it a nice soft landing.

 

[jrap330]

Most beginner sets are small rockets...NO C engines, otherwise blown way past launch site (esp school field) and trees. Beginning sets are A;'s and B's unless your set has a big rocket.......Look for a bigger rocket where Estes estimates 300-500 feet for a C........school yards are small and that is where I do most of my launches ..lost a ton of rockets So you are correct...B motor is the sweet spot, but if you have a min diameter rocket (18mm)...I go with an A or B withe streamer. After a while if you don't care you loose it go with streamer.

It could be borderline stable, my Bullpup with a C 6 had 3 C launches 2 horizontal and 1 vertical. (good)....so I no longer launch with a C. You can always had some nose weight, with clay, epoxy, caulking etc.

 

[Rakk187]

Yeah, estes reccomends B's and C's, with altitudes upto 675 ft with a C6-5, so thats what i bought for motors, and then a scoutmaster buddy of mine gave me a multipack of A's. The field in the picture is actually pretty sizeable, two soccer fields end to end, then down an embankment followed by more tall grass all the way to the street, i figured that would meet the requirement of 400 sq ft that estes recommends for C engines.....

On a side note: along with a smaller parachute to provide a faster descent, what about cutting the hole out on the top of the parachute? Any benefits to that?

 

[Antares JS]

On a side note: along with a smaller parachute to provide a faster descent, what about cutting the hole out on the top of the parachute? Any benefits to that?

Yes. That's called a "spill hole" and provides a faster, smoother descent.

 

[jrap330]

Spill hole yes...and also sheaving the lines...tied them together so chute does not open so much. Again , that plastic fin can can survive a streamer . Other issue, depending on eyesight...mine is poor , it is easy to loose track of the rocket 500-600 feet up, especially on clear, white cloud day (perfect). So keeping small rockets low is a good thing.

 

[BABAR]

ENT Surgeon have a lecture with a section that sort of applies here.
A surgeon spends the first 5 years learning how to operate
The next 10 years learning when to operate
The next 10 years learning when NOT to operate.

The time table doesn’t necessarily get so stretched out for rockets, but it is hard to wait to launch a just completed project (but harder still to lose it on first flight.)

Small motors with short delays are your friends on windy days.

 

[jrap330]

Why short delays? I always believe long delay so it descends further down

 

[Nytrunner]

Why short delays? I always believe long delay so it descends further down

As it heads back down, it picks up speed again. Too fast and you get zippered body tubes, cut shock cords, and nosecone bounceback (can be damaging to tubes/fins/nose)

 

[Fen1x]

Years ago I had a rocket do the exact same thing. Cleared the launch rod and suddenly nosed down 90 degrees and headed for a house. Turned out we had inadvertently ran a igniter lead over a fin We figured it out when one of the guys was wondering why the leads had come flying back at him. Fortunately the engine burnt out long before it reached the house.

 

[neil_w]

The first time I flew my IRIS-T it did something like this. Took a weird turn right off the rod, and I was very lucky to get it back. I was concerned something was wrong with the rocket.

Second flight was arrow-straight.

I chalk it up to "sometimes stuff happens".

 

[BABAR]

Why short delays? I always believe long delay so it descends further down

Small motors don’t generate as much altitude and more importantly, generally don’t impart as much kinetic energy. Once the “propellant” portion of the motor burns out, the rocket is no longer being propelled, but still traveling upward at or near maximum velocity, so a really BAD time to deploy a chute. The “delay” in a black powder motor is basically powder that generates smoke but little if any thrust. The smoke helps you see the rocket, but the main purpose is to allow gravity and drag to slow the rocket. Those flying with electronic deployment have both the advantage and the responsibility of setting electronics to detect apogee (cessation of upward flight) and “perfectly” timing deployment. Those of us flying black powder don’t have this. Believe it or not, you (or the rocket manufacturer, if you choose the “recommended” motor, are “programming” your deployment timing when you “select” the motor you put in your rocket. You are hoping that your rocket, flown in the conditions you select to launch it, will be “about” at apogee when delay burns through and the ejection charge fires. Too early, and the rocket is flying too fast and you will get a zippered tube or ripped off chute. Moderately late, rocket starts accelerating ballistically and you get the same thing . Markedly too late and your rocket “re-kits” itself on impact, with the secondary risk that the delay charge (which even if it doesn’t propel the rocket is still very hot and can light dry grass or brush on fire ) or the ejection charge (which particularly if the rocket is in pieces from impact) can set a ground fire.

So while you are correct that too long a delay means your chute deploys at a lower altitude, it is a really bad idea. Especially in windy conditions, where the rocket May weathercock into the wind and go a long distance horizontal (possibly outside your expected recovery area) before ejection occurs.

 

[MALBAR 70]

Welcome to TRF and to rocketry, sounds like you had fun even though you suffered a loss. It happens from time to time.
"
I was looking at the picture of your flying field and said, Hey! I know where that is!"
I'm in Athol, which isn't too far from Hardwick at all. I have scoped out that field a few times when my kids were playing soccer. There is a good bit of open space, but I think for that site, A's and B's are your best option. In a larger or draggier model, ( Estes Amazon/ Mars Lander) you might get away with a C.

When things get back to normal and they start having club launches again, I suggest you and your nephew check out CMASS.
If you want to fly bigger engines (and bigger rockets) the club is the way to go, as they have access some large flying areas in Acton and Amesbury.
Hopefully we'll meet up at a launch later this season.