NEWB?

Hey everyone! I've been gathering info from this site for a few weeks now but have yet to post. Wow this site would have been awesome to have when I was a kid in the ealy eighties! Well, my girls and I have been building some rockets, I bought a starter kit with the Estes Amazon and Crossfire, plus I got a Big Betty for me. As it turns out the kits are just too difficult for my girls, 7 and 9, so I've really been the one building them. I'm having a great time. I've built the Amazon and am just finishing up the Crossfire, my question is, how loose is too loose for the nose cone? Is there a way to tell? They both seem a little loose to me, although they don't fall out when turned upside down. Thanks in advance for any help!!

There isn't really, it is just important that it isn't too tight. If it is too tight, it won't pop off at apogee and you get a lawn dart.

(This isn't mine, but it is a good, BIG example)
As long as it doesn't fall out upside down, you should be fine. If it is too loose, just wrap some tape around the shoulder of the nose cone. Welcome to the hobby! :clap:

Welcome aboard!

Tell us more about your experiences in the early 80s. The 80s were my first BAR experience. I'll never forget walking into a hobby store in Phoenix in 1983 and catching my first glimpse of an FSI F-100 engine. It may be small by today's standards but back then, it was the biggest engine I had ever seen. I didn't know anything beyond the venerable D's even existed...

Yes, those were fun times!

Don

You can add a bit of masking tape to tighten them up if you want. For low power, you usually want the nose cone to be a snug, but not tight fit. It definitely shouldn't fall out if turned upside down, and even if shaken a bit. However, it should still come off smoothly and cleanly.

For larger rockets, the rule is usually that you should be able to pick up the rocket by the nose without it coming apart. That's not as much of a concern with smaller rockets though, as they aren't as prone to drag separation (and for most low power rockets, the strict adherence to that rule would probably give you nose cones that were tighter than needed).

For low power rockets (single D and lower), my rule of thumb (besides the 'hold upside down and the nose shouldn't come out test) was to do a 'blow test'. Basically, pack the rocket like you would for a flight without an engine, then simply blow into the engine end with a short, sharp puff (like blowing out a candle, but without taking a deep breath first). Usually pursing the lips like you would blow into a trumpet. I found this test to be very reliable...if everything doesn't come out cleanly, you need to adjust...

This of course assumes you're not a 'spitter', or you're trying to blow as if you were playing a clarinet...resulting in the taste of cardboard and sulfer...

FC

dbrent said:

Tell us more about your experiences in the early 80s.

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My 6th grade teacher had a rocket program in school is how I was introduced to model rockets. I continued building at home, but never got beyond D class kits. My fav was prolly the SR71 Blackbird, never was much of a high flyer but sure was cool to watch. I've had vikings, mosquitoes, payloaders, space shuttles, mean machines and one like that I think was called the javelin. There is more, I just can't remember their names. I saw a kit in a store the other day and it brought back all those memories so I thought I would introduce my kids to the hobby, they are a little young still, but they can't wait to fly them. I am kinda dissapointed that my oldest wanted to paint the Crossfire Pink, but hey, she's into it so pink it is.
Some of the stuff on this site is mind blowing, boy rocketry has come a long way!
Thanks for the help with the nose cone fellas!!

FastCargo said:

For low power rockets (single D and lower), my rule of thumb (besides the 'hold upside down and the nose shouldn't come out test) was to do a 'blow test'. Basically, pack the rocket like you would for a flight without an engine, then simply blow into the engine end with a short, sharp puff (like blowing out a candle, but without taking a deep breath first).

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I use a rolled-up piece of 8 1/2 x 11 paper to slip into the motor mount and stick out the rear, then blow on the open end of the rolled-up paper tube. You also kinda need to use something like this for a "Big Betty" style rocket where the fins stick out the rear and you can't blow directly on the motor mount.

Tommy, have you gone through all the info posted for beginners on the "Beginners & Educational Programs" forum? There is tons of good info to be found there.

And welcome to TRF!

also be sure to check your local National Association of Rocketry or Tripoli Rocketry Association club/prefect to meet some great people and learn about rocketry in the flesh. reading and watching online are great, but i didn't realize how much noise a K motor makes until i saw it on the lake bed

Thanks for all the tips and links guys. There certainly is a lot of good stuff on the begginers forum.

Welcome to TRF and back to rocketry Read, enjoy, share your experiences and PARTICIPATE! Good to have you aboard

jim

I'm not big on blowing a rocket, so I use the time honored tradition of being snug enough to not fall off when it's upside down, but loose enough that when you hold it by the nose cone and give a shake, it separates from the body tube. I would argue that there is such a thing as too loose, we call it drag separation. If you like the sr-71 you'd better get one now as they are out of production but still available. Rockets with big, draggy bodies are especially vulnerable to drag separation. this is bad because when this happens, the low drag nc goes faster then the body with all it's drag, so the body slows down and pulls out the recovery train. This can occur with a hard yank and cause the shock cord to cut thru the body of the rocket - a zipper! So snug is good.

good luck! I BAR'd with that launch set. We still fly the amazon even though it's been repaired several times.

Tommy, Indiana has a big launch "Thundrstuck" every year. You should attend it and you will really see how far rocketry has advanced! Welcome to TRF.

powderburner said:

I use a rolled-up piece of 8 1/2 x 11 paper to slip into the motor mount and stick out the rear, then blow on the open end of the rolled-up paper tube. You also kinda need to use something like this for a "Big Betty" style rocket where the fins stick out the rear and you can't blow directly on the motor mount.

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Well, shoot! Why didn't I think of that?

Darn interwebs and all that knowledge sharing...



FC

Thanks again guys! I will look into that Thunderstruck launch.

Welcome to TRF. There's a lot of brain power around here and If you have a problem ask away.

And if you go to Thunderstruck bring your low-power rockets. Many low power rockets fly between the racks of Hi Power launches. This way you can get even more addicted to rocketry when the smell of APCP is hanging in the air:wink:

Welocme to TRF Looks like tou're on the right track. I'm going to my first organised launch in July and it looks like fun so you may want to hit one too. As it is this place serves as a club for me. If you have any questions feel free to ask any of the mod team or anybody else for that matter
Cheers
fred