rebuild or go bigger

[kruland]

Hi all.

Back story - I got my L1 at the end of last year and hadn't flown any high power since then. Last weekend, I went to Nebraska Heat with THOR (great bunch of people with lots of fun flying, stop by some time) and tried my second HPR reload only to have the case get torched open and set fire to my only high power rocket

So, what to do? I *need* another HPR rocket for Airfest - and because I have precious little free time - I need to build something quickly. Should I just fly what I have, build another 29mm and pick up another case, or just go for my L2? Any suggestions on quick to build, fool proof (did you look at the pictures) L2 kit?

Kevin

[cwbullet]

go bigger

[jpummil]

Hey Kevin!
Opinions WILL vary greatly, but 29mm is the sweet spot IMHO! Got my L2 this spring, but I expect that most of my purchases will be 29mm motors just because of their cost/fun ratio

[troj]

Last weekend, I went to Nebraska Heat with THOR (great bunch of people with lots of fun flying, stop by some time)

Yep, they are. But then, I'm a bit biased. Glad you could come up! Come play with us again, sometime!

and tried my second HPR reload only to have the case get torched open and set fire to my only high power rocket

That sucks.

So, what to do? I *need* another HPR rocket for Airfest - and because I have precious little free time - I need to build something quickly. Should I just fly what I have, build another 29mm and pick up another case, or just go for my L2? Any suggestions on quick to build, fool proof (did you look at the pictures) L2 kit?

What to do depends on A) your budget, and B) what interests you. A rocket you can't afford to fly becomes a source of frustration, or of an exit of the hobby. Likewise, a rocket that doesn't interest you.

Giant Leap, Wildman, Mac Cow, LOC, PML -- all have great choices that can easily be built by the time AirFest rolls around. Heck, we'll be building the lower half of a 24" rocket this weekend!

What makes you happy? What kind of rockets trip your trigger?

-Kevin

[edwinshap1]

You can make a cheap, easy to fly level two rocket, or you can make an expensive level one rocket. It all depends on what you want to fly. If you really want to have that HPR L2 on your membership card, go for it, but I've found that but for my L2 cert, I've flown all L1 and below motors. They're cheaper to get a rocket in the sky, and they're just as fun to fly. (That rhymes, in case you didn't know why )

[o1d_dude]

38mm motor cases are much easier to clean than those peewee 29mm cases.

I'm pretty sure you can just climb down inside the 3" and 4" motor cases to clean them out.

[COrocket]

If you go for L2, you could get a sweet deal on a new 38MM CTI case, cause it looks like your Aerotech case is toast. 3-4" rockets are pretty fun to fly if you step up to them. Any kit that uses motor deploy would be a pretty quick build. Something like a Patriot or similar would do the trick.

[New Ocean]

I certified level 1 about 10 years ago, and then certified level 2 last month. That may be slower than normal. But even if you move faster, I really don't think you need to cert level 1, fly once again, and then go level 2. Why burn out (no pun) so quickly, instead of enjoying level 1 for a while?

[kruland]

Yep, they are. But then, I'm a bit biased. Glad you could come up! Come play with us again, sometime!



That sucks.



What to do depends on A) your budget, and B) what interests you. A rocket you can't afford to fly becomes a source of frustration, or of an exit of the hobby. Likewise, a rocket that doesn't interest you.

Giant Leap, Wildman, Mac Cow, LOC, PML -- all have great choices that can easily be built by the time AirFest rolls around. Heck, we'll be building the lower half of a 24" rocket this weekend!

What makes you happy? What kind of rockets trip your trigger?

-Kevin

Troj, It was a pleasure to shake your hand. I wish I had the quick thinking to place you with this handle. Pickrel is a fairly short drive (3hr) for me and makes for a pretty nice day out. I plan on coming back a couple times a year now.

My L1 was a complete scratch job. It was over built (for a L1) which I know now, but nonetheless was a good learning & building experience. Unfortunately, it took forever! I've been looking at the Giant Leap Liberty 3" and Rocketry Warehouse Patriot 4". I figure either of these could fly on H or adapted down to 29mm.

I certified level 1 about 10 years ago, and then certified level 2 last month. That may be slower than normal. But even if you move faster, I really don't think you need to cert level 1, fly once again, and then go level 2. Why burn out (no pun) so quickly, instead of enjoying level 1 for a while?

The big problem is I have no HPR rockets any more So I need something...

[neond7]

Go bigger! You can always use a 38/29 adapter to use smaller motors. Personally, I found 38mm to be a good place to be. I've been having a blast with the 38/120 motors, they are perfect for flying at the local parks. For club launches, the 38/240 and up motors put on a good show. Whenever I order a high power motor that requires hazmat shipping, I load up on the 38/120 motors (they require hazmat too).

[dixontj93060]

+1 on a 38mm (w/ 29mm adaptor).

[cwbullet]

+2 on a 38mm (w/ 29mm adaptor).

[terryg]

How long is the rocket? It looks like you could just shorten it, reuse the fins and install a new motor mount. Borrow a case to fly it and then expand your fleet when time permits. Looks like there was a problem with the rear O ring. Is the rear closure damaged? Your might be able to get by with just replacing the case.

[EeebeeE]

Do both...Most everything north of your fincan is probably OK. A new 29MM motor tube and appropriate centering rings aren't that expensive. Nor is the plywood. And if you have a circular saw, you can "stack-saw" all the fins at the same time to ensure uniformity. Draw the design of the fin on one sheet of ply, then strategically screw the other pieces of ply to the back of it and cut all the fins at once. You plan your cuts in such a way that as many screws as possible still remain. Then use a sabre saw to finish up any loose ends. I just did it and it came out fine. If you make your fins slightly larger than they were before, you should make up for the lost stability of the shorter airframe. Download Open Rocket and you can play with different fin designs. This is a good way of getting into scratch building and coming up with your own designs.

Then order a 38mm rocket where the motors are still reasonably priced, but you can fly H-J engines. Get a 4" or 5.5" dia. kit that can take the smaller J engine you need for your L2, but doesn't fly out of sight (Just be prepared to do some walking for recovery if you do not go dual deploy). LOC Precision and Mad Cow have a number of them that are reasonably priced. At the same time, you can also get a 29mm adapter and still fly it with more powerful 29mm motors.

[kruland]

How long is the rocket? It looks like you could just shorten it, reuse the fins and install a new motor mount. Borrow a case to fly it and then expand your fleet when time permits. Looks like there was a problem with the rear O ring. Is the rear closure damaged? Your might be able to get by with just replacing the case.

The rocket *was* 6 feet long. Now it's about 12 inches. Unfortunately, there was enough thrust to get it off the pad before powering into the ground. Almost the entire airframe was crumpled in sick and disguisting ways. To rebuild I need to acquire more tube - which since I still have the NC - I'll probably do eventually anyway.

I think the fins are still fine - other than cosmetic damage from the burning paint.

I cleaned up the aft closure as well as I could and there is a significant notch in it where it would seat against the O-ring. I'll have a couple of experienced people look it over before I attempt to use it. Can a nozzle cause such damage?

[cwbullet]

Can a nozzle cause such damage?

Yes. But so can the pressure if it overpressurized. Then again, I have never seen damage like that. It apepars that there is a linear dimple in a circle around the motor tube.

[fyrwrxz]

Yes. But so can the pressure if it overpressurized. Then again, I have never seen damage like that. It apepars that there is a linear dimple in a circle around the motor tube.

I am not a forensic rocket motor Doctor, nor do I play one on TV, but it appears the nozzle was installed backwards. The 'dimple' looks to be a complete case burn thru which would happen if the seal and 'o' ring wasn't tite against the grain and it looks like there is a phenolic ring seen thru this burn thru, which should have been against the closure. The distance looks about right too, but it just could have been a simple sealing failure. I've thrashed TWO H-165 reloads IN a ROW (!) after building a 38 and 54 mm motor the same morning because of an o-ring in the delay train I kept leaving out. Once you've seated that delay-it ain't coming out without destruction of same. Solution? CTI, baby! (and yes- I do love my AT stuff!-18 cases worth...) We all learn from our fellow flyers. Straight smoke and good chutes, my brother!

[EeebeeE]

Amen to CTI. I know of a lot of people who have posted that they like to build their engines and enjoy the challenge of building an Aerotech motor...but as for me, I prefer successful flights.

[UncleVanya]

I cleaned up the aft closure as well as I could and there is a significant notch in it where it would seat against the O-ring. I'll have a couple of experienced people look it over before I attempt to use it. Can a nozzle cause such damage?

Pictures of this close up?

Personally I would take some time before jumping to L2. Also look at the budget. If you have budget issues - build a new 38mm rocket and fly it on 29mm motors for now. The 29mm are cheaper typically and offer a lot of fun. Granted they are cheaper because they are also less total impulse but that's not the point. You can fly more if you have budget issues if you stick to 29mm.

As for one vendor over another... meh. I fly CTI mostly right now - but that decision was predicated on a lot of things, and not one of them was motor failure. I have been very happy with the AT motors I have flown. My favorite AT motors are the G64W, the H128W (my L1 motor), the J420R, the K695R, and the I161W. As you can see these range from the 29 hobby case through 54mm. CTI makes great motors also, but they cost a bit more and that may be an issue for some.

[bobkrech]

From what you show, there's little left to rebuild.

If time and money is tight, but you want a versatile rocket you can launch almost anywhere, you might consider a 3" lightweight 3/4FNC rocket with a 54 mm MT. The LOC Caliber ISP is a typical example. At under 2 pounds so it's light enough to launch on a F or G without a waiver, but strong enough to launch on a 38 mm or 54 mm J for an L2 cert if you have a big field and don't mind walking a bit. Motor mount adapters are a cheap way to fly with what you have now without restricting what you can do later.

Bob

[o1d_dude]

If you don't mind building Aerotech motors, they are an excellent product for the money. Many reloads can be shipped without hazmat fees.

If you don't mind the cost of a "pre-assembled" motor, CTI will get you in air a lot quicker. Most reloads require hazmat shipping.

At some point, the reload cost equals out and the CTI hardware is a bit less so all in all it comes down to the assembly complexity and time involved. Hazmat is given in that range reloads.

[G2Rockets]

I am not a forensic rocket motor Doctor, nor do I play one on TV, but it appears the nozzle was installed backwards. The 'dimple' looks to be a complete case burn thru which would happen if the seal and 'o' ring wasn't tite against the grain and it looks like there is a phenolic ring seen thru this burn thru, which should have been against the closure. The distance looks about right too, but it just could have been a simple sealing failure. I've thrashed TWO H-165 reloads IN a ROW (!) after building a 38 and 54 mm motor the same morning because of an o-ring in the delay train I kept leaving out. Once you've seated that delay-it ain't coming out without destruction of same. Solution? CTI, baby! (and yes- I do love my AT stuff!-18 cases worth...) We all learn from our fellow flyers. Straight smoke and good chutes, my brother!

I saw this motor up close, and the nozzle was installed correctly as was everything else. I would say it over pressurized and burned through. The flight was nice till about 40 foot. I agree with the CTI!! one guy at the launch used his first CTI. When he finished assembling he wanted to know why we never told him about them.

[CarVac]

While the 29/240 loads are very nice, the HPR 29mm forward closures are evil. The delay well is too tight or something, and impossible to clean up.

[kruland]

The verdict is in. Aerotech said I had the fore and aft O-Rings reversed. It certainly could be the situation.

I probably won't replace the case since I have an unused CTI 29mm starter set in my box. Anybody want some slightly used AT hardware

[Sailorbill]

I saw that flight and it was spectacular, ugly but spectacular.
Don't give up on AT they can be fun and inexpensive just remember to read and follow the instructions. I have been flying since 2000 and I still look at the instructions because things can change. AT and CTI hardware can be found for a reasonable price in the Yard Sale area and on Ebay.
If it was my rocket I would eventually rebuild it after all it was your first HPR.
For AIRFest I would go with something like Bob suggested a light weight 3" or 4" LOC, PML, or scratch rocket with a 54 mm Mount. You can always adapt down for now and go bigger later. The larger rocket can be observed for most of its flight on motors through J. Later you could convert it to Dual Deploy for higher altitude flights.
A rocket that I launched at Nebraska Heat, a PML Endeavour made mostly from LOC parts, has flown for over five years on 38mm motors from H through J. I finally loaded the first 54MM motor in it, a CTI I165-17A C-Star one grain. Nice low flight on an affordable 54MM motor.

Please come back and fly with us. We can be a little crazy but we always have fun.

[kruland]

I saw that flight and it was spectacular, ugly but spectacular.

Ahh, yes. I remember saying to Crystal, "Oh, that's not good", just as I saw flames leaking out the side. I bet nobody every saw John run so fast!

Don't give up on AT they can be fun and inexpensive just remember to read and follow the instructions. I have been flying since 2000 and I still look at the instructions because things can change. AT and CTI hardware can be found for a reasonable price in the Yard Sale area and on Ebay.

I don't think I'll give up on AT. I certainly like the selection especially in the smaller sizes - 29/40-120, 24, and 18 (oh my! and I have a bunch). I have vowed to implement a new construction process - lay out the size diagram and put all the parts right on top. Then work systematically and hope to pull somebody experienced to watch my back.

If it was my rocket I would eventually rebuild it after all it was your first HPR.

Though the roasted fin can is a nice souvenir. Probably carry that around for a while as a little reminder to be careful. My son has already called dibs on the motor case.

For AIRFest I would go with something like Bob suggested a light weight 3" or 4" LOC, PML, or scratch rocket with a 54 mm Mount. You can always adapt down for now and go bigger later. The larger rocket can be observed for most of its flight on motors through J. Later you could convert it to Dual Deploy for higher altitude flights.
A rocket that I launched at Nebraska Heat, a PML Endeavour made mostly from LOC parts, has flown for over five years on 38mm motors from H through J. I finally loaded the first 54MM motor in it, a CTI I165-17A C-Star one grain. Nice low flight on an affordable 54MM motor.

Right now I'm looking at Darkstar Jr. First it looks down right cool, and it seems to be versatile enough to support an eventual L2 - though probably not this year.

Please come back and fly with us. We can be a little crazy but we always have fun.

I certainly plan on it - my son and I had a great time. I'm going to try to make it up for another launch this year - maybe the BOB launch.

Kevin

[UPscaler]

I'd say get something with a 38mm mount in it, if it's in the budget. Wildman or Mad Cow are excellent.


Also, Aerotech should replace that case, due to the motor failure...




Braden

[The Rocket Kid]

Bigger is always better!!

[troj]

Also, Aerotech should replace that case, due to the motor failure...

I doubt that'll happen, since they're saying it was due to the o-rings being put in backwards.

....which is the most annoying thing about AeroTech reloads, in my book -- different sized o-rings. "Now, let's see.... I have a 3/32 and a 1/16...which one is which?"

-Kevin

[G2Rockets]

Ahh, yes. I remember saying to Crystal, "Oh, that's not good", just as I saw flames leaking out the side. I bet nobody every saw John run so fast!

Hey now, just because I have added a few pounds...

Right now I'm looking at Darkstar Jr. First it looks down right cool, and it seems to be versatile enough to support an eventual L2 - though probably not this year.

Dark Star jrs are very nice!!! They are great for L2. Just ask Carmen. Why not this year? Carmen built hers in a day and flew it successfully for her L2, you could have it by Airfest or Bob Launch.

I certainly plan on it - my son and I had a great time. I'm going to try to make it up for another launch this year - maybe the BOB launch.Kevin

It was fun having you there as well! Bob launch is always fun.