Going for L2, what am I forgetting?

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Something I'm going to try out this time: I have a Garmin GPS fitness watch and (no I'm not putting it in the rocket) I'm going to turn it on for my hike to the rocket. That will give me a very accurate picture of how OpenRocket was in estimating lateral distance. My plan is to do one launch of a 3g CTI 38mm motor as a shakedown, then go to a 6g J motor for cert.
 
ActingLikeAKid said:
Something I'm going to try out this time: I have a Garmin GPS fitness watch and (no I'm not putting it in the rocket) I'm going to turn it on for my hike to the rocket. That will give me a very accurate picture of how OpenRocket was in estimating lateral distance. My plan is to do one launch of a 3g CTI 38mm motor as a shakedown, then go to a 6g J motor for cert.
Click to expand...

If you are going to launch twice and take the test, that is a full day. Plan to get there early and have the shakedown flight prepped the night before. Even if the shakedown flight ends badly, you can still take the test and do the cert flight later. Good luck!
 
BDB said:
If you are going to launch twice and take the test, that is a full day. Plan to get there early and have the shakedown flight prepped the night before. Even if the shakedown flight ends badly, you can still take the test and do the cert flight later. Good luck!
Click to expand...
Good point, thanks... Unfortunately, won't make it to the field til 11. But...Since this is only JLCR and motor-eject, there's no filling charge wells and re-arming altimeters to deal with, it SHOULD be a quick cycle. Will play by ear and try not to succumb to "gotta do it" fever.
 
ActingLikeAKid said:
Good point, thanks... Unfortunately, won't make it to the field til 11. But...Since this is only JLCR and motor-eject, there's no filling charge wells and re-arming altimeters to deal with, it SHOULD be a quick cycle. Will play by ear and try not to succumb to "gotta do it" fever.
Click to expand...

Personally, I think that doing a practice flight first is perfect. If you do the prep for that flight the day before the only extra time is in recovering the rocket and if you have a friend with you you can ask your friend to recover it while you take the test. You may even want to do the test first. That way a problem during your shakedown flight won't rattle you.
 
ActingLikeAKid said:
Correct, this is NAR.
I played around with a couple of things and kind of like a half-width (so like 3/8") piece of super-cheap masking tape. Tiny bit of residue, but holds well. And that's what I've been practicing well. May try the streamer idea, I like that.

Rocket is very long and thin. Loose upscale of the Estes Vector Force. 54mm bottom half, 38mm top half. Whole rocket is about 6' long, motor is 38mm.
Click to expand...

Ahh, that rocket. I pop into that thread from time to time. :) I say would go with what has worked for you in the past. No reason to try anything new on a Cert flight. With that being said, I am flying for my Lvl 2 on Saturday and it will be my first time using a drogue chute. I usually go drogueless but I have seen more failed deployments/tangles that way. And first time with redundant altimeters. So take my advice with a grain of salt. LOL. I may do a shakedown flight, but I will have to adapt down to 38mm and I don't have an adapter (54/426 loads wont get it off the pad quick enough). I don't like borrowing things. The load plus adapter will eat up my budget. But anyway, this is your thread. I'm rambling as usual.

I also printed out a sheet with various flights and some build notes. Kind of like a condensed L3 packet. I am planning the J315 but if the weather is just too good, I may go with the J401, I like the smoke but the J250 Just doesn't have the punch. Just in case your certifier (new word) asks off the wall questions. Simple questions but may catch you up and make you look a fool if nothing else. It also goes in my binder later to help keep records and data.

Example:
View attachment 329004

Good luck to you. Nothing to worry about it. A failure is only a failure if you don't learn from it and/or give up.

Mikey D
 
MikeyDSlagle said:
Ahh, that rocket. I pop into that thread from time to time. :) I say would go with what has worked for you in the past. No reason to try anything new on a Cert flight. With that being said, I am flying for my Lvl 2 on Saturday and it will be my first time using a drogue chute. I usually go drogueless but I have seen more failed deployments/tangles that way. And first time with redundant altimeters. So take my advice with a grain of salt. LOL. I may do a shakedown flight, but I will have to adapt down to 38mm and I don't have an adapter (54/426 loads wont get it off the pad quick enough). I don't like borrowing things. The load plus adapter will eat up my budget. But anyway, this is your thread. I'm rambling as usual.
Click to expand...

Yeah, this rocket has been a bit of a booger. But I'm happy with where it is now. Good luck on Saturday as well!

MikeyDSlagle said:
I also printed out a sheet with various flights and some build notes. Kind of like a condensed L3 packet. I am planning the J315 but if the weather is just too good, I may go with the J401, I like the smoke but the J250 Just doesn't have the punch. Just in case your certifier (new word) asks off the wall questions. Simple questions but may catch you up and make you look a fool if nothing else. It also goes in my binder later to help keep records and data.
Click to expand...
Ooh, I really like that idea!!

MikeyDSlagle said:
Good luck to you. Nothing to worry about it. A failure is only a failure if you don't learn from it and/or give up.

Mikey D
Click to expand...

Wise words :)
 
ActingLikeAKid said:
Yeah, this rocket has been a bit of a booger. But I'm happy with where it is now. Good luck on Saturday as well!


Ooh, I really like that idea!!



Wise words :)
Click to expand...

That's the important thing. It's yours. My lvl 1 had a few trials and tribulations as well, changed the name a few times, the design a few more, the av bay at least three. But man when that thing flies...:)

Looks like my file didn't load, well I can't view it anyway. I'll try to fix it tomorrow.
 
MikeyDSlagle said:
That's the important thing. It's yours. My lvl 1 had a few trials and tribulations as well, changed the name a few times, the design a few more, the av bay at least three. But man when that thing flies...:)

Looks like my file didn't load, well I can't view it anyway. I'll try to fix it tomorrow.
Click to expand...

Nope, I got it, thanks! Looking at it in another tab (which I'm going to leave open just in case TRF ate it when the page reloaded).
When I put mine up on that fateful I280DM... I was sad to see it in a pile of carnage after the flight, but MAN that launch was cool. I surprised myself a little at how stoic I was about the whole thing; I think I'm realizing it's less about "having a rocket" and more about "building a rocket".
 
OK, here's my checklist...

Set up table & ez-up
Organize stuff & take a breath
Show paperwork & rocket to RSO, ask if I need to assemble motor in their presence.
Charge Chute Release
Charge Altimeter
Acquire motor from vendor
Connect Eggfinder Tx
Turn on Eggfinder base unit & get sync
Install nosecone and camera
Make sure camera has SD card in it
Make sure all screws are tight
Install altimeter and attach Chute Release to quicklink. Power on Altimeter. Sync to phone.
Install fireproof wadding
Z-fold & tape harness, install.
Check tightness of quicklink
Fold chute & install Chute Release. Shake test & deploy test. Re-fold chute, install CR, burrito chute & put in. Write CHUTE RELEASE ARMED on tape, stick to rocket.
Upper into rocket. Check for tightness, tape as necessary
Assemble motor & drill delay if necessary. Install retaining ring & check for tightness
Fill out card and get rocket RSO'd
Rocket to pad. Bring tape, sandpaper & Eggfinder base unit. Install igniter. Turn on camera. Double-check shoulder tightness. Remove Chute Release note.
Start recording JLA3 (if not still sync'd, resync)
Turn on camera, verify running
Rocket onto rail, double-check smoothness. Attach igniter leads.
Set Garmin to "run", start.
Get back to safety, if cert flight, make sure witnesses present.
LAUNCH. Record on iPhone or fancy camera
Use compass to get bearing if no visual of rocket landing and no Eggfinder lock
When rocket down OR time > 120s, enter last GPS coordinate to phone.
Walk to rocket
Stop camera & turn off Eggfinder Rx. Stop garmin watch. Sync phone to altimeter, stop recording, get data.Collect rocket & walk back.
if cert flight, show rocket to RSO/cert team
Return rocket to car.
Check harnesses and chute
Empty burnt wadding
Attach camera to laptop & download video
Remove motor case and remove spent motor
Wipe motor case clean
 
I have two suggestions. First, don't put anything on the checklist that is distracting or unnecessary, such as setting up table or returning rocket to car.
Second, don't combine necessary items things into a single step as you've done for the step that starts out "Install altimeter..." Each of those step needs its own check.
 
Steve Shannon said:
I have two suggestions. First, don't put anything on the checklist that is distracting or unnecessary, such as setting up table or returning rocket to car.
Second, don't combine necessary items things into a single step as you've done for the step that starts out "Install altimeter..." Each of those step needs its own check.
Click to expand...

This sort of advice is exactly why I posted the list. Thank you.

Need to write DON'T RUSH on my hand.
 
Motors are selected. I350 for shakedown, J357 for cert. I'm pleased with this plan; they're both 5g motors, the J is just a nose more powerful. If the first one goes well, the second one should be about 500 feet higher and 50 mph faster. So for about $60, I get a practice cert flight on a scraping-the-ceiling I motor, then I do my cert on the very-smallest-of-baby-J motors.

Now I just have to cross my fingers for clear skies.
 
Just to devil's advocate here...if you're going to shakedown with pretty much the same motor, why not just fly it with the J on your maiden? If it doesn't go perfectly, you can just buy another J & try again. I guess you'd probably need an on-site vendor for that, so maybe that's a factor.
 
Yeah. Condense your checklist. No need for the table setup and walking. Too many steps and you'll skip a few. I have one that I never use that can be printed 4 to a sheet and cut out so you can carry with ya to the pad. I'll redo it tonight specific for my Lvl 2 flight.

I'd agree to use a smaller motor for the shakedown so you can see you apogee event and see how the rocket falls. If it does indeed have issues, you may be able to see them unfold. Or just forego the shakedown flight altogether. A successful shakedown doesn't mean the cert flight will be successful. The human element is usually the problem and that will still be present, along with the X factor that is just there. Never know what it is gonna do.

PM me you email address and I'll send ya my checklists and various other sheets I have made up.
 
ActingLikeAKid said:
OK, here's my checklist...

Set up table & ez-up
Organize stuff & take a breath
Show paperwork & rocket to RSO, ask if I need to assemble motor in their presence.
Charge Chute Release
Charge Altimeter
Acquire motor from vendor
Connect Eggfinder Tx
Turn on Eggfinder base unit & get sync
Install nosecone and camera
Make sure camera has SD card in it
Make sure all screws are tight
Install altimeter and attach Chute Release to quicklink. Power on Altimeter. Sync to phone.
Install fireproof wadding
Z-fold & tape harness, install.
Check tightness of quicklink
Fold chute & install Chute Release. Shake test & deploy test. Re-fold chute, install CR, burrito chute & put in. Write CHUTE RELEASE ARMED on tape, stick to rocket.
Upper into rocket. Check for tightness, tape as necessary
Assemble motor & drill delay if necessary. Install retaining ring & check for tightness
Fill out card and get rocket RSO'd
Rocket to pad. Bring tape, sandpaper & Eggfinder base unit. Install igniter. Turn on camera. Double-check shoulder tightness. Remove Chute Release note.
Start recording JLA3 (if not still sync'd, resync)
Turn on camera, verify running
Rocket onto rail, double-check smoothness. Attach igniter leads.
Set Garmin to "run", start.
Get back to safety, if cert flight, make sure witnesses present.
LAUNCH. Record on iPhone or fancy camera
Use compass to get bearing if no visual of rocket landing and no Eggfinder lock
When rocket down OR time > 120s, enter last GPS coordinate to phone.
Walk to rocket
Stop camera & turn off Eggfinder Rx. Stop garmin watch. Sync phone to altimeter, stop recording, get data.Collect rocket & walk back.
if cert flight, show rocket to RSO/cert team
Return rocket to car.
Check harnesses and chute
Empty burnt wadding
Attach camera to laptop & download video
Remove motor case and remove spent motor
Wipe motor case clean
Click to expand...

Geez. Don't forget to poop. Agreed on the above, as in my company's philosophy the checklist should just cover the "killer items" that will ruin your day. The longer the checklist, the more likely you're going to miss something important.

Also agreed on the shakedown flight, if the motors are really close then just stick the J in there, that way you're only focusing on one flight.
 
Hmm. OK, reconsidering the shakedown; I'm going to ping the vendor again and see if there's something a bit smaller.
My thought with the shakedown was "does everything do what it's supposed to do" - for example, if I'm heart-stoppingly close to treeline, maybe I adjust the rail; if I have plenty of chute time before ground hit, maybe I go lower on the JLCR, if it's perfect, I go into the cert flight confident. Also - not that there WOULD be, but if there's evidence that something isn't quite holding as well as I'd like, I get the chance to beef it up with some epoxy, an extra screw, etc.
One of the options was an I55 mellow, but...
1. That's really low thrust for the rocket - 1926g loaded, 55N average thrust. That's scraping the very minimum of what NAR wants for thrust to weight, and well below the 5-to-1 that a lot of folks want to see.
2. I don't just want to make sure the rocket flies - I'm confident that it will; I want to make sure it can handle the abuse.
Good points here... I don't think it would hurt anything to do a high-I "shakedown", but I'm not sure how much value there is in it. I will think upon it. :)
 
I endorse your plan for a shake down flight before the cert flight, as well as your other preparations. I planned to do the maiden flight at my local club launch but that launch was scrubbed due to fog. So I showed up at Midwest Power, did my maiden flight, took my test, and flew the L2 cert flight - all by about lunchtime. This rocket was new and had the largest chute I had ever used the JLCR with at that time, so I felt a maiden flight was needed to make sure my descent in both phases was stable and nothing was likely to get tangled.

Sounds like you have your motor picked out already, but one thing I decided to do different was to use an SU motor (J270). I had plenty of experience with reloadable motors but though an SU motor would eliminate some risk of a CATO or other problems. Plus I have the empty case left over as a souvenir.
 
I'd avoid the I55 mellow. If there's any wind at all, it will turn into it and really fly far away. A rocket really needs to be built light to fly that mellow.
 
I would avoid the I55 as well, unless you can launch in near windless conditions. Of course, I'm one to talk, my L3 simmed to 42fps off the rail. I did, however, have no wind for the flight. It was also a multi-day launch, so waiting for tomorrow was an option I was willing to use. :)

For assembling the motor, if RMS/DMS.. If you have someone experienced available, go ahead and ask them to watch you build it. Or go SU. All the motor failures I have had were my fault during assembly, and were AT delay grain related, putting the O-ring/spacer on the wrong side of the delay etc.. Someone with more experience would likely have caught that. For CTI, there's not much to mess up on, so you are probably fine there.

I haven't used a JLCR, but for my DD mains, I like to fire a bit on the early side. I've seen chutes tangle or otherwise have a hard time opening and a little extra time often sorts them out. If you deploy at 200ft, you don't get a lot of time to do that. I have a somewhat luxurious field to fly on though, no trees for miles and the waiver is large on the ground. So breaking it horizontally is tough to do. For L1/L2 size rockets, I often go with about 1000ft. For my L3 I had the primary at 1500ft, with backup at 1200ft. I saw a really dramatic L3 cert flight once where they deployed at 1000, had an issue and finally opened at about 200. Barely had time to slow before impact. I would not have found that to be amusing for my own rocket though...

Good luck on the flight. It looks like you're doing the right things to have a successful flight.
 
ttabbal said:
For assembling the motor, if RMS/DMS.. If you have someone experienced available, go ahead and ask them to watch you build it. Or go SU. All the motor failures I have had were my fault during assembly, and were AT delay grain related, putting the O-ring/spacer on the wrong side of the delay etc.. Someone with more experience would likely have caught that. For CTI, there's not much to mess up on, so you are probably fine there.
Click to expand...
Yup, CTI. I am a "CTI guy" because I have kids who are often on the field with me and young enough to get bored easily and need monitoring. So short of strapping them into their seats and popping in a DVD, I don't want to have grease on my hands and be about to put an o-ring on when one of them needs to pee/starts hitting the other/wants to wander over and check out someone else's rockets/etc.

ttabbal said:
I haven't used a JLCR, but for my DD mains, I like to fire a bit on the early side.
...
Good luck on the flight. It looks like you're doing the right things to have a successful flight.
Click to expand...

Thanks!! and +1 on popping early. GENERALLY, my feeling is "I'd rather walk an extra five minutes to an intact rocket than have a brief walk to a wreck". That said, I once had a rocket get treed because the Chute Release did its thing exactly when I told it to and the chute unfurled perfectly :)
 
And I'm frustrated and saddened to report:

The launch has been scrubbed. Low clouds, good chance of rain, the presence of farm workers and some other factors combined to make an HPR launch just not viable.

Time to put this all on a shelf for a bit and focus on other stuff.
 
Bummer. Now you have more time to fret over it. :-/

We are go for launch down here:

"Saturday 09/30
0% / 0 in
Except for a few afternoon clouds, mainly sunny. High 86F. Winds NNE at 10 to 15 mph."

Of course it will be higher winds on the open field. Hopefully not too bad though. It was forecast for 5 to 10 MPH with a high of 81. Would've been better.

Sorry to hear it got scrubbed. Always a bummer when you are psyched to do something.
 
I'd second the idea of a mid-H to small-I shakedown followed by the big flight. Launching nearly the same motor probably won't save you from rocket-eating trees. You'll be able to see what happens at deployment easier at a lower altitude. I'd also add one more item to your launch checklist: the puff test for the loaded JLCR. A 54mm airframe is still small enough to have the JLCR jam in there (ask me how I know...), but is small enough that a reasonable set of lungs can still blow the chute out. If the chute doesn't blow out easily, repack it.
 
Sad about the launch delay. You will get there in the end.

One item I have on my checklist is to tape the igniter to a fin. That way I don't get to the pad and have the igniter sitting back in the car.

Also, if you have a lot of different cameras on different rockets, I have struck on the idea of putting the instructions for each camera on something about the size of a business card and taping it to the airframe near the camera. That way there is no ambiguity about what button or LED sequence is correct. I will be doing this from now on after messing up priming the camera before my last launch.
 
ActingLikeAKid said:
Something I'm going to try out this time: I have a Garmin GPS fitness watch and (no I'm not putting it in the rocket) I'm going to turn it on for my hike to the rocket. That will give me a very accurate picture of how OpenRocket was in estimating lateral distance. My plan is to do one launch of a 3g CTI 38mm motor as a shakedown, then go to a 6g J motor for cert.
Click to expand...

This exercise is very subject to gigo, or garbage in garbage out. To get anything close you need accurate wind on site at time of launch, temperature, and launch rod angle. Even then it is a monolithic wind, which is not very realistic- wind velocity and direction almost always change with altitude.

Throw in variations in engine performance, humidity, and rod/rail whip and you see the issue.

This is why when a class 3 rocket is simmed in Rocksim Pro there are a whole set of variables that can be changed, and they run a thousand iterations for the splash pattern.


Sent from my iPhone using Rocketry Forum
 
OverTheTop said:
Also, if you have a lot of different cameras on different rockets, I have struck on the idea of putting the instructions for each camera on something about the size of a business card and taping it to the airframe near the camera. That way there is no ambiguity about what button or LED sequence is correct. I will be doing this from now on after messing up priming the camera before my last launch.
Click to expand...

I've thought the same thing for altimeter arming instructions, after forgetting the proper process to follow for the Eggtimer TRS once and ending up with a ballistic recovery. I have an overall checklist, but it's generic for every rocket so it doesn't get into particular arming procedures (it's already a full-sized sheet as it is, don't want to add even more to it). I always mark the Cg with a piece of blue tape on the airframe, should stick the extra slip on that which would also help to remind me to remove it before flight, half of the time I fly with the Cg tape still stuck on the side. :p
 

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