Level 1 Cert rocket

Charlie1964

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Looking at the LOC Precision 5.5" I-ROC for my level 1 attempt. Your thoughts and recommendations would be greatly appreciated. What would be a good motor for this on my L1 attempt? TIA for help.

Charlie
 

Banzai88

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If you haven't already, download and install Open Rocket and you can sim motors and decide what's most suitable to your heart's content!
 

Rob Campbell

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The I-ROC would be a great choice. It's a good low and slow flyer for a L1 cert. I would go for an I motor, either an I-161 or I-245.

Edited to change I-284 to I-245. Both of these motors use the 360 NS case. The I-284 requires the 600 NS case. and is overkill for a L1 cert.
 
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John_461

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My advise is to download Openrocket (free) or Rocksim (costs $ but more accurate) and make an accurate model. Use the actual weights and measurements. The stock components listed in OR are close, but not 100% accurate. Then, based on your simulations select a motor that will fit your launch area.

Now that the responsible stuff is out of the way...how are you going to build it? Are you using epoxy? Wood glue? Hopes and dreams? Is it going to be set up for dual deploy? 'Chute release? What is your fields altitude waiver? And most importantly, how do YOU like to fly? Slow and Loud, Fast and gone in a blink, sparkies, smoky....?

The weight listed on LOC's website for the 5.5 I-Roc is 6 pounds. My experience is to add about a pound to that for you final weight. YMMV. This is a cert flight, build it solid and let 'er rip. post pictures, bask in the glory.
 
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like this?
Jw32vo3.jpg
 

Handeman

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Or use Match a Rocket under Motors on Thrustcurve.org to pick a motor. An H550ST or I180W should get you 950-1000 ft. Assuming you are using AT reloads.
A baby J like the AT J350W would get you only 2000 ft. so this would be a very good rocket for a small field.
 

Neutronium95

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I'd go with the H550. Enough thrust so that even if you build it heavier than planned and you end up with a short rail it'll still have a safe rail exit speed. Since it's a DMS motor you don't have to lock yourself into a set of hardware yet.
 

KenECoyote

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Personally I wouldn't recommend an H550 on a L1 cert build because it is a pretty hot motor.

However, I would think this is a GREAT motor if you want to "certify with style", are used to hot/top impulse motors (if your biggest motor so far is a G64, you may not be ready), have a fiberglass rocket or after certifying.

Reason is that with 550 avg impulse on a 6lb rocket is a "don't blink" launch and the high Gs will cause more stress, so it requires a good strong build, as well as care that it doesn't have drag separation.

Here's a video of a 10lb V2 on a H550 and the announcer said "don't blink".



I don't recall if I've flown a H550, but I've used an I600 several times and it is a hoot! ...and scoot! Lol

Good luck and I hope all goes well! Do keep us posted.
 

Handeman

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Personally I wouldn't recommend an H550 on a L1 cert build because it is a pretty hot motor.

However, I would think this is a GREAT motor if you want to "certify with style", are used to hot/top impulse motors (if your biggest motor so far is a G64, you may not be ready), have a fiberglass rocket or after certifying.

Reason is that with 550 avg impulse on a 6lb rocket is a "don't blink" launch and the high Gs will cause more stress, so it requires a good strong build, as well as care that it doesn't have drag separation.

I don't recall if I've flown a H550, but I've used an I600 several times and it is a hoot! ...and scoot! Lol

Good luck and I hope all goes well! Do keep us posted.
I understand your reasoning, but I don't see why someone shouldn't use it for a L1 cert. By the time they are ready to cert, they certainly should understand the strength and thrust provide by that motor. Granted, it will take a number of H & I flights before they get a real feel for the power of those motors, if they have confidence in their build, I would say go for it.

One of my favorited motors is the I1299N Warp 9. I first flew that on about the eighth flight of my L1 cert rocket. It pulled 82Gs and held together fine. Although I was very confident, I wasn't betting on the cardboard scratch built or homemade pink foam nose cone holding up. I called it the Disappearing Rocket for that flight and it did just that. 362 mph at 134 ft. at motor burnout 0.3 sec. into the flight and since the delay grain gets snuffed out, there was no smoke trail. It did disappear! As you say, "it's a hoot!"
 

KenECoyote

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Granted, it will take a number of H & I flights before they get a real feel for the power of those motors, if they have confidence in their build, I would say go for it.
However, I would think this is a GREAT motor if you want to "certify with style", are used to hot/top impulse motors (if your biggest motor so far is a G64, you may not be ready)...
:)
I'm just throwing it out there to provide the best chance for a successful L1.

Can a new driver get the first gen Viper when it first came out and drive it home fine? Yeah... about 60% succeeded. :p

I've seen a few "don't blink" cert flights and usually the general feeling seems to be "why?" or "that's nuts ". I usually don't hear the results (took too long to find? Broken? Lost?).

Still, if you're up to the challenge and really want to, go for it. I'll still wish you luck and help any way I can.

I'm one who loves challenges and probably have one of the crazier L2 certs attempted (and suceeded), but I also realize that's not for everyone.

For me, L1 cert is best to do whatever is the greatest chance of success since for many, this is the doorway to real HP and this was my route (Sumo on some milder H on a whim).

However, if one falls on their face or the door slams on them and they lose their rocket, they may not be up to do it again. Idk, but I've heard of this before all too often for different cert attempts.

Just my opinion and it's really because I love this hobby and want others to succeed into HP.

At our club's last launch this season two fliers tried to cert before the rain shut us down. One was a LOC Goblin and the other had a custom 4FNC I think. They both chose mild H motors and both succeeded and were super happy. I got videos of both (no need to not blink lol) and it made their day and made my day. I wish this for others too.

(EDIT: Tried to post the two cert flight videos, but no dice. Goblin I added the "We are the Champions" song and the other had the Mission Impossible theme. :) )
 
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KenECoyote

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Looking at the LOC Precision 5.5" I-ROC for my level 1 attempt. Your thoughts and recommendations would be greatly appreciated. What would be a good motor for this on my L1 attempt? TIA for help.

Charlie
Hey Charlie,

Apologies if there was a derail, but it's almost a given when asking for opinions. ;) :p

Questions back to you:
  • What is your building experience?
  • What is the biggest motor you've launched so far?
  • Do you want to cert low and slow or go big?
 

Charlie1964

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I have built many (100+) Estes and Aerotech rockets. I've been building and flying R/C aircraft for 40+ years. The largest motor I have launched is a G motor.

I don't have anything set in stone right now. I thought the I-ROC would be a good L1 (and maybe down the road not too far, an L2 candidate).

I would like to keep it about 1,000 ft. or under for the L1 attempt.

I really do appreciate all the advice and help.

Charlie
 

thzero

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My advice

  1. Build a reasonable rocket for Level 1; under 1000' on a H? Probably unreasonable, but under 2000', yes. MicroMagg (4") on a H128 does about 1200' (sims to 1400'). And it can fly on Fs and Gs. Just an example, not a recommendation, stated preference or other boondoggle.
  2. Build a reasonable rocket for Level 2. I'm sure with 40+ years flying you don't have one airplane that you try a do everything with.
  3. Talk to the people running your local HP club; they'll give you some more advice and recommendations.
  4. Ignore "low and slow" advice (my pet peeve with these threads).
  5. Ignore all the advice and do what is reasonable, and follows the NAR and/or Tripoli rules depending on which club/venue you are launching with.
Personally I did my L1 with a scratchbuilt fiberglass 2.6" Initiator knockoff to ~2500fit with JLCR deployment. And L2 with a 3" custom LOC/Madcow/Fiberglass build to ~3400ft and full electronic dual deployment. <shrugs> I guess its what you are comfortable with.
 

Black Bart

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Apogee Zephyr complete L-1 kit. $99.99 only thing not in the kit is motor retention.
If i was to build again i would not glue in the coupler. 3-2/56 screws on each side. This will a allow you to put in a ebay for dual deployment. The videos on the build are detailed from Apogee. I used a H100 with 8 second delay. Low and slow get you L-1 cret. KISS !
 

Handeman

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I have built many (100+) Estes and Aerotech rockets. I've been building and flying R/C aircraft for 40+ years. The largest motor I have launched is a G motor.

I don't have anything set in stone right now. I thought the I-ROC would be a good L1 (and maybe down the road not too far, an L2 candidate).

I would like to keep it about 1,000 ft. or under for the L1 attempt.

I really do appreciate all the advice and help.

Charlie
I like the questions @KenECoyote asked and agree with @thzero. I also think the 5.5" I-ROC is a great L1 rocket.

My personal opinion is that you shouldn't use the same rocket to cert L2 as you did L1. When you spend time flying L1, you will learn a lot about the motors, power, how that affects the rocket and how to fly your most frequent field. That experience will help you decide on what type of L2 rocket you really want. Besides most L1 rockets used to cert L2, aren't capable of K & L motors. You just have to build another rocket to fly those motors. You might as well build it as your cert rocket.

Because my experience is flying on east coast fields with limited waivers, my suggestions for L1 rockets are 3" - 4" diameter, 4-6 lbs., with 38mm MMT and L2 rockets at 8-12 lbs. with 54mm MMT. Those let you fly the levels without busting waivers or traveling 1500 miles to get west of the Mississippi.

Just my opinions, cert and fly the way you want. It's a hobby, so have fun!
 

KenECoyote

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I have built many (100+) Estes and Aerotech rockets. I've been building and flying R/C aircraft for 40+ years. The largest motor I have launched is a G motor.

In my opinion sir, you are ready for whatever you want to do! :)

We'll be here for any help or advice you need...great group of people here. :D
 

bjphoenix

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A lot of reasons for not using this rocket relate to cost and complexity. I think the simplest way to L1 is a 4" diameter LOC design with a fairly common H motor and motor ejection. I think this will be in the 1000' ballpark. If you want to build a larger and/or more complicated rocket, or more expensive, then that is up to you. The kit manufacturer will probably give motor recommendations but I think it is worthwhile to make an accurate sim and do your own motor research. I didn't have good sims when I did L1, just wrasp. (I built a simple 4" diameter LOC kit and launched it with H and I motors, all using motor ejection.)
 

Zeta

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Looking at the LOC Precision 5.5" I-ROC for my level 1 attempt. Your thoughts and recommendations would be greatly appreciated. What would be a good motor for this on my L1 attempt? TIA for help.

Charlie
Hi Charlie,
I flew my L1 with a PML Explorer, it is 2.5" in diameter and 48" long. On the pad the weight was just under 3 pounds if I remember correctly. With an H115 the apogee was 1580 feet.

Did a quick sketch on open rocket tonight and it looks like your idea to use the I-ROC with an H550 will hit 1000 AGL just about on the nut.

Zeta
 

John_461

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I'm a big fan of short fat slow rockets for cert flights. I think the 5.5 I-Roc is an excellent choice. Even if you decide not to use it for your level 2 flight, it will easily handle a J motor and still be low enough for you to see the whole flight.
I did a quick sim in thrustcurve.org and assumed the rocket's dry weight at 7 pounds, you have a lot of options for motors that will keep you at or below 1000'. The H550 you mentioned will pull about 16G's of acceleration, which isn't terrible, and not quite in the "blink and you miss it range", but keep in mind that 16G's on a 7 pound rocket is around 120ish pounds of force on your motor mount/centering rings. Plan accordingly.
Where I've seen most cert flight failures is recovery. The old saying "Up is easy, down is hard" is very true. Match your parachute to the actual weight of the rocket after it's built and adjust as necessary. ~20 feet per second decent is advised, I prefer a bit slower than that due to the field I fly on. Keep in mind the surface you're going to be recovering on. Asphalt, hard packed desert, freshly plowed fields...nearby tall trees. You can't certify with a broken or lost rocket.
 

Back_at_it

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Fat and draggy is what you want. The IROC Would be a good choice but I’d recommend the 7.6 Magg or Warlock. I asked the same questions a dozen times and got some pretty good answers but ultimately I asked the guys at LOC and went with their recommendation.

I just completed my level 1 using a bone stock warlock on an H550. It was the simplest process you can imagine. Drilled the delay to 8 secs. Added additional powder for the ejection and let’s it go. Flew to 812ft. Landed safely a short walk from the pad.

Best part about starting with a larger 7.6 rocket is that you can use the same rocket for both your Level 1 and Level 2 certs. My Warlock will fly on a J435 to a SIM'd 1993ft stock. I plan to add a length of tubing to allow for me to adjust weight as needed to bring the altitude down bit. Ultimately I'd like to be in the 1500' range for my level 2 but I haven't found the right motor / weight combo just yet but I do have a few months to figure it out.

As for recovery. Keep it as stupid simple as you can. Simple motor ejection. No point in adding complexity of electronics and duel deploy when it's not required. You can play around with that anytime you like. Don't risk a cert flight.
 
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Handeman

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Why not? So what if you don't succeed, you can try again. The flier should do what they feel comfortable with; if that is with motor only ejection, cool, if its a JLCR or other chute release recovery, cool, if its fully electronic deployment then again cool.
Totally agree!
 

Zeta

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I am surprised by the amount of concern that the I-ROC might not be able to handle the H550. LOC rates it up through J...so why the fear ?

The only thing I might consider if I were to build the I-ROC 5.5 is some glass on the fins, the specs say they are 1/8", while its not the force of the motor I am conderned with, it is the landing. I helped a Jr. flier this summer with a 4" dia, LOC rocket that has 1/8 inch thick fins. (not sure if this is a misprint as other 5.5" kits have 1/4" fins) Upon landing a corner of one of the fins was damaged. The rocket was still able to fly again, and dispite the RSO's best efforts to tear the corner off, it was intacked. The Jr. Flier has a repair project ahead of them.
 

KenECoyote

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I am surprised by the amount of concern that the I-ROC might not be able to handle the H550. LOC rates it up through J...so why the fear ?

The only thing I might consider if I were to build the I-ROC 5.5 is some glass on the fins, the specs say they are 1/8", while its not the force of the motor I am conderned with, it is the landing. I helped a Jr. flier this summer with a 4" dia, LOC rocket that has 1/8 inch thick fins. (not sure if this is a misprint as other 5.5" kits have 1/4" fins) Upon landing a corner of one of the fins was damaged. The rocket was still able to fly again, and dispite the RSO's best efforts to tear the corner off, it was intacked. The Jr. Flier has a repair project ahead of them.
Oh, I'm sure the I-Roc can handle the H550 fine. It's more the situation. Earlier we didn't know the OP's experience. For all we knew it could've been only Estes easy builds. Also the step up and build demands for a rocket that flies off a G64 is imo MUCH lower than that of a H550. Wouldn't you agree?
 

thzero

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Oh, I'm sure the I-Roc can handle the H550 fine. It's more the situation. Earlier we didn't know the OP's experience. For all we knew it could've been only Estes easy builds. Also the step up and build demands for a rocket that flies off a G64 is imo MUCH lower than that of a H550. Wouldn't you agree?
And its not exactly a small rocket either. :)
 
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