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NAR Competition Question Thread
#1
Have a question about NAR competition? I'll try my best to answer.

I'm not a casual competitor, but have never finished in the top 3 in any of the national championships.  My aim at contests is to have fun, fly consistently, and improve over time.

kj
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#2
Kj:looking forward to others' thoughts on the events for NARAM 58 next year

Chas
NAR 9790 L1
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#3
(09-17-2015, 01:53 PM)kjohnson Wrote: Have a question about NAR competition? I'll try my best to answer.

I'm not a casual competitor, but have never finished in the top 3 in any of the national championships.  My aim at contests is to have fun, fly consistently, and improve over time.

kj

I'll start the ball rolling, then.  I'm a BAR, and participated in NARAM and regional contests this year for the first time since 1978.

Let's talk G-Streamer duration.  I can design a rocket that sims to over a mile, with amazing hang time.  At least at my home field, at 4,400' ASL.  There's a UROC club member that consistently puts his G-powered rockets over a mile, and he's shared his building tips with me, so I feel moderately confident I can at least give it a good shot.

The biggest problem that I see is that the trackers need to keep eyes on the rocket for timing purposes.  I've also been told (since I've never launched at Walnut Grove) that haze/humidity can cause problems in keeping eyes on the rocket.  How does one balance out all of these competing factors?  My thoughts include:

  1. Add a !#$#$%load of tracking powder and hope for the best
  2. Paint in bright colors
  3. Fly the rocket to a lower altitude to ensure trackers can see it
I should note that I consistently lost sight of my own rockets at this year's NARAM, even B altitude.  I may need new glasses, but this does seem like a real concern.
Bill Cooper
NAR #97213
L1: NARAM 56, 2x Upscale Fliskits Corona
L2: Oct. 2015, Wildman Interceptor A.A.D. 98
Member of UROC, former member of NOVAAR and NARHAMS
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#4
I've been in competition for decades and attended over a dozen NARAMS.. I've never seen G SD flown since it was added to the Pink Book a number of years ago. For smaller motors SD is somewhat of an altitude contest, but with G motors I think it will be essential to keep the altitude down and use a large (10x100", maybe more) 1 mil reflective Mylar streamer.
Dave Cook 
NAR 21953 L2    TRA 1108
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#5
(11-06-2015, 05:58 PM)caveduck Wrote: I've been in competition for decades and attended over a dozen NARAMS.. I've never seen G SD flown since it was added to the Pink Book a number of years ago.  For smaller motors SD is somewhat of an altitude contest, but with G motors I think it will be essential to keep the altitude down and use a large (10x100", maybe more) 1 mil reflective Mylar streamer.

Thanks.  Think I met you at NARAM this year - bald guy, heavy, sat at the next table over under the ramada?  

Anywho, I was already thinking huge mylar streamer.  I know that a harness is prohibited by NAR rules.  What about a rod running along the short edge of the streamer to keep it straight?  I've seen tape reinforcement, but something that big seems to call for more.

Guess I'll get to do some test flights on Sat and Sun to see how high I can go and remain visible at that field.
Bill Cooper
NAR #97213
L1: NARAM 56, 2x Upscale Fliskits Corona
L2: Oct. 2015, Wildman Interceptor A.A.D. 98
Member of UROC, former member of NOVAAR and NARHAMS
Reply
#6
Hi Bill, I think I do remember you from Tucson.

I think the streamer attachment ought to be fine with an appropriately sized piece of plastic tape (maybe 1.5-2" wide given the streamer dimensions) and the line laid out in serpentine fashion under the tape, emerging at the corner as usual for SD. That will definitely be legal (any kind of rigid rod almost surely would be disallowed) and ought to be strong enough as long as you don't eject at high velocity. To make sure of the latter I'd strongly consider flying with a deployment altimeter HPR style; the needed mass (maybe 35-40 gm) would not be a problem and long motor delays are notoriously inaccurate. Then you could think about trying to use the 2nd channel for some kind of dethermallizer, but killing the lift on a fully deployed streamer seems hard. You can't just let it go due to the no-separation rule.
Dave Cook 
NAR 21953 L2    TRA 1108
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#7
75Grandville Wrote:I'll start the ball rolling, then.  I'm a BAR, and participated in NARAM and regional contests this year for the first time since 1978.

Let's talk G-Streamer duration.  I can design a rocket that sims to over a mile, with amazing hang time.  At least at my home field, at 4,400' ASL.  There's a UROC club member that consistently puts his G-powered rockets over a mile, and he's shared his building tips with me, so I feel moderately confident I can at least give it a good shot.

The biggest problem that I see is that the trackers need to keep eyes on the rocket for timing purposes.  I've also been told (since I've never launched at Walnut Grove) that haze/humidity can cause problems in keeping eyes on the rocket.  How does one balance out all of these competing factors?  My thoughts include:

[ul]
[li]Add a !#$#$%load of tracking powder and hope for the best[/li]
[li]Paint in bright colors[/li]
[li]Fly the rocket to a lower altitude to ensure trackers can see it[/li]
[/ul]
I should note that I consistently lost sight of my own rockets at this year's NARAM, even B altitude.  I may need new glasses, but this does seem like a real concern.

So for regular SD events, you get two flights, and the times are added together.  You also need a returned flight for your times to count.  One strategy would be to make one all up high performance flight that might not get returned, and one slightly less high performance flight to make sure one flight is returned.  Or you know, go all out on both flights and hope you can get one back.

Personally in any high performance design for this event, I would go with some powder to show the ejection point, and a very visible streamer. 

The attachment point per the rules need to be at one point on the streamer, and it needs to handle the expected loads and then some. I have seen music wire stiffeners used on the leading edge of the streamer in competitions in the past, but the tape and cord method works fine in most of the lower impulse classes.  As long as it's sized appropriately I don't see why that wouldn't work at G impulse.

If you are looking to use Mylar for your streamer, I wouldn't go any thinner than 1mil.  2mil might be better.

kj
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#8
(11-07-2015, 01:15 AM)caveduck Wrote: Hi Bill, I think I do remember you from Tucson.

I think the streamer attachment ought to be fine with an appropriately sized piece of plastic tape (maybe 1.5-2" wide given the streamer dimensions) and the line laid out in serpentine fashion under the tape, emerging at the corner as usual for SD.  That will definitely be legal (any kind of rigid rod almost surely would be disallowed) and ought to be strong enough as long as you don't eject at high velocity.  To make sure of the latter I'd strongly consider flying with a deployment altimeter HPR style; the needed mass (maybe 35-40 gm) would not be a problem and long motor delays are notoriously inaccurate.  Then you could think about trying to use the 2nd channel for some kind of dethermallizer, but killing the lift on a fully deployed streamer seems hard.  You can't just let it go due to the no-separation rule.

Just trying to think this dethermalizer thing through.  What if, rather than a traditional attachment, I ran a line through the center of each fold, like a set of blinds.  Then at 5 minutes had some sort of take-up spool that would reel the line in, collapsing or refolding the streamer, so that the rocket drops?  

Of course, I have no idea yet how one would get the streamer to deploy properly, then reel it back in, but it's something to consider.
Bill Cooper
NAR #97213
L1: NARAM 56, 2x Upscale Fliskits Corona
L2: Oct. 2015, Wildman Interceptor A.A.D. 98
Member of UROC, former member of NOVAAR and NARHAMS
Reply
#9
As long as it's only attached to the streamer in one place, sure. I think you'd need at least two attachment points to make something like that work, one at the base so the streamer can unfurl, and one at the top to reel in the folds. And that would not be allowed in NAR competition.

kj
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#10
Appreciate the comments on G Streamer. They follow my thoughts on that event. 75Grandville's comment about haze and humidity show that in all flights you have to fly the field and conditions.
I had looked at certified motors and it looks like there on some like the G80-10 for all out and others with lower impulse that might be required to get a qualified flight returned.

Chas
Chas Russell
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