TARC

Just curious as how things are going for various TARC launches and what teams are turning in for scores. What kind of configurations are you seeing for motors and what kind of results are they getting.

Just a thought on designs that I've been an observer for;

Two of the teams here used a clustered booster of Estes motors that didn't work as planned. Both of those flights had problems with the cluster lighting all motors. Yes, a 12V car battery was used to make sure to fire all igniters, which they all did from inspection. All booster motors fired except one on both, and threw the flight off. This is a major hazard waiting to happen for those of you that haven't seen this happen. I think that it would be an excellent addition for NAR to advise teams of the possible dangers of this happening just as a precaution. Maybe they have, and I didn't catch it. The big problem is that when you have BP clusters, any motors that don't light, fire when the other motors ignite the second stage and burn from the top down. Both times this happened, and it started fires from the 3rd/4th motor in the booster burning as it hit the ground, torching the grass. Another problem is that if the team uses an Estes E motor in the upper stage, the burn time is so long that the flight is already underpowered and heading south after getting up a short ways, and the motor is still burning as the rocket hits the ground, and it also (possibly, happened on one) starts a fire.

Nothing like being prepared with fire extinguishers.

It's just my .02, but I think it would be a great idea if NAR put together a summary or short technical paper on igniters and staging for TARC contestants. It wouldn't be telling them how to stage, but cover the technical details of types of igniters; wire gauge, current requirements, etc. along with minor details of proper igniter installation techniques for both composite and BP motors. If this small amount of information was readily available to teams, I think there would be a lot more successful flights, not to mention the safety benefits.

Just my .02

-Boomer

Reply to
Boomer
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I'd just look at the results of last years TARC.

Ah, it is good to see that the students are learning.

You are supposed to put a wad of flame proof wadding on top of each motor used in a cluster to prevent this. This should not as big a problem with thick Estes clay cap closures, as it was with older paper cap motors. It is a lesson that is learned and never repeated.

The Estes E is a fine sustainer motor for rockets weighing up to one pound, but only if you get the rocket up to speed in the right direction first. However, I would question the need for the long burning E on these low altitude TARC flights.

Especially if you fly before the April showers and greening up of old dry vegetation.

There are many publications (not mention RMR messages) from a wide variety of sources on the technical details of staging and clustering. YOu don't need to be a rocket scientist to do this research. I personably feel that TARC should make it MORE difficult to make a successful flight (or change the reward metric). However, rules for this year have made it easier than last year.

Alan

Reply to
Alan Jones

Aloha, No flight yet. The kids (called no-hopers from here on) were supposed to do their flight last weekend, but postponed till today due to not having their stuff together. We have low clowd, high winds, and rain today. I doubt they will get it done today. If they dont qual today or sunday, they are out of luck.

Take Care, Larry in Oklahoma

Reply to
AkaZilla

Two TARC teams at last week's CRASH launch. I only saw two of the launches.

One bird was a 3 stage BP; went horizontal and impacted under sustainer thrust. Hadn't found enough pieces to determine flight failure cause when I left. I believe it had a 3x clustered booster.

Second flight was a 2 stage (apparent) BP; good loft and altitude seemed fairly close. Again, had to leave before it was recovered.

One of the teams had a very nice carbon fiber airframe/NC model. Wide range of technology and construction techniques in that one.

Reply to
Gary

Three straight TARC launches at Fermi were cancelled due to winds over 20 MPH (the lab has an on site weather station with data on the web)

Helped out with the Fermi group last Sunday and again yesterday. Last week there were 4 schools making practice flights. Many failures from marginal stability to recovery failures. Many broken fins due to grain direction. Several with inadequate launch lugs. Too many used 1/4" tubing for lugs, only to discover that's the OD, and the rockets would only fit on a 3/16 rod that flexed way too much under the load. No official attempts. Most rockets not flyable afterwards.

This weekend it was more of the same. Plus some cluster failures, including one that failed to light the one motor required for upper stage ignition demolished one teams rocket. Several lawn dart recoveries. One official attempt that failed, one that was ABSOLUTELY PERFECT: 4 D12s to 1 D12 absolutely straight the whole way, ejected at apogee, and thermalled a while. The kids had a long chase, but came back with 2 intact eggs and an altitude of 1277. "We're going to Virginia!"

No launch today due to the holiday.

Suggested changes for next year:

1) Additional rule requiring minimum rod size (if a rod is used, one team had a tower, and rails are certainly an option) of 1/4" and make it clear that 1/4" OD brass or aluminum tubing will NOT fit. In fact, you need to go TWO sizes over in order to have a non binding fit.

2) Change the contest schedule so those of us up north where it's winter for half the year aren't stuck flying in freezing wind-chill or crammig all the flying into the last weekend of the event. I know I suggested this last year, and was ignored. This has become a sticky issue for both clubs in the Chicago area. I think it's safe to say that neither club will continue to support future TARC events without a schedule change that allows this event to be flown when our climate is more appropriate for rocket flying.

3) Allow any commercial sport rocket altimiter to be used. This wasn't the problem it was last year, but there is no reason to limit choices for an event where maximum performance is not the goal.

******************************************* Question for other teams, or their mentors:

For those new to the event this year, when did you send in your registration, and when did you get all your contest materials (book, altimeter, Rocksim)? One person at yesterdays launch mentioned that they didn't get all their stuff until January, thus didn't have long to actually work on the project. Certainly no time with decent weather to test and refine their work.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

Two TARC teams got qualified flights at Lucerne 4-3-04.

Reply to
Jerry Irvine

Aloha, The same bunch of kids tried again today. They kept with the 3 black powder motors in each stage concept. Lower winds and a lighter rocket helped them. They got 1306 feet. These guys built their own ground support equipment from scratch.

Take Care, Larry in Oklahoma

Reply to
AkaZilla

I'll bet this flight arced a lot. Accelerometers report the length of the flight path. But which ever one was official is the one you go by. And since the goal is to reach a target, an arcing flight would throw their result off regardless of which one is used. The goal is consistency.

I'm waiting the results of Chris Kidwell's R&D project. He's been flying a rocket with 12 different altimeters in a huge payload bay. SHould be interesting...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

What roll program are they using? E.g. what booster and upper stage fine cant angles? It is important to consider the motor ignition failure modes, and rolling the vehicle is key to achieving more vertical and safer flights. You cant really do this with rocksim, so maybe it is getting overlooked. Perhaps some fin cant should be mandated for TARC clusters as a safety issue? Clusters should also have more static margin to keep the flight trim angle to a reasonably small level.

Alan

Reply to
Alan Jones

The team handbook and rules state that at the finals a 1/4" rod will be available. Anyother rod/rail size must be provided by the team. In addition the team handbook says plan on using a 6 foot long 1/4" rod. Seems that this is sufficient for teams that read the handbook and rules.

From looking at the Team America Web site Illinois had 31 teams submit

9 qualification flights (29.0%). Other states in your area had the following results. Wisconsin 8 teams, 5 qualification flights (62.5%). Michigan 17 teams, 8 qualification flights (47%). Indiana 18 teams, 6 qualification flights (33%). Iowa 4 teams 1 qualification flight (25%). Missouri 10 teams and 6 qualificaiton flights (60%). For the entire counrty 609 teams submitting 205 qualification flights (33.6%). In Virginia we certainly had problems with the weather (High winds this year and cold last year) but the teams that took this competition seriously (started early enough) were able to find sufficient opportunity to fly in good weather.

The two altimeters allowed to be used are inexpensive and readily available. In addition they are simple and reliable.

Reply to
Don Hooker

launches and what

what kind of

used, one team

make it clear

you need to go

will

team.

1/4"

handbook

Gotta agree, although I've long since stopped being surprised at how few folks actually read the rules (check out the questions asked on the NARTARC forum if you want an example or two or 400)

it's winter for

crammig all the

this last

continue to

allows this event

flying.

submit

the

(62.5%).

teams, 6

flight

For the

(33.6%).

winds

competition

You forgot Minnesota (3/7, and an additional team that didn't qualify was out there trying....)

Just like everything else, as this competition matures, it's going to take more commitment to win.

This wasn't the

choices for an

readily

And rugged! I've witnessed one keep working after a) falling from

1489' without benefit of a parachute (the eggs survived too, which is impressive considering they were in a Pratt capsule (sometimes the snow really helps :-) and then b) falling from 1360 feet behind a streaming parachute, and then c)falling from 1200 feet behind a streaming parachute.

your

September

September

long to actually

test and

The materials consist of the altimeter, Rocksim, and Stine's handbook. The altimeter isn't necessary until later on. An adequate version of RockSim can be downloaded for free pending receipt of the real thing. Stine's book is available in many public libraries. If teams used Trip's suggested guidlines, they'd have spent the fall building single stage rockets anyway....

I do think TARC needs more experienced rocketeers as mentors. Teams that I've seen that haven't had the benefit of that have had to do an awful lot of learning the hard way.

FWIW,

--tc

Reply to
Ted Cochran

I saw several teams discover their rockets didn't fit on 1/4" rods, so they flew off 3/16x3' rods. Results were not good :-(

For the final month of competition, we had 5 straight Chicago area launches cancelled (winds hit 44+mph one day), and only 2 were held. We had ONE team qualify there. I understand that one more qualified at another launch. No idea when/where the other 7 occured.

From mid November to mid April (this Sunday) NIRA has no regular launches scheduled due to the weather.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

Nice stastick. What do you attribute this to?

Reply to
Greg Cisko

Err... Statistic... :-)

Reply to
Greg Cisko

I wasn't trying to attribute this to anything. I was only observing that the ability to submit a qualification flight by the Illinios teams was on par with the rest of the nation and that other teams looked to be doing the same or slightly better with similar weather conditions to content with. Don

Reply to
Don Hooker

I mentored two teams this year.

The first one signed up immediately and their first flight was in December 2003. They then ranged throughout Virginia and Maryland for any launch that was available and was flying 2-3 times a month at organized launches. Some launches they choose not to launch at due to the weather conditions. This team conpleted two qualification flights.

The other one had their first flight in January. They only attended the local (closest) launch. They flew 1 time a month. The launch they attended in February and April had wind conditions that were not suitable for this type of flying. This team failed to complete a qualification flight.

The ability to complete a qualification flight rests with the ability and desire of the team. If they work hard it will happen.

Reply to
Don Hooker

I just checked the TARC website, and don't see any results posted that would tell me who qualified and who didn't. Where did you find it.

Well, that would be good. Except we hibernate through our CHicago winters. NIRA hasn't had a scheduled launch since November 16th of last year, or perhaps October 19th as the November launch might have been cancelled due to weather.

Our first launch of 2004 is scheduled for this Sunday, one week AFTER the TARC deadline. Until someone figures out how to change our weather, I do NOT expect this to change...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

The Team America web site list of teams entered did have information about which teams submitted qualification flights. This has been removed and replaced with a list of the finalista and alternates.

Reply to
Don Hooker

OK, they must have been updating it thos morning. Now the list of registered teams has been replaced with 101 teams invited to the finals, and 20 alternates. IIRC last year the first 5 alternates were called.

Does any one know what the cutoff was for a qualifying score. Last year it was around 200'.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

It was much tighter this year. The team that is the 2nd alternate reported an altitude of 1156 ft (94 points). Looks like teams had to be well with 100 ft this year.

Buzz McDermott Dallas, Texas

Reply to
Buzz McDermott

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