CTI N5800 challenge

[WILDMANRS]

CTI N5800 minimum diameter altitude contest
CTI is pleased to announced the "Fly the N5800 to a record contest".

Over the last couple of years there have been several attempts to fly a 98mm minimum diameter rocket to extreme altitudes and speeds with the Pro98-6GXL C-STAR N5800 reload. However, AFAWK none of these rockets survived the flight.

CTI would like to encourage others to build a stronger/better rocket and demonstrate that such a flight is actually possible. Therefore this contest.

The winner will be the first to:

* Fly a minimum diameter 98mm rocket;
* With Pro98-6GXL C-STAR N5800 reload;
* Make a full and safe recovery;
* Obtain the official TRA record for this flight;
* Flight before the end of 2012.

Prize: Two reloads of your choice for the Pro98-6GXL hardware (or any smaller-sized reloads).

Jeroen


Wildman's will add
Anyone attempting this we will give 25% off the reload and hardware.
you must supply us with the date and place of the attempt

[Neil]

CTI N5800 minimum diameter altitude contest
CTI is pleased to announced the "Fly the N5800 to a record contest".

Over the last couple of years there have been several attempts to fly a 98mm minimum diameter rocket to extreme altitudes and speeds with the Pro98-6GXL C-STAR N5800 reload. However, AFAWK none of these rockets survived the flight.

CTI would like to encourage others to build a stronger/better rocket and demonstrate that such a flight is actually possible. Therefore this contest.

The winner will be the first to:

* Fly a minimum diameter 98mm rocket;
* With Pro98-6GXL C-STAR N5800 reload;
* Make a full and safe recovery;
* Obtain the official TRA record for this flight;
* Flight before the end of 2012.

Prize: Two reloads of your choice for the Pro98-6GXL hardware (or any smaller-sized reloads).

Jeroen


Wildman's will add
Anyone attempting this we will give 25% off the reload and hardware.
you must supply us with the date and place of the attempt

How about launching an 800+ pound Saturn 1B on four of these....does that count? And if it does count, will it count for the individuals who are donating their motors to make this happen. This will be a record no one will ever touch with N motors. Just a thought and a liberal interpretation of the "rules".........

[Yoehahn]

Im attempting this in 2013 wether the contest is running or not. Ill be at LDRS at Black Rock so thats the only time I could attempt this crazy thing.

[cjl]

Well, I'm in. This should be an interesting challenge

[GaryT]

Interesting indeed.

[bandman444]

Should be fun.



Bryce

[CCotner]

Your Beveling is AWESOME! That's the max thickness at the top and at the root? And what are you using to adhere it to the CF?

[bandman444]

Tip is .02"
Each edge is .02"
Root is 1/4, with 1/4 fillet on each side making it 3/4 wide.

We use magic to keep them.

[nh4clo4]

We use magic to keep them.

aaah. Well, then, you should be fine.

[mannyskid]

We use magic to keep them.

Research, time and money......that's the magic.

[CarVac]

If you have magic, why have fins at all? Just use your magic make sure it goes straight up. For that matter, why don't you just use magic to lift it to 30,000 feet before magically igniting it, and magically clearing the air out from in front of the rocket? Magically deploy a magical parachute at apogee, and magically guide it to land at your feet in the end?

Just being facetious.

[cjl]

If you have magic, why have fins at all? Just use your magic make sure it goes straight up. For that matter, why don't you just use magic to lift it to 30,000 feet before magically igniting it, and magically clearing the air out from in front of the rocket? Magically deploy a magical parachute at apogee, and magically guide it to land at your feet in the end?

Just being facetious.

If you figure out how to do that, could you please let me know

[ClayD]

If you figure out how to do that, could you please let me know

you need vortex generators....

[Aksrockets]

Should be fun.



Bryce

Fins look nice!
Do you have any concerns with thermal expansion? I talked to the one of the head engineers at Rocky Mountain Composites ( http://www.rockymountaincomposites.com/) about the N5800 challenge. He said that he would be concerned that the bond between the CF and the Aluminum would weaken because of thermal expansion. We talked about types of epoxy, stiffness, etc for large MD rockets. He concluded that the best (in terms of composites) would probably be a Carbon fibre fin with a leading phenolic edge (he never heard of cortonics).

Just another idea for a high strength fincan: Has anyone considered a molded fincan, using cotronics 4525 epoxy as a gelcoat? It would be considerably more difficult to mould a fin can but would it survive?

Alex

[daveyfire]

He said that he would be concerned that the bond between the CF and the Aluminum would weaken because of thermal expansion. We talked about types of epoxy, stiffness, etc for large MD rockets. He concluded that the best (in terms of composites) would probably be a Carbon fibre fin with a leading phenolic edge (he never heard of cortonics).

For typical laminates (e.g. ±45s), CTE is largely fiber dominated; carbon is ~27e-6/ºC and aluminum is 23-25e-6/ºC, so they'll pretty much stay together. (Sidebar: we always used to lay up carbon tubes on aluminum mandrels for this reason.)

Carbon fin + phenolic leading edge works well, if executed properly.

[mannyskid]

Just another idea for a high strength fincan: Has anyone considered a molded fincan, using cotronics 4525 epoxy as a gelcoat? It would be considerably more difficult to mould a fin can but would it survive?

Alex

I have thought about this for a long time. I'm working on a rocket (M2245 challenge) with foam fins and a molded fin can. It could be turned into an N5800 rocket though.

[CarVac]

When you mean molded, do you refer to mating two separate cloth "clamshells" like a conventional molded nosecone? I can't imagine that being very strong when compared to a normally laid up planar fin, unless it's too wide to be aerodynamic.

[cjl]

you need vortex generators....

So THAT'S the trick. I knew there was something I was missing...

[bandman444]

Not the altitude, but flew the motor.

Didn't even hit Mach 3

http://www.youtube.com/watch?v=&feature=youtu.be&a


http://www.youtube.com/watch?v=TMbIrYpB9vw

[kopius]

Firstly a HUGE congratulations to our adopted Aussie Mike, who is the first to tame this wild motor. It was unfortunate that the weather did not hold as we had another 2 Australian N5800 attempts, which although very different to the successful flight, went through vigorous development aiming for the same outcome. Plans are being made to see these fly at a later stage.

For those that are interested in Mike's phenomenal rocket, you can view the build thread here http://www.ausrocketry.com/forum/vie...hp?f=10&t=3593

[dixontj93060]

Thanks for posting this link.

Firstly a HUGE congratulations to our adopted Aussie Mike, who is the first to tame this wild motor. It was unfortunate that the weather did not hold as we had another 2 Australian N5800 attempts, which although very different to the successful flight, went through vigorous development aiming for the same outcome. Plans are being made to see these fly at a later stage.

For those that are interested in Mike's phenomenal rocket, you can view the build thread here http://www.ausrocketry.com/forum/vie...hp?f=10&t=3593

[The Fatman]

Has anyone heard if this is being extended for 2013?

[G_T]

For typical laminates (e.g. ±45s), CTE is largely fiber dominated; carbon is ~27e-6/ºC and aluminum is 23-25e-6/ºC, so they'll pretty much stay together. (Sidebar: we always used to lay up carbon tubes on aluminum mandrels for this reason.)

Carbon fin + phenolic leading edge works well, if executed properly.

"Carbon fiber can have a broad range of CTE's, -1 to 8+, depending on the direction measured, the fabric weave, the precursor material, Pan based (high strength, higher CTE) or Pitch based (high modulus/stiffness, lower CTE)." - http://www.christinedemerchant.com/c...teristics.html Units are inch / inch degree F.

Aluminum is 13. So, the difference can be considerable.

From another source: http://physics.info/expansion/ - carbon, diamond, 1.18e-6/ºC, carbon, graphite, parallel to plates 6.5e-6/ºC, perpendicular to plates 5e-7/ºC. But carbon fiber is not a pure graphite and the properties vary quite a bit, as pointed out by the previous source.

Sorry about the mixed units; I didn't bother to make consistent.

Here is some info from one of the manufacturers: http://www.toraycfa.com/product.html - "Minimal deformation due to thermal effects, with coefficients of thermal expansion in the axis direction on the order of -0.4 to -1.0 x10-6/K." Note this is a negative coefficient of thermal expansion.

Gerald

[daveyfire]

Typical CTEs for a single lamina are negative in the cross-fiber direction and positive along the fiber. A negative CTE is usually a trick of the layup schedule, rather than an inherent material property.

[G_T]

I'm presuming:
http://www.hexcel.com/Resources/Data.../3501-6_eu.pdf
http://www.hexcel.com/resources/data...sheets/as4.pdf - interesting that the fiber by itself, presumably measured along the fiber, has a negative coefficient of thermal expansion.

http://www.ezentrumbilder.de/rg/pdf/...ern%20engl.pdf - I'd like to find a similar table of data including CTE for various available carbon fibers.

Gerald

[maxvelocity]

Not the altitude, but flew the motor.

Didn't even hit Mach 3

http://www.youtube.com/watch?v=&feature=youtu.be&a


http://www.youtube.com/watch?v=TMbIrYpB9vw

That was awesome!