N altitude attempt and V2.0 "build"

[scatsob]

Hello all, I have been around since 2001 and was a member of a forum a while back and thought it was this one but maybe it changed. Just wanted to post a success story from high altitude .

This rocket has been years in the making and finally flew at Aeronaut a little over a week back. I bought the tubes back in 2005 when carbon was less expensive and sat on them. The fins are modified blacksky fins, a buddy of mine at UC Berkeley machined them to my specs. All the electronics are in the nose and I used dual perfectflite stratologgers setting off separate Rousetech CO2 systems. There was no wind all three days, which was abnormal but awesome, and it boosted straight up on an N1000. Burnout was at 20,000 feet right at Mach 2. One altimeter recorded an apogee of 45,722 feet AGL and the other 45,696 feet AGL. Perfect flight and recovery, I will submit my paperwork to Tripoli next year for an official attempt at the N record.

 

[UPscaler]

awesome flight! Congrats!



Braden

 

[scatsob]

awesome flight! Congrats!



Braden

Thank you

This will also be a "build" thread for the second version of this rocket using filament wound fiberglass. The nose cone of this rocket cracked (it is a laid up one) so I got a filament wound one and the current avionics bay fits right in. I will post progress as it happens but it will be relatively boring as the fins just bolt on.

 

[GregGleason]

Congrats!

I'm not familiar with those fins. Also, what were your specs?

Greg

 

[Green Jello]

You did single deploy from 45K? How far was it from the pad? Congrats!

 

[scatsob]

It was single deploy and was just under 9 miles from the pad coming down on a 6' chute. As for the fins they are my profile and machined from 1/8" aluminum. Here are the specs.

75" long
15 lbs w/o propellant
34 lbs on the pad
9" parachute bay
6' main
12" chute on the cone to make sure the rest comes out
40' of 1/2" nylon shock chord
blacksky fincan

 

[scatsob]

Here are some pictures of the setup and some of the new airframe.

Below is the crack in the nose cone. The glass was thin to begin with, the new filament wound one is much more substantial.

Here is the old rocket next to the new airframe tube and nose cone. The new nose cone is a another 4" longer than the old one and I am adding 1" to the parachute bay for a little easier packing so the new rocket will be right at 80" tall.

Next are a series of pictures of how I set up the nose cone. I epoxied in a threaded rod to secure the electronics in the nose cone with a wing nut. The shock chord is attached to a separate U bolt. You can see were the Perfectflites went on the side of the sled with all the wires. On the other side the bottom box houses the two batteries and the top box has the walston transmitter. The two Rousetech units attach to the side with the batteries through the bulkhead.

This is the ACME rail guide both epoxied and screwed to the airframe.

The next two pictures show how the upper recovery section is attached to the motor. The first picture is of the bulkhead that screws to the top of the motor. that bulkhead mates with a section of coupler tube in the upper section and cinches them together. Again, there is a separate U bolt for the shock chord to stave off unscrewing of the bolt as it descends.

Here is some fin detail for those interested.

Here it is almost ready to go, just need to epoxy the coupler tube in the payload section and sink a threaded rod into the nose. Then its just a few recovery and electronic system changes and its ready for Aeronaut next year.

 

[rheil]

Wow, great flight and nice rocket. Well done!

 

[VARifleman]

What a great flight, good luck with your official attempt!

 

[Rocketjunkie]

Great flight! However, Tripoli requires GPS for record flights over 30K feet.

 

[scatsob]

Great flight! However, Tripoli requires GPS for record flights over 30K feet.

Thanks for the kind words everyone . And yes, I will be sure to have a Tripoli electronics in the rocket for the next flight .

 

[VARifleman]

GPS is flyer supplied, tripoli approved, GPS electronics.

 

[scatsob]

Huh, I guess I misunderstood or they have changed that. I think they used to supply the electronics. I have some research to do. A lot has changed with the altitude record stuff since I was last into it.

GPS is flyer supplied, tripoli approved, GPS electronics.

 

[CarVac]

Huh, I guess I misunderstood or they have changed that. I think they used to supply the electronics. I have some research to do. A lot has changed with the altitude record stuff since I was last into it.

They supply electronics (Raven2's) for sub-30,000 foot flights, but you supply GPS for any flights predicted to go over 30,000 feet. The rules may not have updated, but I think you have to use one with a Ublox-6 or newer gps chip.

 

[scatsob]

Wow, looks like I will be getting my HAM license then. Maybe I can bum the use of a receiver for the launch and just buy a transmitter/GPS. Thanks for the info .

They supply electronics (Raven2's) for sub-30,000 foot flights, but you supply GPS for any flights predicted to go over 30,000 feet. The rules may not have updated, but I think you have to use one with a Ublox-6 or newer gps chip.

 

[JimJarvis50]

Wow, looks like I will be getting my HAM license then. Maybe I can bum the use of a receiver for the launch and just buy a transmitter/GPS. Thanks for the info .

A HAM license is good to have, but you only need to have the gps file recorded on board. You do not have to receive it on the ground. You also don't have to inform Tripoli of an altitude attempt, or for that matter, even announce it prior to the flight.

Jim

PS. You might also perform a simulation of your flight with RasAero or the like. Check out what you're losing with those rail guides.

 

[scatsob]

I will have to check out this rasaero program. I used openrocket for stability but it was more than 10,000 feet off for altitude prediction. I know even rasaero will have its problems with supersonic Cd prediction. When my group was designing a supersonic business jet for our senior project we had to rely on actual supersonic Cd data from real aircraft (XB-70, Tu-144, Concorde).

A HAM license is good to have, but you only need to have the gps file recorded on board. You do not have to receive it on the ground. You also don't have to inform Tripoli of an altitude attempt, or for that matter, even announce it prior to the flight.

Jim

PS. You might also perform a simulation of your flight with RasAero or the like. Check out what you're losing with those rail guides.

 

[CarVac]

I will have to check out this rasaero program. I used openrocket for stability but it was more than 10,000 feet off for altitude prediction. I know even rasaero will have its problems with supersonic Cd prediction. When my group was designing a supersonic business jet for our senior project we had to rely on actual supersonic Cd data from real aircraft (XB-70, Tu-144, Concorde).

RASAero tends to be fairly accurate, as far as past history is concerned.

 

[scatsob]

Just ran a few predictions in RASAero. It gives over 50k with no appreciable difference with or without rail guides on the N1000. I am hoping that CTI releases a moon burner for the 6GXL case, that is the ticket for high altitude flights.

 

[JimJarvis50]

Just ran a few predictions in RASAero. It gives over 50k with no appreciable difference with or without rail guides on the N1000. I am hoping that CTI releases a moon burner for the 6GXL case, that is the ticket for high altitude flights.

Really?? I guess I'm going to have to check that for myself. I've run simulations - not quite the same context - where it makes a very surprising difference. I'll report back. Ditto on the 6XL moonburner.

Jim

 

[scatsob]

This is my first experience with RASAero so I might be doing it wrong. Our personal pads use rail and I nor my father have the time to build a new launcher. What kind of difference were you seeing? I can't imaging it reducing altitude more than a thousand feet if that.

Really?? I guess I'm going to have to check that for myself. I've run simulations - not quite the same context - where it makes a very surprising difference. I'll report back. Ditto on the 6XL moonburner.

Jim

 

[CarVac]

Ditto on the 6XL moonburner.

Jim

Jeroen posted a photo of what is supposedly a 6XL moonburner in the CTI thread...

More like an N1500, but a bit higher kick off the pad. And different PRO(TM)pellant too.

If this is a hint for us to work on a larger WT reload; we got your message ;-).

Jeroen

 

[scatsob]

If it's close to 20k Ns it will be a 70k± motor. fingers crossed.

 

[bandman444]

Jeroen posted a photo of what is supposedly a 6XL moonburner in the CTI thread...

I thought that picture ended up being the N5600 WT they certified not to long ago.

 

[Jeroen_at_CTI]

I thought that picture ended up being the N5600 WT they certified not to long ago.

The picture was of the moonburner Pro98-6GXL_MB.jpg. In stock; awaiting cert. A little less than 20k Ns though.

Jeroen

 

[bandman444]

Thanks Jeroen, it was just weird it was mentioned first and didn't make it in the last cert session with the N5600WT.

Can't wait to get my hands on one regardless.

 

[scatsob]

Fantastic! What is the total impulse and average thrust? Thanks for bringing all these great loads to the market .

The picture was of the moonburner Pro98-6GXL_MB.jpg. In stock; awaiting cert. A little less than 20k Ns though.

Jeroen

 

[Rocketjunkie]

I get 17,000 N-s with a D grain in the 6GXL case. N1000 Cast 2 yesterday for Balls projects.

 

[JimJarvis50]

This is my first experience with RASAero so I might be doing it wrong. Our personal pads use rail and I nor my father have the time to build a new launcher. What kind of difference were you seeing? I can't imaging it reducing altitude more than a thousand feet if that.

OK, I did a few simulations with RasAero using the PML style rail guides (with shoe frontal areas of 0.233 and 0.134 for the 15 and 10 versions, respectively). I get:

- No guides - 43,800
- 10 guides - 40,400
- 15 guides - 38,300

The simulations were performed on the rocket shown in the tower. The tower, by the way, was conceived that morning with a trip to the Home Depot in Fernley. The tower was born about 4 hours and $30 later. I can't exactly say it was successful because, due to the cloud cover last year, the rocket didn't fly. But I'm pretty sure it would have worked (once) just fine.

Jim

 

[scatsob]

Here are some pictures of the new arming setup. It still uses the deans connectors but they are below the bottom of the nose cone to allow for a better hatch attachment that the V1 rocket. During the 45k flight the hatch actually broke off the rocket during the flight and this will solve that problem.