My First Flight of 2014, 5" O3800 in MD

[DeeRoc29]

Saturday, 1/4. FAR in CA.

I had the opportunity to fly my 5" O motor project for the second time (first flight was at XPRS last Sept). The motor case is 5" OD 6061, 45" long. This time I ran a 72/10 formula. Came out to about an O3800, 30K Ns. The rocket is minimum diameter, 9 feet long, and weighs about 30 pounds w/out motor. It was scratch built with hand-laid FG tubing, "tfish-style," using the motor case as a mandrel, mylar, and several wraps of 6 oz cloth. Fins are a composite of G10, balsa, and CF. Nose cone is PR 5" FW.

The flight yesterday was mostly successful. Motor burned loud and strong, no anomalies. Drogue was released on cue at apogee via dual Stratologgers. No main, though. The altimeters both lost power after apogee, I'm guessing due to the arming switches I got at Radio Shack. They worked fine at XPRS, but this time it appears the excitement at apogee somehow jiggled them enough to turn off the altimeters. Thus, the second charge never fired. The rocket landed hard about 1.2 miles away. One fin took the brunt of impact and cracked. Otherwise the rocket is fine. Stratologger data was uploaded later and revealed apogee at 30K and peak velocity (FWIW) at 1533 mph. Yes, paint was bubbled and leading edges of the fins were cooked. All fun.





Say what you will about California, but you can't beat our weather!! 70 degrees and calm in the dead of winter



For odd-size cases like this one, I make my liner tubes out of 6 oz glass, Aeropoxy, and a bit of lampblack. They hold up like a champ.

Thanks to the FAR guys for their tremendous support of the rocketry community.

 

[DeeRoc29]

And video.

[video]https://s189.photobucket.com/user/derekjamieson/media/IMG_0300_zpse8c80cdb.mp4.html[/video]

 

[mpitfield]

Love the sound of that motor, nice looking flight. Too bad about the main but on the up side now you now have something to work on.

 

[patelldp]

We're you using the red momentary push switches?

I've been using those recently, do I have reason to be concerned?

 

[DeeRoc29]

We're you using the red momentary push switches?

I've been using those recently, do I have reason to be concerned?

These. They are push-on/push-off type. I will never use them again.

 

[3stoogesrocketry]

LOL Dan if your using a momentary switch you gotta be concerned . You want a ON / OFF push button switch . Here is a picture of my half scale Nike Smokes electronics . It uses heavy duty rocker switches mounted 90 degrees to thrust or shock loads so they cant accidently get turned off . If you are gonna be making it to the CTRA invitational this year , im flying it on a L3150 .

Eric

 

[marcusSRG]

Sweet dude!!

 

[mikec]

These. They are push-on/push-off type. I will never use them again.
View attachment 158497

Were they the soft or hard "click" type? Were the altimeters turned off or just momentarily interrupted and reset? I'd have thought it took more than a short power glitch to reset an SL100. I use RatShack switches regularly and haven't had problems.

 

[DeeRoc29]

Were they the soft or hard "click" type? Were the altimeters turned off or just momentarily interrupted and reset? I'd have thought it took more than a short power glitch to reset an SL100. I use RatShack switches regularly and haven't had problems.

Hard click type. It was clear that the altimeters were turned off. They were off when I recovered the rocket. I pushed the switches again and both altimeters turned on and stayed on. Odd. I've used these type of switches many times, too. Never had a problem until now. I think I'll use the Aerocon screw switches exclusively from now on.

 

[crossfire]

For a project like yours I would use twist and go. Its not going to fail like the switch. I have not done an O project yet but when I do it will be the twist and go method. Looks like you had a very nice flight and not to bad of recovery.

 

[DeeRoc29]

For a project like yours I would use twist and go. Its not going to fail like the switch. I have not done an O project yet but when I do it will be the twist and go method. Looks like you had a very nice flight and not to bad of recovery.

How would you disarm the electronics? Other than pull it apart?

 

[gdjsky01]

WOW!!! ConGRATS. Sorry I could not make it... I had a party in the early afternoon.
I would have love to see it. O- well. Sounds like a great flight. Lets due launch sometime.

 

[crossfire]

At the pad I have never had to disarm the electronics, but yes you must remove one of the bulk plates to disarm it. To me that's a small thing to do to make sure I have no switch failure on a project of that size. Here in the Midwest we use the twist method on a very large number of flights. It just removes another failure point for a project.

 

[tfish]

"tfish-style" you're funny. Don't you know you can't do extreme flight with hand laid fiberglass rockets?
Nice flight. I might need to borrow your liner method.
I need to go out to FAR one of these days.

Tony

 

[DeeRoc29]

"tfish-style" you're funny. Don't you know you can't do extreme flight with hand laid fiberglass rockets?
Nice flight. I might need to borrow your liner method.
I need to go out to FAR one of these days.

Tony

The case ID is 4.625, so I used a 4.5" OD pipe (from the same scrap metal yard that the case is from) as the mandrel for the liner. The liner from the XPRS flight is reusable. This liner would've been reusable too if I hadn't glued the grains in.

 

[tfish]

How many wraps, and what weigh cloth did you go with? I have a 6 foot piece of 5" tube that has been hanging around for a couple years that is looking for something to do with it's self.

Tony

 

[DeeRoc29]

Six wraps of Raka 6 oz. cloth, peel ply. Seven wraps would've fit, but tightly.

The liner from the XPRS flight was five wraps of 10 oz. but required some sanding to fit.

 

[mikec]

I think I'll use the Aerocon screw switches exclusively from now on.

Definitely safer. I assume you know the power went off at apogee from altimeter logs? I wonder if either the rocket sections hit each other or there was a reset at apogee on both altimeters and then the switches were actually turned off by the impact force. Seems unlikely that typical deployment forces (fairly low-g, normal to the switch mechanism) would switch two switches off the same way.

 

[rocketsaway]

How would you disarm the electronics? Other than pull it apart?

I tape along the outside coming out thru the vent ports. kiss
If someone finds the rocket, very easy to disarm. (which has happened)
But, at what point will the tape come off w/ probs, dunno. (I use very sticky tape)


btw- those orings look good to go for another. ; /

 

[blackbrandt]

Now one caution on twist and tape, I did that on the flight of my Onyx on an H399, and the electrical tape (covered in 1 layer of duct tape), ripped off from the aerodynamic forces at Mach 1. Thereby causing complete altimeter turnoff (thank God I kept the charge in the motor).
Just something to thing about.

 

[Viperfixr]

Really, really awesome project and flight. Thank you for sharing!

 

[CarVac]

Now one caution on twist and tape, I did that on the flight of my Onyx on an H399, and the electrical tape (covered in 1 layer of duct tape), ripped off from the aerodynamic forces at Mach 1. Thereby causing complete altimeter turnoff (thank God I kept the charge in the motor).
Just something to thing about.

If it's solid-core copper wire, and you twisted a significant length, it is indeed (however loath I am to admit it) unlikely that that would come undone even if the tape was stripped off.

 

[UPscaler]

Twist and tape my friends. No switches needed :wink:

Not exactly effective on MD rockets though.

Braden

 

[Rocketry nut]

I too will vouch for the twist and tape method. I usually give the wires 3-4 twists, wrap a little masking tape around that to hold it and then add a little more masking tape to tape the wires to the side of the rocket. Never failed me. Even with my Wildman Eagle Claw on an L2300.

Btw awesome motor and boost!

 

[Rrwjr]

I too will vouch for the twist and tape method. I usually give the wires 3-4 twists, wrap a little masking tape around that to hold it and then add a little more masking tape to tape the wires to the side of the rocket. Never failed me. Even with my Wildman Eagle Claw on an L2300. Btw awesome motor and boost!

I also use this approach on a number of my rockets. Only difference is I use electrical tape versus masking tape.

 

[patelldp]

In my previous comment I neglected to say congratulations! That's a really nice rocket, sad to hear it was damaged.

Motor looks great as well!

 

[DeeRoc29]

Thanks, Dan! And thanks to all who've replied with comments and suggestions.

 

[TopRamen]

Wow! Nice Launch!:clap:

 

[DeeRoc29]

Thanks!

Here's a ground cam and another pic before flight.

[video]https://s189.photobucket.com/user/derekjamieson/media/001_zps194d45ed.mp4.html[/video]