Broke my highest and fastest flight!

**bandman444** · 15th January 2012, 10:13 PM

Yesterday I flew my Das BlitzzKreig on a J570W.

It simmed to Mach 1.1 to 6000ft but that was one hell of a motor (I haven't seen one go that fast in a long time) And the real altitude ended up being 8127ft!!!

Which blows my 6000ish flight out of the water

It used a Perfectflite MAWD for deployment, but I can't get a good velocity out of it. I definitely know it went through Mach because the data during boost gets crazy, but everything else is good.

This was my second attempt at dual depolyment and was not entirely successful although the data shows it. Drouge charge seperated the booster completely.

Attached is the txt file, then the full screen shot, then the boost screenshot.

If you have any suggestions on how to get some velocity out of this data that would be great.

Uploaded a poor picture of the booster section after it came in hot after shredding the kelvar shock cord.

**T-Rex** · 15th January 2012, 11:30 PM

http://www.ajdesigner.com/constantac...avelocitya.php

This formula assumes constant acceleration, which you don't have because it's not a straight line, however, should get you in the ballpark.
Too may paint fumes in my head to work the math for you at the moment, sorry.

**trippkid** · 15th January 2012, 11:38 PM

Could be totally wrong, but I'm am not seeing anything more than 1000fps, which I figured out to be roughly 681.81 mph. I could be completely off base though, no advanced math here.
Sorry about your rocket, I have one too that I have been waiting to put together. What happened with the Kevlar. Was that the stock cord that came with the kit? How much BP did you use for the charges?
Matt

**T-Rex** · 15th January 2012, 11:50 PM

crap, told I had paint fumes on the brain... that web page is for acceleration, not velocity.

Just pick a couple points, in the steepest part of the curve, change in altitude over change in time will give you velocity in that portion of the flight.

for example, 8128ft/21sec =387.04 ft/sec is the average velocity from launch to apogee.

**bandman444** · 16th January 2012, 12:03 AM

@Trippkid No I didn't get kevlar in the kit. I just flew it drougeless with about 5ft of kevlar. I used a .4g Drouge charge and a 1.0g Main.

The kit performed perfect, all I need to make it better was about half the charge a 5x the drouge harness.

I was flying it on a 38/1080 case which puts the forward closure less than .5" away from the eyebolt.

That is all I will change, and once I get a new bosster tube I can't wait to see it on a J825R!!!

The problem with the data is that the first 2 seconds are completely inaccurate and cannot be used for simple analysis.

I have a program that will find the greatest difference in altiude and find "max velocity", but it said that at .75sec I was going over 2500fps. Mach 2+...no way

**dixontj93060** · 16th January 2012, 01:10 AM

Sad result on the booster. Are you sure it's repairable? That PVC tends to be pretty brittle.

**Eric1** · 16th January 2012, 01:23 AM

That must have screamed off the pad!!!!

**mikecamerota** · 16th January 2012, 03:49 AM

It was so F N fast definetly badd azz i flew a h 160 687mph and it looked like a snail

**Zeus-cat** · 16th January 2012, 05:12 AM

Trying to obtain velocity data from a MAWD (or other baro altimeter) has been discussed before. Unfortunatley, there is no good way to do it. The altitude data you have is rather poor on a point by point basis to allow reliable mathematical analysis; especially when the rocket is moving fast. The good news is that baro altimeters do provide fairly reliable apogee data as the rocket is moving fairly slowly at apogee and the sensor can accurately measure the altitude.

**bandman444** · 16th January 2012, 07:23 AM

Hey Eric, think you could get me another booster tube? I want another shot!

I used two drops of CA to keep those fins on. I could easily take them out and put them on a new booster tube.

8,127...I'm still amazed.

Velocity analysis from barometric data is not bad, it is just that when you are transonic you can not take good data which renders them useless.

Honestly that thing was so fast, words don't describe. If I could get another tube then I may try the only faster motor J825R!!! (then maybe I1299?) what is the speed of PVC...?

**edwinshap1** · 16th January 2012, 09:01 AM

it was crazy, i thought it'd ramp up, but the moment i saw smoke that thing was pushing it hard, nice and straight until it got near mach im guessing, because then it started to get some SERIOUS wiggle, big big wiggle just before burnout, so beautiful

**Eric1** · 16th January 2012, 09:08 AM

Originally Posted by bandman444

Hey Eric, think you could get me another booster tube? I want another shot!

I used two drops of CA to keep those fins on. I could easily take them out and put them on a new booster tube.

8,127...I'm still amazed.

Velocity analysis from barometric data is not bad, it is just that when you are transonic you can not take good data which renders them useless.

Honestly that thing was so fast, words don't describe. If I could get another tube then I may try the only faster motor J825R!!! (then maybe I1299?) what is the speed of PVC...?

OH HECK YES!

As for speed let's find out!

**Eric1** · 17th January 2012, 01:08 AM

Yo Bandman,

A new Booster tube is only $10.00 plus shipping.
One suggestion, Foam that Nosecone!

Here is my last Boost.

**bandman444** · 17th January 2012, 01:13 AM

I never though to foam the nose cone. I will have my tracker in there, but why do you say that.

Who won the how high can you fly a Das BlitzzKrieg contest?

What motor is that?

**Eric1** · 17th January 2012, 01:34 AM

The Nose is 0.08" thick I would like to remove all doubt on the compression factor.
You could still leave space for the tracker, Just foam upper 2/3rds.
I'm probably just tripping!

I have not heard about the contest winner??

**Adrian A** · 17th January 2012, 01:45 AM

Originally Posted by Eric1

OH HECK YES!

As for speed let's find out!

The J570 actually kicks it harder off the pad than the J825 does, because the J570's thrust starts out really high and then ramps down throughout the burn.

**Eric1** · 17th January 2012, 01:48 AM

Originally Posted by Adrian A

The J570 actually kicks it harder off the pad than the J825 does, because the J570's thrust starts out really high and then ramps down throughout the burn.

I am so gonna replicate this flight!

**mikec** · 17th January 2012, 02:04 AM

Originally Posted by bandman444

I definitely know it went through Mach because the data during boost gets crazy, but everything else is good.

I agree that it should have broken mach, but the boost data is really messed up; baro data from mach flights I've seen is fairly clean except around the transitions. I tried doing a running average on the first difference of your data, but it still didn't look right.

How did you have the altimeter vented?

**gagreen** · 23rd January 2012, 10:18 AM

Originally Posted by bandman444

I never though to foam the nose cone. I will have my tracker in there, but why do you say that.

Who won the how high can you fly a Das BlitzzKrieg contest?

What motor is that?

sorry to get back about this late. had no entries at all. kinda disappointed in the contests...

Sorry about the delay

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Broke my highest and fastest flight!

WOW!!!

i blinked

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