Rocket Separate - Internal Pressure?

[new2hprockets]

I recently launched a MadCow Super DX3 for an L1 Certification and it separated right at launch. See Pictures. Originally i thought this was around a Center of Gravity being off but curious if specific to Internal Pressure as well. I do not have a vent hole in the parachute bay, do I need one?
1) Guidance on CG or Internal pressure area

Any additional needed please let me know.

 

[new2hprockets]

View attachment 593000

 

[waltr]

That is odd.

What motor?
Weight of booster and upper sections?
How tight was the coupler?

This is way too low to be chute bay air pressure verses outside air pressure. Typically need a few hundred feet altitude change for pressure difference to cause this.

I did not see any flame or smoke between the sections but images are small.
Could be the motor ejection charge went off. I've had this happen when I messed up putting a reload motor together.

If the coupler is a bit loose and the motor has a high initial peak thrust that backs off then could be simply momentum of upper section (similar to drag separation).

CG variation would not do this.

Did the rocket survive?

 

[Kelly]

Has to be ejection charge, or some leak-through of pressure through the forward seal. Way too early for altitude difference or drag separation.
Thinking some more...
Was the motor inserted all the way to the thrust ring? And did it stay there? (Wondering if it might have moved forward at ignition, causing a piston effect)
Did the rocket seem to hang up on the rail at all? (Wondering if something LIKE drag separation occurred, where the rail buttons hung up momentarily but the rest of the rocket kept going)

 

[ONAWHIM]

Was this flight designed as motor staging or with altimeter and charge(s)?

 

[Rob Campbell]

Looks like motor gas leakage pressurizing the parachute compartment. If the ejection charge had gone off, there would have been smoke coming from the rocket at the separation point.

 

[new2hprockets]

That is odd.

What motor?
Weight of booster and upper sections?
How tight was the coupler?

This is way too low to be chute bay air pressure verses outside air pressure. Typically need a few hundred feet altitude change for pressure difference to cause this.

I did not see any flame or smoke between the sections but images are small.
Could be the motor ejection charge went off. I've had this happen when I messed up putting a reload motor together.

If the coupler is a bit loose and the motor has a high initial peak thrust that backs off then could be simply momentum of upper section (similar to drag separation).

CG variation would not do this.

Did the rocket survive?

Rocket survived. Minor Damage.

 

[Glasspack]

That's cool you only have minor damage on it........ I imagine it flew full power with the upper airframe
& recovery gear being dragged.... Until it tumbled all over itself.

 

[Rex R]

I wonder what the motor looked like after the flight. To me the photos show a non healthy motor.

 

[Dave S.]

Was this a motor where you used one of those drill type tools to adjust the delay?

I have thought that if the drill tool was applied too forcefully you can crack the delay grain.

That would allow the initial pressure from the motor to shoot up thru the rocket to pop the nose cone off.

If that is what happened, the nose cone would pop off very early in the flight. Maybe even when it was still on the rail.

 

[Art Upton]

I am no expert, but if the motor leaked pressure then there would be smoke and even some fire at the top of the base tube. This is not a staged rocket for the other posters that I can see.

I think it hung up on the rail about half way up and caused the payload separation, but that is only a guess.

 

[watheyak]

I feel like I can see smoke coming out the top just to the left of the tube in the past pic. Faintly...

 

[Chad]

If that was an RMS motor did you put the tracking/delay grain and ejection charge in? The motor leaking out of the top is the only thing i can think of but i would expect to see smoke coming out if that were the case.