Deformed QJet casing

[kuririn]

Anybody have any ideas on how to get a deformed QJet casing out of a plastic fin can?
Short of cutting apart the fin can?
I tried to remove it shortly after recovery while it was still warm but only managed to get it halfway out.

 

[neil_w]

Hmm. One possibility maybe: cut the end off and then try to work it out from the inside, like you'd do with a BP motor?

 

[kuririn]

Hmm. One possibility maybe: cut the end off and then try to work it out from the inside, like you'd do with a BP motor?

But it's plastic, not paper.

 

[neil_w]

But it's plastic, not paper.

Might still have a better shot at loosening it up from the inside with the end removed. Also, with the end removed, it might be easier to crush it a bit to loosen it up.

I'm just spitballing here.

 

[kuririn]

Might still have a better shot at loosening it up from the inside with the end removed. Also, with the end removed, it might be easier to crush it a bit to loosen it up.

I'm just spitballing here.

Thanks for your ideas.
Well, I went ahead and muscled it out with a pair of pliers.
Heard the fin can cracking while I was pulling it out.
Here's why it wouldn't come out:

Huge bump in the casing from the motor burn.
Sheesh.
This is a motor from a bulk pack (B4-4) that was sent as a replacement for an early production bulk pack that had numerous problems.
They fixed the clay nozzle erosion problem but not the engine casing and inconsistent delay problems, it would seem.
If this was in a paper motor tube it would be stuck forever.
Laters.

 

[5x7]

Thanks for your ideas.
Well, I went ahead and muscled it out with a pair of pliers.
Heard the fin can cracking while I was pulling it out.
Here's why it wouldn't come out:
View attachment 602322
Huge bump in the casing from the motor burn.
Sheesh.
This is a motor from a bulk pack (B4-4) that was sent as a replacement for an early production bulk pack that had numerous problems.
They fixed the clay nozzle erosion problem but not the engine casing and inconsistent delay problems, it would seem.
If this was in a paper motor tube it would be stuck forever.
Laters.

I have had that happen too. The casings can get really soft so the opposite is true-the paper motor tube keeps the casing in shape. Gary R. has stated before he felt it was the delay that causes that, so it’s not a pressure bulge. I have been able to bend a q-jet in half after a flight.

 

[BABAR]

Hmmm, fight fire with fire?

Break out the nozzle, put a soldering iron in (May want to do this outdoors with gloves and safety glasses on.)

Heat up the iron and keep tension on motor. I’m thinking as the plastic softens in will become pliable and “fold” back in.

Then again, the heat be more likely to just expand the case and make it worse.

 

[SolarYellow]

Another potential use for my old iron-on covering heat gun...

Also, most of my ideas about cutting lightening holes in MMTs or just using ring segments at the front and back of the motor case to reduce rear weight in the rocket might have just changed.