removing cesaroni ejection

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watermelonman

watermelonman

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I have my Cesaroni 54mm hardware on the way! Wow, excitingly big.

At this motor size I plan on using electronic recovery exclusively. I do not need the DAT or any other tool to remove my ejection charge entirely, correct? Pop the paper off the top, remove black powder, and tape back down?
 
watermelonman said:
I have my Cesaroni 54mm hardware on the way! Wow, excitingly big.

At this motor size I plan on using electronic recovery exclusively. I do not need the DAT or any other tool to remove my ejection charge entirely, correct? Pop the paper off the top, remove black powder, and tape back down?
Click to expand...


yes to all. Or just leave it there as a motor deploy back up. I don't usually remove the charge.
 
Assuming the delay of the motor is not exhausted by the time the rocket hits apogee, I would leave the charge in place.
 
Some members here also recommending that after you remove the powder charge that the cavity be stuffed with dog barf before taping up. You could probably also plug the flash hole and fill the ejection charge well with 5min epoxy.
 
I pop the paper off, scrape the powder out then use a half a sheet of estes wadding and some aluminum tape over the top. Never has done me wrong. But like the others have said if the delay is long enough, just leave the full delay and the charge as a back up. Of course if you have some design that has the motor closed off form the drogue bay this wont work.
 
Thanks all!

Yes, maxvelocity, sealed off booster sections are exactly my concern.
 
Why exactly do people seal off the ejection touchhole with something? Can someone give me a reason for it or the consequences of not closing in the hole?
If there is going to be any issue with I assume flame coming through why would having an ejection charge there stop anything, it is only there until the delay burns through and touches off the charge. Except for that partial second before the charge goes off that is the only difference between having a open ejection well and a charge on board.

I suspect that like a lot of things in this hobby because someone else did it that way it and then another flier and then another flier; it becomes the thing to do but no one really knows why.

I guess I have been very lucky as I have just been pouring the black powder out and flying with an open ejection charge touch hole now for 7 years

Greg
 
I think that CTI even recommends filling tapped plugged forward closures with a screw or something, if one is not using the tapped hole for something functional. I personally don't care for motor ejection as a backup. You have to protect shock cords and chute from regular ejection and motor ejection.
 
No mention of plugging hole, just this

"NOTE: If using an electronic recovery system, pry the white plastic disc from the end of the delay/ejection module and transfer the powder to your remote
ejection charge holder and follow the recovery system instructions. Reinstall the module into the reload assembly. We recommend that you leave the delay
unadjusted for these applications to minimize delay residue ahead of the motor forward closure."

The tapped hole module is not what the original poster was referring to since he referenced not using the included ejection charge. Tapped front delay module doesn't come with black powder.

Greg

Greg
 
rms said:
No mention of plugging hole, just this

"NOTE: If using an electronic recovery system, pry the white plastic disc from the end of the delay/ejection module and transfer the powder to your remote
ejection charge holder and follow the recovery system instructions. Reinstall the module into the reload assembly. We recommend that you leave the delay
unadjusted for these applications to minimize delay residue ahead of the motor forward closure."

The tapped hole module is not what the original poster was referring to since he referenced not using the included ejection charge. Tapped front delay module doesn't come with black powder.

Greg

Greg
Click to expand...

I read it in a thread somewhere. I was surprised because I have not plugged tapped closures that I did not use and so far have not had issues. I will try to find the thread.
 
rms said:
Why exactly do people seal off the ejection touchhole with something? Can someone give me a reason for it or the consequences of not closing in the hole?


I suspect that like a lot of things in this hobby because someone else did it that way it and then another flier and then another flier; it becomes the thing to do but no one really knows why.

Greg
Click to expand...

Bingo!!!!!! This is exactly what has happened. I see it with threaded rod on L3 stuff too.
 
If you plan to fire your separation charge via altimeter earlier than the longest delay on the motor I guess you could leave the ejection charge well empty and not fill it but you'll still have heat and flame from the motor inside your body tube unnecessarily.

Secondly, Your rocket design might also seal off the motor tube with a bulk head - so you don't want heat, flame and pressure in that section.

Thirdly, your flight might go way over the max delay before hitting apogee so you don't really want the residual burn from the motor cooking the inside of your rocket before you get to apogee if you've removed the charge and not sealed the well.

Fourthly, the delay grain is not perfect so even if you think there is time to apogee, it can go off early.

All in all, the insurance to remove a potential failure mode for a small amount of effort is worth it for many.
 
Zebedee said:
If you plan to fire your separation charge via altimeter earlier than the longest delay on the motor I guess you could leave the ejection charge well empty and not fill it but you'll still have heat and flame from the motor inside your body tube unnecessarily.

Secondly, Your rocket design might also seal off the motor tube with a bulk head - so you don't want heat, flame and pressure in that section.

Thirdly, your flight might go way over the max delay before hitting apogee so you don't really want the residual burn from the motor cooking the inside of your rocket before you get to apogee if you've removed the charge and not sealed the well.

Fourthly, the delay grain is not perfect so even if you think there is time to apogee, it can go off early.

All in all, the insurance to remove a potential failure mode for a small amount of effort is worth it for many.
Click to expand...

The heat and flame is caused from the powder that has been removed, so no worries there.

Second, without powder, there is no pressure.

Third, still the powder does the cooking.

Fourth, remove the powder, it makes no difference how long or short the delay is.

Guys, the ejection delay does not burn under pressure(like the reload amount) in a motor after motor burnout. The nozzle throat is way larger than the hole for the ejection charge so any slight pressure build up goes out the bigger hole. The ejection charges work by having black powder touching the delay element when it burns though the top.
 
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