Estes Wadding Not Ejecting

The Rocketry Forum

Help Support The Rocketry Forum:

brockrwood

Well-Known Member
TRF Supporter
Joined
Jun 10, 2015
Messages
520
Reaction score
308
Location
Denver, Colorado, USA
Hi, folks. At my latest launch of LPR rockets at a local park I noticed that that the Estes wadding did not come out of the body tubes on these two rockets:
Cosmic Cobra: BT-56 tube (about 1.3 in in diameter)
Scratch Built: 29mm tube

i used 5 1/2 squares of wadding in the 29 mm and about 5 squares in the Cosmic Cobra BT-56.

Both nose cones came off at ejection. Both parachutes came out.
But the wadding, scorched on one side, stayed in the tube.
Is it supposed to eject?
Is it ok if it doesn’t?
Is there a special way I should insert it? (I just shove it in.)
Should I try a different wadding? Dog barf? Squares of flame resistant crepe paper?
Is there a rule of thumb for how many squares of wadding to use? Am I using too much?
 

bjphoenix

Well-Known Member
Joined
May 4, 2011
Messages
799
Reaction score
66
How much to use is hard to judge. It is there to protect the recovery materials so if they weren't damaged then you used enough. Too much would be if it is packed in there so tightly that it couldn't come out. If the nose cone and recovery equipment came out then I wouldn't worry about it beyond that. 5.5 squares in those diameters seems good enough to me. You didn't say how long the tubes were- with large volume of tube there isn't enough ejection charge volume in an Estes motor to blow everything out. I've seen a few recent failures because of this.
 

Spitfire222

Well-Known Member
TRF Supporter
Joined
Apr 7, 2020
Messages
305
Reaction score
354
I also often don't get some or all of the wadding, whether Estes or homemade, out upon ejection. I figure as long as the ejection charge provides sufficient pressure and the recovery equipment comes out successfully, it doesn't matter much of the wadding is blown out or not.
 

BEC

Well-Known Member
Joined
Feb 19, 2009
Messages
3,905
Reaction score
863
Location
Auburn, WA
Motor(s)? Ejection charges vary.

As long as the recovery system is deployed as it should be (and is undamaged) its OK. I'd probably replace the really cooked stuff before the next flight. The rest is certainly reusable.

The amounts seem about right for the size tubes to me.
 

brockrwood

Well-Known Member
TRF Supporter
Joined
Jun 10, 2015
Messages
520
Reaction score
308
Location
Denver, Colorado, USA
How much to use is hard to judge. It is there to protect the recovery materials so if they weren't damaged then you used enough. Too much would be if it is packed in there so tightly that it couldn't come out. If the nose cone and recovery equipment came out then I wouldn't worry about it beyond that. 5.5 squares in those diameters seems good enough to me. You didn't say how long the tubes were- with large volume of tube there isn't enough ejection charge volume in an Estes motor to blow everything out. I've seen a few recent failures because of this.
The 29mm was 13 inches long. The BT-56 on the Cosmic Cobra’s BT-56 tube is 10” long not counting engine mount or 12 1/2 inches long counting motor mount.
 

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
9,195
Reaction score
3,877
Hi, folks. At my latest launch of LPR rockets at a local park I noticed that that the Estes wadding did not come out of the body tubes on these two rockets:
Cosmic Cobra: BT-56 tube (about 1.3 in in diameter)
first, congratulations on getting a successful flight on the Cosmic Cobra. It belongs in the pile of “exceptions” that prove the rule that Estes makes great rockets.

the Cobra body tube is simply too short to hold the blades, the chute, and the wadding. The Cobra is 19.5 inches long, the Helicat is almost the same rocket except they made it longer, 30 inches, and it is comparatively a dream to pack. Anyway, the Cobra is in that select group of “What the heck were they thinking when they designed and sold this” rockets from Estes. It in there with a bunch of rockets with 18mm motor mounts that should have been 24. But I digress…..

doing a little research, based on this I think this is a BT-56 body tube

options

best is to buy an 18” BT-56, cut two three inch or so long pieces which can be cut and rolled one inside the other to make a coupler (or just buy a coupler, I never have one when I need one so I just make them from body tubes), and extend the rocket another 10 inches or so with what is left. If after construction and finishing you are still under 113 grams loaded with motor and wadding, you are good on a C6-3, otherwise I’d bump to C5-3.

@rklapp is big on Qualman Baffles, and they make one in BT-56 size


but I am not sure lengthwise it would fit without things still being tight.

another option is to get a top flight thin mil chute, which I THINK would fit between the rotor blades easier than the suppled chute. If you do this, and spray it with flame retardant (hey @rklapp , what kind did you use?), stick it between the blades, you probably can get away with only a couple of sheets of wadding, and you MAY even have room for that Qualman baffle.

whatever you try, TEST it first by loading everything but the motor including wadding just like you were getting ready to launch. take a medium breath, put your lips around the plastic nozzle, and see if you can blow out the nose, chute, and laundry. If you can’t do it easily, something is too tight.

good luck, and make sure you designate a spotter for the cone AND one for the rocket. Too often everyone is watching the cone and forgetting about the rocket!
 

brockrwood

Well-Known Member
TRF Supporter
Joined
Jun 10, 2015
Messages
520
Reaction score
308
Location
Denver, Colorado, USA
first, congratulations on getting a successful flight on the Cosmic Cobra. It belongs in the pile of “exceptions” that prove the rule that Estes makes great rockets.

the Cobra body tube is simply too short to hold the blades, the chute, and the wadding. The Cobra is 19.5 inches long, the Helicat is almost the same rocket except they made it longer, 30 inches, and it is comparatively a dream to pack. Anyway, the Cobra is in that select group of “What the heck were they thinking when they designed and sold this” rockets from Estes. It in there with a bunch of rockets with 18mm motor mounts that should have been 24. But I digress…..

doing a little research, based on this I think this is a BT-56 body tube

options

best is to buy an 18” BT-56, cut two three inch or so long pieces which can be cut and rolled one inside the other to make a coupler (or just buy a coupler, I never have one when I need one so I just make them from body tubes), and extend the rocket another 10 inches or so with what is left. If after construction and finishing you are still under 113 grams loaded with motor and wadding, you are good on a C6-3, otherwise I’d bump to C5-3.

@rklapp is big on Qualman Baffles, and they make one in BT-56 size


but I am not sure lengthwise it would fit without things still being tight.

another option is to get a top flight thin mil chute, which I THINK would fit between the rotor blades easier than the suppled chute. If you do this, and spray it with flame retardant (hey @rklapp , what kind did you use?), stick it between the blades, you probably can get away with only a couple of sheets of wadding, and you MAY even have room for that Qualman baffle.

whatever you try, TEST it first by loading everything but the motor including wadding just like you were getting ready to launch. take a medium breath, put your lips around the plastic nozzle, and see if you can blow out the nose, chute, and laundry. If you can’t do it easily, something is too tight.

good luck, and make sure you designate a spotter for the cone AND one for the rocket. Too often everyone is watching the cone and forgetting about the rocket!
Thanks for all of these great tips and suggestions!
 

brockrwood

Well-Known Member
TRF Supporter
Joined
Jun 10, 2015
Messages
520
Reaction score
308
Location
Denver, Colorado, USA
the Cobra body tube is simply too short to hold the blades, the chute, and the wadding.
Hey. This idea literally just popped into my head. What if I just snip an inch or so off of the ends of each rotor blade? It would still autorotate, no?
 

brockrwood

Well-Known Member
TRF Supporter
Joined
Jun 10, 2015
Messages
520
Reaction score
308
Location
Denver, Colorado, USA
whatever you try, TEST it first by loading everything but the motor including wadding just like you were getting ready to launch. take a medium breath, put your lips around the plastic nozzle, and see if you can blow out the nose, chute, and laundry. If you can’t do it easily, something is too tight.
I had a humiliating problem trying to do the “use a puff of breath” test recently. I tried to do it on the scratch built 29 mm rocket. Nope. The rocket has swept back fins. My now fat face and big head doesn’t fit between the fins. Doh! Embarrassing. The next time I build a rocket with swept back fins I will have to put in the motor mount and do this test before I put on the fins.
 

rklapp

NAR# 109557
TRF Supporter
Joined
May 8, 2020
Messages
2,255
Reaction score
1,691
Location
Oahu, Hawaii
first, congratulations on getting a successful flight on the Cosmic Cobra. It belongs in the pile of “exceptions” that prove the rule that Estes makes great rockets.

the Cobra body tube is simply too short to hold the blades, the chute, and the wadding. The Cobra is 19.5 inches long, the Helicat is almost the same rocket except they made it longer, 30 inches, and it is comparatively a dream to pack. Anyway, the Cobra is in that select group of “What the heck were they thinking when they designed and sold this” rockets from Estes. It in there with a bunch of rockets with 18mm motor mounts that should have been 24. But I digress…..

doing a little research, based on this I think this is a BT-56 body tube

options

best is to buy an 18” BT-56, cut two three inch or so long pieces which can be cut and rolled one inside the other to make a coupler (or just buy a coupler, I never have one when I need one so I just make them from body tubes), and extend the rocket another 10 inches or so with what is left. If after construction and finishing you are still under 113 grams loaded with motor and wadding, you are good on a C6-3, otherwise I’d bump to C5-3.

@rklapp is big on Qualman Baffles, and they make one in BT-56 size


but I am not sure lengthwise it would fit without things still being tight.

another option is to get a top flight thin mil chute, which I THINK would fit between the rotor blades easier than the suppled chute. If you do this, and spray it with flame retardant (hey @rklapp , what kind did you use?), stick it between the blades, you probably can get away with only a couple of sheets of wadding, and you MAY even have room for that Qualman baffle.

whatever you try, TEST it first by loading everything but the motor including wadding just like you were getting ready to launch. take a medium breath, put your lips around the plastic nozzle, and see if you can blow out the nose, chute, and laundry. If you can’t do it easily, something is too tight.

good luck, and make sure you designate a spotter for the cone AND one for the rocket. Too often everyone is watching the cone and forgetting about the rocket!
My guess is that the blades pushed back the pressure wave. The wadding occasionally will get stuck but don’t think it’s a problem as long as the laundry deploys. I probably wouldn’t use the baffle with the blades. I’m always overthinking how far down to push the Qualman baffle. Too far will blow the pressure out the nozzle like @BABAR said. Not enough means limited space for recovery. It’s more of an art than science. 😀
 
Top