Engine cap missing after flight

[knitpickle]

The engine cap was missing from our rocket when we retrieved it. Is it possible to fly without it? Will the engine come away from the rocket? Is there some kind of fix we can do?

We're lucky to even have the rocket back - it's first launch was a little too eventful - during our 6-year-old's birthday party he launched it and it was carried by the wind onto a power line. Good Guy Energy Company sent out a bucket truck on a Saturday morning to retrieve it. I'm not sure who was smiling more - the 6 year old or the power company guy. We learned our lesson!

Thanks in advance for any advice.

Robin

 

[fyrwrxz]

Hi Robin- Welcome to TRF! Good to see somebody starting out the youngsters early! We need a little more information, but I suspect you are referring to the ejection charge cap-usually red or yellow that contains the ejection charge to pop the parachute out. It's normal for these to 'leave the scene' as they are not normally considered reuseable. What size/type motor was it?

 

[shreadvector]

They are obviously NOT talking about an Aerotech motor since this was a child's birthday situation. I would guess they are referring to an aft motor retainer found in many Estes beginner kits - especially in launch sets.

You need something to hold the motor inside the rocket so it does not eject when the ejection charge goes off. Some models will be fine if you wrap some masking tape around the outside of the top of the motor so it gets a little fatter and will fit snug into the motor mount tube. This is called "Friction Fitting".

 

[shreadvector]

By the way, Estes plastic motor retainers were bayonet locking style for a long time but they are transitioning to screw on retainers. They are found in the new Atomic Sky kit for beginners and the two stage Extreme 12 for more advanced rocket builders. I've got both.

 

[JeromeK99]

Which kit are we talking about? Perhaps a picture of the back side.

Some of these kits might require a minor fix to launch with a friction fit. Many of the bayonet style motor retainers are also the rear most "centering" anchor for the motor tube. You will need to wedge something between the side of the motor tube and the outer body tube.

Jerome

 

[knitpickle]

Hi Robin- Welcome to TRF! Good to see somebody starting out the youngsters early! We need a little more information, but I suspect you are referring to the ejection charge cap-usually red or yellow that contains the ejection charge to pop the parachute out. It's normal for these to 'leave the scene' as they are not normally considered reuseable. What size/type motor was it?

Nope, this is a simple Estes Taser and the part missing is called the "engine cap" in our instructions. It fits in after the engine is inserted. It's similar to the red piece in this photo:
https://www.wired.com/geekdad/wp-content/uploads/2009/06/img_3236.jpg

 

[knitpickle]

Thanks for the masking tape idea. What will happen if this isn't enough to hold the engine in place? Is it dangerous, or will it simply not fly?

 

[lawndartman]

Oh it will fly. When the motor burns 'Thrust' pushes the rocket forward. The tape holds the motor for ejection. Without the tape, the motor will fly out the back and does not push out the nosecone and chute. So, at launch the motor pushes forward, at ejection it pushes backwards. The cap keeps the motor in the rocket for ejection, tape will do the same. Keep flying, keep having fun! Tim

 

[Zeus-cat]

The cap should be twisted after you insert it. That way the locking tab(s) interlock with the base of the rocket. It seems you didn't get the tabs locked or possibly the broke off when the ejection charge went off. As JeromeK99 said you may need to do a little field engineering to stabilize the back end of the motor mount and then use tape to friction fit the motor in place for flight. I have a feeling that this is probably a stop gap fix at best as these rockets are really intro rockets. If you want to keep flying rockets you may want to check out some kits that you actually build as they will be more robust. Fliskits and some of our other vendors make some great kits for newcomers.

 

[fyrwrxz]

They are obviously NOT talking about an Aerotech motor since this was a child's birthday situation. I would guess they are referring to an aft motor retainer found in many Estes beginner kits - especially in launch sets.

You need something to hold the motor inside the rocket so it does not eject when the ejection charge goes off. Some models will be fine if you wrap some masking tape around the outside of the top of the motor so it gets a little fatter and will fit snug into the motor mount tube. This is called "Friction Fitting".

Fred- good call-obvious after your post. Apologies about the assumption-been a while since I've flown Estes.

 

[JeromeK99]

From the looks of the picture, this particular rocket does not have a typical motor tube. The plastic fin can holds the motor in place. You will need to add a motor tube. File down some of the plastic and glue in a paper motor tube. At this point you could even add a traditional motor mound with an "engine clip". It is a fairly easy fix.

Jerome

 

[shreadvector]

Nope, this is a simple Estes Taser and the part missing is called the "engine cap" in our instructions. It fits in after the engine is inserted. It's similar to the red piece in this photo:
https://www.wired.com/geekdad/wp-content/uploads/2009/06/img_3236.jpg

The Taser is smaller in diameter than the Patriot rocket in that photo and it has a different aft motor retainer. It is still quarter turn locking but different.

Try wrapping a motor with masking tape and see if you can get a snug fit.

This is one reason new kits will have screw on retainers. It is easier for people to get a retainer fully on screwing it in rather than an unfamiliar quarter turn.

 

[new2hpr]

The far easier solution is contact Estes about your loss.
Depending on who you reach, they might just send you a new kit, as parts are only in China and not generally available separately to them.
Pretty small expense for them to keep you a happy customer.
-Ken