Help

[aaronvanhorn]

I am building a mad cow DX3 and I am new to the rocketry hobby. I was looking through the build and noticed that I didn’t have any engine retainment in the forward engine compartment, do I need something to keep the engine from moving up into the rocket when shooting it off?

 

[David Schwantz]

Unless you are building BP ( estes ) the engine will come with a thrust ring already installed. What size DX3 are you building? So there is no need for an engine " hook ".

 

[Zeus-cat]

You need motor retention on the rear to keep the motor from ejecting out the back. Aeropack retainers work great.

 

[aaronvanhorn]

Unless you are building BP ( estes ) the engine will come with a thrust ring already installed. What size DX3 are you building? So there is no need for an engine " hook ".

It’s a paper Super DX3

 

[neil_w]

That's a 4" rocket with a 38mm mount... I'm confused how that could be someone's first rocket.

 

[watheyak]

If you don't want to do model rockets, that's a great first rocket.

 

[aaronvanhorn]

That's a 4" rocket with a 38mm mount... I'm confused how that could be someone's first rocket.

I have done a lot of smaller rockets, but I am going to use this to get my level 1 and 2 certifications

 

[neil_w]

Ah ok, sorry for my misunderstanding. Welcome to the forum!

 

[aaronvanhorn]

Ah ok, sorry for my misunderstanding. Welcome to the forum!

That's a 4" rocket with a 38mm mount... I'm confused how that could be someone's first rocket.

I

Ah ok, sorry for my misunderstanding. Welcome to the forum!

No problem at all! Thank you for the help. Glad I found the forum!

 

[bmonagle]

I have done a lot of smaller rockets, but I am going to use this to get my level 1 and 2 certifications

FYI, I used the Super DX3 for my Level 1 and Level 2 certs. Great rocket for that, big enough to not go too high for the cert flights.

Blair

 

[tOD]

I used a Super DX3 for my L2. Mine has a 54mm motor mount. I also have the Aeropack 54/38 adaptor, which I used for the L2 flight. Here's a photo I took of the motor mount. That's an Aeropack 54mm motor retainer attached with JB Weld.

 

[tomsteve]

do I need something to keep the engine from moving up into the rocket when shooting it off?

no. the single use AP motors have a thrust ring built into them. the reload cases have a thrust ring in them. its wise to keep the top of the motor mount free so longer motors can be used.
you will want to look into a motor retainer,though. that way the motor wont pop out the back when the ejection charge goes off.

 

[SeanW78]

This is exactly what I used for my first high power build. You're going to love it.

 

[Funkworks]

I am building a mad cow DX3 and I am new to the rocketry hobby. I was looking through the build and noticed that I didn’t have any engine retainment in the forward engine compartment, do I need something to keep the engine from moving up into the rocket when shooting it off?

Look at how the F and G motors all have a wider (larger diameter) portion near the top. Well the top is actually the bottom, and that larger portion is what carries the weight of the rocket.