38/720 casing question

[Jordi Grau]

Hi all,

I'm currently working in a final degree project and I'm designing a nozzle for our university rocket. As it is close of power to the I600R engine I would like to use its casing for my nozzle. My idea is to make the nozzle metalic and screw it in the casing. The problem is the follwing, I do not now the dimentions of the screw and I cannot buy a casing to measure them yet.

Could someone give me a hand?

Thank you in advance

 

[heada]

I'm assuming you're talking about Aerotech motor case. You can start here:
https://www.aerotech-rocketry.com/resources.aspx

It has been a long time but there used to be full dimensional drawings including the cases.

 

[Jordi Grau]

I'm assuming you're talking about Aerotech motor case. You can start here:
https://www.aerotech-rocketry.com/resources.aspx

It has been a long time but there used to be full dimensional drawings including the cases.

Thank you! I've been looking there but they do not give insight in the thread of the case, I contacted aerotech, lets see if they can give the info to me.

 

[TimothyG]

Your best bet is to find someone locally that has a casing and endcap that you can directly take measurements off of. I'd be very careful producing something you get one shot at from measurements and dimensions you got indirectly through the web. It's amazing how many times a simple mis-measurement stops a project.

 

[Jozef]

why don't you just replicate in metal the nozzle in the motor kit? The stack up tolerances with the o-ring and seal disc are critical

 

[mikec]

My idea is to make the nozzle metalic and screw it in the casing.

If you make it out of steel, that violates safety codes. Aluminum would melt, I think. Using a graphite nozzle and the existing aft closure would be simplest and safest, I think.