E-Match position in a Cesaroni

[pologoalie8908]

So my first advanced rocket build is almost complete. I guess i have a beginner question when it comes to advanced motors and rockets. I will be using a Cesaroni - P38 - 1G (G78) and it come with an "e-match". My only previous experiences were with ESTES motors and the wirey little clip igniters.

For this e-match, does it need to be fed to the tops of the motor or just to the bottom?

 

[DeepOvertone]

as far into the motor as you can get it. All way to the back of the motor up against the igniter pellet.

 

[crossfire]

Yes all the way to Top of motor

 

[pologoalie8908]

ok i guess its just a flip of what I am use to. And the ejection charge at the top will be fine? Sorry for thew beginner questions.

 

[heada]

Even in the Estes motors, you were putting the starter at the forward end of the burning surface. In AT, CTI and Loki, that's all the way up. On Estes, it's all the way up also but the 'up' is only just past the nozzle opening.

 

[Titan II]

From the directions.....

Insert the igniter head into the nozzle and push until it stops against the top of the motor core. With the igniter in this position, bend a loop into the igniter leads one cap length from the nozzle exit (Figure 4).

 

[jimzcatz]

RTFD!!!

 

[BrendanH69]

Please also be aware of the possibility that your Pro38 1G or 2G motor, depending on it's manufacturing or purchase date may require a modification to the ignition pellet before your use it. Your local dealer or a local club member may be able to guide you through this. I've copied the links to both the CTI bulletin and the pellet mod below, if required.

CTI Bulletin_Pro38_1G_Pellet_Issue_v1.2.pdf

CTI Pro38_Pellet_Modfications_v1.2.pdf

 

[Orien]

From the directions.....

Insert the igniter head into the nozzle and push until it stops against the top of the motor core. With the igniter in this position, bend a loop into the igniter leads one cap length from the nozzle exit (Figure 4).

What are these mysterious texts you speak of?

 

[Zeus-cat]

I offer the following tip to people who are new to igniters for composites. Once the motor is assembled and before it is inserted into the rocket, lay the igniter next to the assembled case. The tip of the igniter should be positioned so that it lines up with the top of the motor grains. Bend the igniter where it lines up with the bottom of the nozzle. This is a simple way to check that the igniter is installed all the way when you insert it into the motor.

 

[JoePfeiffer]

Note that you may encounter someone at your launch who is used to Aerotech or big CTI and will tell you to put the igniter a short distance from the top. For your motor they are wrong because of the pyrogen pill in the motor itself, and will keep your motor from igniting (yes I've seen this, and on a cert flight).

 

[dhbarr]

I offer the following tip to people who are new to igniters for composites. Once the motor is assembled and before it is inserted into the rocket, lay the igniter next to the assembled case. The tip of the igniter should be positioned so that it lines up with the top of the motor grains. Bend the igniter where it lines up with the bottom of the nozzle. This is a simple way to check that the igniter is installed all the way when you insert it into the motor.

I make a little sharpie mark.

 

[Stefan2k4]

And the ejection charge at the top will be fine?

Most composite motors are core burning motors and need to be lit at the top of the grain to ensure the full length of the core ignites early and builds up pressure properly. At the top of the core should be the delay grain and in these motors the delay grain is designed to light when the motor lights and therefore doesn't just burn the length of the delay but also the length of the motor burn time as well. So, for example if the motor has a 4 second delay, and the motor had 2 second burn, the delay will actually be designed to burn for ~ 6 seconds. You don't have to worry about this as it has already been accounted for because it's just how these motors work.