RMS 24/40 igniter ?

[compass1]

First things first .
This is my first post to The Rocketry Forum. It has been a great source of info for me.
I'm finally making my move to mid power.
My ? is about the procedure for the insertion of the igniter int a rms 24/40 f24-7w reload. The instructions say to insert the igniter all the way into the load until it bottoms at the delay element. Is this correct ? Seems to me that the delay would ignite at the same time the propellant does.
Please explain.

 

[BobH48]

That is correct.

The delay does ignite at the same time as the propellant. The propellant burn time is factored into the delay.

 

[Gillard]

That is correct.

The delay does ignite at the same time as the propellant. The propellant burn time is factored into the delay.

Bob's correct, also if this is a first with the reloads then you might want to rough up the C slot where the igintor head sits, helps the reload light.

 

[sam_midkiff]

First things first .
This is my first post to The Rocketry Forum. It has been a great source of info for me.
I'm finally making my move to mid power.
My ? is about the procedure for the insertion of the igniter int a rms 24/40 f24-7w reload. The instructions say to insert the igniter all the way into the load until it bottoms at the delay element. Is this correct ? Seems to me that the delay would ignite at the same time the propellant does.
Please explain.

I've also found it nearly impossible to insert a copperhead into the slot, and tend to put it in while building the motor. I don't see this as significantly more dangerous that putting Estes ignites into blackpowder motors before checking in, and would never do this with a larger motor. Feel free to correct me if this sounds stupid.

Sam

 

[SCE to AUX]

Building the igniter in when assembling the motor is actually the procedure recommended in the instruction sheet for some of the smaller motors, IIRC. I never felt very comfortable with that. Accidental ignition has nothing to do with it, though. A copperhead is no more likely than an Estes igniter to fire unintentionally.

If the igniter won't slip up through the nozzle of the motor after assembly, I worry about it not blowing out through the nozzle properly after ignition, and causing the case to over-pressurize. The fine threads on the 18 and 24mm cases don't look like they have a lot of margin before they let go (as designed).

For the motors with really small nozzle throats, I generally select an igniter with very little pyrogen, and a correspondingly small diameter. Sanding the grain slot and painting a bit of pyrogen into the top of the grain helps ensure ignition, even with a deliberately selected "wimpy" igniter. Quest Q2G2s work reliably when used like this, and slip easily into the smallest motors even after assembly.

 

[Luv2launch]

I find that when you have an igniter that doesn't fit into a reload it is mainly due to the pyrogen head being a bit on the big side I will put it in while building the motor and have had no problems.Once it has ignited and the motor is coming up to pressure if it is a copperhead most of the copper leads will be vaporized so they don't have a chance to block the slot and have it over pressurize if it was a firstfire jr I might worry a bit but again once the pyrogen has burned there isn't much left that can get in the way of the leads to cuase a problem.

 

[Pippen]

I just want to say welcome to TRF!

 

[Marlin523]

Thanks for posting. Good question! I don't have anything to add but I look forward to reading and responding to your future posts.