RMS 24/40 Question

I was surprised to find out during my first attempt at assembling a 24/40 RMS using an E18 that the instructions indicated a piece of masking tape be used over the ignitor slot in the propellant grain. Not having to do this on 29/40-120 RMS I was curious as to why on the 24/40. The only reason I can see is there is a spacer between the motor grain and the delay grain. The tape must be there to prevent the ignitor from sliding into this space and igniting in the void. Am I correct?

Swimmer

You got it. The tape is just there to insure that the igniter ignites in proximity to the top of the fuel grain.

You actually have to use tape on the 29/40-120 hardware if you are using the E or F loads. the instructions on the 24/40 hardware probably doesn't ask you to put tape on the F loads that go the whole length of the case. It is just for proper placement of the ignitor

-Brian Barney

Mark,
I also found out masking tape will not stick to AP. I had to fold it over the edges of the grain and then push it into the liner.

Brian,
Yes, it does say to use tape this same way on a 29/40-120 RMS when using F reloads. I have never flown F reloads but will have the chance soon as I have a few of them now.

Thanks, you guys for the info.

Swimmer

If you have problems with the tape sticking, or do not have any tape handy when loading an RMS on the field, you can assemeble the motor so the spacer is between the nozzle and propellant. This is how the original instructions that came with the first reload kits say to do it. The down side to doing this is the smoke may be a little darker (spacer burns more), and it will be more difficult replacing the igniter if there is a misfire.