Igniters in CTI Motors

[cerving]

Since CTI is having problems with the BP pellets in some of their smaller motors, is it a legal modification to be able to simply pop out the pellet from the top grain and use a more conventional igniter (i.e. pyrogen dipped ematch)? I know that CTI recommends cutting the pellet in half, so I would think that this is a natural extension of that...

 

[Steve Shannon]

Since CTI is having problems with the BP pellets in some of their smaller motors, is it a legal modification to be able to simply pop out the pellet from the top grain and use a more conventional igniter (i.e. pyrogen dipped ematch)? I know that CTI recommends cutting the pellet in half, so I would think that this is a natural extension of that...

I have no problem with it at a Tripoli launch.

 

[ECayemberg]

Since CTI is having problems with the BP pellets in some of their smaller motors, is it a legal modification to be able to simply pop out the pellet from the top grain and use a more conventional igniter (i.e. pyrogen dipped ematch)? I know that CTI recommends cutting the pellet in half, so I would think that this is a natural extension of that...

Just a note that I've used "normal" igniters on occasion in CTI motors over the years. Never removed the pellet.

In other words: though a dipped pyrogen igniter and a Pyrodex/BP pellet may be redundant, I've never personally experienced a motor over pressurization from doing so. So I've never bothered removing the pellet.

 

[jimzcatz]

FYI,but I'm sure you already know. The CTI pellets are actual BP, not Pyrodex. That might be the issue. I too have never had an issue.

 

[stevemco]

I used an Aerotech igniter with a PRO29 reload recently. Very rapid ignition.

 

[cerving]

I have no problem with it at a Tripoli launch.

Thanks Steve. This is for a TARC team that I'm mentoring, so it has to be OK with NAR rules.

 

[mikec]

Afaik problems have only been reported with Pro38 1g motors, are you using those?

 

[tfish]

Afaik problems have only been reported with Pro38 1g motors, are you using those?

and some 2G... https://www.pro38.com/pdfs/Bulletin_Pro38_1G_Pellet_Issue_v1.2.pdf

the actual 'fix'.. https://www.pro38.com/pdfs/Pro38_Pellet_Modfications_v1.2.pdf

Tony

 

[Steve Shannon]

Thanks Steve. This is for a TARC team that I'm mentoring, so it has to be OK with NAR rules.

You probably need to specifically ask someone connected to TARC, maybe even Trip Barber. He’s very responsive.

 

[mikec]

The CTI notice explicitly says that only Pro38 is affected, so I don't think this is necessary for smaller diameters. Strictly speaking if the manufacturer doesn't tell you to do it it's a motor modification.