I do not do air starts, but know several that do.Any suggestions for the best way to support the igniter portion inside the motor to prevent setback due to Gs without raising the chance of a nozzle obstruction and CATO?
Hmmm.. Would superglueing the ignitor head to the top grain work?Head end ignition is best.
Many use a small wooden dowel to hold the igniter. Allows it to be easily inserted at the pad.
I like to put the igniter while assembling the motor, I glue a piece of nylon string to the forward insulator to hold the igniter in place. I use Aerotech and Ex motors. This is secure, no dowel parts to clog the nozzle but more time and work at the pad.
M
Maybe. Glueing to propellant can be difficult, the outside layer of AP tends to pull off and the glue creates a inhibited spot.Hmmm.. Would superglueing the ignitor head to the top grain work?
I believe for CTI, anything 75mm and larger does not use the starter "pellet". At least my 98mm,I could be mistaken, but I don't think all CTI loads have the BP pellet.
I'm not sure on AT, but at a guess, in descending order of easy-light:
Blue
Black/Fast Jack
White
Red
Green
( I look forward to being corrected )
I think it is against the safety rules putting an igniter into the motor when your not loaded on the pad yet.Head end ignition is best.
Many use a small wooden dowel to hold the igniter. Allows it to be easily inserted at the pad.
I like to put the igniter while assembling the motor, I glue a piece of nylon string to the forward insulator to hold the igniter in place. I use Aerotech and Ex motors. This is secure, no dowel parts to clog the nozzle but more time and work at the pad.
M
There's some room in the rules for airstarts, obviously the igniter needs to be suitably inert... disconnected and/or shorted. Like any other flight, the RSO has the final say on this.I think it is against the safety rules putting an igniter into the motor when your not loaded on the pad yet.
Every launch I have been to including argoina you cannot have your igniter in the rocket until its on the pad. When I do my 2 stage the igniter will not go into the sustainer until the last final moment. anything can fail. Be the most prepared. I know when I RSO any rocket with a igniter in it will not pass until it is removed.There's some room in the rules for airstarts, obviously the igniter needs to be suitably inert... disconnected and/or shorted. Like any other flight, the RSO has the final say on this.
Well I said not at RSO. At the pad yea. It probably depends on the design of the rocket. If it is complex enough they may come to you camp and see how you are setting up and RSO it there.That won't work for airstarts... the sustainer's igniter pretty much HAS to be installed before the rocket is on the pad, particularly if you're using a separation charge and shear pins to keep the stack together. If the igniter is disconnected from power and shorted, it's as safe as if it were not there... have you ever heard of an igniter firing spontaneously with no power?
I built a two stage rocket but haven't flown it yet. My plan was to follow the Public Missiles Thunder-n-Lightning manual for how to best keep the upper stage igniter at the top motor grain. You can download this from their website.Any suggestions for the best way to support the igniter portion inside the motor to prevent setback due to Gs without raising the chance of a nozzle obstruction and CATO?
So ok to have separation charge igniter hooked up to off altimeter but not ok to have motor igniter hooked up to off altimeter.You can have the separation charges all hooked up just have to have the altimeter off. What I am saying is do not have the igniter even in the rocket. If the igniter is in the rocket hooked up to the altimeter at the sustainer and something happens it could be bad.
If the motor goes off bad thing. Having the charges hooked up is one thing. When you arm your electronics on the pad whats worse ejection charge goes off or motor goes off????? If something goes wrong with the electronics your better off if the ejection charge goes rather then the motor. That is the risk we all run when we arm the electronics on the pad. The last thing you want to do is have the igniter go off because of a issue with the altimeter at the RSO or as your headed out to the pad. The last thing you do before you leave the pad is arm your arm your electronics that light the motor.So ok to have separation charge igniter hooked up to off altimeter but not ok to have motor igniter hooked up to off altimeter.
That's one way to do it and an accepted method at the club I launch at.What are your thoughts about having sustainer motor igniter hooked to electronics but not inserted into motor? Just leaving hang outside the motor. Then follow your procedure but all you have to do before attaching sustainer to booster is insert igniter into motor?
I'm getting ready to build my first hope two-stage and trying to learn from everyone here and at my launches.
That sounds good to me.What are your thoughts about having sustainer motor igniter hooked to electronics but not inserted into motor? Just leaving hang outside the motor. Then follow your procedure but all you have to do before attaching sustainer to booster is insert igniter into motor?
I'm getting ready to build my first hope two-stage and trying to learn from everyone here and at my launches.
Same thing. All I am saying is it has to happen out at the pad not at rso or camp. safety safety safetyI believe the TRA rules say "at the pad", not "on the pad".
It doesn't have to be on the pad, but all igniters for high power motors must either be installed at the pad or at a preparation area that is the appropriate safe distance from spectators. When installing the igniter and until the igniter has been removed or the rocket launched the rocket must remain pointed in a safe direction.I think it is against the safety rules putting an igniter into the motor when your not loaded on the pad yet.