Igniters in motors at the pad - POLL.

All,

Obviously your motor needs to be in your rocket at the RSO desk in order to get a weight. But then you need to insert the igniter when the rocket is vertical on the pad. Often, this is troublesome, because you are trying to hold up your rocket with one hand while inserting the igniter with the other.

So, do you do that, or do you slide out the motor, insert the igniter, and then slide the motor back in?

Bat-mite said:

But then you need to insert the igniter when the rocket is vertical on the pad. Often, this is troublesome, because you are trying to hold up your rocket with one hand while inserting the igniter with the other.

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That's what rail standoffs are for.

I... Leave the rocket alone while inserting the igniter?

Not quite so obvious to me why the weight of the igniter would be a material issue during a safety check. But the answer to your question is: I grab my nearest rocket buddy and bring him out to the pad to hold the rocket at a comfortable height for igniter insertion.

Sorry read all the words in the first post this time.

For me igniter already installed... I just twist the bare wire ends together; it's not gonna light.

I bring a c-clamp out to the pad. I stand off the rocket about 8 inches above the blast deflector, by clamping the c-clamp over the rail. This gives me plenty of room to play with. After, I drop the rocket down to a few inches above the pad. This gives me maximum rail length while still allowing a standoff length.

Ah yes, the old "inserting igniters on the pad" thing.

On the one hand, I do see the reasoning behind this practice, and I do fully understand why being ultra careful in regards to range safety is important. That said, I have a few rockets where this is quite bluntly a major pain in the @#*. Inserting igniters into the rocket on the rail when I've got a twelve motor cluster, or airstarted second stages, or some other more non-standard setup is clumsy & inefficient at best, a time-waster where I've sometimes got all the other flyers in that round ready to go and they are all waiting on me to get mine ready, and I believe LESS safe at times due to a very tricky setup being done "under the gun" and in less-than-ideal conditions. Add to that the fact that many AT instructions tell people to insert their igniter when they are assembling the motor (which can be very confusing to newbies in particular), and you have some uncertainty at times.

So what to do? In practice I've found these issues are usually easy to address. When I DO have a complicated prep/setup, I usually go to the RSO beforehand and ask directly whether it would be ok to bring my rocket to the table with the igniter(s) already installed - I am prepared to show and tell WHY this makes more sense (and likely safer) in this particular instance. Most often, that RSO makes the judgement call and ok's it, usually with the requirement that I do the prep work there by the table rather than back at my own area, which is not a problem for me. This way I can do the prep work at my leisure with no pressure, no one is waiting on me, and I can do the work MUCH more efficiently and ensure that it is all done so that the launch/flight is SAFER. Everybody wins.

As is often the case, a little communication and sound reasoning goes a long way.

s6

Everywhere I have flown, it's been a non-issue.
There have always been something to use as stand-offs or pads were fitted with them.

There were 3 or 4 times out of hundreds where I did have someone steady the rocket while I inserted the igniter.
This involved 3-4 foot dowels with igniters taped to the top, not what I would call typical.

Folks tend to forget the inherent dangers of what we do, & get lulled into complacency.
Well run launches help negate all these issues, with little inconvenience to those flying.


There have also been a couple of M moon burner off center bores that required, laying the motor flat on ground to "find" the core, and this was always done at the away cell where it did not infringe on anyone else's pad time. Then place motor into rocket & onto pad.

I don't mind any of these small inconveniences, considering the safety issue of doing it this way.

Stand-offs. Lifting the rocket is a pain, and if you have a GLR motor mount with snap rings then removing the motor at the pad is not an option.

Igniter discipline is like trigger discipline. The finger goes on the trigger when the gun is pointed at something you intend to shoot. The igniter goes in the motor when the rocket is pointed where you want it to fly. You also arm the altimeter and confirm its status before inserting the igniter.

Multi-stage flights are the exception. I don't have a good answer on how to do this apart from lifting the rocket while it is on the rail.

The igniter should be the last thing you install in your rocket.
I'd rather have a no event when hitting the button than forgetting to arm you recovery system.

There are certain instances where you need to build the motor with the igniter installed.

JD

This is a great discussion.

I pre-insert the igniter into the motor.
Put the motor in the rocket just before it goes on the pad.
Hook up the wires and Whoosh.
*sings* Another bites the trees....

patelldp said:

Igniter discipline is like trigger discipline. The finger goes on the trigger when the gun is pointed at something you intend to shoot. The igniter goes in the motor when the rocket is pointed where you want it to fly. You also arm the altimeter and confirm its status before inserting the igniter.

Multi-stage flights are the exception. I don't have a good answer on how to do this apart from lifting the rocket while it is on the rail.

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Well put. Same goes with not arming the recovery electronics until the rocket's sitting upright on the rail (I know at least one altimeter won't even allow itself to be armed unless upright, we weren't aware of this while a friend was trying to check his electronics before standing up his rocket and it just wouldn't give the right tones).

So I can't exactly vote in the poll since neither response is true for me. I haven't been at a launch where the rail didn't have a stop (I use the 1" rail, and typically the way its attached to the rest of the stand creates a shelf that my retainer rests on), so the motor is freely accessible to insert the ignitor without having to remove the motor OR support the rocket. Here is a picture of my L1 cert prep, rocket resting on the rail attachment and ignitor not yet installed (still in its tube). The extra blue-tape at the bottom was for holding the ignitor wire after it exits the motor to keep gravity from doing its job, I now use a single piece of tape to serve both purposes, and tape the ignitor closer to the end of the rocket to have a more pessimistic affect on CG if anybody checks at the RSO table.

I've never had an issue with a pad obstructing the motor. I have had a few slot burners/ moon grains that were a pain to get into.

Situations like clusters, head end ignition, and staging obviously are going to be treated differently than single motor flights.

Bat-mite said:

All,

Obviously your motor needs to be in your rocket at the RSO desk in order to get a weight. But then you need to insert the igniter when the rocket is vertical on the pad. Often, this is troublesome, because you are trying to hold up your rocket with one hand while inserting the igniter with the other.

So, do you do that, or do you slide out the motor, insert the igniter, and then slide the motor back in?

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https://www.harborfreight.com/1-inch-capacity-steel-spring-clamp-39569.html

Put this $0.99 solution into you pocket. Bring it with you to the pad and attach to the rail to hold your rocket up so you can insert the igniter.

NAR allows you to insert model rocket igniters into your rocket before RSO. HP at the pad unless other arrangements make with the RSO.

Bob

The igniters that is used for motors are not very sensitive... but if you really want to be safe shunt it until just before launch. I mean I don't see how igniters could go off on its own but I can see e matches doing that since they take so little current to fire. E matches have even been known to go off from being crushed, stepped on, banged against a heavy object, etc. since their pyrogen is very sensitive (chlorate based)

I like the A clamp idea, Bob.

The problem I have is not there are no rail stops; of course there are. But they are usually very close to the deflector, and low enough that it is difficult to see up in there. So I like to raise the rocket to eye level before inserting the igniter.

I like the saw-blade blast deflector in Will's photo!

SammyD said:

I like the saw-blade blast deflector in Will's photo!

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They are "spent" diamond blades that I get from rental yards. They are no where near as sharp as regular saw blades.

Tony

taiwanluthiers said:

The igniters that is used for motors are not very sensitive... but if you really want to be safe shunt it until just before launch. I mean I don't see how igniters could go off on its own but I can see e matches doing that since they take so little current to fire. E matches have even been known to go off from being crushed, stepped on, banged against a heavy object, etc. since their pyrogen is very sensitive (chlorate based)

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CTI's that come with pellets installed are started with e-matches, plus many people start motors with dipped ematches. So ematch sensitivity is an issue. That said, feeding an igniter into a moonburner on the pad can be a pain, especially for 29mm and 38mm motors.

Sam

By the way if I'm lighting motors at the pad with dipped e matches, how do I know the continunity test of their launch system won't set it off? Do I tell the RSO that it's a sensitive e match and they'll use a different launch system (like ones designed for fireworks for example)

Thanks Bob - now I have another reason to go to Harbor Freight!

I have never seen a club pad system fire any CTI motor starters dipped or not when continuity testing.

If you are not sure, just hook up one [by itself ] to the pad clips and have the LCO check continuity. That'll tell you quick if you have compatibility between what you use and the pad system.

taiwanluthiers said:

By the way if I'm lighting motors at the pad with dipped e matches, how do I know the continunity test of their launch system won't set it off? Do I tell the RSO that it's a sensitive e match and they'll use a different launch system (like ones designed for fireworks for example)

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If you're concerned about this, then you can test continuity on the ematch before you insert it into the rocket.
But I agree with Jim in that I've never seen an ematch light from a continuity check before...

I didn't vote as there was no option for inserting the igniter up into the motor while the rocket sits on the pad's rail standoff and I sit on a small Coleman folding camp stool.

View attachment 253855View attachment 253857

BAR Crayon Rocket 29mm in second picture is sitting on a pair of clothespins but I no longer launch off whippy 1/4" rods. 38mm version of BAR Crayon Rocket in first picture launches off rails.

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The rails I fly off of have some sort of standoff. I don't have much of an issue with getting them in.

Our club's rails have stand-offs; but they keep them low so as to maximize the amount of rail guidance you get. So my original post was about the difficulty of elevating the rocket above the level of the stand-off so that it is high enough to see how to get the igniter in there. If they put the stand-off higher, it would be easier to get the igniter in, but you would have less guidance while getting up to speed.