Large number of launch failures
So, I am noticing that we have a significant number of ignition failures at each club launch. This is happening to newbies and experienced rocketeers alike, so, it isn't just about "user error" of failing to install the ignitor correctly. I'd like to ask that whomever has the club system in their basement go through the system and clean the clips in preparation of our next launch.
The other thing is that I think our wires are heavy, and these are pulling the ignitors (and the little plastic plugs) out a little bit when we attach the leads/clips. Not sure yet what we can do about that, but it's something we should investigate. I am thinking about building a thin set of leads with micro-clips and then rigging that to the club's aligator clips for next month, so there's less weight pulling on the ignitor. I may then also buttress the plastic plug with a bit of masking tape. Hopefully, that will insure it won't take me 3 tries to get a bird in the air.
Charlie has the club's equipment.
You're welcome to make some small pigtail leads and use them. Tag any wires and other personal launch kit with your name so that when teardown comes around, they don't get stashed away with the club's kit.
I have a cache of the small toothless alligator clips, akin to the type Estes supplies on its launch system, that I could employ to fashion a few such pigtails. The clips I have are better because they're formed with a reinforcement ridge in the flat portion of the jaw. I'll make a few up with lighter gauge wire and some gold plated quick disconnect tabs. I recently purchased a roll of 28 gauge red/black wire (for wiring my av-bay electronics) which is really light wire.
I have 3D printed some "spacers" for use with the club's wires. Helium-brained, I left the bag of the 30 spacers I had printed on the bench in the "rocket room". Next launch for sure! I designed these to keep the clips from shorting.
As for igniters, the Estes igniters NO LONGER have a pyrogen on them. That coating is merely a prophylactic to protect the nichrome bridge wire. That wire MUST contact the grain to ignite the motor. The wire only glows red-hot, nothing more. In one of the NAR "Sport Rocketry" magazines a year or so ago, there was an article on augmenting the Estes igniters with a fabric glue and some black powder. I have been using collodion and black powder to augment mine. I've given these to some club members in the past whenever they had an onerous issue with igniting their motors. They're pretty much guaranteed to ignite an Estes motor. For the LARGER of the Estes motors — D, E and F — their nozzle throats are large enough to cram an e-match into. Those never (99.99999% of the time) fail to spawn ignition.
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Dirty clips can sometimes be an issue. If you see some that are fouled, we usually have some sand paper and can clean them up. Or you can volunteer to help Charlie clean up the rods and clips after each launch. 😁
I have the occasional failure to launch, but I don't think I have too many as long as I am paying careful attention to:
- Make sure the igniter/starter/initiator is touching the propellant, and also not shorting out itself (a common source of problems). I try to carefully pull the starter wires apart slightly before inserting them into the nozzle. I can show you at the next launch.
- Careful placement of the clips on "good wire" (not the paper) and squeezing them down so they are holding tight.
- Keep the clips apart by either putting the clothes pin between them, or running the wire leads around opposite sides of the launch rod so they naturally pull apart, not fall in together.
Hope that helps, but your and Brian's other suggestions sound like nice ideas too.
I'd be happy to give the rods and clips some sandpaper scrubbing as we are setting up next month (as long as it isn't bitterly cold), and see how that goes.
FYI: some internet wisdom is to dip the estes ignitors in testor's metallic silver paint (apparently flammable?) -- I'll have to check that out and perform a test at home. I also saw a video on youtube where the advice is to hold the head of the ignitor, pull the wires apart slightly so that inserting the plastic plug doesn't cause them to short.
All good advice. There's a lot of learn and a good number of steps to go through to insure a successful light.
Actually, I've read that clear nail polish is mostly nitro-cellulose which is highly flammable. That nail polish and a little dip into black powder before the nail polish is set should suffice.