Heatshrinking eMatches

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Heatshrinking eMatches

Here is what I do with all my ematches that I use, to prevent the possibility of shorting out the connections on my aluminium charge wells.

1. Cut a short piece of heatshrink
2. Add it over the eMatch
3. Add safety glasses or faceshield to person
4. Apply heat gun to shrink tubing

I have never had one go off with the heat gun application, but I wear a faceshield each time anyway.

Here is a tip to make sure it isn't getting too hot. If you hold the wire close to the eMatch your fingers will tell you if you are overcooking the heatshrink .

Also, note that I have used clear heatshrink. I get the Spaceport America Cup team I mentor to do the same thing. You can't hide any bad joints inside clear heatshrink, like you could if using the black stuff .

Share and Enjoy!

 

[cwbullet]

Interesting. I have never had it happen, but this could prevent it.

 

[jqavins]

Wouldn't tape to just as well? Cheaper. No risk, however remote, of mishap with the heat gun.

Mind you, I like heat shrink tube and it's a neat idea.

 

[user 30299]

Thanks for posting your e-match heat shrink method. I need to look into this.

I always line my charge wells with the Estes wadding paper. I found some wood dowels that
fit perfectly down in the wells. So I just cut a "square" of wadding and push it down in the well.
It forms a perfect wadding liner. It also leaves a little extra wadding extending above the lip of
the well which I can then fold over the e-match and the BP.

 

[cwbullet]

Wouldn't tape to just as well? Cheaper. No risk, however remote, of mishap with the heat gun.

Mind you, I like heat shrink tube and it's a neat idea.

Electrical tape could be an option also.

 

[Crazyrocket]

I use electrical tape and usually add it after I wire up the ematch to the altimeter (this is after I check resistance of the ematch). I could imagine that if you do the heat shrink all at one time to all you ematches, it might same a little time during prep as you are less likely to forget to add the tape (as in my situation).

 

[CaptHaywire]

A little hot glue on anything shiny would work also.

 

[kjhambrick]

I imagine this has been posted here before but I couldn't find anything like it.

Someone showed me long ago how to use the two lower corners of an Aerotech motor baggie and masking tape to hold my Drogue and Main e-match ejection charges.

Cut off the two lower corners of the Motor Baggie, maybe 2-inches wide and 4-or-5 inches tall.

For dual-deploy do the following two times:

Add a measured 4F BP ejection charge to the cut off corner of the baggie.

Tap the BP into the very lower closed corner of the baggie.

Insert an e-match head into the BP and align the wire vertically along the closed edge of the baggie and pinch the wire thru the baggie with your thumb and finger(s) to hold it in place.

Make two horizontal folds so you end up with a tall, narrow 'bag' with the match head buried in the BP all confined in a smallish volume.

Fold the baggie twice vertically, starting at the bottom, again confining the BP and the e-match head in the very bottom fold.

Wrap horizontally with a little masking tape.

The malleable e-match copper wire serves to hold the folded baggie in a nice small square package and the baggie insulates the hot end of the ematch.

I like the HPR anti-static baggies best but I've never had one go off unintentionally due to static discharge doing it this way even with a plain-ole MPR baggie.

This is a pair I'll use for a Blue Raven Ground Test this weekend to test Blue Raven Firmware version 196 ( and my memory ) for my upcoming Level 2 Attempt in Nocturnal Missions ( when my lovely assistant, 3-y.o. Evie will be visiting with Daddy ).


Note that the Main wire is shorter than the Drogue wire.

This is because my drogue tube is longer than my main tube and I always position the charges aft of a handfull of dog barf followed by the shock cord, then the chute just below the shoulder to be ejected so that the BP gas pushes the recovery laundry and the shoulder out the hole in a more-or-less orderly manner.

Anyhow ... If anyone cares I can document the procedure step-by-step.

HTH

-- kjh

 

[user 30299]

Electrical tape could be an option also.

I would think masking tape would be an easier tape to handle when wrapping such a small item.
It would offer the same protection. Some electrical tape just does not want to "cooperate" when
wrapping wires unless you can give it a yank.

 

[cwbullet]

I would think masking tape would be an easier tape to handle when wrapping such a small item.
It would offer the same protection. Some electrical tape just does not want to "cooperate" when
wrapping wires unless you can give it a yank.

I can see your point. I have not had much of an issue if I precut pieces.

 

[FredA]

I use PVC pipe caps for charge wells and don't need to worry about shorting.