Note from Ed O'Beirne from Conceptus, Inc.

[quade 4]

Ed saw our postings about the issues about the Conceptus tongue switches sticking and sent me a little note explaining a few things. He's given me permission to repost it here for everyone to see.

Quote

In case you're curious, I'll explain what the problem with your switch probably was, and what I've done to help prevent that sort of thing from happening in the future. Until now, I used aluminum dies to dip into the plastic to generate a "condom" sort of membrane with a sort of "shoulder" around the inside to keep the actual membrane from pushing down on the button by itself. This technique resulted in a membrane which was thinner at the corners and along the edges than on the flat surfaces. This created a natural weak spot for penetration. Unfortunately, it's also the corners and edges that sustain the most abrasion when in use - being put on and taken off of the camera, the helmet on and off of a shelf or surface, moving around the plane, etc. This occasionally results in the formation of a small, usually invisible, puncture at a corner or along the edge. The saliva introduced into this puncture creates a one-way-valve effect. So when the user pushes in with the tongue, the air inside is pushed out of the otherwise totally sealed switch, but no air was able to re-enter the switch due to the saliva. This usually holds down the switch so a rapid-fire of exposures occurs until either the switch dries out or the user pinches the membrane in such a way to re-admit air through the hole. This problem may also be exacerbated by the increasing ambient pressures encountered as the user descends in altitude, since what little air remains inside the switch is effectively compressed. This has always been a delicate situation for me since I wanted a thinner membrane for a more sensitive "click" while having a reasonably durable switch.

The new manufacturing technique builds up the corners and edges of the membrane, plus the interior shoulder, independent of the actual center of the membrane. This allows for a very thick and durable edge with a very thin and sensitive membrane center. What you should find is a very responsive "click" with a more durable switch overall. The only shortcoming is that the thinner membrane is inherently more susceptible to direct puncture by sharp objects, but fortunately such threats are also relatively uncommon in the skydiving world since all sorts of other things are very sensitive to puncture.

Nonetheless, if a user experiences a puncture with either the old or the new switch design, it can usually be fixed by first identifying the puncture, drying the switch out as much as possible, putting a tiny drop of paint thinner or toluene over the puncture, letting it sit for 10 seconds, and gently stirring the resulting paste to cover the hole. After 24 hours drying time, it should be ready to use. Of course, I am always more than happy to replace any switch which malfunctions for just about any reason, but if you need it fast, this might work. If a user ever needed it RIGHT NOW, he could use a drop of superglue for a couple of rolls, but it will fail pretty soon, so I'd recommend sending it back when able. The exact same advice goes for the bite switch, but punctures occur only if bitten too hard or with the sharp canine teeth.

Pretty fair deal!

Ed's going to send me a new tongue switch to check out and I'll jump it as soon as it gets to me. I'll let you know how it works out.

quade -
The World's Most Boring Skydiver

[YahooLV 0]

me too! Thanks, ED!

Blue skies

http://www.curtisglennphotography.com

[Zlew 0]

wonder how he heard about the post...

Z

[ltdiver 3]

Me three.

ltdiver

Don't tell me the sky's the limit when there are footprints on the moon

[SniperCJ 0]

When he e-mailed me he said he just ran across the post on the forum.

I think it speaks volumes of people like Ed and the Mirage folks who check the boards occasionally to see whats going on in their areas. Way cool!

I'll post my thoughts also on the new switch when it gets here.