Why wasn't the "Personal Shield" used again ?

[Eldarion]

In S01 E03 Rodney McKay used an Atlantean device which he called "Personal Shield" that protected him from any injury caused by outside influence such as falling,shots and ... but after that episode the device was never used again ,at least as far as I've watched the series (s03e06).
I'm planing to watch the rest BTW.

[Eldarion]

Found the answer :
It has an internal power cell which will eventually deplete under strain, and does not appear to be rechargeable once this occurs.

More info/Source :
http://stargate.wikia.com/wiki/Personal_shield_emitter

[dial-langara]

Wasn't there one used again in 3x13 Irresponsible? Lucius had one, I thought. It seemed to be different from the one that Rodney used though, since he could eat, and take it off and put it on someone else.

[garhkal]

I thought that WAS the one rodney used.. But Was taken by lavine when he had the people on atlantis under his 'spell'/?

[blueray]

That was different one. Mckay's was destroyed when he went through that electric being thing.

As someone said somewhere (may have been here) Mckay's own fears of everything is what made it want to "protect" him from food.

[Brother Freyr]

The battery couldn't be replaced by the end-user. Hmm, are we certain Apple Computer didn't sell wearable tech in the Pegasus Galaxy?

[garhkal]

Since we still don't know much on ZPMs its reasonable to assume they could not figure out how to recharge the one that Mccay depleted.

[Brother Freyr]

[jackisback]

I always wished they had a episode where they really had a serious ground war with the wraith with a few of the personal shields protecting RONON and JOHN that had been supercharged by Rodney with a ZPM...

[LionHamster]

It seems odd that there's no method to make more of them considering that with atlantis having all those labs they wouldn't have a method of making the stuff invented by the labs considering the molecular assembly devise merlin had

[Xaeden]

That's the thing though; it has all those labs. Atlantis was their research center. It was not their everything. The city has limited space and that space is primarily split between laboratories and living centers. Taking away from those two things to devote space to factories is unnecessary when they could just build factories off-world and have them produce whatever finished products that were designed in Atlantis.

It's also far more efficient. Any products produced in factories (yes, factories - see the note at the end) wouldn't just be made for Atlantis, it would be made for the entire galaxy wide population of Ancients. Atlantis already would have received a lot of incoming and outgoing traffic. Add shipping into the mix and you have the Stargate constantly tied up and an excess number of ships and people coming and going (you want to go sit on a pier and quietly think about your newest scientific breakthrough? sorry, that's not going to work because there's a constant stream of people and ships coming and going). That's bad for everyone. You get less product going out than you would from a factory on a planet designated only for production purposes because you have to compete for Stargate time with all the people coming and going from their capital and it's hard for you to get work done if you're a scientist. You want to zip off to an outpost to consult with someone? Sorry, the Stargate is being used to ship drones right now.

Meanwhile, instead of being one large center for the galaxy's top scientific minds, they'd have to split everyone up between different cities to make room for these factories. Meaning, the pool of people that can they could easily be consult with, team up with, and talk with on a daily basis would go down.

So while it would be nice if Atlantis was an all purpose center for the few hundred humans now working there and it would have even been nice for the Ancients in the last years of the war when Atlantis was among the last holdouts as the rest of their holdings fell, for the Ancients who controlled the galaxy and set up things up the way they did, trying to swiss army knife Atlantis would not have been in their best interests.

*Nothing in the show indicates that the Ancients had the technology you speak of - What a person who came back to the mortal plane with all of his ascended knowledge intact could create and what the pre-ascended Ancients could are two very different things. Nevertheless, the molecular construction device is just a machine. If the Ancients did have them, they'd need to devote a lot of space to mass produce objects just as a lot of space is devoted for modern assembly machines (mass production would involve a lot of them all working at the same time, as I'm sure you know). While they could have had a few in research labs for creating experimental devices, those would be at the top of the list of the things to be shipped back to Earth when they left 10,000 years ago.