Wrong. FDM is used commercially to produce parts - including airplane parts. (I know, because one of my (OpenBeamUSA.com) vendors is printing cosmetic trim pieces for the Airbus A380). Commercial systems have no problem with overhang because they use a water soluble support system. And if you want something prototyped out of production representative material, it is one of the faster (and hands off) way to do it. I've used FDM for Ultem, Polycarbonate and ABS parts before.

The reason you don't see this in the hobby market, is because Dimension's patent on water soluble support, and heated build chamber, is valid until 2014 (or 2016). That's why there is no hobby grade 3D Printer on the market that is completely enclosed and they only have a heated bed. Most people enclose their printers if they are printing with ABS for a variety of reasons.

-=- Terence

Posted also on the Kickstarter comment section:

Kickstarter project creator here: I'm the guy behind OpenBeam (http://www.kickstarter.com/projects/ttstam/openbeam-an-open-source-miniature-construction-sys).
And in case anyone's wondering - we shipped the majority of our rewards a *month* before the original promised date. That probably puts me in the top 5 percentile of projects...

Let's take a look at the new rules one by one:

“What are the risks and challenges this project faces, and what qualifies you to overcome them?”

- Okay, this is perfectly valid. I am surprised KS haven't done this earlier, because there are quite a few clueless guys (http://www.kickstarter.com/projects/277210494/paint-be-gone) - *(http://www.kickstarter.com/projects/277210494/call-key) and http://www.kickstarter.com/projects/277210494/key-pad-case) out on here who seems be doing the "throw s*** at the wall and see what sticks" model of development.

"Product simulations are prohibited. Projects cannot simulate events to demonstrate what a product might do in the future. Products can only be shown performing actions that they’re able to perform in their current state of development."

"Product renderings are prohibited. Product images must be photos of the prototype as it currently exists.
Products should be presented as they are. Over-promising leads to higher expectations for backers. The best rule of thumb: under-promise and over-deliver."
Okay, so KS want a working prototype. I get that; that's pretty straightforward. But it doesn't stop someone from *faking* a prototype on camera. This however, won't stop a project like iCase (http://www.kickstarter.com/projects/1791911961/i-case-iphone-4s-and-iphone-4-bumper-case) from being a train wreck, as the protoytype would likely have been SLA, painted, and the problem wouldn't have been apparent until the metal parts were CNC machined and fitted and found to short out the iPhone's anntenna.

The OpenBeam project would have passed these requirements; we had a physical prototype for shooting the video, as part of a good product development practice.

"Offering multiple quantities of a reward is prohibited. Hardware and Product Design projects can only offer rewards in single quantities or a sensible set (some items only make sense as a pair or as a kit of several items, for instance). The development of new products can be especially complex for creators and offering multiple quantities feels premature, and can imply that products are shrink-wrapped and ready to ship."

And how would KS define "Multiple copies" of a reward? This I have a problem with. When you're in production, you are trying to get the manufacturing volume up to bring the costs down. If I were launching OpenBeam now, would I be limited to selling one stick of aluminum and one of each bracket to my backers (who wouldn't be able to do anything useful then with this?) If I packaged it up as a "kit", like I had on my KS, would I have gotten around these restrictions? Who decides whether multiple copies of the same item is required for the item to work (ie, construction toy kit), and when it becomes a way to side step your rules? How much "individual judgement" is there to allow the listing of a project, and do you consider the project creator's background (ie, having successfully delivered on a previous project) when you allow them to post? With the amount of controversy about what gets allowed (*cough* Tangibot (http://www.kickstarter.com/projects/mattstrong/the-tangibot-3d-printer-the-affordable-makerbot-re)*cough*) and what doesn't on Kickstarter already, this rule is probably going to make your selection process more Apple App-store like (arbitrary with no recourse for the project creator if you are not selected).

(Edited to add: The real problem, that KS probably don't want to admit, is that none of their hipster workers have a sufficient engineering / science / technology background to effectively monitor and approve Kickstarter projects to begin with. That's why they let stupid shit like Z-Torque (http://www.kickstarter.com/projects/1202837765/z-torque-bicycle-cranks-ride-faster-longer-easier?ref=live) in, but plenty of GOOD projects get rejected).

-=- Terence

There's two issues here: There's the issue of whether current (or more stringent) security measures can still be beaten by a determined foe, then there's the issue of actual Li-Ion batteries going kaboom. I'll address the later.

Li-Ion batteries are some of the highest energy-density storage devices available to the general public. As such, they *are* dangerous. I design battery packs for a living, and let me tell you - if not for microprocessors and safety circuits, we wouldn't use Li-Ion batteries.

They are the only batteries that I know of that can fail dangerously when over-discharged. You start creating internal shorts of lithium whiskers between the cathode and anode, which bypasses any cell safety circuits.
They go boom very spectacularly if you overcharge them. The model RC heli folks have found this out the hard way, as they tend to run bare cells without protection circuits to save weight. (http://www.youtube.com/watch?v=hcwOwf55Rtc).
They have very low internal resistance, which means in a short circuit, they can release energy very quickly. Every manufacturing engineer at the company I work at have welded calipers to cell tabs, from accidentally touching the wrong stuff while taking measurements.

For a good cell manufacturer - and I'm talking about the LiShens, Sanyos, Kokams, and Panasonics of the world, the failure rate is 1 in 1 million. It's just a fact of life. The fly-by-night operations in China, responsible for some of the god-awful counterfeit cells out there, god knows what those failure rates are. And the vendors who use these cells tends to not put in the safety features (look up a BQ20Z70 chip, for example) to make a failure more likely.

The nightmare scenario would be some dude getting some last minute work in at the terminal, plugging the battery in for charging. Then the plane takes off with the laptop in the overhead compartment where the oxygen lines for the safety masks are kept, and the cells let go. Judging from how much energy a single 18650 cell can contain, it could easily do some very serious damage.

With the prices on Li-Ion dropping and more devices using them, it's no wonder that almost all of the 22 incidents reported occured in the last 3 years. Still a small number considering the amount of airplanes in the air at any given time, but enough for someone to pause and think...

Yeah, but you'd have to film it in 30 second clips, as that's about how long you have in zero G. Better have a hell of a fluffer to make sure the guy's always good to go. Not to mention that if the girls' getting deepthroated or teabagged while they transition into the 2G pullup, both parties might be in for a hell of a surprise.