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Comment Re:Useless Change (Score 3, Informative) 383

One more MAJOR advantage of a camless design (if not the single greatest advantage) would be the ability to have extremely canted valve angles. Retrofitting an existing cylinder head design with camless engine technology is only scratching the surface. The biggest benefits would be gained by designing the cylinder head ports around the capabilities of the valve actuators. With cylinder head differences like this, we're literally talking about the difference between NASCAR horsepower levels and streetcar horsepower because cylinder head designs are the undisputed most important factor in making horsepower.

With traditional cylinder heads (on OHV engines), valve angles are limited by the rocker arms. Rocker arm rotation about one axis is trivial, but when the valve is canted it makes the valvetrain design exponentially more complex and prone to wear due to lateral loads as the angle is increased. A camless engine design wouldn't have this limitation. That being said, the camless designs have their own challenges, namely soft valve seat landings due to a nearly perfect square-wave lift profile.

Comment Re:Don't understand engines, eh? (Score 4, Informative) 383

They call it a "Digital Cam" because when you graph valve lift vs time it literally looks like a square wave. The ramps really are that steep!

This compares to a conventional cam with a sudo-sinusoidal shaped wave lift profile (neglecting the effects of high RPM valve float).

Criticize as much as you want, but a truly functional electronically controlled camless engine would be the holy grail of internal combustion engine design. You can easily pick up 20 horsepower on many engines just by swapping to a performance cam, but you often compromise efficiency. But with a camless engine, in theory, you could have cylinder deactivation, low compression starts, the elimination of throttle plates (lower pumping losses), "full race-cam" profiles for performance, a cam profile for smooth idling, low emissions, etc....
Truly the best of both worlds!! That being said, there are disadvantages....

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I read an interesting SAE paper 20+ years ago describing a working prototype camless engine. The performance gains were impressive, but as I recall, there were two main obstacles:

1) Noise, Vibration, and Harshness. (NVH)

2) The valves landed harshly leading to valve seat wear. The SAE paper suggested using a method for softer valve landings.

Comment Too ambitious (Score 2) 75

3D printing hype is getting out of hand.

Why would anyone buy an unfinished looking $53,000 3D-printed car like THIS, when you could buy a 500+ horsepower 2016 Shelby GT350 for about the same price? The resale value alone would make the 3D printed choice foolish.

If 3D printing was as promising as this article makes it sound, then why can't I buy individual parts like custom 3D printed hoods? It's certainly more realistic to buy individual parts than 3d printing an "entire" car. It's just not anywhere close to being cost effective.

Submission + - Microsoft's 1TB Surface Book will cost you a hefty $3,199 (engadget.com)

logaecology writes: Microsoft talked about the Surface Book having up to a 1TB solid-state drive when it announced the laptop/tablet hybrid, but you couldnt actually buy it on launch — 512GB was as good as it got. Well, that extra-capacious model is now available fo...

Comment Re:Everything (Score 1) 889

^^^ THIS

I logged in just to mention Everything.
It's my favorite free program for Windows and and I don't care what the zealots say. There is NO comparable alternative for Linux.

One nice feature on Everything is the ability to add text files containing file lists to your search.
I use it to search multiple computers simultaneously and this way they can even be powered off.
The external file lists can be stored and synced on Google-Drive or an equivalent cloud storage.

I haven't tried it yet, but I might try creating a daily cron job that generates a text file list of all of my linux files and then try to use Everything via Wine as a viewer. It's a very clumsy alternative, but that's the best alternative I can think of.

Comment Re:Aren't those just called FLAPS? (Score 2) 55

I STRONGLY disagree. This Is VERY innovative technology.

Flexture / compliant structural engineering is NOT trivial.
We're talking about a complex interaction of kinematics, material science, fatigue, structures, non-linear dynamic loads, and in this case even thermal loads because temperatures drop significantly at altitude and you're not going to want a brittle material failure. Not to mention the controls engineering and software required to control and monitor the structure or the exotic manufacturing processes required to make open celled structures. Are we talking about isotropic materials? Because if we're talking about composite materials, the complexity just became exponentially more complex. Did I even mention the Aerodynamicists role in this project yet?

Frankly, I'm having more difficulty trying to think of engineering displines that are *not* used by this technology.

Here's a "Simple" two dimensional cross section of a compliant wing design. http://www.topology-opt.com/wp...

In a real world 3D example, it's not likely that the 3D design would be a extruded version of the 2D profile.

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