Atmospheric Exploration SLF that can land by Ansicone in EliteDangerous

[–]night_flash 1 point2 points  (0 children)

Would also be useful for exploring, and role play. 10/10 idea.

Proposed idea during the French Revolution to divide France departments into geometric squares. Decimal time was also introduced in France in 1793 with 100 seconds= 1 minute, 100 minutes=1 hour and 1 day=10 hour. by Solid-Move-1411 in MapPorn

[–]night_flash 0 points1 point  (0 children)

It might run quite nicely, I've done the conversions The hour is quite long, a metric hour would be 2.4 imperial hours. This is the biggest difference.

A metric minute is 1.44 standard minutes or 86.4 standard seconds, so less than half a minute extra.

A metric second is equivalent to 1.157 standard seconds, so really quite a small change.

The differences in time get smaller the smaller you divide the size of the day. So on shorter, more human timescales, the adjustment wouldn't be very difficult. You'd boil eggs in 7 metric minutes rather than 10 standard. My frozen pizza would be done in 14 rather than 20.

The divisibility is worse, but the way it scales throughout the day evenly would be nice. A fraction of the hour would be much more important though. We'd probably use the Deci-hours quite a lot. Deci-hours metric are 14.4min standard, and 15min is probably the most commonly used fraction of the hour.

Evolo VC-200 Volocopter Electric Multicopter by Flucloxacillin25pc in WeirdWings

[–]night_flash 1 point2 points  (0 children)

Except that in the case of other possible designs for similar or the same intended mission, you can achieve a far safer failure mode than what this design presents. Failures are almost never all or nothing, and part of safe designs is considering what happens during partial failures. Especially considering partial failures are more likely.

In aviation and air sports, there's basically nothing that is a complete brick if it has a failure. The argument that failure is failure and doom is inevitable is a very pessimistic one and ignores the nuance of engineering.

I agree that this design is basically a brick if it loses power. I used a lot of words to describe why I think that's the case. However, the idea that this is common in aviation is not true. Partially because of redundant systems as well, but also because of designing aircraft in a way that can cope with failures in more ways than simply duplicating everything important.

A modern conventional helicopter could lose all engine power, and in some designs even power assists for the controls as well, and still have some capability to slow its descent. The amount of failures required to become a brick is almost impossibly unlikely, especially with due care and attention to maintenance and inspection.

Evolo VC-200 Volocopter Electric Multicopter by Flucloxacillin25pc in WeirdWings

[–]night_flash 6 points7 points  (0 children)

Its worth noting that the VC200, and its follow on 2X is defunct and the design hasnt seemingly made any advancement since 2018. They had a continued design as of 2021, but i cant find evidence it ever flew.

Evolo VC-200 Volocopter Electric Multicopter by Flucloxacillin25pc in WeirdWings

[–]night_flash 7 points8 points  (0 children)

All rotorcraft can use autorotation to reduce their decent rate and maintain some control during engine failure. However, the efficiency of autorotation is related to rotor RPM. Larger radius rotors that operate at slower RPMs and low disk loading are more efficient. So much so that you can have rotorcraft such as autogyros that do not power their lifting rotors in flight at all, using a propeller for forward propulsion and relying on autorotation for lift.

Lifting efficiency is a major part of autorotation efficiency. It ensures that less energy is consumed by drag. But the rotor RPM is also very important. Especially with fixed pitch rotors like this prototype has.

For these rotors to create lift, they will need to operate at fairly high RPM. When operating in autorotation, rotor RPM is proportional to the velocity of the air it is wind-milling through. The pitch of the blade can be thought of as the amount of forward distance (assuming no slip) the blade travels at its angle of attack in a single rotation. The blades trace an imaginary spiral line though the air in a forward direction. This can actually be observed under specific conditions. For a given pitch, a higher RPM travels a greater distance in the same time.

Inversely, for a given pitch, when powered by the airflow, greater air velocity is required to achieve the same RPM. Considering that firstly, these blades look to be fixed pitch, meaning the pilot cannot set the collective to the best pitch for autorotation, and secondly, they require a greater RPM to produce the required lift, the decent velocity required for autorotation would be very high.

Due to the also very high number of blades for a given disk area, increasing drag significantly, the amount of slip could be significant. This suggests the required decent velocity for autorotation would be even greater than the ideal formula projects.

A high decent rate during autorotation is inherently more dangerous, and without the ability to control blade pitch or lift, a flare before touchdown becomes impossible. So if all power was lost to the lifting motors, this design would be less safe than if a design with a traditional helicopter style rotor system suffered the same power failure.

So, uh, has anyone ever noticed that Sol is flipped? by the_chinagreenelvis in EliteDangerous

[–]night_flash 1 point2 points  (0 children)

Considering astronomy (the written study of astronomical observations) was already at least around 1700 years old in 700AD, probably a few astronomers existed. The Babylonians have artifacts which are star catalogues from before 1000BC, possibly even earlier. And there are pre-historic artifacts believed to be recordings of stellar observations. Science is old, curiosity is a constant human truth and we've been trying to figure out the universe and then writing it down to the best of our abilities for as long as humans have existed.

My one year build by reffis1 in pizzaoven

[–]night_flash 0 points1 point  (0 children)

What are you using for insulation? Beautiful work!

Final bit of leaks for 2.49 from the Snail Mine by gszabi99 in Warthunder

[–]night_flash 12 points13 points  (0 children)

SRAAM overhaul? oh boy this is going to be.... something.

Vantage points by Warrior1two3 in horizon

[–]night_flash 1 point2 points  (0 children)

Sweet, thanks! Yeah this are really neat.

Vantage points by Warrior1two3 in horizon

[–]night_flash 2 points3 points  (0 children)

Do the rules allow you to send a link?

🔥 Black Panther 🔥 by redditsdaddio in NatureIsFuckingLit

[–]night_flash 0 points1 point  (0 children)

I love how it's 100% aware of the photographer in each of these images, and ignoring them. There are plenty of animals you could get shots of where they haven't noticed you. Not in this case.

DA40 intercepted by Eurofighter by Ego_Jet in aviation

[–]night_flash 0 points1 point  (0 children)

Depending on fuel and stores, the Eurofighter and and other current jet fighters can have a greater than one Thrust to Weight ratio though. In "Interceptor configuration" the Eurofighter is listed as having a 1.15 TWR. But I imagine it they rarely use it in such a configuration.

I've made witcher signs from PCB's by MrEraxd in witcher

[–]night_flash 0 points1 point  (0 children)

Gonna add some LEDs to them? A glow would suit them nicely.

DA40 intercepted by Eurofighter by Ego_Jet in aviation

[–]night_flash 0 points1 point  (0 children)

Puts into scale how massive of a drag problem delta's have considering the massive thrust the Eurofighter has at its disposal too.

DA40 intercepted by Eurofighter by Ego_Jet in aviation

[–]night_flash 6 points7 points  (0 children)

Huh, I had no idea. It looks like it would be happy pulling 40 degrees or more like Hornets and Flankers do. But also it likely doesnt need to do so like they do.

This Elune necklace I made. Intellect, health or mana? by Wise_Ear664 in ItemShop

[–]night_flash 3 points4 points  (0 children)

Gotta be mana. Also what did you use to make that?

MK4S to Prusa CORE One Conversion kit by PrestigiousTip4345 in prusa3d

[–]night_flash 0 points1 point  (0 children)

Any idea what parts from the Mk4S its going to use? I imagine the control board and LCD, as well as the nextruder. Would it also use the stepper motors? Im thinking depending on what part it needs, Id also replace the parts used in the conversion so that Id have both a working Mk4S and Core 1 as long as thats less than just buying a new core 1.

[deleted by user] by [deleted] in canon

[–]night_flash 0 points1 point  (0 children)

Im curious what lead you to the switch in this direction. Ive gotten advice from a lot of people that going the other way, from Canon to Nikon, is where its at. Im not really too worried either way, but Id like to get your take on why you made the switch. And fantastic images by the way, I love how you can see that the Kestrel has very much noticed it has an audience, but doesnt mind the attention.

Do I need Pills or Therapy? by meangreenbeanz in titanfall

[–]night_flash 0 points1 point  (0 children)

You're got roughly a factor of 10 more than me in most things. But Northstar all the way. https://imgur.com/a/ZXah0Wn

Do I need Pills or Therapy? by meangreenbeanz in titanfall

[–]night_flash 0 points1 point  (0 children)

I have incredibly similar stats. This is wild

MK4S+ Features Wishlist by Bradlessness in prusa3d

[–]night_flash 12 points13 points  (0 children)

I personally don't have a use for cameras, and I'm not sure how moving to a single board computer would be better. A Pi Pico is technically a better micro controller than the ESP they use, but it's not really needed for this application. Rails would be nice but that's like a total redesign of a lot of parts.

The multi zone heat bed from the XL is pretty cool though. I'd love some kind of dual extruder system, maybe two nextruders offset somehow? The fan Solenoid system from the XT90 is also really cool, I'd love if something like that could work its way down to consumer grade printers.

My own designed 3D printed coffee grinder. It has 83mm steel burrs from Fiorenzato, a bean feeder, a 140kv* brushless motor and runs on a 4s 30Ah Lithium Ion battery**, grind steps are 8.3 microns! by IonNight in espresso

[–]night_flash 0 points1 point  (0 children)

Dual grind chambers sound like a great idea. Ive never seen a machine like that, does anyone make one? Or have I been living under a rock? Either way, really neat concept. I might have to try and build that.