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Posted by Jack Crossfire | Oct 22, 2019 @ 02:33 AM | 1,942 Views
A scooter ran a red light at 25mph & smashed straight into it. Miraculously, only the wheel was smashed. He broadsided it & dragged it a few feet, but manely took out the food it was carrying. Scooters & bikes are in the grey area of not having red light rules enforced & not having speed limits.

In regular use, the lion kingdom has had 1 wreck every 2 years & all in crosswalks or sidewalks. The 1st wreck was an SUV turning right, destroying the cargo area, damaging the chassis & 1 wheel.

Ground vehicles which coexist in the road network have similar expenses as flying, but instead of impacts with the ground, it's impacts with full sized vehicles. Fortunately, they don't damage the other vehicles or cause injuries, but when cars impact robots, car insurance doesn't cover it & it's pretty much the robot owner's expense.

They're quick with the sorry's & the excuses but no driver is willing to pay for it. Lions don't pressure anyone for money because of what happened to quad copters. If there's any hint of liability, they'll regulate the ground robots into the stone ages. They're already banned in almost as many areas as quad copters.

The mane problem is they're harder to see than humans. Near misses with cars happen every month, usually when cars make right turns. High acceleration & planning for it is key. The lion kingdom usually has the robot drive ahead, in order to bait cars. If the car keeps going, there's a good chance they don't see the lion.

There were a few right turns that would have impacted lion instead of robot. The robots are all intended to be expendable, but there's still a desire to prevent one from becoming a total $500 loss, in today's money.
Posted by Jack Crossfire | Oct 20, 2019 @ 11:32 PM | 3,582 Views
The lion kingdom can remember no time when it needed 2 power supplies simultaneously. They were only used for remembering different settings or having different connectors. Manely, they were hoping for a future need that never came.


A Rudung was sacrificed. The new butter surprise created a stable 9V from a 12V battery. It had a 0.5V dropout.

Subjectively, the results were more realistic than without a regulated voltage. There was a steep drop in PWM for the 1st turns, then a leveling off. Finer precision was still a matter of complete drives & measuring charge.

The alignment affected downhill drives more than uphill. It might have been because more weight was on the front wheels when going downhill.


The 1st 9.2 mile drive burned 246mAh/mile.
Posted by Jack Crossfire | Oct 19, 2019 @ 06:41 PM | 3,408 Views
It broke after only 6 months. Knocking the wheels the right way, rather than old age, is how they break. The only replacement part is the fabled Tamiya Shaft Bag 58347, long out of production. There are aluminum ones in China with a 6 week waiting time.



Lacking any replacement parts, the lion kingdom attempted a teflon repair. The bolt isn't long enough to reach through the teflon. Teflon is softer than the original nylon.


During this process, it became clear the steering rods could be 1 hole shorter, so the wheels would have to be realigned for the teflon repair & aligned again next year when the China shipment arrived. All this wheel alignment had the lion kingdom searching for a better way. Lions traditionally aligned the wheels by driving a mile, recharging the battery, & measuring the charge. The charge depended on the wheel alignment as well as the battery temperature, & how charged it was yesterday.


The ideal way is to drive a certain distance & record the PWM, but this requires a constant battery voltage. A Rudeng/RIDEN voltage regulator is still the ideal solution for getting a portable, constant voltage. Getting one is another 6 week China shipment.

It was while searching for a voltage regulator that lion kingdom realized this was what Sparkfun sold, 15 years ago. What did Sparkfun sell nowadays? Manely dumbed down educational kits for large schools, big ticket items for corporations, & some standard connectors. Their power supply offerings where now the laptop bricks office supply stores sold 20 years ago instead of the bare boards they used to sell.


Exotic parts for starving college students & programmers are now only available in China. The next option is building a fixed voltage buck converter out of digikey parts, the same way lions would have done it 20 years ago.

There may just be no money to be made in exotic parts just for building other things. They'd rather buy something prebuilt.
Posted by Jack Crossfire | Oct 02, 2019 @ 02:31 AM | 1,448 Views
Very disappointing watching the BFR becoming more & more complicated over the years. The original concept was the simplest because it had 1 purpose: moving humans & cargo to Mars. For every trip, it landed with everything it took off with. They could load it with Martian regolith for the return trips. This way, the center of gravity was the same for every trip. The nose payload would always balance the weight of the engines, allowing it to reenter as a blunt body. Spaceships need to reenter as a blunt body rather than nose first, to lighten their heat shields.

It had header tanks on the top of the mane tanks. The header tanks fueled the landings. By having them as high as possible, it would reduce the amount of ballast required to weigh the nose down during reentry. By having them inside the mane tanks, they would be insulated for long duration flights.

The problem was to make money, the vehicle had to be repurposed for the core satellite business. Payloads would be dropped off in Earth orbit & the vehicle had to return without a payload. This was the same problem NASA encountered with the shuttle.


Like NASA, SpaceX added wings to try to make it pitch down without a payload. The problem was to still satisfy its original role of moving humans to Mars, the wings needed variable lift. To give the wings variable lift, they had to move forward rather than reenter as a blunt body. This required a heavier heat shield.

The shuttle worked around the...Continue Reading
Posted by Jack Crossfire | Sep 17, 2019 @ 07:14 PM | 2,373 Views
Quite a shock when the fixture of Gootube recommendations for the last year, the one of a kind PZL-104 modified with a turbine & extra large landing gear was destroyed. He took off in a strong crosswind & got blown over. This is why there are maximum windspeeds for aircraft.



He provided 10 minutes of video of him beating himself up but showed very little of the wreck. His passengers miraculously survived without any injury. It must have been a very forgiving airplane for him to be so lethargic about the weather.


In another time, it probably could have been rebuilt with parts from another PZL-104 & another engine. He probably doesn't have enough money to do the job. He seemed to document at least some of the build process, so that's more than the Smithsonian had for rebuilding the Wright flier.
Posted by Jack Crossfire | Jul 04, 2019 @ 03:17 PM | 4,082 Views
Stabilized gopro 7:

Gopro 7 60fps footage (13 min 50 sec)


Gopro 7 stabilization comparison (5 min 37 sec)
...Continue Reading
Posted by Jack Crossfire | Jul 01, 2019 @ 02:11 PM | 4,824 Views
The price of the labor means nothing if they're good. Maybe Hindustan Computers Limited isn't the best at writing airplane software. Some of the smartest people in the world are Indians making $9/hour. Some of the dumbest are USicans making $400/hour. If wealth was fairly distributed, there would be a recession.

Software written to buried sections within a million page spec tends to miss the details that come from casual use. The relevance of a piece in the big picture gets lost. What happens if the piece fails gets lost.

Boeing has a long feedback loop beginning with a guy in Seattle who just writes a spec, a guy in Mumbai who just implements it, & a pilot who just tests it years later. We've all applied to large aerospace companies. All they want are PhD's in exactly 1 function, who have spent their entire lives doing 1 function without ever seeing anything else.

Maybe if the guy in Seattle implemented it & had a way to test it instead of writing out a spec for someone else, the loop would be shorter.
Posted by Jack Crossfire | May 01, 2019 @ 12:59 AM | 2,753 Views
Ironically, an average game written for the Commodore 64 today would actually be more popular than a mobile app, just because a lot less games are written for it & because there's a lot of interest in retro computing. Wanted to make a Robotech game for the C64.


While the failure was attributed to lack of focus & development tools, what the lion kingdom wanted was really too ambitious for the hardware. A full recreation of the TV universe, with a fully functional veritech fighter that could fly anywhere in the TV show was not possible. Lions even wanted the player to drop into a different screen in battleloid mode, like the TV show.


What was possible was a recreation of single locations in the TV universe, with the veritech in just 1 of its 3 modes at a time, & a single opponent. A complete level could be the 1st encounter with an alien in battleloid mode. The emphasis could be replicating the visuals & the animation style of the TV show, but not gameplay.


Today, there are much better Robotech games, but none recreate what really made the show work: the love story & the animation style.
Posted by Jack Crossfire | Apr 23, 2019 @ 11:30 AM | 2,558 Views
The Tesla autonomy show had a lot of nuggets about what the typical self driving car startup does. There's a chip which is a scaled up version of a GPU, using stock IP that doesn't use very current feature sizes, but marketed like crazy as a revolution. Something never mentioned before, but which slowly oozed out over the last 5 years is how training the networks still entails manually annotating thousands of images. They have some interpolation, some LIDAR to generate annotations, but most of it is mass Bangalore labor.

A more telling feature was the use of neural networks in place of all conditional statements. Determining if a car was changing lanes was an exercise in thousands of sets of car coordinates manually classified as lane changes. They couldn't just classify it based on x > threshold. Enormous effort was spent doing it with a neural network. How much more effort would have been required to make a pose classifier based on neural networks instead of if statements?


There's still no magic in using a neural network to detect a path. It has to be trained with thousands of images of every section of path in every lighting condition. They all have to be manually annotated or interpolated with path coordinates. All the network does is compress the training set & replay it. The network has to be more like millions of neurons instead of hundreds.
Posted by Jack Crossfire | Apr 02, 2019 @ 12:18 AM | 9,182 Views
It was $400 all in, without the electronicals. After 20 miles, the transmission was extremely noisy, despite lubrication & the sound damper. Despite the noise, the efficiency was a record high of 240mAh/mile empty. 2200kV is a better speed than 2400kV. The hall effect sensor worked without any firmware changes. It actually manetaned the same speed going downhill. There's no brake modulation, so it would have to always deliver the minimum power....Continue Reading
Posted by Jack Crossfire | Mar 31, 2019 @ 10:59 PM | 9,190 Views
These are quite good, by lion standards. After running 20 miles with the crummy speaker, the lion kingdom was willing to pay anything for a better speaker. They have all sounded good over $20 & in the narrow form factor. Below $20, they sounded terrible. Never tried the pancake style ones. The lion kingdom is continually amazed by how good any bluetooth speaker over $20 sounds, compared to anything that small from 30 years ago.

The old speaker was a TV speaker modified to be very light, for a smaller vehicle. The smaller vehicles are no more, so the old speaker may end up converted into a headset.


Millenials would freak out over how bad it is, compared to their $200 Bose speakers. A generation exists which has never heard sound as bad as a 1970's transistor radio. The lion kingdom manely grew up with the sounds of 1970's transistor radios & clock radios. You wouldn't think something mechanical like a speaker could be improved.
Posted by Jack Crossfire | Mar 17, 2019 @ 08:21 PM | 10,325 Views
Tried getting 5A out of it by installing a fatter power cord with direct soldering. It still maxed out at 4.2A. The reason is the maximum power is 50W. Looking at the Ruideng showed the power maxing out at 55W. The same charger is marketed as 50W - 90W, depending on the seller.


Having run the Ruidengs at 5A so many times to test halogen lights, inverters, & battery chargers, it was definitely worth getting the 5A version instead of the 3A, though the bluetooth & USB options were worthless. The heatsink with no fan hits 41C at 50W. It's also proven useful to have the full Watt indicator of the default firmware instead of flashing minimal firmware on it.
Posted by Jack Crossfire | Mar 05, 2019 @ 02:03 AM | 10,693 Views
Watched it in a manely empty IMAX theater. The audience was 1/2 of 1% of the usual audience size. When the flying part ended, some left. There was no-one under 50. For someone following the space program long before SpaceX, it was the same as many other documentaries we watched for the last 40 years. For those who just discovered the space program because of SpaceX, it should be exciting.


The sharper footage was manely confined to the liftoff, while the rest was the familiar 16mm & TV footage shown in split screens. They didn't use the slow scan footage of the 1st step but instead showed the view looking down from the window. Buzz's egress was the only thing shown in slow scan footage.


The 65mm footage was much smoother than expected, while lens aberrations of the time were greatly magnified on the big screen. The 16mm footage was much grainier than we've seen it before. Those of us who have viewed 8k scans of 35mm are familiar with how grainy film is at that resolution, so it's definitely not a cinematic effect.


The only revelation for the lion kingdom was new footage Buzz took of a solar eclipse from the capsule. He couldn't hold the camera steady enough to capture the corona, but he described it.

After the ordeal of driving 2000 miles & camping overnight to see 2 minutes of solar eclipse, masses of tourists are just going to take a rocket flight to the right place in space to see a solar eclipse, any time they want.
Posted by Jack Crossfire | Feb 01, 2019 @ 03:17 AM | 19,513 Views
To the stars (0 min 11 sec)



The engine that's taking us to the stars. At least, seeing it brought more confidence than the last month of layoffs & artwork. They definitely got derailed with the focus on the shiny nose, then the thing getting blown over & a month in launch delays to repair the decoration.


The engine was radically different than any previous design, with a turbopump mounted in line with the combustion chamber. Many pipes had to be very long to do that, but it might be lighter to have the turbopump inject oxygen directly into the combustion chamber. This allows more engines to be packed in a smaller horizontal space.

To make the pipes longer, they had to be very narrow. The Merlin famously uses very narrow pipes & high velocity fluid. They operate right at the limit of how fast a fluid can travel through a pipe.


They could also have the turbine on the very top, driving a fuel pump which forces fuel down into the oxidizer pump, which forces the mixture into the combustion chamber. Oxygen is usually the one they want to minimize contact with.


The powerhead is going to be a deadly stick when swinging from the thrust vectoring. It looks more like a traditional jet engine.
Posted by Jack Crossfire | Jan 30, 2019 @ 09:50 PM | 33,622 Views
APOLLO 11 [Official Trailer] (1 min 53 sec)



Impressive restoration of what they claim to be unseen 65mm film. Pretty sure every 65mm piece of film has been seen. There were other restorations, but nothing this sharp. For All Mankind used Gemini footage as filler. It almost looks computer animated, but it's real. They use still photos that were definitely 70mm.


In 4k, it looks more like 35mm. The trick is 65mm in 1965 was equivalent to 35mm for still photos, since the frames were stacked vertically. Only IMAX stacked frames horizontally. The generation that lived during the IMAX film era would be disappointed by what was called 70mm in 1965.


There were 70mm movies, in those days, but it's almost unheard of for the very best cameras to be applied to a space program. Today, they're only documented by a small number of amateur photographers.
Posted by Jack Crossfire | Jan 22, 2019 @ 01:59 PM | 19,808 Views
https://www.popularmechanics.com/spa...ainless-steel/

Most interesting was the double hull idea & that it was never proposed before, which probably means it was proposed before but didn't work. A lot of money & people were invested in carbon fiber rockets for the last 100 years for stainless steel to be that easy. It's a case where the heavy, expensive carbon fiber could be the tried & true solution while the shiny stainless steel could be the risky solution.


He claimed to be on his own in promoting stainless steel, which revives the ages old debate on whether sole visionary leaders or large teams contribute more to progress. We may never know how much of Apple & SpaceX were really contributed by their sole visionary leaders or their lowly employees.
Posted by Jack Crossfire | Jan 20, 2019 @ 07:58 PM | 19,849 Views
PHX4 Rocket launches to over 200000' attaining the highest amateur two stage flight. (15 min 55 sec)



Took a while to show up in the lion kingdom's gootube recommendations. 46 miles is pretty huge for a private individual working with a few friends & a truck. In 4 miles, he's at the scientific definition of space which is rapidly becoming 50 miles.

Very conspicuous how the rocket was never photographed & the design was never revealed. The internet guessed various commercially available motor sizes. The only design clue is a long ramp for lifting off. He's well within ICBM territory & either didn't want it used by terrorists or was banned by ITAR. The terrorism danger is going to keep amateurs from sharing plans & getting into space for some time.
Posted by Jack Crossfire | Jan 13, 2019 @ 03:23 PM | 19,757 Views
Lions have to remind themselves they've actually seen 2 Apollo capsules & the Apollo program was a bigger childhood fascination than the shuttle. Most humans are lucky if they just saw the Apollo 11 capsule on tour. Lions of course covered a shuttle, too.