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Posted by Jack Crossfire | Aug 07, 2018 @ 04:17 AM | 762 Views
Amazing night views from a Falcon 9 (1 min 7 sec)


The lights of Fl*rida appear after stage separation. Then, we see lightning over the gulf of Mexico as the grid fins deploy, lit by the flickering light of the 2nd stage engine. Then, the sparks fly & the grid fins glow purple as we enter the hottest part of reentry.

https://www.rcgroups.com/forums/show...entid=11134499

It looks quite serene compared to block 3's barbeque, masking the growing spray of water in the octaweb. Can only imagine, after it hits the hottest part of reentry & the camera goes out, the water boilers are going full tilt, the grid fins are glowing, plasma is roasting the interstage & it's a pure hell.
Posted by Jack Crossfire | Jul 26, 2018 @ 05:23 AM | 789 Views
Falcon 9 over Pleasanton (3 min 7 sec)



There were actually very few good photos of the arc & no closeups, compared to east coast launches. The problem was fog. Everyone bent on getting good photos went close to the launchpad, under the fog. The few slackers stayed hundreds of miles away.

ISO 6400, F1.8, 1/30, 28mm for the video
ISO 400, F5.6, 30sec, 50mm, no mirror lockup for the stills

Surprised how much more interesting a video is when it shows a rocket over where you live. The USlaunchreport videos are the same white dots with the noise of a cell phone, but boring because they only show the context of a spaceport.


The color came out quite dramatic. The atmosphere & space are clearly deliniated by red & white. Was surprised how red the flame 1st was. There was no saturation effect, just a very high gamma setting, obliterating the haze. The reentry burn was another surprise. It showed it really was a Falcon 9 & the stories were real. It's another sign of a world Elon created, in addition to all the cars being Teslas.
Posted by Jack Crossfire | Jul 15, 2018 @ 04:48 AM | 807 Views
Finally had a go with Freecad's anaglyph feature. It's the 1st time the lion kingdom had anaglyph support in a modeling program. Maya couldn't do it, 15 years ago.
Posted by Jack Crossfire | Jul 14, 2018 @ 01:50 AM | 1,192 Views
If you held your breath, you'd last a minute on Mars without a space suit. You could feel the ground & the cold of Idaho, see an atmosphere naked eyed, but feel no air if you waved your arm. Taking your last breath would reveal a hard vacuum. You be unable to inhale & die.

Still, you could probably run out of an airlock & back in after a minute, just to feel it with your own body. A face mask could fill in while the airlock repressurized.
Posted by Jack Crossfire | Jul 13, 2018 @ 04:05 PM | 1,037 Views
As usual, the lion kingdom was the 1st to notice the heat shield isn't black, but the same color as the BFS renderings. It's a bit of fiction becoming reality & shows the BFS's color wasn't just a mockup. It's also different than the material used on the block 5 Falcon 9.


It's probably not the famous PICA derivatives but some metallic compound involving titanium. PICA was orange. It's been 80 years of trying to develop a better heat shield.
Posted by Jack Crossfire | Jul 08, 2018 @ 01:48 AM | 1,358 Views
The July 4 cruiser swore allegiance to the god emperor & chief & could make a lot of noise. It was going to be a night of fire, noise, & mane hair.


The 8 year old glow stick barely lit up. Either it expired or lion vision has deteriorated too much to see anything since using those as a kid.


The fireworks were pretty minimal. It was an overcrowded street with limited visibility & humans who were too busy yelling at each other to notice their god emperor. It was a pretty awful place for a fireworks show. The speaker wasn't needed, since they had barely audible music & the radio station didn't seem to be broadcasting the soundtrack, anymore. The FM banger came in a lot better in downtown. Then, during the 1 mile drive from the show, the $60 steering servo died. The metal gear came undone from its servo horn.

This part never got threadlock because of its tendency to crack plastic. The next idea was to threadlock just a bolt in the metal gear, let it dry, then install the servo horn. This is why you should never overhaul less than 50 miles before an important mission.
Posted by Jack Crossfire | Jun 03, 2018 @ 02:42 AM | 2,087 Views
That was a huge amount of work, intermittently, over the last 6 weeks. Still not texture mapped. Sort of gave up on something hyperrealistic, but it's still decent for a game. Don't forget griddy mcgridfin.

grid (0 min 14 sec)

Posted by Jack Crossfire | May 30, 2018 @ 11:58 PM | 1,889 Views
Drilling the holes in a space shuttle injector plate, in 1977. It was 1 of the 1st high quality photos a lion ever saw on a computer & the moment it became clear how laborious spaceships were to create. Decades later, lions realized after all that work drilling the holes, they had to plug the holes back up when they cracked.
Posted by Jack Crossfire | May 29, 2018 @ 10:00 PM | 1,782 Views
Finally cracked open the ice budget & attempted the 1st refrigerated transportation. This requires going both ways with ice blocks, significantly reducing range. 2 ice blocks were quite heavy, but it didn't show a significant increase in tire wear after 10.7 miles. Power consumption increased to 328mAh/mile. The weather started hot & got cold by the end. Sandwiched the salad between the ice blocks. The top ice block finished more melted than the bottom. The salad arrived still cold, which isn't very conclusive unless another test is done without ice, in the same weather. Ice cream definitely needs to be tested.


Whether ice on top or ice on the bottom is more effective is unclear. Most heat should get in from under the robot, but cold should travel down.
Posted by Jack Crossfire | May 26, 2018 @ 01:29 AM | 2,240 Views
Fixing the camber spread the tire wear over a larger area in the center but introduced bigger problems. It significantly reduced the range because of the higher rolling resistance & made the servo skip cogs because of the increased rolling resistance. Went back to the stock camber which wore down the inner edges & searched for a coating to resist the wear.


The solution was to glue fabric straps to the inner edges with E6000 adhesive. After hundreds of miles, they didn't wear off & the power consumption dropped to 280mAh/mile. Initially, the straps were common shoelaces, but kevlar would be the ultimate strap. The key is getting the strap to cover the entire wear pattern. If wear hits a strap edge, it'll peel off.

Earlier coatings were white electrical tape & CA glue, which instantly wore off. E6000 adhesive without fabric seemed to wear off.
Posted by Jack Crossfire | May 12, 2018 @ 05:44 PM | 1,982 Views
NASA Mars Helicopter Technology Demonstration (1 min 23 sec)


The speech:

https://www.nasa.gov/press-release/m...-rover-mission

More details on kiwipedia:

https://en.wikipedia.org/wiki/NASA_M...licopter_Scout

After decades of rumors about such a thing, which no-one took seriously, it was finally included on the next Mars rover. The finer details had a few shockers.  It uses solar charged lithium batteries, coaxial blades, has no blade shroud, & no obvious way to right itself.  It weighs 4 pounds & looks quite top heavy.  It's basically the exact opposite of a copter you'd expect to be sent to Mars.


The equivalent atmospheric density on Mars is 100,000ft on Earth or 3x higher than the highest a copter has ever flown on Earth.  A quad copter would not be efficient enough to do the job.  It's inevitably going to crash & roll over, so apparently this simple use of long legs is able to recover without human intervention.  Maybe the blades can kick it upright long enough to get going or it can tumble down a hillside until it reaches a flat spot.  There are still many ways it can get stuck, so it needs a major investment in autonomous programming which can avoid getting stuck.






The dark, blurry footage from JPL shows the solar panel on top of the blades blocking airflow, no obvious use of a flybar, & lots of vicon balls for tracking position.  You'd think a solar panel below the blades would allow more lift & get dusted off by the airflow.


A copter that could travel great distances on solar power & recover from crashes is what we all wanted, 40 years ago.  The solution seems so simple, it makes you wonder why China didn't already give hobbyists such a thing.  
Posted by Jack Crossfire | May 10, 2018 @ 10:28 PM | 2,309 Views
Mane engines stepped up to 190,000lbs thrust with higher ISP.
Merlin vac increased to 220,000lbs.
The merlin vac is still throttled down to 210,000lbs to study vibration.
The octaweb is stronger aluminum 7000 instead of aluminum 2000.
The rocket base is now titanium with water cooling.
The black sections are a proprietary material, probably derived from shuttle tiles, but without the porous sections which absorbed water.
The avionics & IMU were redone.
Current 2nd stage recovery efforts are only to determine the mass impact of recovering it without impacting BFR development.
Falcon 9 launches would cost under $6 million if they could reuse the 2nd stage.
He wants to launch the same booster twice in 24 hours, in a demo mission next year.
The new COPVs are the most advanced & tested ever made.
Posted by Jack Crossfire | May 10, 2018 @ 02:36 AM | 2,845 Views
Got a somewhat acceptable wing by creating 4 profile sketches, then lofting them. Freecad can't create a solid from a surface, so you have to create 2D slices for the lofting operation, with matching curve & line segments. Freecad did manage to interpolate the sketches into a smooth curve. Suspect this process would be much easier to tweek & give smoother results if it was built up from equations rather than paw sketching, but the reference design is going to change. The automated version would have to use a constant number of line segments for each profile sketch instead of curves.




The only way to create windows was writing the basic equations in a python script. There are no basic cutting, pasting, copying functions in the sketcher. The lion kingdom wanted see through windows instead of textures.

The script created a window creation tool. Then the tool cut out windows you can see through. OpenCAD has a few rounding errors, causing some windows not to open. Offsetting by 1mm in random places seemed to work. There's the issue of a tinted, reflective texture. The whole model may end up being from equations. Tweeking is a buster because it takes a long time to recompute the model.




The parts -> thickness tool doesn't work at all with booleans or constantly locks up. The only way to make hollow solids is sketching a cross section & revolving/lofting with solid mode enabled.
Posted by Jack Crossfire | May 09, 2018 @ 02:01 PM | 3,126 Views
Long thought to be unfixable, the camber is determined by a bend in the wishbones. It turns out the wishbones can be flipped over, giving a closer to ideal camber position. Further refinement is within the limits of changing the suspension height. The result was much closer to ideal, but increased the rolling resistance, put more stress on the steering servo, & decreased the range. The steering horn jumped cogs much more often.


There are servo savers & a return to sloppy steering or going back to stock camber & tire wear. Steering with the direct servo link was so solid in this spherecam video, it didn't need any stabilization.

3DRRrrrrrun (3 min 18 sec)

Posted by Jack Crossfire | Apr 26, 2018 @ 10:34 PM | 3,068 Views
Shapelock was long theorized to be an effective adhesive on plastic, but never used it in 7 years. Decided to finally apply it to the front wheels & made a test blob.


For this application, it was easier to use hot air than boil it & reheat it with hot air after applying it. It melted the plastic slightly. No amount of hammering could kick the test blob off. After a 10 mile drive with 5 at higher speed, it was declared a success.


The repaired shaft was misaligned, there's absolutely no way to release the shapelock & we know the consequences of misaligned wheels, so they still have to be replaced. Creating shapelock fillets around the bearing is another necessary step in fabrication.
Posted by Jack Crossfire | Apr 26, 2018 @ 12:40 AM | 2,678 Views
4 months after the last wheel failure, the same left front wheel broke off again.

https://www.rcgroups.com/forums/show...e#post38834656

& the right front tire continued to have wear problems. At least it got a good video before it died.

19 minutes at 7m18s per mile (2 min 40 sec)

Posted by Jack Crossfire | Apr 25, 2018 @ 01:16 AM | 2,223 Views
If the price is based on 100 passengers, with only 40 staterooms, they're planning on people traveling in family units with some of those families having kids young enough to sleep in the same room. The actual price per room is $500,000.

This is might have been Elon's parent's organisation, but it's definitely not the mane social organisation today. Lions still insist the mane customer will be confirmed bachelors looking for the ultimate retirement home.

Most families today from baby boomers to generation X to millenials still have a single male breadwinner earning most of the money & a "partner" earning pinch money.

What's advertised as $200,000 per person is really $500,000 a man has to produce for a room, whether traveling alone or with 2 family members. There might be a way to split it with a room mate, but that still hits $250,000. Suspect that's the mane way most of us will go, but since we wouldn't have to sleep at the same time, there wouldn't a real need for each person to have an entire room.
Posted by Jack Crossfire | Apr 22, 2018 @ 12:13 AM | 2,633 Views
https://www.instagram.com/p/BRwgf8bgGWV/


Our 1st & only view of the inside of the interstage. It probably would have cost a few thou from the BFR budget to put a roof on it or strip out all the guts, so Musk said forget it. They did strip out the pushrod that ejects the 2nd stage & hastily strung an extension cord to a warning light. The extension cord had a little left over. 2 wires in mid air appear to be additions. They could be a radio antenna used by someone else. What are the chances of retired Falcon 9's being sold as cell phone towers?

You can see everything mounted directly on the convex top of the LOX tank. Not content with plain old rods, they used horn shaped rods. It must be the most weight optimized way to transfer torque from a narrow diameter to a wide diameter.

There's a triangular enclosure which could only be a triple redundant brain box, where the 3 computers are mounted symmetrically. All the software flying the 1st stage & the IMU are probably in that box, all calibrated for its orientation on the LOX tank. We also see what could only be the nitrogen thruster tank & the pesky hydraulic fluid tank. Surprising such a small tank is all the nitrogen it takes to fly it back. There's no effort to balance it by mounting the tanks symmetrically.

The torque rods are already looking a bit rusted. The guy obviously doesn't know a 4k copy of the video is stored on the quad copter, but barely knows enough to hit send on an instagram app to upload low res telemetry.
Posted by Jack Crossfire | Apr 18, 2018 @ 04:41 PM | 2,449 Views
10mph in modified flip flops (3 min 37 sec)



Was quite pleased by how stable it was at 10.9mph. For most of its life, it couldn't go straight at 10mph, even when completely empty. It now goes straight even with a camera pole on it. Better living through FIR filters.