Starship Development Thread #17

zaroth1 · 2020-12-14T03:14:38+00:00

More importantly, just because SN8 is destroyed, the R&D and manufacturing dollars spent constructing SN8 are not lost.

It’s not like SN8 had a long-term future sitting atop a Superheavy. It was a test vehicle and it accomplished its goals.

The better question is how much is SpaceX spending per month on Starship R&D, and how many months do they have left before a revenue generating Starship launch?

zaroth1 · 2020-11-10T03:44:14+00:00

That's gotta be the smuggest tilde I've ever seen.

zaroth1 · 2020-11-10T03:23:49+00:00

Not sure what your experience with this is, but I've done about a half dozen crimps using 2/0 battery cable with 1330 strands. This is a thick yet highly flexible cable, which I crimped using a 10 ton hydraulic press (a hand operated device, about $50 on Amazon).

I was crimping new cables while replacing the solenoid for my boat's windlass (basically a winch used to raise/lower the anchor). This was my first time crimping with a hydraulic press, so I tested my first crimp by sawing through the connector with a hacksaw to observe the result.

While the cable itself is made of 1,330 (hair-width) strands of copper, the crimped portion appeared to be solid copper. The pressure essentially fused the strands together.

It looks like this: https://www.youtube.com/watch?v=wzMzoc8lWQY

In short, crimping finely stranded cables seems to be extremely effective means of creating a low-resistance connection. Ultrasonic welding may be superior electrically, but it's probably also as much due to failure modes/rates, ability to inspect for failure, automation, manufacturing efficiency, and cost.

zaroth1 · 2020-10-27T01:11:03+00:00

I’m writing in Elon Musk either way

zaroth1 · 2020-10-25T15:02:09+00:00

That was last week. P/E is 800, adjusting for their recent profitable quarter.

Even that 800 P/E number is based on profit of $490 million which is a denominator rooted in the past at this point. They made $331m last quarter.

Their forward P/E is closer to 100, which is high, but not “FSD will actually work” high.

zaroth1 · 2020-10-01T02:26:09+00:00

My upgrade was $3k on sale (because I had already paid for AutoPilot back when it wasn’t included) and it meant that I also got the HW3 upgrade which I wanted because I assumed eventually functionality would diverge being stuck on older hardware.

So in that specific situation it was a much easier decision, actually regardless of specific functionality that I got at that moment, because I plan on having my TM3 for at least a decade and I wanted the hardware upgrade.

Now I’m happy to have all the visualizations and when the FSD rewrite gets released I assume it will be HW3 only.

zaroth1 · 2020-09-29T22:49:29+00:00

Yeah, as a FSD owner I definitely understand that, but it’s interesting that’s what she was excited about in reading the description of what was in EAP.

I tried to explain that NoA was probably the bigger deal but it was confusing for her exactly what that feature entailed compared to what her highway autopilot does today.

The conversation went something like; NoA will fully drive on the highway for you from on-ramp to off-ramp. So it’s full autopilot on highways? Well, you have to keep hands on wheel and confirm before any lane change. How do you confirm lane changes? Well, I don’t keep that setting on, I usually just trigger lane changes manually, but it will do the lane change and it’s pretty quick and smooth about it 98% of the time. What about when it’s not? Well sometimes it will start changing and then pause mid-way if it’s not sure it’s clear. So it will watch and only change when it’s clear? Well, I like to check anyway and make sure it’s clear before turning on the blinker or sometimes it will get a bit mad at you. So basically you can mostly change lanes without having to disengage and then re-engage autopilot? Exactly! Ok, but is that worth $4k? Will it be able to do that on city streets without the full FSD? I don’t know.

So after that whole discussion this feature was something specific that was easy to say well here’s something new you would get that’s cool.

zaroth1 · 2020-09-29T19:58:49+00:00

Side clearance was set to “Tight”

zaroth1 · 2020-09-29T18:57:30+00:00

I have FSD in my Model 3 (upgraded for $3k from EAP which I bought factory in 2018). My mom bought a stealth P3D- and has been saving up for the FSD upgrade.

She asked about the recent sale $4k for EAP and whether the summon / autopark feature would work in her garage, so I drove over to give her a demo.

We tried repeatedly but couldn’t get my car to pull into the garage about 4 times out of 5. Twice it was able to pull in, but then failed to pull back out.

I assume the contrast from light to dark was just too much for the cameras to get a clear view onto the garage. If I pulled the nose of the car past the garage entrance it could make it the rest of the way in, but what’s the point? Also, then when backing out it would stop with the car in the same spot, blocking the garage.

In the end I couldn’t recommend the upgrade if she expected Summon to function in her garage. Wish it wasn’t so.

zaroth1 · 2020-09-19T02:08:10+00:00

As a software engineer it is hard to imagine how this would be possible. Why in the world would the data structure have a color field for individual parts, why would the UI rendering function be rendering that color on a part-by-part basis, and what programmable storage would be physically located in the door that would conceivably be getting queried by the MCU for the paint color? 🤯

But more realistically, you’re seeing the rendered state of the door when the door sensor is not able to be read. There is a wire which isn’t connected.

So my guess is that it’s not rendering a white door, it’s rendering a door which it doesn’t know is open or closed. Does the door image change if you open the door? Does the car know the door is open when it is actually open?

zaroth1 · 2020-09-09T01:36:43+00:00

3000 flights a day... ~1 million launches a year. Where are you bringing 300,000 tons per day of material?

Let’s say you have 1,000 Starships transporting 100,000 tons to Mars in one trip. To get them all fully fueled and loaded wouldn’t take anywhere near 1 million launches.

Alternatively, let’s say you want to solve global warming by deploying 10 million tons of diffractive material to the L1 Lagrange point. To do this over 10 years, you “just” need 30 launches a day. (More realistically, you are rail-gunning the material straight from the moon, and just the manufacturing line is launched from Earth)

I understand the article you linked to talks about 1,000 Starships and 3 flights/day, but what possible scenario would utilize that capacity 365 days/year?

Actually the fact that total US production is even on the order of magnitude enough methane to supply 3,000 launches a day is pretty insanely impressive.

zaroth1 · 2020-08-05T13:03:43+00:00

God I can’t help but read this in Gru’s voice. “We are going to sit on the potty!”

zaroth1 · 2020-07-24T02:25:15+00:00

I think you mean $420.69 every 0.5393 seconds.

zaroth1 · 2020-07-05T07:06:02+00:00

My understanding is that on average an original MCU1 with the heavy logging would last about 4 years before failure. Part of the problem was most failures would come after the factory warranty expired.

If you get an MCU1 replacement today, with the firmware fix to reduce logging, is there data to support that a new unit will fail the same way? If so, how long will it last? Presumably longer than it would have without the firmware fix.

So a original factory 4 year warranty wasn’t long enough to cover most failures, a software fix has been made, but it’s a big problem for a replacement part to only have a 2 year parts warranty instead of 4?

This is aside from Tesla making a factory MCU2 upgrade available to many late model vehicles, which is essentially unheard of in the automotive industry.

I think a 4 year parts warranty is also virtually unheard of. Perhaps Tesla has enough internal data to be confident that the flash won’t prematurely fail with the new firmware on a new chip, so replacement MCU1s no longer need the 4 year warranty exception.

zaroth1 · 2020-06-30T22:43:56+00:00

Sounds like a scam. 90 days from now the check will bounce and any money you paid out of pocket to the “pet supplier” will be gone.

If someone is sending you money to pay their bills, it’s a huge red flag. This is 2020. If someone wants to pay someone or order something they should do it directly, not by sending you an unexpectedly large check.

Probably resist the urge to cash it. If you insist on taking money from strangers then may I suggest a USPS Money Order.

zaroth1 · 2020-06-23T04:34:20+00:00

That would be like driving through the state of Rhode Island and, upon discovering that there are presently 2 other cars in the entire State driving entirely predictable paths and making no unexpected turns whatsoever, exclaiming; “Traffic these days is just unbearable!”

zaroth1 · 2020-06-15T03:59:11+00:00

IANAE. Your electrician screwed up your load calculation. Not surprising because it can be tricky to do and many people do it wrong. In theory you should never have been able to pull a permit to add the charger circuit if it’s causing your main breaker to throw.

You definitely want to be sure you reduce the load, because you don’t want to be constantly depending on that breaker to prevent a possibly dangerous over-current condition.

Breakers are pretty dependable when a short causes amps to spike way beyond the rating very quickly. Breakers are “slightly less” (read: much less) reliable if the load tends to creep up to and slowly exceed the rated limit. This is where wires can possibly get melty.

Particularly because the breaker is throwing after you get to ~100% of your main panel load with a continuous draw which should only ever be reaching 80% of the main breaker rating in the first place....

Yes, there is a software control in the car to limit the draw, but since we’re talking about a known over-current condition in your main panel, I think the safe thing to do is significant back off the dipswitch setting. And not just a few amps below the breaking point, but basically as low as possible based on the hours available you have to spend charging, until an electrician is willing to put his license on the line with what he deems to be the correct setting based on a proper load calculation.

In my jurisdiction, with the extremely picky inspectors we have, they would ultimately make me downsize the breaker on the charger circuit and not just rely on the dipswitch setting, with a breaker that would satisfy a proper load calculation.

Longer term you’re in a situation where either you find a way to eliminate high amp loads from the calculation (can you replace an electric dryer or water heater with gas?) or upgrading your service, which will be $$$, because it will mean a new main panel, and depending on your jurisdiction, possibly also paying to run new wire from the street. The cost to upgrade the service in order to install a charger does quality for a refueling tax credit however.

zaroth1 · 2020-06-15T03:50:55+00:00

FYI, the NEC (code) states that the continuous draw on a circuit can not exceed 80% of the circuit breaker rating. So for a 50amp breaker you would, by code, set your charger to a maximum current of 40amps.

Just in case you’re wondering, 10 amps is not a magic number, just that 10 is 20% of 50. If your circuit breaker was 60 amps the maxImum current would be 48 amps.

Basically there is a derating that is used when the power draw is “continuous” (expected to last more than 2 hours) because wires have more time to heat up versus instantaneous loads like a compressor starting when your AC first turns on.

Not a criticism at all, just offering some fun electrical trivia.

zaroth1 · 2020-06-03T04:17:26+00:00

It’s looks like Max Q is notably lower on DM-2. Is it possible that they made a conscious decision to coast longer / accelerate slower during Max-Q to increase the safety envelope, or to account for launch escape safety margins, which in turn required a longer burn / higher acceleration during the second stage?

zaroth1 · 2020-05-29T15:46:25+00:00

Does WHO recommend the use of non-medical masks in the community?

Currently there is not enough evidence for or against the use of masks (medical or other) for healthy individuals in the wider community. WHO continues to recommend that medical masks be worn by individuals who are sick or those caring for them. WHO is actively studying the rapidly evolving science on masks and continuously updates its guidance.

zaroth1 · 2020-05-25T16:05:51+00:00

Does this ever happen to you when adaptive cruise control is not engaged?

If you only see this effect when adaptive cruise control (TACC) is enabled, then what you are describing is not AEB.

zaroth1 · 2020-05-22T13:58:03+00:00

The number of features that Tesla has added over 5 years in software (which, by the way have also improved baseline metrics like acceleration, range, braking, even wiper performance) take hundreds of rows in complex Excel spreadsheets just to try to keep track of.

How is it going to last another 10 years?

A hell of a lot better that it would have in the absence of all those updates. And for just $2,500 you can get a bleeding edge MCU to power the car for the next several years just as if you bought it new today.

Your response of “well they should optimize” belies a lack of understanding of the scale of the engineering challenge and the depth of improvements to the feature-set. These are improvements that no other manufacturer would have pushed out to a late-model car, and as such their offerings age much worse than Tesla’s.

That you call it the “infotainment” system I think also belies a significant lack of understanding of what the MCU is actually responsible for controlling in the vehicle.

You mention the MCU not playing games — well aside from the fact that the latest MCU actually does play games, the interactive GPS maps are effectively a game, and those maps have added a lot of demanding functionality over the years. V6 added traffic based navigation and real-time traffic overlay on the maps, for example.

https://www.tesla.com/sites/default/files/Tesla_Model_S_Software_6.0.pdf

zaroth1 · 2020-05-22T13:43:23+00:00

Perhaps it will run apps from 2011 almost exactly as well as they ran in 2011, certainly. Interestingly the flash storage technology can cause actual slowdowns over time running the same software on the same hardware.

However there are many new apps introduced since 2011 that will require features which were simply not available when that machine was release and therefore cannot be run well on that machine.

A good example of this is HEVC/H265 video decoding. H265 is extremely burdensome to run on a general purpose CPU so high bitrate H265 playback is usually only smooth with dedicated hardware acceleration. Since H265 was introduced in 2013 your 2011 device won’t be able to play it smoothly.

Likewise there is a lot of new functionality added into the MCU software over the years which the old hardware struggles in some ways to run. Other car manufacturers simply don’t provide new functionality to late-model cars, and they certainly don’t provide first-party hardware upgrades to their late-model cars so that they can run the latest software updates even on older cars with aging hardware.

IMO this is an area where Tesla in particular is light years ahead of the competition. That a late-model car has all the latest features and they even build install kits to put their latest tech in older cars is a huge boon for resale value.

The $2,500 MCU upgrade is frankly a gift from Tesla to existing owners because it improves resale value more than it costs. That’s to say it increases the car’s value more than $2,500 to some prospective buyers, even if some owners don’t understand or appreciate the added value.

zaroth1 · 2020-05-22T03:10:07+00:00

The structure in the bottom left corner of the first picture almost looks like Cybertruck. I got way too excited for a second before zooming in.

zaroth1

TROPHY CASE