Saturday, July 15, 2023

Owning a Rivian After Three Weeks

Well, after never having a car loan in 37 years of life I have a very large car loan, larger than my house mortgage in rural Kansas. That’s the obvious downside. With that out of the way, wow, this car is a game changer!

For starters, charging at home is unbelievable, it’s such a great experience. And yes, in my little apartment that means running an extension cord out my second floor, back door to my little off street parking. I was doing only 120 volt charging most of the first two weeks, which added maybe 30 miles of range in a 10-12 hour overnight. While not very much, my normal round trip daily driving is 16 miles round trip to work, so it’s actually totally acceptable. However, I stretched the cable, bought a NEMA 10-50 adapter, and managed to plug into my 60 amp 240 volt electric stove and oven plug! That managed to charge something like 70 miles of range in less than four hours! I realize that these numbers are minuscule, and when taking a road trip most vehicles get 400-500 miles for a three minute gasoline stop. However, that gasoline is costing you money, probably $50 or more, while even my 70 mile charging session I estimate was less than $4 since I was charging at night when the electricity rate is less expensive. It feels kind of like getting interest on a savings account, my mileage balance goes up over night and at the end of the month my total electricity bill will likely be only $15 higher. I didn’t realize how much enjoyment I would get out of charging my car at my apartment over night. Plus, I’m driving a brick of a vehicle, a more efficient little car could probably get away with 120 volt charging. I should write a blog post about how offering free standard 120 volt outlets is a very easy way for businesses to support electric vehicles, without having to install $1000 charging stations. 

I’m probably going to write more about the charging aspect, because it was just so cool to fill up at home. I haven’t tried a single fast charger yet or public charger yet, looks like I probably won’t for another month or so.

Other things to like, people are definitely going to say the acceleration, but frankly I’ve only accelerated fast a handful of times, because it all happens so fast that on a city street or in Bay Area traffic it feels reckless. I told a few people, I was excited for an electric 4Runner style vehicle with a 300+ mile range, off road capabilities, and ability to car camp, that I would have bought it with 300 horsepower, not the 800 hp the Rivian has. The backup camera and overhead views are great! The cruise control, with the radar range finders on the front of the car are really nice. I’ve had that on a few rental cars and it’s great! I have not tried to activate the driver assist feature where the car does the steering, I’m skeptical of that functionality based on some previous use of it in Teslas. The front trunk is cool. I can easily see how road tripping or car camping that compartment is going to come in really handy. The wireless phone charging is pretty cool. It’s not super fast, but it’s fun to get a few percent charge into my phone on my 20 minute commute. One pedal driving is really nice when it comes to stopping. When you have mostly let off the pedal the regenerative braking slows you down, so you don’t have to hop off the accelerator and on to the brake really fast like you do in an internal combustion engine when the traffic in front of you suddenly stops. I think I like sport mode better than all-purpose mode for driving, it’s only about 1% less efficient, but the SUV is lower to the ground and has a stiffer ride. In all-purpose it feels sometimes like I’m on a boat bouncing up and down, and it’s pretty high for me to get into. 

I only used the navigation once, and it seems to work well but at this point that’s the bar for entry… not a cool feature like Google Maps was on iPhone in 2008. I haven’t camped in it or taken it off road yet. I've only begun to explore the features in the menus. I haven't used the camp speaker yet. The automatic hood is unnecessarily complicated. It's cool, but too many moving parts, but probably cost like $1500 compared to a traditional hood hinge at $25. I have the 21" all purpose, longer range tires. At some point I'll probably switch to 20" all terrains, but clearly like most new electric vehicle drivers I am worried about range, so it's nice to see the 338 mile range estimate in conserve mode with these tires.

Already, for short trips at least there is basically no going back to  a gas car. When I'm idling in a traffic jam, it's so rewarding to know that I'm not emitting smog in that moment. I know that somewhere a coal powerplant is pumping out a cloud of smoke, but in the moment, driving the EV, I just don't need to worry about carbon monoxide if I run the vehicle in the garage. It makes traffic jams more pleasant. I wasn't expecting to have an emotional reaction to not idling a car, but I do. My lungs are strong, but fragile, and I've always been frustrated when I don't have clean air to breathe, like when people are idling a car unnecessarily and I'm near the tailpipe. I've bicycled behind cars and trucks at times to go fast, but there is often the wafting smell of the emissions making it a little harder to take a deep breath and keep up with the car. It's a satisfying feeling, one I didn't expect.

At the end of the day it's a mechanical and electrical collection of parts, yet somehow it represents a way forward for us to take a little bit better care of the air in the world, and also have a really exciting time in the process.

Friday, July 7, 2023

Design, Manufacturing, and Testing are the basic categories for all types of engineering.

It's taken me years, but I now feel that most engineering roles can be broken down into design, manufacturing, or testing. This is probably more applicable to hardware than software, but it's not limited to hardware. To summarize:

  • Design - People at the start of the product lifecycle process, who design the thing to meet requirements.
  • Manufacturing - People who build the product.
  • Test - People who make sure that the product meets the requirements.
To some extent this is a narrow view, because when it comes to things like requirements, there is a market and a business case that drives the whole engineering process. If there was no business case, it's just a hobby and not a business. Why am I writing about this?

2011 through 2018 I was at a company with very developed processes, and rather static hierarchy, which all worked very well for that company. The company was well over 100 years old, so they had a long time to sort out a system that worked well for them. Then I joined the world of startups and young companies, because it's thrilling and an adventure. However, young companies don't have their processes and hierarchy all worked out. 2011 through 2018 I started in analysis (a sub-set of testing) and then moved over to design. When I started in the startup world I started in design, and then moved over to manufacturing. Through several different organizations I now see how the three basics of design, manufacturing, and testing are really the foundation of bringing a product to market. 

A really small company can have the design engineers build the product and test the product, however that doesn't scale very well beyond the first one, not even to 10 total units. So in the world of race cars, Mars landers, and other highly highly specialized, super low volume products it works, but by the time the volumes creep up to something like the Concord airplane or B2 Bomber (about 20 units total), there needs to be division of labor to keep up with any sort of production schedule and make sure that each role is adequately resourced. Some sort of program schedule takes shape and goes something like this:
Design, Manufacture, Test

Obviously that's an overly simplistic representation of a product development process. In today's world, a lot of testing can happen before the final product is manufactured through virtual analysis tools. And of course, the goal is for the prototypes and production to be the same... but of course that rarely happens and leads to a whole other topic of change control. Also left out of this discussion is requirements for the product. The better the requirements are defined in the beginning, the easier this whole process will be down the road. Defining requirements is hard, and frankly, there comes a point where it makes sense to just start designing and building the product prototypes in order to learn all of the formerly unknown requirements.

I once had the experience where the assembly design (and bill of materials) was released/confirmed on a Wednesday and the very next day the expectation was that we would build it... needless to say supply chain had not bought all of the parts to make that possible. I've also been asked in the past why it's hard to build something without a released bill of materials from design engineers, with the simple answer being, if you want manufacturing to buy all of the parts and use all of them in the product, then yes we need a bill of materials to go off of. I've had another example where some test engineers were adamant that the wrong assembly was built, and yet all three physically built prototypes, and the original virtual design, and the work instructions were all in agreement about the particular issue.

In all three examples, people were upset. They felt like they had been failed by their peers, but it was really a misunderstanding of what their peers needed as inputs in order to do their jobs well. Yet going back to 2011, when I was in analysis (testing), I remember saying that a 25 mm steel plate would work in a location, the design guy said nothing, but the manufacturing engineer said that was unreasonable and we needed to figure out how to use a smaller plate, so we did, because we now had a better requirement (no 25 mm thick plates on this assembly), and this all happened two years before prototypes were built. I remember that interaction as something of the gold standard for getting design, test, and manufacturing in the same room, two years before the assembly was first built, and four years before production, so that when we went to production that particular assembly was very smooth.
The general flow of engineering information.

And again, this image is a simplistic understanding of engineering. However, for the purpose of this article, this is really about organizational structure, schedules, inputs and outputs. It's not possible to do everything at once. Many things can be parallel pathed but you can't drive a car without wheels. You can't drill a hole without a tolerance. You can't weld two plates together if you don't know the materials. Hopefully this small overview gives non-engineers a little more context into the different areas of engineering, as well as perhaps new engineers information about different roles that I didn't understand until I had years of experience engineering. My advice to new college graduate engineers, get your hands dirty doing a little of all three. It doesn't really matter what you do the first two years of your career, just learn how things are designed, manufactured and tested. You can figure out which part you like best when you understand the engineering industry better.