My sailing buddies and I are always asking each other, “why is sailing dying”? Sailing is a very self selecting sport. People generally love it or leave it very quickly. We are in the “love it” camp, and we are always super excited to take people that are curious about sailing out sailing. I would strongly suggest not taking classes. Just get on a boat. It is hilarious how easy it is to find a sailor that will take you out. And if you enjoy that experience, people are always looking for crew to help them sail their boat. So I’d suggest your next step would then be that. You’ll learn so much faster going out for Wednesday night races at your local club. You’ll learn both how to sail and whether you even enjoy it. A lot of places even have a “crew seat” where you literally show up, not knowing anyone, and people see you sitting there and ask your qualifications and if they have room on their boat and are comfortable with the match, take you, a complete newbie and stranger, out sailing.
Classes make it easy feel like you’ve learned “levels” of sailing or to feel like you could rent a boat in the Caribbean. But, they hide a lot of what sailing is really about. Maintenance, rigging, de-rigging, showing up for no wind, learning the rules of sailing, etc, etc. They also miss out on one of the most amazing aspects of sailing: community. Learning from other sailors is key. You’ll borrow parts from (and lend to) other sailors. You’ll help organize races for them and they for you.
Sailing is a beautiful, beautiful lifelong endeavor that I wish everyone could be exposed to and pursue if they’d like to. Look up your local yacht club or Hobie / beach cat fleet or other sailing club and just ask if you can get a ride. Show up early, listen and do what you’re asked, be polite, stay until the boat is totally put away, and repeat. Try different boats with different clubs and people eventually.
Eventually, maybe take a class (RYA not ASA) to formalize your knowledge or fill in the gaps. You’ll clearly know what they are at that point. Eventually maybe buy your own boat, or do as many people do, just keep crewing. Truly good crew are really rare and boat owners will love and appreciate you.
If you’re in Austin, TX, check out Austin Yacht Club or austincats.net.
If you’re in Charleston, SC, check out Charleston Ocean Racing Association (CORA).
Or if you’re somewhere else and interested, message me, and I’ll do my best to find a place and make an introduction. The sailing community is a small world.
There are many sailing schools around SF, but one that stands out is https://www.cal-sailing.org/ - as it's by far the least expensive and low-commitment option to get on the water, and they have dinghies in which you'll learn very fast (but also get wet). Instructors are regular volunteer club members and mileage may vary, so make sure to go out with a few different ones.
Another good way to get started is to find crewing opportunities for casual racing on https://www.latitude38.com/crew-list-home/. Many skippers will take no-experience folks out for fun. (It may take a couple of attempts to find a skipper/crew you enjoy hanging out with)
I found CSC friendly but basically the boating equivalent of opening the encyclopedia at random and reading -- whichever instructor I ended up with would just decide what he wanted to teach/do that day, no structured curriculum. Presumably one could eventually learn enough to pass the test and be able to take dinghies out yourself, but I didn't have the patience--I bought my own and learned more in 30 minutes than I ever did at CSC
If you want to learn how to sail and actually how to sail as the person in charge, you need to be in a dinghy. Its small enough that every thing you do will affect the course and speed, you can feel every little difference and nobody else will confuse the issue by moving or changing anything without you noticing. Sure, having instructors around giving you tips is necessary but you are doing it and the feedback is immediate.
My buddy has a 36' Pearson in the Berkeley marina, sometimes we bring folks out with us.
You can also join the Berkeley Yacht Club (BYC) without a boat, it's not too expensive. There's a bar and social events, good way to meet sailors with boats in the marina and go sailing on a variety of them. They hold races in the bay pretty often, and are sometimes desperate for able bodied ballast.
Spinnaker might be great - I don't know them - but if you're in the market for sailing lessons in SF Bay I can highly, highly recommend Club Nautique out of Alameda[1].
The quality of instruction is very high, with a focus on safety and building a strong foundation of knowledge. Especially if you ever might want to charter in remote locations or sail across oceans, it's really an excellent foundation.
If you have the space the best way to learn how to sail is just buy a cheap dinghy and take it out as much as you can. While you’re looking for a dinghy just read a book on theory. Something like a laser is the ideal platform to learn on and you can go out in the bay and check out Angel island and other fun stuff like that. If you want to get more experience with things besides pure sailing then just crew someone’s boat for free. When you’re done, sell your dinghy, get your money back, and buy yourself a sloop. This is pretty much how I learned how to sail.
School is fine too but you’ll realize that you’re mainly just paying for access to the dinghy anyways. The instructor isn’t going to teach you anything that’s not in a book or that you won’t learn crewing someone else’s boat.
I never ended up on a real-sized sailboat. But, I had fun on a little Sunfish as a teenager. They are nice because you can reasonably learn to sail them over the course of a couple days, and if you flip the boat over you can probably right it without too much drama. Just don’t bonk your head.
I did some river/lake sailing as a kid on the East Coast but now the urge is calling to me! I remember the "righting the boat" test being the scariest/most fun part of the experience -- super glad I went through that and feel confident on a small boat.
Now...I used to remember all the knots we learned but that memory is mostly gone
Other people have echoed the same advice, I’ll add to it.
Take enough of a learn to sail class that you understand the basic theory —- I took one at my local yacht club.
Then, find a racing fleet! Racing boats need crew weight to help the boat sail towards the wind (so you can be useful while you are still learning), and not all the jobs require as much sailing knowledge as others (my first job was to pull the free end of the line while someone was winching in the sail).
Skippers value consistency —- the boat can’t race without a crew, so literally just reliably showing up is a valuable thing.
Cal Sailing Club is a great way to start. You'll learn more quickly on dinghies than keelboats and the skills will benefit your entire sailing career as you move on to bigger boats.
Also check out the Friday night races at Berkeley Yacht Club. Skippers always need crew so it's pretty easy to get a ride. Just hang out at the gate between 5 and 6pm with your gear and say hi!
Cal Sailing is a good way to get on the water and learn the basics. You can learn dinghies, keel boats and windsurfing. After you're comfortable with basic keel boat crewing, you can probably get a ride on a boat in the Friday night beer races at the BYC. I started at Cal Sailing and eventually raced at the Rolex Big Boat Series at the St. Francis.
Larry Ellison started at Cal Sailing and Lowell North was dinghy chair in its previous incarnation as a UC Berkeley club.
There is a great school called Modern Sailing School in Sausalito. I highly recommend taking a class from them. I took one in the past and they are great!
Will help you figure out if you are into sailing or not.
mold making is also pretty complicated -- anything in the 1,000-1M parts produced will _probably_ be an aluminum mold (cheaper than steel) but they're still heavy and large to keep around.
I haven't met any injection molding shops in the US that do a huge amount of specialty parts like toys. The industry tries to get as many medical device jobs as possible.
This scratches a corner of my brain I didn't know I had. It's the start of the month and I'm writing investor updates, and seeing an author who...wants to treat writing a book like it's a startup and a book advance like a raise...neat!
Half of college I'd take the Crescent from Philadelphia to Atlanta, then back at the end.
It was great -- you could bring on as much as you could carry (I brought a beanbag chair my junior year) and the food was always good. You meet some incredible people on Amtrak.
Being in SF now I've wanted to check out the Amtrak scene to do some West Coast exploring!
That's another very, very interesting case we thought about tackling. That sounds like something that's ripe for transformer-based vision models to keep the overall size of the model down.
What kind of timescales do you get when measuring parts in an electron microscope case? Are these crankshafts whizzing by, or something like a ship propeller where people spend days making sure every inch is covered?
It's so incredibly frustrating when you're past final assembly of some system, and only then do you see a defect that requires a teardown! You touched upon a really fun piece of defect detection -- quality metrics are highly dependent upon the customer, but that makes it fun for us
Great paper links too, I really appreciate that! My French is a little rusty, but I love the comic at the start!!
LLMs like GPT-4o have some pretty impressive image performance. It can actually pick up some of the more obvious defects on our buckets (Steph tested it out just now).
Two problems though with the OpenAI approach:
1. You'd need a cloud connection to send those images up to and get the answer back down so that's cost in terms of your round-trip latency, network infra, and the OpenAI account itself.
2. It doesn't do well with the very subtle defects - mild shape changes, loss of features from short shots, etc
It might be worth using in the offline pipeline for auto labeling though!
> Nice! I have so many questions.. How stable is the injection molding process once it's fully proven out, up and running? Is it a bathtub curve shape, do defects keep randomly popping up?
They tend to pop up randomly -- mold wear is a big one -- and that's a function of material selected for the mold itself (resin vs aluminum vs steel.)
> What do you use on your end to label the ejector pin locations, parting lines, etc? Does this process use Hexagon software inputs to make that easier?
Right now we have an in-house tool for this - but it's a bit painful on our end so we're always looking for good alternatives!
> If you're not relying so much on a skilled operator, would you be using a CMM for dimensional inspection anyways, and then would this be better solved with a CMM? How can you get quality parts if you don't have a skilled operator anyways to set up the machine correctly and correct the defects? Are you ever going to be able to replace a good machine operator? Or this just helps reduce the inspection toil and burden? Do they usually need 100% inspection, or just periodic with binning?
Injection molding is usually for mass manufacturing - think multiple parts coming in bursts every minute or so - which makes CMM a tough to integrate without way slowing down your line. There's also the case of big objects like bumpers and chairs that might not be easy to CMM. We're not shooting to replace machine operators - just make their lives easier. With injection molding our customers so far usually really want 100% inspection instead of sampling.
> Don't most of these machines have the parts just fall in a bin, with no robot arm? Doesn't this seem like instead of paying a good injection mold tech, now you're paying for an injection mold tech and a robotics tech, if you have to program the arm path for every part setup?
Depends on the shop! Some have automated packaging systems that someone has to stare at. Some are trying to add in automated packaging a build out a defect plan. Keep in mind you don't necessarily need a full robot to get bad parts off your line - a little shoving arm to just boot the bad parts off a conveyor works fine in some cases.
> How many defects are "dimensional" and how many are "cosmetic" ?
Varies wildly by design - but I'd say we see more cosmetic than dimensional. Maybe because the ratio of cosmetic surface to interface surface is fairly high.
> Can a defect detection model accept injection mold pressure curves as input? Isn't that a better data source for flash and underfilling?
I'll have to keep that in mind - it's a great idea. The hard part there is that you'll need a per-machine calibration and a lot of data collection. Could be good though!
> Is this supposed to get retrofit, or go on new machines?
Ideally both since it's a separate camera system, although I'd love to try to integrate with the machines themselves.
I have seen machines with visual pressure curve output on the operator screen for each part. I also think some machines have automatic pressure monitoring already built into the machine control, but it's certainly not transformer model based.
I didn't know they were using resin molds, that takes cheap aluminum prototype scale up mold to a whole new level.
Last time I checked, the mold design software itself has the same UI as 1999 AutoCAD.
How many images/angles can you effectively sample and compare on that hardware in a 30 second cycle time? How would you process images from more than one camera? If you have 8 cameras, can the defect recognition software run on 8 threads?
Are injection mold operators mostly located in low labor cost areas? Is any reshoring happening?
Injection molding houses are heavily concentrated in LCOL areas -- but it's a massive market, so, so much of modern materials are plastic that there's a lot that's done in the US/Canada/Mexico, in North America, and Germany/Italy/Austria.
For just the automotive industry, there are 120 injection molding contractors in Michigan alone. Onshoring and reshoring are desired for really customer facing parts -- you spend a lot of weight on packaging to mitigate scratches when you produce abroad then assemble domestically.
Staying with automotive, electrification is driving the injection molding industry -- as your weight shifts to "big battery with a shell around it" more of the total components of a vehicle are injected.
Zooming out of automotive, biomedical device packaging is a huge injection molded business that's stayed in the US and is growing.
Steph here - each image takes about ~250ms on a small single board compute like an Nvidia Orin Nano. On something larger like an RTX 4080 GPU it's less than 100ms. Because we're running big models we can't really just spin out more threads ourselves, we throw them over to the GPU (or deep learning accelerator - depending on the platform) and the driver's internal scheduler decides how to get it done.
In a robotic packaging scenario most of the time is spent by the robot picking up the objects and moving them, so for a 30 second cycle we usually get less than a second to take multiple pictures and make a decision about the part. For a smaller number of images - like 4 - it's pretty easy to handle with cheap hardware like an Orin Nano or Orin NX. If we've got more images (like 8) and a tight time budget (like less than 2 seconds) we'd usually just bump up the hardware, like going to a higher tier of Nvidia's line of Orins or using compute with an RTX 4080 GPU or equivalent in it.
Making synthetic data from a 3D model is really nothing too special - it's just a tiny subset of what video game engine does. But there's one extra step required for defect detection: you need to think about where the defects occur (and where the non-defect witness marks occur) and simulate those. Like any startup our biggest advantage here over the big companies is we move fast and customers usually like us. Our second biggest advantage: defect detection just isn't sexy, so it's not top of mind for most folks.
I think yes there probably should be tariffs on Chinese EVs (we're pretty big on on-shore manufacturing) but that's essentially a crutch. We'll need a lot of automation and design work to push down US-made EV cost to be competitive. If we want electrification to increase and onshoring to occur we've gotta bring prices down to something folks can easily buy that solves their problems.
> Do you see what I mean? Technology doesn't change the relative costs, which matter, even if it changes the absolute costs, which don't.
I get what you're saying, and I somewhat agree. But I think it does leave out the desire some consumers have to purchase domestic. For example, I might be willing to buy a domestically made vehicle if the price is under $25K even if it's more than a similar vehicle made overseas. But if the price is over that, I'm going with the cheaper import.
The idea of the domestically manufactured vehicle is just that, an idea.
There's the fiction of quota and part manifests.
Then there's the reality that, well I assemble a thousand parts in China into one "part" then I import that one "part."
There are a ton of people employed by the autos industry in the US but that's so broad. It basically means there are a ton of people employed by organizing our life around cars. While some are involved in some kind of manufacturing, relative to the amount of manufacturing and manpower in China, it is small.
So every way you look at domestic, it seems less and less like it really means "domestic," and more and more like it's a form of vague but powerful storytelling.
I don't think it's good for anyone to be so wedded to storytelling. And anyway, you could try e-biking in weather, it's fine, sometimes it's even fun, and then suddenly you're like, well do I need more than the occasional rented car?
That's a fair point. Personally, I don't want a car at all but it's highly impractical for me not to have one where I live. I didn't own a car until my 30s and before that I biked or took the bus everywhere. However, where I am now public transit is severely lacking and the weather is often not conducive to biking.
Did some digging and found a sailing school that I haven't asked about classes (yet) https://www.spinnaker-sailing.com
There's even a school that offers boatbuilding lessons in Sausalito -- a bit too far/much of a time commitment for me! https://www.spauldingcenter.org/current-offerings