E-SUP Drive System | Build Version 2

First water test OK! Motor Driver VESC required fine tuning as efficiency was terrible.

At home Ingress, Drive, Endurance, Characterization and Validation

Silicone Mold to make my own 1-way Diaphragms. Part is not robust- I have a new idea to simply use existing neoprene washers and 3D print retainer around it.

Building a Second Motored Kit so my family and friends can accompany explorations of the waters around us. This is a lighter system for use on a SUP board to enjoy shallow low tide waters and for friends to join rides with the first Electric Foil board I made . I learned my lessons with the first one, especially to perform ingress and drive validation with an Water Tub at home, rather than debugging while afloat in the Bay!

Target specs: 5mi Range, 8mph Max (ideally sufficient to plane on water surface)

Status: Ingress Protected Battery and Drive box Complete. VESC and Throttle have been tuned for better efficiency. Will perform more Propeller optimization. Otherwise ready to enjoy on the water!

Summer 2024 Nature between CA and OR

Wonderful time exploring nature this summer with the kids. My personal projects have been lagging a bit due to the time to seize outdoors but satiated for now so I’m feeling the bug to pick up some new projects again!

Mountaineering: romping on some Cascades between CA and OR. Summit of Mt. Hood and Mt. Shasta! Tried for Mt. Rainier but high winds prevented a push for the summit.

Sea Time: I’ve been trying out spearfishing this past year and have appreciated learning more of the lives of these sea creatures. Training my breathhold and efficient swimming have started to garner some Rockfish in the Monterey Kelp forests. It was really fun to snorkel for Crab by hand and avoid getting pinched in Oregon! Foraging for kelp as a side dish was delicious (apparently it’s all edible!) among the rocks and tide pools.

Flying with Zipline!

I’ve Joined Zipline and I’m excited to bring my personal passions of Aviation into the professional domain! Thus far, they've provided nearly 1million life-saving medical deliveries with the Aerial drones they've developed. I'm excited to contribute to the next generation aircraft system to help people on a greater scale!

I’m intrigued by how they have been approaching and defining the problem, and some of the clever solutions they’ve been exploring, such as- Novel propeller design for quieter operation, Package precision guidance Droid, and Safety countermeasures such as Acoustic Detect-and-Avoid and ballistic parachute.

Restoration and Paternity Time

I’ve been taking a few months extra off this summer to enjoy time with our kids ( 5yo Lucia and 8mo Laiken )… and to have some fun in the PNW!

I’m finally taking on some of the bigger jumps at the bike park in PDX. It fascinates me dissecting the dynamics, for example, leaning forward at the lip of of the jump is helping to extend the range while leaning back into the face of the jump and pressing with the legs provides more pop. I’m still working the whip!

Got to climb Mt. Adams 12,200’ again with my pilot friend. Nice time of year to camp on the way up too. I’m hoping I get the time to try Mt. Rainier later this summer!

My DIY E-Foil is working great! I took it out on Hagg lake after doing my first sprint Triathlon. The disbelieving expression of "I’m seeing a space-ship” on the faces of other boaters is honestly kind of satisfying [ Project Write-up is here! ]

What's the '“problem” with generalized robots?

Here’s a little of what I’ve been working on at Google X for the last few years: generalized robotics. To my understanding, we have built the largest fleet of mobile robots capable of interacting on the human scale (ie. Picking up things, open drawers and doors, wiping tables). There’s still a ridiculous way to go in this field! I’m finding the most important thing in navigating all the possible solutions and technologies is to understand the problem

Generalized Robots: as a ‘helper’ robot it has to navigate unstructured and cluttered environments. As opposed to most robots currently out in the world being choreographed, remote controlled, or with explicitly coded reactions. For example in Mechanical Design, it’s “how big or strong or small or fast does the gripper need to be?”, “Should the cameras be high up to see all around or lower to see under tables, or on the arm for different vantage points?”. Ultimately these all hit multidimensional tradeoffs, so only when understanding the value and the problem can we dive into all the crazy solutions and technologies. There’s still a lot to reflect on, happy to chat and hear other thoughts.

DIY HydroFoil Flight!

This thing is really working!

[ added July2023: more detailed write-up here! ]

I tried making my own waterproof motors a few years ago and tested them on the lake but switched to a new strategy in the past few months. As I struggled to make rapid progress earlier, I made a Dyno for the drive system where I could test at home to debug components rather than hauling the project out to a lake for each incremental test.

In the latest sessions, I’m cruising at ~9-14mph with 9+mi of range (batteries providing about 32aH)

Before building anything and knowing what components can even achieve this, We need to Estimate our Target:

A hydrofoil works the same as an airplane, but underwater. Thus I can use the Lift/Drag ratio of this Foil, knowing the required lift (me and the board) and the approximate cruise speed, to determine the drag required overcome. It’s also important to include the air drag of things above the water (primarily myself).

Motor Dyno:

It ain’t pretty… Scrappy is the word. Just a modest 80gal bin of water. The motor is providing static thrust upward into a loadcell with instrumentation on the ESC to monitor Power, Ah used, Mosfet temperature etc… This helped me to debug the entire drive system and learn more about which propellers would be optimal.

At present, the batteries are the limiting factor as they limit output current to 65Amps which produces >30kg Static thrust. Riding on Foil requires just 30-40amps. The ESC and Motor are rated for twice as much current, 150amps. I’m content as it is for now, but may like to access more power in the future!

The data out of this has helped to quickly inform incremental design: such as monitoring the heat rise (yellow line) helped me try out different heatsink and active cooling strategies.

Electric Surfboard motor- DIY waterproofing

Overview: ~2kW motor enclosure. Some interesting challenges such as water proofing, heat dissipation, and trying to build this with hand-tools. I’ll post a video and some other notes soon. I tested this on the water and could propel me on a paddleboard slightly faster than I could paddle at maximum. Overall, it worked pretty well- putting out a handsome 10-20kG static thrust. Despite some small leaks! The power output had fluctuated largely because I didn’t optimize the propeller-motor size, and the Motor Controller was not programmed for this kind of loading.

Motivation: We like to go paddling but in the SF bay area most places are either the Ocean or the Bay. The typical breeze and currents and larger expanses to cover make it tantalizing to have a boost. Ideally being able to rip would be awesome. I was also interested in experimenting with Ingress Protection strategies for motors.

Challenge: Making a watertight enclosure with electrical cables and a spinning shaft is not so trivial. The motor will definitely warm up and must have a way for heat to exit, so a 3D printed plastic enclosure will ultimately fail and metal would be preferred. Since this will be in a saltwater caustic environment, aluminum is preferred over steel, especially since it is relatively easier to cut and shape with the tools I have at home!

Process and Results: this was designed around a ~2kW motor I had lying around and during the pandemic lockdown, I had to utilize very scrappy processes at home, such as hand drilling bolt patterns, and brazing aluminum. To seal around a spinning shaft, I discovered ‘Rotary seals’ which are a little O-ring flange with a spring for tightness. To seal around the existing cables and plug other holes around the cap I used hot-glue… This was not a good solution as the hot glue can contract and delaminate when immersed - epoxy would be a better DIY solution for sealing this.

brazing aluminum was a little tricky as it needed a more stable temperature between wetting of the rod and not to hot to burn through the substrate

Aluminum Enclosure and Initial Plastic Enclosure

Working With Composites

Here are some quick ideas about composites (including Carbon Fiber and glass fiber) for people that may be new to working with them. They may kick-ass in certain in high performance applications but can easily be used incorrectly.

Some Counter-Intuitive lessons about Composites:

• Look carefully at this Fig. 9. This shows the Strength-Weight ratio of common materials:

• • The first thing to note is Carbon Composite’s high Strength-weight ratio. WOW, it’s basically 10x that of steel.

  • The next thing to remark is that Steels and Aluminum Alloys have VERY similar strength-to-weight. That can be reasoned from the idea that “Aluminum is 1/3 the density of steel and 1/3 the Tensile strength”

  • Finally, the very impressive thing to note is that WOOD has similar strength-to-weight ratio as steel and aluminum!

  • (Some of these great insights I learned from this awesome book. It’s enjoyable to read and reinforces tons of fundamentals with tangible examples from the Formula 1 performance realm: Engineer to Win )

• Carbon Fiber is NOT ALWAYS YOUR BEST CHOICE:

  • CF is very stiff (notice the steep stress-strain) which is good if you want very rigid like airplane fuselage or surfboard, however if you need something tougher or more resilient with greater energy absorption, you may prefer something else like Glass Fiber. For Example something where the entire body is intended to flex: Skis, snowboard, longboard, that absorbs bumps for smoother ride would prefer E-glass (glass fiber) over Carbon Fiber. (In other words, Glass fiber can bend further without breaking.)

SpringFree Trampolines utilize FIBERGLASS rods to provide high-cycle energy return

General Design Practices: [Here’s a great overview with much more detail]

• Flexibility: Carbon Fiber has 10x the specific Tensile strength of steel… Although Fiberglass (E-glass) has lower Tensile strength than Carbon Fiber, it has much greater elongation meaning that it absorbs much more energy before fracture. Thus contrary to popular assumption, Carbon fiber may not be the ideal material if the structure is intended to undergo large strain.

• Shear Buckling is how it will fail: Composites are generally sheets laminated over a light body like foam or honeycomb. When the sheets are in tension, they’ll take load happily, but Compression is often the source of failure because these thin sheets will ultimately have an urge to buckle. They could buckle inward and crush the core material or buckle outward and tear or delaminate from the core material. This is the case even in basic cantilever bending where one side is in tension and the opposite side: compression.

• Weave orientation: 45-45, 0-90, 30-60-90 are all typical weave patterns. Align fibers with dominant axis of bending however it is important to supplement with fibers in the 45 or 30-60 to resist out-of-plane buckling and torsion. Furthermore, additional angles avoid warpage of the part during curing.

• Taper the strength: When reinforcing a region (such as the center portion of a beam suffering peak bending stress), it is important to taper/feather reinforcement layers so as not to create a hard transition and stress concentration.

• Kevlar Fiber can add toughness

• TPU layers can add some toughness and improved bonding with core materials

Farbrication, Diagnosis and Repair Methods

• Vacuum bagging, autoclave prepreg

• Casting molds, applying pressure

• Peel-ply stretched plastic to provide smooth surface finish video here

Identifying Fractures:

• Thermal dissipation: carbon is a good thermal conductor. Thus applying heating and cooling to a fractured region can highlight hidden fractures when viewed with thermal camera.

• Microscopy: Composite fractures will generally splinter and create jagged line. Additionally broken fibers splay and raise up along a fracture. Microscopic imaging while stress loading a region is another effective method for identifying potential fractures

There’re a lot more great tidbits and nuances I’d love to hear so please share comments

[X]

Thrilled to join [X]! Formerly part of Google, this is a collection of startups developing ambitious leaps in technology to help the future of the planet. I'll be doing mechanical engineering in robotics. The culture of exploration and growth couldn’t be better match! (visit: X.company)

It’s been an arduous journey over many months with lots of uncertainty and rejections- from promoting my projects (ie this website), pestering connections, reaching out to strangers, exhaustive interviews at Apple, Lyft, Astra Space, Lucid Motors, Wing, and more. Thankful for the all people and luck that came my way. Happy commiserate with anyone on new directions, job hunting, and sharing ideas, so let's chat!

Gallery of our 6month Fulbright Grant in Finland

We’re back in the US and settled after our wonderful trip to Finland. We learned so much on society, culture, and design. Exploring such a new world together with our baby daughter, tromping around in the snow and long-distance iceskating in the winter, biking and swimming under the endless sunlight in summer, it was profound.

Take a look at some of the highlights here: https://asaweiss.com/finlandfulbright

All-Electric Ferry in Norway's Fjords - First of its Kind

While touring the Fjords in Norway, we took an opportunity to transit from Flåm to Gudvangen on an All-Electric Carbon-Fiber Ferry. I contacted the Engineering officer for a tour of the power and drive systems. He was happy to detail the superiorities over the diesel powertrains he formerly worked on.

Based on my former work with Boosted Electric, it was really interesting to discuss similar engineering challenges from a skateboard-sized scale brought to a 753ton ship-scale. (i.e cooling, cabling, waterproofing, efficiency, servicing, etc…). Perhaps I will update with deeper details at a later time

With pristine splendor like this, it’s obvious why electric can help preserve it

Catamarans are nice and steady

• Completely silent, no emissions, and serves bubbly champagne.

  • I don’t recall the specifics but the ship sailed nominally at ~200A and 180v… so it has a ton of power to spare!

• Dual 450kW main motors [600hp]- Max Speed 19.5kn

  • Utilizes a geared transmission for efficiency

  • Variable pitch propellers

  • Glycol cooling system, uses heat exchanger with ambient Fjord water

• Batteries - 1800kWh, Range - 40kn / 2.5hrs @ 16kn

  • Utilized several dozen brief-cased sized bank of batteries produced by Samsung

  • Integrated into Glycol cooling system, in addition to Forced convection

• Charging 15-25min charge time (through a motorized crane carrying really fat cables! It was apparent even those got hot enough to warm your hands on a cold day and age the rubber)

Other Specs:

Dimensions: 42m Length, 15m Width, 753 ton weight

Manufacturer: Brødene Aa AS, Built 2018

Champagne: 200 Norwegian kroners, bubbly.

New airplane designs

There are some new design ideas I’ve been interested in trying out with my longtime hobby of RC aircraft. I also recently found some great Aircraft Design and Analysis software ( XFLR5 ) to aid in creating these things, it is fabulous. I’ve had a lot of airplanes immediately crash on their maiden flight but now I’ve finally developed an approach to make these things a success from their first flight. I plan to write more in depth on the calculations, analysis, and concepts, involved shortly but here is an update of my progress.

I cut some corners with the first prototype as it has been a few years since I moved from fixed wing to building drones (tricopters, bicopters, quadcopters, hexacopters, etc…)

But now that I’ve recently revisited fixed wings after taking flight lessons and paragliding certification, there’s even more I’m appreciating about flying them. Here’s an overview of the design, analysis and builds.

Gyro Stabilized Binoculars

Simple idea to mitigate roll and pitch shake of my binoculars while I stare at the neighbors staring at me watch nature and inspect the quality of the ice on the lake for skating.

Some unusually annoying challenges: (read my upcoming ‘traveling and making’ post for more gripes)

• 3D printed screws: I prefer metric but the truth is that most Binoculars (and camera gear) like to take 1/4-20 threaded screws. Considering European hardware stores stock exclusively metric [even metric lumber!], I improvise with a 3D printed 1/4-20 thread. An M3 bolt is inserted into the core to reinforce. The 3D printed portion is to mount the entire mechanism onto the binocular.

• A lathe is a luxury: A gyroscopic disc would be delight on a lathe… A 3D printed disc is not perfectly balanced so I am using screw features to modulate the balance on each side.

• The first iteration of this disc instantly launched a screw when it spun as it tore through the plastic edge. I’ve reinforced the edge, turned down the spin speed and using much smaller screws for balancing.

Operational Status: Surprisingly good helping to maintain target, it does pull a little but definitely soaks up any shake. It rumbles a little. Needs a little time balancing the weight of the gyroscope. Will update when something notable happens with my neighbors.

Helsinki's Incubator and Tech Hub

Maria 01 is quickly becoming the largest incubator in northern Europe. I had a chance to interview one of the organization’s leaders, Robrigo Ribeiro.

This is part of my ongoing project to explore design and innovation everywhere.

We are somewhat familiar with the workings of incubators in SF Bay area, so it’s interesting for me to learn about startups outside the US. Here are some concepts from our conversation that I had not considered previously:

Destruction breeds creation: The 2014 downturn at Nokia with Microsoft left a lot of talented engineers and thinkers out of a job. Naturally they started gathering for new ideas and creations. We generally believe mass layoffs to be a terrible thing but given the right environment it can seed many new companies.

Motivation for prominence: There’s an interesting cultural dynamic that is being overturned: Finns have a philosophy of ‘humility’ and ‘don’t stick out’ yet there’s the compulsion to plan for the future which involves growing with this technological era. Although they have a proven forestry industry, consumer tech such as Nokia has dimmed from the global scene and that involves growing with this technological era.

Make it or State it: A large portion of the upkeep is upheld by the city and state. I understand that US investors like to buy into a ‘Fad’ (i.e E-scooters, mobile apps) and are more shy about hardware investments nowadays. I can imagine state funding like this helps less flashy technologies to get off the ground rather than chasing the allure of astronomical ROIs.

I’ll be having another visit this week to continue interviewing and seeing some of the startups at work.

https://maria.io/

Musical Intervals Visualized

I love making music, primarily guitar and piano (Fun fact, I was a music composition minor!). I’ve always been fascinated by theory and I finally sat down to visualize what is happening when notes are put together. Ever wonder what the standing waves for our most common intervals look like? Click the image to see more!

C Major chord (red) vs. C Minor chord (blue)

E-Sled Electric SnowMobile

I am continuing to explore Nordic innovation. Whilst visiting Rovaniemi, Finland, I met the world’s only consumer operating Electric Snowmobile company, Aurora Drivetrains. These 115HP sleds have held their ground competing against gas-counterparts in several events and I was thrilled to have a test-ride and discuss their tech. The high-performance in adverse environmental conditions give the drivetrains huge potential to be transferred into other vehicles such as ATVs, Side-by-Sides and JetSkis. I have been working with drivetrains and electric vehicles for several years so there’s a lot I could dig into here.

I took this opportunity to discuss with their lead Mechanical Engineer and Co-founder some unique design challenges:

• Extreme Temperatures [-40degC to +30degC operating zone]

  • Batteries: Cold temps reduce max discharge, prohibit charging, and adversely affect cycle life. They’ve come up with a liquid glycol heating system integrated with the batteries and along with a standby heater to get started. Once moving and hot, the glycol system is regulated with ambient air to keep cool.

  • Motor: Due to cold ambient temps and using their temp regulation system, they are able to squeeze over 115HP out of a custom brushless motor the size of a gallon ice cream tub.

  • Traction Belt system: The rubber belts must not crack at cold temps and overly soften at higher temps. Currently they are using industry standard cable-backed tracks running on PPE sliders. Friction and deformation as it rolls quickly heats the belt snow is intentionally kicked up by the front skids to cool the belt. They are working on increasing the efficiency of the sliders.

• Environmental / weather sealing

  • Currently using mostly standard automotive IP66 connectors but the goal is to make the entire system fully submersible… and since it’s electric it doesn’t need air to keep driving!

I was impressed they have developed so much with just 3 engineers. All the parts are made in-house. The dozen or so vehicles are already in use with researchers in sensitive arctic ecosystems and local tour companies which provide a great testing grounds for future production and exposure with the public. The upcoming challenges are streamlining/cost reduction and getting market momentum for these high torque, stealthily silent, and zero-emissions snow machines.

Hunting Aurora

I dabbled quite a bit in astrophotography and timelapses but aurora are harder to catch but much easier to photograph ( if the conditions are right! ). It takes some diligence and planning so Here are some quick tips on catching aurora:

• Download an aurora tracking app [I use ‘aurora’ and ‘northern lights’]. Finland also has a SMS alert option you can subscribe to online for instantaneous notification.

• Solar activity is measured on a ‘KP’ scale ranging 1-10. Regions closer to the poles require a lower KP to show aurora. It seems to average 2-3 KP each day, but every couple weeks there’s a few days with KP 4 or 5. I haven’t seen anything above a KP 5 yet.

• In Rovaniemi Finland I’ve seen the aurora on a few evenings at KP of 3.6 and a reported ‘chance of seeing’ at 30%.

• Time planning: short to long term

  • Aurora showing may only last 15minutes and occur once or twice in an evening. If your app reports high chances, stay vigilant or just wait outside for a few hours with some Aquavit to stay warm.

  • The sun rotates every ~27-31days and has a with it a few streams of cosmic stardust

  • Time of year: Winter darkness is better with longer nights. However I have heard the closer to the vernal and autumnal equinoxes also present good activity. Forget about summertime.

  • Solar activity is generally believed to cycle every ~11yrs with the next solar maximum (more sunspots and aurora) around 2024 :(

• Photography

  • The built-in phone camera may capture ~80% of the magnificence of an aurora. To get more out of your phone, download a ‘pro’ camera app that allows you to force longer exposures up to 1-4 seconds. You’ll need a tripod or steady base as well.

  • dSLR: these obviously work great. You can get decent handheld shots and even video. Keep in mind a wide lens and tripod are ideal. Additionally a hot-pack may help to prevent the lens from fogging if you’re doing some extended timelapse captures.

I used to waste a lot of time capturing timelapse videos and developing motorized camera dolly’s, I would’ve loved to snag a sequence of the aurora— too bad my batteries died due to the cold!

There’s a lot more on engineering and my design projects, take a look around the site!

see the blog for the latest posts: https://asaweiss.com/journal

Let's get this started!

Hi there! This is the first post, scroll no further!

Let’s set the scene:

My Wife (Jane), My 5 month old daughter (Lucia), and I have moved to Jyväskylä, Finland for my wife’s Fulbright grant during Spring 2019.

We’ve been here just over a month, learning and reflecting on so many things we never anticipated.

I’m taking a break from my work as a Mechanical design engineer in Silicon valley. Initially it was hard to leave but I’ve found some great things to spend these days on:

• Trekking to daily adventures on ice and snow with Lucia

• Deeper exploration of engineering topics (such as: applied composites, CFD, Advance FEA, PCB layout)

• Visiting companies to discuss innovation

• Teaching an engineering workshop for students

• prototyping some of my own potential kickstarter products

Thanks for your interest in this kind of stuff, let’s get in touch! Email me or find me on linkedin / facebook / instagram / youtube (there’s too much to keep up with these days…)