David Hansen 🚲🇺🇸🇳🇿 @boxcardavid Twitter profile

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David Hansen 🚲🇺🇸🇳🇿

19 days

If you’re dabbling in electric motors and want to dabble way harder then read James Mevey’s 2006 master’s report from Kansas State. It’s comprehensive, approachable but not oversimplified, and to top it off he hand drew his figures.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Another unbelievable price drop on small robot actuators. This doesn’t include housing or controller but $49.35 total will get you those. Need to do some spacex math on materials to figure out the floor price, this shit can’t keep going can it?

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

@KennethCassel I prefer not to know

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

27 days

@sdamico A co2 meter is eye opening to have, recirculation in cars puts co2 into many thousands ppm and explains a lot of road trip tiredness for me.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

Linear actuators under $10 are almost small enough to swallow

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

People assume that @UnitreeRobotics copied Boston Dynamics’ design for their robot dog, but really it’s an MIT Cheetah-derived design (open sourced by legend Ben Katz). BD’s design is actually insane, engineering run amuck, thousands of fiddly parts including clock spring cables

J Bannister

@MechanimalChief

1 month

@AISafetyMemes Notice how it's the much lower cost chinese knock-offs, Unitree in this case, and not the far more pricey original anatomy developed by Boston Dynamics with over 2 decades of US taxdollars(and now owned by a Japanese car company). Funny how that works.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Take a look at JLC for cnc if you haven’t recently, they’re doing instant quotes now at ~40% Xometry prices. This kills off a lot of 3d printing for me, just cut aluminum. A motor housing that is mostly hollow and not optimized? Quantity 1, under $100, shipped.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Japanese robot twitter makes me wish translation was automatic so I could scroll their threads. They’ve been trying these cheap spinning 360 lidars that are around $10 and they seem gtg. Think roomba lidars, and basically going to zero cost.

でべ

@devemin

3 months

アリエク、ミニ Lidar 1,219 円（+送料）！なんか安いの見つけた！速攻注文してみました〜！！前にもジャンク激安 Lidar 出回ったけど、今回のは小さいタイプ✨ 情報や型番がいっさい見当たらないww

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 years

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

If you’re thinking about making motors and actuators just give it go by hand first, see how you like the process. It’s one of them ‘choose your struggle’ type things.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

18 days

The @ImpulseLabs_ induction stove temp sensing patent is out, it was killing me to not know how it worked. Skimmed the patent and the system is very clever, they’re measuring heat flux in/out of a plunger instead of direct measurement. It puts the D in PID temp control.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

Holy shit, this new motor is a cheaper version of the standard Cheetah, down from $349. The price war will be tweeted.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

JLC now has Electric Discharge Machine (EDM) Ring the dinner bell

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 months

Hollow core torque motors are really useful, annoyingly expensive, and hard to encode but the prices are almost reasonable, maybe another year. The cost makes sense when you take one apart or build one from scratch, hella nesting components as the magnets try to bite you.

Peter Holderith

@_baldtires

2 months

hollow shaft motors are too expensive so im making my own hopefully it will work!!!!!!!!!!!!!! HOPEFULLY IT WILL WORK!!!!!!!!!!!!!!!

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 months

It looks like @Figure_robot is using a cycloidal reducer for some or all of the joints on their new humanoid. Goldilocks reduction ratios of like 30:1. They deleted a few of the major components from the animation but these pins floating in space hint at what's going on.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

Siggear is selling a cyclodial motor that is very thin and small, claiming 20nm peak and backdrivability. It’s not listed on aliexpress or alibaba but I see a store on 1688 dotcom. Have any of the Japanese robot folks tested them out?

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

Sugoi

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Y’all pushed the price up and I didn’t even give out the link. They will adapt.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Giant 400Nm actuators still aren’t cheap but the price will fall fast. It’s just 3kg of steel, aluminum, and neodymium (nothing magical) but the base motor isn’t a common machine-wound drone motor size. Scale will fix the price. 400Nm is almost double that of a Honda Accord.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Myactuator has an exosuit on their website now without any info. They also reference a screw-motor, hopefully it's something fancy like an inverted planetary roller screw.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@CooperZurad Imagine seeing a whatsapp qr code on an american shop's website, I want that world

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

29 days

Fyi can buy the front half of a DC power supply on aliexpress for $80 and hook it up to an old ebike battery. Mobile.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 years

@benwbear I’d sub to a startup conspiracy weekly email

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

Drill batteries are perfect for most prototype projects these days, they’re rugged and it’s easy to buy battery holders on Amazon. Make sure the batteries have an internal BMS (like Makita) or else you’ll destroy a bunch of packs (like my Bosch) before you realize what’s up .

Tom Jacobs

@TomPJacobs

1 month

It’s a walk! Thanks Andy

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 years

@daniel_kraft @SunilPaul The percentage of ML folks that can’t tune a PID controller is shockingly close to 100

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

15 days

I've been seeing more Mitutoyo calipers in Aliexpress product pics and I don't know why but it makes me happy

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 months

Not sure what reduction is happening here, I’ll have to take a look frame by frame on my computer. Anyone have details on the actuators?

Figure

@Figure_robot

2 months

Figure 02 coming 8/6

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

Myactuator is moving fast, the cycloidal lineup has tripled, they have a USA distributor, and their humanoid has a rendering. It’s cycloidal heavy, and I believe they’re using the so-called rotary vector (RV) reducers which is a planetary followed by pinwheel type cycloidal.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

Cool, this older 1X bot def has a capstan drive, and it appears to be a diff style single braid of fiber over the shoulder drum vs the rotor output shaft. It’s well supported with a bearing opposite the rotor, probably with an encoder. I’m really curious how they tension these.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

7 months

You don’t need a PID controller when a P controller and dirty bearings will do

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

Sangbae's new humanoid has cheek motors

C Zhang

@ChongZitaZhang

3 months

New paper from Sangbae Kim group after long silence

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 years

@magcartly @McJesse Thingiverse please

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

26 days

Pray for us all if JLC’s McMaster clone is really 10x cheaper. I will not be fact checking this particular comparison, but JLCMC pricing is incredible.

Daily McMaster-Carr

@McMasterDaily

26 days

Air-Powered Gripper Angular, 2.5 lbs. @ 72.5 PSI External Force $143.33 Each 6220K41

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

12 days

You can totally do a 3d printed cable/tendon actuation system if you want to dip your toes into that whole world. It is exactly the pain in the ass to assemble, tension, and maintain that you fear it might be.

The Humanoid Hub

@TheHumanoidHub

12 days

NEO & Gen3 Optimus are using cable drives. Key insight from Aaron Lucas: Cable drives are not new but face challenges like limited fatigue life and require precise maintenance. Innovative cable management and advanced materials offer potential solutions. WAM Arm from 2010:

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

Shit

David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

@simonkalouche I’m gonna throw a pizza party if the MIT Cheetah clones on aliexpress ever go below $150

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

120nm $280 holy hell

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

It looks like Myactuator is cooking up something new, anyone have details on the black actuator? It appears to have three wiring racetracks, and the output is huge compared to the diameter. Have they squeezed a cycloidal reducer into a GIM (Gear In Motor) style topography?

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

Humanoid robots will be mainstream once they don’t need a delivery box, they’re self-delivered by walking onto public transit.

Brett Adcock

@adcock_brett

4 months

Exciting news! Figure is shipping our first small fleet of humanoid robots to a client today 📦 🤖 Sunday starts a large-scale AI data collection effort to train our neural nets + robot starting to do useful work

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

Actuators prefer to have IMUs

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

6 months

Can you guess why rotor magnets would extend past the stator teeth? Very clever new design out of China.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 years

Ebikes will just be called bikes in 5 years. Current bikes will need a new name, an equivalent to 'landline phone'

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 months

Cheap Steadywin gim8108-8 (~100usd) has some smart stuff. Stator mounted to the casing for part count, rotor+reducer is one assembly. Reducer is undersized for the motor (cheaper), but equals torque efficiency vs smaller motor. 81 = stator dia 08 = stator height 8 = gear ratio

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

Steadywin/LK-Tech fat 100x15mm updates They’ve made a lot of small changes to the design, the end plate is now on the controller side and is cast then machined. Most of the changes are to save cost.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

@karantalati @kwharrison13 I can attest that selling used scooters sucks ass, hard to turn into cash

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

@karantalati Wanna drop by SODO and ride something weird?

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

10 months

@Austen These accessories will sell like crazy

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

Is 1X using Dyneema fiber for their tendons?

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@yacineMTB Robots sold by the pound

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

This is so cheap I almost feel some sort of weird guilt

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

@KennethCassel You know you’re about to lose some money when this guy shows up

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

@Mammoth Add Hakko smoke absorber fighting for its life

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 years

Fire sale on Radmission right now, tell your bike-hesitant friends and fam @RadPowerBikes

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

This one is a better size for a tablet-shaped pill and even cheaper

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

20 days

My neighbor is a hydro engineer and his company once lost a Bangladesh bid to dam a river. They were going to use heavy equipment, but lost to some company with 10,000 Bangladeshis filling sandbags for two weeks for ~$1/day each. Somehow this relates to cheap humanoid robots.

Kat Scott 🐀

@kscottz

20 days

Tech Bros: humanoid robots will soon be doing every job. Me, an actual roboticist: single purpose robots will soon be doing dull, dirty, and difficult tasks with human assistance.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@kylemarieb I think that’s right, the cost plummets so fast that the argument ‘oh it should have been a gantry robot’ just doesn’t matter. Smartphones have way more sensor, computer, and connectivity than they need 99% of the time, but they’re cheap AND useful as hell.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

7 months

A cycloidal reduction actuator finally dropped on aliexpress. Impact-tolerate torque for cheap, here we go. Unknown reduction ratio, but this is 50nm, 700g, and likely backdrivable*. *haven't tested.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 years

How multimodal are you?

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

10 months

@myrrlyn Regen while braking, reclaim 5% (rest goes to mostly aero drag, some friction) then use a bit of it. Lame, but not wrong.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@build_boost ‘Is that directly subsidized by the ccp?’ ‘No, but it is indirectly in like 15 ways”

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 years

This is a Brose mid drive with a sealed (broken) belt drive. At our office we’ve nuked Bosch and Shimano motors. Premium still doesn’t equal reliable with ebikes. When someone new to ebikes asks me to recommend one I still don’t have an answer.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 years

This is the entire pitch

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@Robotbeat We’re in the good old days

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

15 days

Cattle is 牛, short for 牛頓／牛顿 (niúdùn, “newton”) Chat wins again

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

6 years

@joebarnard The Wright brothers used one of their bicycles to test the theoretical values of lift and drag

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

The larger Unitree humanoid puts out about 400 watts of heat while operating, the same as four humans. Rooms filled will robots will need a lot of air conditioning.

Unitree

@UnitreeRobotics

10 months

Unitree [General-pupose Humanoid Robot H1] Evolution V2.0 Embodied AI, Price below $90k Preview over half-a-year achievement The highest-power-performance robot of its counterparts with similar specifications in the world, weigh ~47Kg, maximum joint torque of 360N.m

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

11 months

I hate parking scooters

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@simonkalouche This is like, I won’t bother doing an overly beefy print for prototyping or an exotic-ish fdm material because I can wait 6 days for aluminum with some normy PLA prints to fill the gap. Midwit meme with PLA to the max.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

@conditionalZep1 They’re the alien dreadnaught factory

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 years

@drivingmzstacey @WorldBollard @get_streetlogic @weelautonomy Don’t cross those things

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

@TomBabin Air volume does equal suspension, but I’ve talked to hundreds of riders and most of them find skinny tires to be scary/intimidating and they generally feel fatter equals more stable. This isn’t true from a dynamics view, but heavier tires def damp out the steering.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

@simonkalouche Pursuit of humanoid/legged robots is important because it leads to cheaper high torque motors that I can buy on Aliexpress.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 months

@Robotbeat You might own this but big rec if not

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

Working on an Actuator Pizza Party now, probably at our office or UW Seattle, will have some actuators doing motor control-ass things. I’ll bring this electric bike hub motor with a 16 bit encoder inside it.

David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

@simonkalouche I’m gonna throw a pizza party if the MIT Cheetah clones on aliexpress ever go below $150

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

8 months

@NWUrbanist I’m going to start a party based solely on the platform of impounding cars without plates (no de facto criminal charges for drivers). This solves all the problems.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

18 days

@a19grey @ImpulseLabs_ @sdamico Indeed, I’m hoping this gets Sam to write a thread on it. I’m too lazy to do it well.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

28 days

“90% of it in 6 minutes” What a guy.

Joel Blake

@joelmfg

28 days

Few people realize you can stamp metal w/ less than $1000 in tooling*. My team did a whole webinar on it. Start at the spot linked below, you'll get 90% of it in 6 minutes. * The case study bracket is complex ($6k tooling, ROI 2750 pcs). A simple blanking tool might cost $800

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 months

@TurnerNovak One of your best

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

@BillyZelsnack @UnitreeRobotics I love BD’s shit but their failure to make it cheap was a real bummer, now the world is gonna be full of Chinese bots

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

2 months

@dangaron @TheRideshareGuy @Waymo Waymo will wait as long as you need to load a car seat. Parents with young kids are a completely new market.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 years

@AsherDeMontreal Microixmobility

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

6 months

Your hardware startup needs this

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

This humanoid is truly open source, they literally list every bolt along with the CAD and links to purchase. $108k and some time gets you to parity with these demos.

Zipeng Fu

@zipengfu

4 months

Introduce HumanPlus - Shadowing part Humanoids are born for using human data. We build a real-time shadowing system using a single RGB camera and a whole-body policy for cloning human motion. Examples: - boxing🥊 - playing the piano🎹/ping pong - tossing - typing Open-sourced!

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

6 years

My google alerts used to be really quiet

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

3 months

MIT Humanoid - Tailoring Solution Accuracy for Fast Whole-Body Model...

This work is published in IEEE Robotics and Automation Letters .Title: "Tailoring Solution Accuracy for Fast Whole-Body Model Predictive Control of Legged Ro...

www.youtube.com

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

15 days

the specs are getting weirder

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

12 days

These are all old but way fun

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

@KennethCassel Desire for trumpf increases exponentially over time

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

6 months

@okthisisnagy That 45kg servo is a classic

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

5 years

@EmilyEAckerman @PittTweet @StarshipRobots Please keep us updated @EmilyEAckerman

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 month

@MechanimalChief @teortaxesTex @AISafetyMemes Not correct, BD’s Spot doesn’t use the gear-in-motor design that Katz pioneered for its legs

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 years

@TurnerNovak @anothercohen Simple Agreement for Future Indentured Servitude

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

4 months

@TimMLatimer And it doesn’t help you to do technical diligence for investor friends. They just kinda dislike you afterwards for finding the flaws in the company they wanted to invest in.

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David Hansen 🚲🇺🇸🇳🇿

@boxcardavid

1 year

I expect Boston Dynamics will revisit the BigDog concept, but as a bike (50x range and efficiency)

Evan Ackerman

@BotJunkie

1 year

Marc Raibert says that Boston Dynamics AI Institute is working on (among other things) an "ultra mobile vehicle" modeled on the dynamics of a human on a bicycle #ICRA2023