Launch HN: Vassar Robotics (YC X25) – $219 robot arm that learns new skills

Looks like you might've found that magical thing which is product-market fit. I'm rooting for you.

$200 is a really nice entry-price point. If I'm being honest, I'm marginally interested in this, but doubt that I'd actually use it too much. But the price point is justifiable for someone who is just interested in it from a learning point of view (if I bought this, used it a few times and learned a bit more about AI as it relates to robotics, it'd have paid itself off easily).

Rooting for you to succeed.

So true. Every time I solder surface mount components, I always wish I could have a steady hand. Sadly, this arm doesn't have that kind of accuracy. The output shaft of the servos we use has about 1 degree of wiggle room and the mechanical structure adds more.

To get better accuracy, if sticking with this kind of RC servo, it's basically required to have two servos per joint to preload each other to kill that wiggle room. It's something I've been calculating, but I just can't figure out a way to offer it at a good price.

Interestingly, for arms that are popular in academia, even when the price goes to $10k (like ARX or Trossen), the wiggle room is still there (better, but still there).

Thank you for the feedback! Thinking out loud: • Adding one DOF to match ARX kinematics is doable, with a price increase of $30–40.

• A tool changer is a great suggestion. A few of my friends are working on kinematic couplings, which would be ideal for this. I’ll need to give some thought to how to pass electrical signals and power to the tool, while also keeping it lightweight.

• Could you share what functionality you want in terms of encoders? The ST3215 uses 12-bit magnetic encoders, which can retain position after power loss. Are you looking for higher resolution? For torque sensing, if the order volume is large, I can add this for just a $20-30 price increase.

• Finger tip force sensing: Is this for applications like picking up an egg?

> You need some technical specs on the website. How many DOF does it have? Does it have joint angle sensing? If so, what's the resolution? What's the interface to the servos? What's the payload capacity? Does it have integrated motor controllers? How long is it, and what does the dexterous workspace look like?

The post says "kit that keeps LeRobot SO-101’s kinematics" so it's probably very similar to [1] namely 5DOF and a gripper, using STS3215 servos [2]

> As a roboticist, what I'd vote for, in order, is:

As they are making a robot at the $219 price point, I very much doubt they have the money to add anything to the design.

[1] https://huggingface.co/docs/lerobot/so101 [2] https://uk.robotshop.com/products/magnetic-encoding-servo-st...

Are there any affordable robot kits you recommend for learning control, CV, RL etc.? I was budgeting for the SO-101 so I think I'll get OP's device and then something that's not an arm for variety.

Thank you! Let me know how you like the SO-101 design. If you have complaints, I might be able to find a way to fix it ;)

Curious where you sourced the parts? In Canada, shipping kills it for me. When I priced out the robot + electronics + $100 in shipping, I am around $700 - far cry from the $100 on the "sticker".

Literally same. Just finished printing the leader arm and not I have another 20 hour print for the follower.

Interesting. Their servos seem to be PWM servos, which are available at a very good price. I would look into how to hook up all the servos—you’ll probably need an MCU to convert USB to PWM for each servo.

Thank you for the suggestions. I hear you. When I was at college, the school system basically only allowed Amazon plus a few industry-specific suppliers. Please allow me to prioritize manufacturing and testing so that I can ship the product as soon as possible and with the highest quality possible. Then I will start expanding sales.

Also, the servos we are using actually have a version that has lower torque/force output, which would be safer for students but also limit what they can do with it. Would you be interested in the "safer" version for classes?

SO-ARM101 has a leader-arm, which is the arm with same exact dimensions and same servos - but used to read/record the trajectory. You move it with your own hand and teleoperate the follower-arm in real-time. Follower-arm is visible in the demo videos.

If you fully control the environment: exact positions of arm-base and all objects which it interacts with - you can just replay the trajectory on the follower-arm. No ML necessary.

You can use LLM to decide which trajectories to replay and in which order based on long-horizon instruction.

It's just bunch of motors on a stick. Doesn't come with a computer at all. But that's still worth >$200, as 1) building an arm that works is a project of its own, and 2) hardware standardization is crucial for code reusability.

RC aeroplanes need some practice and a bigger field compared to FPV drones. I think I spent a week flying in simulators and another 2 weeks crashing several times to get a basic hold on it. It's kind of like training a robot foundation model to learn a new embodiment

That being said, I enjoyed every moment flying my planes. I built and flew quite a few quadcopters but they never felt that free because there's always that control algorithm between the pilot and the motors, while aeroplanes are basically just mapping the movement of the joystick to the servos. I believe the UK has a lot of great local clubs, and I believe that's the best place to get started.

Side note, when your son gets more experience in the field, he might wanna build his own gas turbine to power his planes. And this association based in UK is the best on this planet: https://www.gtba.co.uk

For UK delivery, let me look into how to set up international shipping. Will get back to you by end of the day.

If the goal is the building. Balsa kits (an xacto knife, 2 bottles of super glue [thick/thin], CA-accelorator) are the way to go. Discuss gliders are easy to manage the risk of learning how to fly, and are light, so crashes will only be mildly catastrophic. I have this one, and it was easy-ish to build (~20 hours?)

http://wrightbrothersrc.com/products/gambler.htm

If the goal is the flying. You can't go wrong with an easy star. I've crashed mine a million times. You just patch it back together humpty dumpty style with thick CA + accelerant. Bonus points for the prop being in the back, so if you run into stuff you (probably) won't draw blood.

https://mrmpxhobbies.com/product/rr-easystar-3/

Note that the hobby does require some skill w/ flying and need some level of risk management. There are cords that let you plug your transmitter into a computer/fly over a simulation that can help with the former.

Building RC planes is a little harder IMO, but not much.

The main difference in building planes is you have to pay attention to center-of-gravity much more; minute differences will make the difference between your plane flying amazingly, like a brick (nose heavy), or not at all (tail heavy). There's also more work to do in setting control linkages and surface throws. But, overall, it's not too tough with most models.

Takeoff with planes can be very stressful the first few times; you have to choose between ground/runway takeoff, which typically results in a very inefficient model due to landing gear drag and is prone to flipping over, throwing the plane by hand, which requires practice and can be quite hazardous with a "pusher" style plane with the prop at the back, and building some kind of bungee launcher, which you then have to set up and lug around.

Then you have to decide how to fly - line of sight or FPV. Line of sight flying is quite an acquired skill and has a very steep learning curve - you basically have to learn to "become the plane" and understand how your control stick inputs are affecting the attitude of the plane without being able to see it very well.

FPV plane flying, while less popular than LOS, is very easy and much more rewarding IMO. The reaction time in all but the most extreme plane stunt flying is much less dramatic than in FPV quads.

And, due to quirks of the general hobby flight control software scene, most hobby FPV planes have a working loiter-in-a-circle setting while most FPV quads have a barely-functional GPS rescue mode and little to no ability to actually hover (it's very rare for an FPV quad to "just stay put"; this is the realm of camera drones).

I fly FPV quads when I need a focus/adrenalin boost and FPV planes when I just want to relax and chill. You can fly planes in an adrenalin style, but they're much more conducive to just looking at the scenery and goofing around. Massive bonus points that most plane builds are almost silent compared to an FPV quad so you don't worry about bothering people so much.

Planes, like quadcopters, are as complicated or simple as you want them to be. They're available fully ready to fly, as kits with different levels of work needed, or you can build from scratch and choose your own parts and design.

Flying is pretty different, though. If you're used to a copter that will just stay put when you release the controls, flying planes will be an adjustment.

I’ve just set up shipping service to the UK. You should be able to place an order now. Let me know if you have any questions!

I looked at your video of alternatives and number 5 looked pretty good to me. Though, a better image of the product itself seems like the lowest hanging fruit for improving the landing. :)

For stuff like this, it would be cool if you had a hosted demo of what you clicked through in the video.

Man, I gotta say that I tried really hard to see if I could ship before that, but I failed ;( Chasing suppliers is pretty much like dating: sometimes no matter how hard you try, you just can't make it happen.