We found out at the reorder. The buyer went to place a second run and the distributor came back saying the part had been end of lifed back in March. We had built four hundred boards on it since then and there was no drop in replacement.

The notice had gone to a shared purchasing inbox that nobody owns. It sat there with about two thousand other emails. The part was in three assemblies and nothing in our system linked it to the products it went into. Even once we knew, working out the blast radius took two days of opening spreadsheets and asking people what they remembered.

We ended up buying the last of the stock through a broker at roughly three times the price to cover open orders, then respinning the board anyway. The respin was the cheap part. What do other people do to make an end of life notice land on someone who can act on it?

https://imgur.com/a/8Jk2ZQG

I’m working on a mechanical parade float built on a 28' L x 10' W flatbed trailer. Our design features an animated/kinetic, flying Santa sleigh with reindeer moving up and down over a downtown shopping scene.  See attached obligatory AI slop picture

Design & Physical Parameters:

Overall Height & Space Constraint: The absolute maximum height for the entire rig from the trailer deck is 10 feet (keeping us safely under parade clearance limits). 

Clock Tower Footprint: The back ~6 to 8 feet of the deck space is occupied by a 6' x 6' base replica of a historic Main Street clock tower (approx. 10' tall). This leaves us with roughly 20–22 feet of deck length to execute the full motion arc for the sleigh and reindeer. 

The Motion: We want the reindeer to swoop up and down in a smooth, sweeping flight path. 

Drive & Linkage Ideas: Open to ideas other than what’s in the image. I like the visible rotating design of the offsets if we want this to be a visible mechanism. A hidden design also works too.

Power & Target Speed: Our plan is to yoink the guts from a treadmill so we can control the speed of the motor. We have plenty of generators in the back of the pulling vehicle.

Where we need engineering expertise:
Linkage Selection in Tight Height Profile: Given our ~10-foot ceiling limit, is a four-bar linkage or a pantograph mechanism better suited for driving a large dynamic load without binding or extending beyond our vertical clearance?

Any advice on linkage geometry or pivot design/placement would be greatly appreciated!

We have solar power plants that point mirrors at a single point to generate heat for power. Why not do that for salt water?

And if the biggest issues is salt build-up on equipment, why not do it on the coast and build it so water flows in naturally, have multiple points where water can be sent ponds with some kind of dome over them, and then be heated up by the mirrors. When salt builds up, switch to a different pond/dome and collect the salt from the previous one. Salt mine and clean water/power in one?

I am a laymen, I don't know anything about this on a technical level. Just a thought. I asked AI to generate an image to conceptualize this but I can't post the image here, so here is a link:

Reddit - /preview/pre/just-a-thought-about-desalination-v0-m46za11k7hth1.jpeg?width=1080&crop=smart&auto=webp&s=29a661531e8687a668a811f4e2eb7f36cb820b80

has anyone here tried to simulate physiological flow using a peristaltic pump? i have a kamoer dip1500 dosing pump which has a stepper motor, and i'm wondering if i could use an L298N and an arduino uno to control the speed of the pump and create a rough simulation of diastole/systole. the pump will be hooked up to a test chamber with a silicone phantom of a cerebral aneurysm and the flow doesn't need to be incredibly realistic. is there anything i should know going into this that will be a challenge?

What mechanism can be used to adjust the belt tension if the distance between the two pulleys can be varied?

Backyard project headed by myself and my 8yo. Radio controlled tracked combat vehicle.

We're looking at about a 50cc 2 stroke engine as main propulsion because it's cheap, reliable, widely available off-the-shelf parts, which is a big part of the design strategy. We're trying to work out the best way to steer the thing, and I've concluded that a sort of reversed clutch would be best.

By that I mean the drive shaft spins freely until we engage the clutch, and then it transfers power to the drive sprockets. This would allow us to set the engine at optimal RPM for whatever configuration we want, but still have control over speed. A planetary gear would allow for reversing in the same manner.

My problem is I can't seem to find anything on this when I do an internet search. Am I just using the wrong terminology in my searches, or is this actually that novel a concept? Seems like it should be a fairly common idea because I can see it being useful in all sorts of different applications.

Anyway, we'd really appreciate some help finding resources/info. I'd hate to have to custom build or switch to a belt drive clutch system. Either would be a downgrade under our intended design strategy.

Thanks!

Hello guys,

Just joined my new job and we had to work on some leak detection benches.

I clearly had no clue about this cause I’ve never seen it nor worked on it. Although I made some research and now it’s more clear that before obviously.

Anyway I’d like to have some good expertise on this topic in order to know on what points I have to make real researches and what are the critical points…

I already apologise for this topic, as it is a quite vague question but I am really open to any suggestions or explanations!!

Regards

Hey everyone,

To start off Just some basic information: I live in the rust belt of the US, so we have lots of snow in the winter and pretty hot summers too. Temperature change is one of my concerns.
I dont need help with printing itself, just material choices.

Heres the meat and potatoes: I have a mount for a GMRS antenna I want to install into the where the shark fin used to be on my car. I've successfully removed the shark fin and have enough measurements to basically create a gasket out of TPU and some other supporting parts. Its just a 1.5" hole in the glass roof so its quit easy.

I will also being using some sort of automotive gasket adhesive used for rubber trim pieces to seal water out, while the TPU provides some structure.

Heres my question: Would this project work better with a dedicated rubber or silicone substance instead, or is a TPU, sealant combo good enough? This is concerning every aspect of heat fluctuations, water infiltration, and TPU creep, and the adherence of the sealant to TPU. Thank you!

PROJECT IDEA: PIFER—AUTONOMOIS ELDERLY CARE ASSISTANT

PROPOSED TIER - T1

WHAT I'M DESIGNING -

It basically comes to you when u call it and then it search, find it, pick it up, carry it and physically hand it to you as long as it's smtg in its db. I'm deliberately containing the problem bc I'm not trying to build a hospital grade product but rather smtg that can deal w labelled objects and colour IDs instead of a full SLAM and YOLO system.

The rover has a two wheel base and a castor with two bo motors, motor driver, wheel encoders, IR sensors, MPU6050 and a camera. The chassis will be 3d printed.

It will have a 6 DOF servo arm with a TPU gripper. The chassis will be 3D printed (PLA for everything except the gripper). Metal gear servos, pca9685 and ina219. I might use movelt2 later.

I'm also 3d printing a 16 slot carousel for pre-filled pill dispensing.

I'm also interested in uwb person tracking and uwb can do a lot of things apart from tracking tbh and I gotta research more on that. But some sorta person tracking is essential cuz if the person moves after giving a command the robot has to update the target and keep going toward them yk. I'll combine uwb with imu and wheel encoders instead of trusting sensors cuz I think it's better (IRL relying solely on sensors is kinda dumb)

For software, I'm using C/C++ for esp32 firmware, platformIO/Arduino, FreeRTOD, python, ubuntu/bash, GitHub, ve code, ros2 w rclcpp/rclcpy, tf2, RViz2, rosbag2, nav2, opencv, april tags, arUco for initial object/location identification, numpy/scipt and maybe even webots/SLAM for simulation and mapping. YOLO will come if I have time left to move beyond labelled objects.

I'm using esp32 as mc and laptop as the processor for now and we'll upgrade to a raspberrypi later. The laptop will run ubuntu and handle ros2, computer vision, navigation, voice processing and task planning. The esp handles motors and sensors.

I want to say pifer bring me xx medicine and it'll use a wake word, speech to textand python itent parsing with llm/api possible for more commands. The robot understands that xx is an object and that it's given a task to retrieve it. The cam can't recognise every random object ry so the first prototype use labelled objects with colour ids and permanent object db storing names, ids,images and carousel slots. Current environment info however is separate so that temporary data like object or person locations and obstacles will be cleared after a mission or when the robot is placed in a new environment.

The thing is, it actually has to drive to the object, position itself and pick it up when the camera locates the marked object. It sounds rlly big to me as this will be the first time I'll be building smtg like that. Also, I'll be 3d printing for the first time (lmk if hack club can fund for my 3d printing too cuz that'd be great :D).

Now, I'll be experimenting a lot in this project lol I want to integrate a lot of things into the arm, so it may end up completely different from what I currently think is possible and could change the entire arm BOM.

Something like a modular origami continuum arm with..

1. Vacuum-driven FOAM actuation (contraction + omnidirectional bending)

2. Variable stiffness via granular jamming (separate vacuum line)

3. Vision-guided reaching (camera + controller)

4. Interchangeable end-effectors (TPU gripper, whole-arm grasping, chameleon ejection)

5. Foldable compact return

Every single one of these ideas exist already and has been demonstrated its working properly. But the integrated system I want does not exist yet! Well the reason why it doesn't isn't lack of imagination but rather because the subsystems r actively gonna fight each other if u try to put them together. So, I'll have to find solutions that don't exist yet to get everything to work together. I'm not missing anything conceptually. But I need to build and test everything. Even if i get one thing that's actually deployable to my arm, it'd be a great upgrade.

I don't know how reliable or doable these will be in an actual handoff, especially with different object materials and movement, which is the point of including them. I really want to experiment and research further. I'm not expecting every experimental part to be perfect. Even if all these ideas are unreliable, the retrieval/handoff system should still work.

But I want to build and test the experimental parts rather than leave them theoretical.

INSPO:

A ton of things actually but let's js say fetcher by fetch robotics.

PAST PROJECTS:

https://drive.google.com/drive/folders/10T2iZUamxqS5Na1c6ef0lcidV1DDl3Ut

(Ntg much lol js some shi built to learn. Not necessarily a project.)

WHY THIS COSTS MORE THAN 200$:

This doesn't! (Not yet.)

Like i said, I've never 3d printed for an actual project before so I don't really know how many parts I'll have to buy instead of 3d printing. I haven't even decided if I'll make a pcb yet. So the price can go higher during the build. I can only assure you it won't exceed 300 usd. And because this is literally a multiple projects being combined into one thing, it can cost a few pennies. Also idk how many times it'll end up hitting somewhere accidentally no matter how hard I try not to let that happen.

ROUGH BOM:

Raspberry Pi Zero 2 W $12

ESP32 Development Board $3

16GB microSD Card $2

Pi Camera $4

imu $1

Wheel Encoders $2

ir Sensors $1

tof Sensor $3

Microphone $2

Speaker $2

Amplifier $2

bo Motors $2

Wheels $2

Caster Wheel $1

Motor Driver $1

2S 2200mAh lipo $8

lipo Balance Charger $5

18650 Battery Pack $4

5V bec $1

6V bec $1

6V 5A Servo bec $2

Fuse $1

Power Switch $1

xt60 Connectors $1

jst Connectors $2

M3/M4 Hardware $3

Plywood Chassis $3

Standoffs $1

Metal Gear Servos $25

Spare Servo $3

pca9685 $1

Servo Horns $1

Servo Wires $1

Gripper $5

tpu $3

pla $5

Arm Hardware $5

ina219 $2

28byj 48 Stepper $1

uln2003 Driver $1

Carousel Gate Servo $1

Home Sensor $1

Carousel Material $8

uwb Tag $9

uwb Anchors $20

uwb Batteries $2

uwb Enclosures $2

Vacuum Pump $8

Vacuum Tubing $3

Vacuum Valves $4

Foam $2

Granular Jamming Material $3

Perfboard $1

Level Shifter $1

Heat Shrink $1

Solder $1

Wire $3

Cable Sleeving $1

Breadboard $2

3D Printing $15

Misc Hardware $10

Total $180

Note: these are approximate, and I expect the final cost to move once I start building. The arm and 3D printing especially may need extra parts after testing. I'm also expecting to burn through some servos/connectors/wiring during iteration because that's how these projects go.

The Raspberry Pi is included because I eventually want the robot to run on it, but it won't be the main computer initially. I'm developing on my laptop first, then moving the ROS/Linux side to the Pi once the robot works.

The estimate is below $200, but I'm keeping some margin because I don't want the project to fall apart after underestimating a random *200 component lol.

I didn't mention any PCB or routing because I'm not using a PCB right now. I'm thinking of making it modular with a breadboard so I can take it apart and reassemble it easily, because I'll probably do that a lot while building it.

I'm also thinking of making the outside a cozy, waterproof body instead of a box full of electronics like Baymax from Disney's Big Hero 6 ykwim. I don't know the material yet, but I want it soft and friendly-looking. Obviously not literally a Baymax copy lol, just that friendly shape instead of a scary robot with wires everywhere.

Inside it I'm also thinking of an automatic pill dispenser, so the robot could dispense medicine instead of only carrying it. It'll also have a biometrics monitoring system.

The biometrics and dispensing ideas were suggested by my teacher, so I'm still thinking about what else I could add that would be genuinely useful rather than another random sensor stuck onto the robot.

So yeah, I'm still looking for other good features I could add to this thing. If anyone has ideas for something that would actually be useful for elderly care and that I could realistically build and test, please let me know.

Hey all!

Trying to create a mist booth similar to a spray-tan-booth.

Booth-size will be 2m tall. Diameter approx. 80cm.

I want a short burst of mist to cover the object inside within 20-30 seconds. 20 to 50 ml per application. The liquid will be provided in a 30 liter container. Density will be similar to water. No aggressive chemicals. Approx. 10 nozzles.

My questions:
- pump: pressure for the mist? I assume 200-400 bars. Is this sufficient? Would like a selectable „burst-mode“ to clean the system. Or a continuous clean-mode with water.
- don’t wanna re-invent the wheel: any OTS manufacturers that you know?

I will do the booth design/venting/controls by myself.

Short edit:
Thanks for all the comments! Definitely gonna go for low pressure. The risk will kill the feasibility of the product or the human inside worst case.

Misting/spraying is new for me. Will research backwards from droplet-size/amount to other methods. Air-stream might be a route as one suggested.

Hello, I am a student trying to spec a motor for a robotics project. I am having trouble understanding this data sheet here: https://media.jaycar.com.au/product/resources/YG2732_datasheetMain_35975.pdf

Specifically, the datasheet says that at maximum efficiency:

• Torque is 47 mNm
• RPM is 60
• Power output is 0.62 W

However, I checked the unit conversions and 47 mNm multiplied by 60 RPM does not equal 0.62 W (It is 0.3 W instead). So it is off by a factor of 0.5? I think the 'power output' definitely refers to mechanical power, so it's not a confusion between the input electrical and the output mechanical power.

Is this motor datasheet incorrect, or is there an extra factor here I'm missing? Thank you for any help.

I'm not talking about a rack and pinion with only half of the gear having teeth, though I know about those. I'm currently thinking that it would be moved via rotational force, so maybe it could be a type of screwworm gear, I would just need it to be able to do clockwise and counterclockwise rotation without the motor having to turn clockwise and then counterclockwise, if that makes sense

Edit: 18+ It's an NSFW project. I have an idea for a toy that would be encased, which would move a sphere up and down the length of the rotating shaft, applying stimulation without the need for all the big equipment that you usually see accompanying things that move toys

I’ve heard repeatedly about the potential issue with freshwater shortages coming in the next few decades and it seems so wasteful to let all this freshwater into the Atlantic Ocean. So couldn’t we build a dam to stop all the water from flowing into the ocean or to at least create another great lake?

I know that they temporarily blocked off Niagara Falls when they had to do some repairs in the past, so why couldn’t you just make a permanent dam?

Assuming that, for some reason, you didn’t want to flood and destroy Quebec city along with Montreal, you could build a dam around Cornwall, Canada, and keeping a significant amount of water.

Suppose I'm watching a live event from the USA while the content is being streamed from Africa.

How much delay is normally introduced between the actual event and what I see on my screen?

What are the main causes of this latency (encoding, CDN, network distance, buffering, etc.)?

And what techniques are used to reduce live-streaming latency as much as possible?

I was reading a book and one of the super tech characters had replaced their water cooling system for their computer with a liquid oxygen cooling.

I don’t know much about engineering, but I’m pretty sure that would just be a bomb waiting to happen. Maybe I’m incorrect. Have you guys ever seen liquid oxygen used for cooling?

https://www.alibaba.com/product-detail/Hot-Selling-Easy-to-Carry-Room_1601208009994.html (link to the product page)

I'm looking at a small OEM mini fan heater (specs below) and want to know if it's feasible to convert it to battery power instead of wall power, without making the unit much bigger.

Specs:

• Power: 50W
• Heating element: PTC (though the same sheet also lists "heating wire" — unclear which it actually is)
• Size: 3.5 x 7.4 x 12.6 cm
• Weight: 330g
• Currently corded/AC powered

I wanted to make this into a fun little project that I would actually use and I understand that heaters use a significant amount of power, but would a tiny heater like this still not be able to use batteries?

If I were to drive a fast car from 0-100kmh at its peak acceleration and the moment I hit 100kmh, I slam the transmission into neutral, will the car continue to briefly accelerate (for example hit 110kmh) with the momentum carried from the 0-100kmh. Or will the car cease to accelerate immediately the moment the car is in neutral?

Hello, I'm trying to make a rack and pinion that can carry an ultrasonic distance sensor from 0 to 4 inches vertically and back down that is controlled by a microservo for the pinion. I know that microservos don't have great torque, but is there something I should look into gear-ratio or diamter wise that can optimize the torque?

Today in my ML class, my instructor mentioned that in an emergency, the government/emergency services can locate a person using GPS satellites.

I know GPS satellites mainly broadcast signals and the phone calculates its own location. So how does emergency services actually get the person's location?

Does the phone send its GPS location through the cellular network, or is there another mechanism?

I'm trying to understand the technical process.

Let's say we have enough Material if a trillionaire decided to build a replica in the middle of Kansas would it possible to build a 1:1 of mountain Everest?

Hello. Layperson here with some questions on deformation.

I read about elastic and plastic deformation and thought about how hair bends and takes different shapes so easily (through wind, movement, just gravity, etc).

Say there's something limp (e.g straight hair, pasta noodle, cable, or just a square piece of fabric) in zero gravity. Something that doesn't seem to have a default shape it returns to (in a layperson's view at least).

If I keep bending this object in different ways, and it stays however way I put it, is this object constantly plastically deforming?

Is the material considered flexible and weak (weak as in the measure of how much stress before permanently deforming or breaking)

And an extra question.

The way I understand stiffness, it affects tension, and tension also happens when an object bends.

So if yes to the previous questions, why does a rubber band seem flexible and strong yet easy to bend (in a way that stays however it's put)? Like this

I need to come with a mechanism that detects Weight as low as 30g and maybe up to a few kg. The mechanism only needs to act as a switch not need precise values.

FSRs look appealing because of how little space they take. Thickness might be a potential constraint.

Only issues ive seen so far. Is FSRs dont seem they are used for static loads like an object resting on it for long periods of time. As the values drift over time. This might not be an issue for our case as we only need a binary output. The only other concern is that can static loads damage/deform the sensor permanently?