NYC has new sidewalk shed designs that include an angled roof instead of the normal flat roofs. Interestingly the roofs are angled toward the building instead of away. Despite the roofs allowing some passthrough of rain and snow; people are wondering if there could be an issue with drainage and snow acumination since the angle is pointed toward the buildings.

None of the sources for the new sheds talk about the angled roofs significantly. So, I am wondering what others think about angling the roof towards the buildings.

Sidewalk Shed Monitoring and Removal - Buildings

I'm trying to find a way to lower items 1-5 lbs about 30 feet in 5-15 seconds. The challenge has been doing this automatically in a controlled manner, without having to manually reset it, and without resorting to a microcontroller. (people add/remove the items from the top and bottom though)

(I'll ramble why in a comment)

I have abandoned most constant sources of drag and those that require a user to manage the lowering or else let the load run away or slow to a stop.(i.e. a munter hitch, multiple wraps around a static bar, fishing rod drag-washer-stacks).

so far I'm not convinced I have a good answer: -governors; without a 'throttle' to adjust I don't know if I can get enough braking force out of these -dampers; having trouble with static friction in ones that want to spin fast i.e. eddy current damping, driving a dynamo. Alternatively having trouble finding an appropriate slower damper and speed reduction to go with it because the mechanical advantage makes the resistance curve to the load essentially flat or they heat up and de-tune (i.e. viscous fluid rotational dampers). -escapement mechanisms; too slow, bulky, and/or not easy to reset. Also concerned with bouncing upsetting the mechanism if using mechanical advantage to lower faster but I haven't tested this yet.

Another problem I've had while prototyping is the rope slipping on a pulley. The idea being that one end would be pulled up to a ready position when the other reaches the bottom. Using two opposing spools fixed to the axle solves this

I feel like I've gone in circles in figuring out how to calc out this connection. I'm bolting a rectangular tube to the web of an I beam. They're aluminum members, both are same depth, and I can't cope the tube to bring the load closer to the center of the beam.

So I'm going bolt double angles from the tube to the girder web. Bolt bearing, shear, rupture is good but I'm not sure about how to check the girder web. How do I consider the eccentricity that the bolted angle introduces into the web?

Hi everyone,

I operate a petrol station in Kosovo and I'm planning to install an Automatic Tank Gauging (ATG) system.

I'm considering magnetostrictive ATG probes from ECOTEC or Eaglestar.

My underground fuel tank has the following specifications:

• Total capacity: 50,000 liters
• Two separate compartments of approximately 25,000 liters each
• Internal diameter: 2,480 mm
• Horizontal cylindrical construction with rounded ends
• Existing threaded opening, believed to be 2 inches, on the tank manhole cover

My questions are:

1. Can a magnetostrictive ATG probe typically be installed through this type of opening?
2. What type of mounting adapter, riser, or compression fitting would normally be required?
3. Does the probe need to be exactly the same length as the tank diameter, or can it be longer?
4. Has anyone used ECOTEC or Eaglestar ATG systems? Are they reliable?

I'm looking for technical guidance before purchasing. Any installation will be performed by a qualified technician using appropriately certified equipment.

Thanks!

Eeglestar set from alibaba

Ecotec set from alibaba

I am a high school senior who is either looking at Electrical engineering or medicine. Either way, I want something fairly hands on instead of totally white collar, so electrical engineering seems to be a good fit (unless I am mistaken). How will AI continue to change the career in the upcoming years?

Thanks guys!

Agility says Digit 5 will get 90 minutes of runtime from a 9-minute charge, a 10:1 run-to-charge ratio, up from 2:1 on Digit 4. Capacity, chemistry and cycle life weren't disclosed. From an engineering view, how do fast charging and swappable packs compare on cycle life, heat, cost and fleet uptime?

I need to look at the output on a 200v AC servo drive. 3ph.

The drive is good, but we are having problems with the motor coils. Is a linear motor, so there are 2 coils driven by one servo drive. One coil for sure is bad, but the other was re-wound and tested good. After swapping some things around, now the "good" coil is testing bad. Motor is not stable. Like to get a scope on the phases and actually see what is happening.

I have experience with HV systems. Just never used a scope on a 200v AC 3PH before. I know about the probe grounds.

Would keeping the windows wound down help reduce them?

A flying car would require much more energy since it has to gravity and air drag. If it's electrical (eVTOL) it would have a miniscule mileage since ATM hydrocarbons are the most energy dense form of fuel for most vehicles.

I'm not even going to mention the exponential growth in safety concern from doubling the degrees of freedom. Every driver would need to be a qualified helicopter pilot.

We can't even get AI to self drive reliably (I assume the air thrustors have to be actuated by AI) on a normal car. Nor are our batteries good enough for any army to consider battery powered drones.

Am I missing something beyond the very cool engineering? This looks like Elon Musk reinvented the hyperloop concept for the positive end of the Z axis.

We're building a system designed to deter geese on a lake, and one of the main challenges is figuring out how far away they are (up to around 200 meters).

The system will be mounted on a post and uses a camera with 10x optical zoom and a YOLO-based vision model to detect geese. We're planning to purchase a laser rangefinder soon, but I'm trying to figure out the best approach before spending the money.

Option 1: Laser Rangefinder

We could either aim the rangefinder directly at the geese (Obviously at distances greater than the NOHD) or at the water near them. My concern is that water tends to absorb laser light, so unless the water is murky or has algae, we might not get consistent readings. Hitting the geese directly could work, but accurately aligning the rangefinder with the camera and hitting relatively small targets at 200 meters could be difficult.

Option 2: Camera-Based Distance Estimation

Since the lake surface is relatively flat, my other idea is to use the camera's orientation to estimate distance.

We already have an IMU on the system, so theoretically, if we know the camera's orientation and the height of the system relative to the water, we could calculate the viewing angle and estimate how far away a goose is based on where that viewing direction intersects the lake surface.

We could also potentially combine both methods to improve accuracy.

My question is: Am I overlooking something or overcomplicating this? Would either of these methods be reliable at distances up to 200 meters, or is this going to be significantly more difficult than I'm expecting?

Any insight from people with experience in laser ranging, computer vision, or similar systems would be greatly appreciated!

Spec sheets look great on paper but living with the tuning tools,firmware quirks and resonance issues on the floor is another story. On my side it depends on the layout on bigger lines we run Kinetix or Kollmorgen when plant specs dictate it, but whenever we're dealing with tight enclosures and need to keep heat out of main box, mine is usually Elmo drives running third party brushless servos over ethercat. Whats your favourite drive and moter pairing right now? Who has the least painful autotuning and scope tools?

Now, I'm not asking whether or not stator vanes serve a purpose. They absolutely do.

However, I'm just trying to determine whether they serve any 'meaningful' purpose (beyond marketing spiel) on a standard 120mm case fan, spinning at sub 1,500 RPMs?

Context:

I'm running a de-shrouded GPU (RTX4070S) with dual Lian Li P28s. And while I'm absolutely happy with the performance (<60c in summers), I'm wondering if I'd be better off "upgrading" to 'proper' static pressure optimized fans with stator vanes, like the Corsair SP120 Elite, especially considering the heatsink has a tight fin stack.

...

A but unrelated, but I used to run my deshrouded GTX460 (Asus DirectCU) back in the day with a Nidec VA450DC fan, a particularly vicious 5,500 RPM server fan with 120x38mm thick frame, dual ball bearings, 40W power draw (3.3A), and massive stator vanes at the back.

That Nidec was... kind of nuts.

It dropped the temperature by almost 20c over stock fan while turning just 1,600 RPMs, a fraction of its total throughput, while being barely audible. Even at 1,200 RPM, where it was effectively silent, that Nidec comfortably surpassed the stock fan pushing peak 3,000 RPM.

I've been a big fan of stator vanes ever since... no pun intended.

I just spent 2 days traveling interstate 75 north from Florida to Michigan. A large majority of bridge transitions want to absolutely destroy my vehicle suspension and potentially rip my front end apart. Why are we unable to design a smooth and lasting bridge transition?

Anodized Architectural 6063 Aluminum Round Tube 0.205" Wall Thickness, 1-5/8" OD, 6 Feet Long https://www.mcmaster.com/product/4568T19

If i purchase 3 of these aluminum tubes and put them into this:

https://a.co/d/0hkXN6TY

What is the strength rating of the legs?

hi everyone, i wanted to ask how would i make a system to quickly empty a 16g threaded c02 canister ideally using a solenoid valve.

i was thinking about something like one of those c02 bike tyre inflaters but with a solenoid controlling the flow

What would be the impact on power grids on both sides of the border? Writing this from Canada.

I am a mechanical engineer student currently on a placement year. Today I had a meeting with a supplier grilled at by the supplier for basically providing shit drawings since I didn’t include a fabrication drawing, weldment info and machining drawing. Even though my manager had gone through my drawings beforehand to makesure it’s okay.

My question is when I send off a drawing do I include all fabrication drawings ,machining drawings weldment info into the same pdf as the assembly drawing or all in different pdfs.
Also how are you able to spot that dimensions are missing so quickly?

I have never heard of fabrication drawings and machining drawings beforehand. I always believed that all I need is a full assembly then BOM and dimensions of BOM.

Does anyone have any tips on how to format or improve my drawings before sending it out

Thank you in advance

I'm working on designing a custom 3D-printed adapter for a PM140 planetary centrifugal mixer (2,800 RPM). The adapter holds a cylindrical container inside the mixer's existing holder.

I've designed a two-piece adapter that fits around the container and sits inside the machine. I'm currently experimenting with PETG and considering polycarbonate for the final design.

I'd appreciate some engineering feedback on the overall design, particularly:

• Rotational movement: Does the container need to be rotationally locked inside the adapter, or could it spin independently without significantly affecting mixing?
• Mechanical retention: Would you recommend a friction fit, silicone gripping pads, or mechanical engagement?
• Design improvements: Are there any obvious weaknesses or changes you'd recommend?
• The bottom of the device that I'm making this adapter for clicks and progress forward so the adapter must prevent this mechanism from being engaged.

I'll attach pictures of my design. I'm particularly interested in the physics behind the mixing process and any practical suggestions for improving the design.

Thanks in advance for any input!

Hello everyone, I gifted my father a sterling engine I got from Temu (or AliExpress) that works with an alcohol lamp, it has a small "wand LED light" that you can plug to a USB cable and it turns on when the engine is working.

I can see that the power produced by the engine is unstable as the lamp flickers as the engine starts and when it slows down.

Would it be possible to safely charge a phone (even just a little just as a curiosity) with this engine? If so, would I need to build anything else to make it work?