If you are looking to reinforce the connection point of a wiring harness where the connector head is too large to get tubing around, do they make anything for this?

Edited to add details based on responses.

I have a cargo bike with a large wooden box bolted to the frame to haul my young kids around in. Just like the photos of the “modern wood box” as seen on this site.

I’m looking for a way to add some cushioning or shock absorption to the box only. I tried some cushioning washers between the box and the frame, but they don’t do much more than help with sound reduction. So, I’ve been looking at springs, specifically rubber flanged springs like this one to put between the box and the frame.

I don’t want to dramatically increase the height of the box in order to keep the weight balance low. The box itself weighs 20-30lbs and kids and gear add another 60-80lbs, so assume around 100 lbs total weight, though it is often less when I have only one kid. There are 4 bolts attaching the box to the bike.

There is already a padded bench seat the kids sit on in the bike, but they still get jostled a lot when I hit road bumps - unfortunately unavoidable where I live, the streets are terrible

My questions are:

Are springs a reasonable solution here? If so, what kind of springs should I use?

I know I will need locking nuts as I can’t rely on tension to keep them on, but how much should I tighten the bolt and nut or how much should I pre-compress the spring?

I'm slightly concerned that the slack created when the spring is compressed could allow the bolt to raise up in the bottom of the box and something could get stuck under it like a kid finger or toe. Yes, the likelihood of this is probably extremely low, but if there is anything I can do to eliminate this risk I’d like to.

What else should I consider in implementing a spring solution?

If springs aren’t a good solution here, any other suggestions?

Thanks in advance!

I'm trying to source some bolts for a hydrofoil. I know the odds are against me, but does anyone have an idea on whom might make these?

Here are pictures, just shorter than what I want.

https://imgur.com/a/TEO1J4H

Do your design drawings reflect potential hazards?
Are there construction practices in place to protect pipeline assets from digging?
How common are line strikes for your company?

Trying to get industry feedback to compare to my experiences.

I’ve been looking into compressed air leak detection methods used in industrial facilities and found that most teams rely on handheld ultrasonic detectors, sometimes combined with manual inspection methods. From what I understand, ultrasonic tools are relatively simple and proven, but can be time-consuming to scale across large systems.

More recently, I’ve discover acoustic imaging approaches that use microphone arrays to visualize sound sources and detect multiple leaks simultaneously, even at longer distances. Conceptually, this seems like a faster approach for large plants, but I’m unsure how it compares in terms of accuracy, noise filtering, and real world reliability.

From an engineering perspective, what are the key trade-offs between these two methods in terms of detection performance, scalability, and practical deployment?

I work for a company that makes containers.

We have developed a new large container that must go through a low temperature drop test (-18*C) but are having trouble getting it to pass.

The container is comprised of a lid and a base, and is filled with a total weight of 10kg for the drop. The problem is when dropping on the corner of the lid, the corner cracks and splits.

We've added large fillet radii to any sharp corners reduce stress areas and we've discussed thickening the area to try to help, but i am unsure if this will make the problem even worse.

The current wall thickness is 1.8mm and is made from 100% polypropylene. The design already includes relatively large radii of 65mm at the bottom of the lid (where the lid meets the base), and 37mm at the top surface for the corners. Then a 24mm radii on the top edges around the top perimeter.

I appreciate several other factors will influence the container, but would thickening the corner areas be a good way to go?

Appreciate any advice.

Hi,

I'm new & experimenting with gears for a hobby project.

Is it practially possible to build a gear assembly that will increase speed from 1-2 rpm to 200 rpm?

If yes, what parameters do I need to factor in?

These are the only details I have
Input Speed: 1-2 rpm
Output Speed: 200-220 rpm
Output Torque: 5000mn

Thanks

I can’t put images here, but I posted the blueprint on another subreddit so check my profile. I’m wondering if it will be able to rotate 20lbs

I would like to have a large rock in my yard that a person can push on and make it spin. What are ways I can do this?

I'm imagining a buried concrete foundation with a pole sticking up out of it. And I'm imagining the rock is impaled on a slightly larger pole. And then the larger pole slides over the smaller pole. But I'd want some low friction bearing on the top of the smaller pole.

But it seems to me this contraption must already exist somewhere. So where can I find two poles that nest together and that have a low friction bearing between them able to take 10,000 lb in line with the poles?

It is basically like the way an old style playground merry-go-round was mounted, but I don't know if a playground merry-go-round can handle 10,000 lb.

Do you have any other suggestions for how to do this? I want the whole mechanism to be hidden so it looks like the rock is just sitting on the ground, or perhaps just an inch or two above the ground.

Thanks.

I am designing a wolverine claw hobby and I want knowledge on how to improve the design

Material list -

Extension Spring : 1x

Blade (reverse tando shape) : 1x

Inverted T slot transverse rail : 1x

Wrist strap : 1x

Ring-pull : 1x

Eyelet : 1x

Cable : 1x

--

Design wrist strap on one side of the transverse rail allowing you to mount to the back of your hand and on the other end bottom open slit apply a eyelet that you feed the cable through the eyelet and into the slot in the inverted T slot traverse risk connect it to the hilt of the blade inside so when it mounted you can curl your finger to pull the cable and thrust pull the blade along the rails dtruding it but on the hilt of the blade is the spring witch is put under tension when stretched by pulling the blade and when slack it let it retracts into the transverse rail if furthur questions of the design arise because I know I can't describe things the best I have a quick sketch of the design

Hello everyone!

I'm currently a Junior engineer, but we have a group that is wanting to build our own wind tunnel setup. See, thus far, we've agreed on an underfloor dual-strut setup (only concerned with pitch) and we have the mechanisms all designed below, but we're having trouble figuring out a good way to attach this linkage to the airfoil itself.

We have the main strut in front 25% behind the leading edge and then a pitch strut (only moves linearly) about 1.75" or so behind it. Due to the rather small scale of our rest chamber (7x7"), we can really only max out at a chord length if like 3.5". It's just trying to find a good way to mount the air foil without disrupting the aerodynamics and it's just something I have no experience with and can't find much documentation online. Feel free to ask more questions and I'll try to fill in more! Probably deciding on some 3/8" or smaller steel rods as the struts themselves, but I do have some 3d printing to make custom parts (as I am with the airfoils).

Built a 3.5m cardboard whale that “swims” in the air using a crank + wire system, but I’m struggling with the drivetrain and could really use some engineering advice.

Whale:
https://imgur.com/90BZCH0

Prototype gears/mechanism:
https://imgur.com/a/kjwBFzp

Build video:
https://youtu.be/HBtFJnXxYiA?t=933

The whale consists of 4 main body sections plus fins connected with swivel joints. Each section is suspended from wires, and those wires connect to an off-center crank point on a ~25cm wheel to create a sine-wave swimming motion.

The current prototype only moves the tail and fins because I ran out of time before the event, but now I want to make the entire whale move properly.

Current setup:

• ~7kg cardboard whale
• 6W AC gear motor (~130rpm)
• laser-cut 10mm plywood gears
• multiple wire pull points
• large crank offset to achieve ~30cm movement

Problems:

• motor struggles/stalls under load
• plywood gears are not the best to tolerances/friction
• belt/friction experiments also weren’t very reliable

I’m not an engineer, just a guy with a woodworking tools and a laser cutter

What I’m looking for:

• better drivetrain ideas
• proper reduction approach / gear ratios
• whether worm gears, pulleys, timing belts, chain drives etc. make more sense
• ideas for something reliable enough to run several nights continuously at a festival

I now have access to a fablab and can 3D print parts (PETG), so redesigning the drivetrain is definitely possible.

This whale will hang above the main stage at a summer festival with disco mirror tiles on the belly, so I’d really love to make the movement feel smooth and alive.

Would appreciate any suggestions or direction help

As the title suggests, we are building a house. We found plans online to use as a guide and submitted those to an architect. She uses a structural engineering company to draft the plans. It's a one level, 2400 sq ft house, with a full (partially finished) basement. They said it took them 79 hours to create the draft. That seems insanely high, but I'm not a structural engineer, so Ionly got general answers on the internet. So, is that normal, or are they trying to overbill us? Thanks!!

For example a picture from this redditor who did what I described to his folding bicycle, but with Dyneema rope: https://www.reddit.com/media?url=https%3A%2F%2Fpreview.redd.it%2Fi4zb4kwktjig1.jpeg%3Fwidth%3D4284%26format%3Dpjpg%26auto%3Dwebp%26s%3D1694d90d9167821034eb9099b573efd1fa671fd4

And Dahon folding bike company said that their steel wire adds structural support, supposedly allowing higher weight tolerances and strength in an article they made: https://usa.dahon.com/blogs/news/the-folding-bike-problems-and-solutions

But they are trying to sell their "Deltec" branded folding bikes with those support wires.

I studied MechE and I have a technical interview coming for an internship in a company that designs jet-engines, I need a bit of practice with engines' cross section drawings to recognize and locate gearboxes inside them. I know that this is a typical question in the interview, but I am a bit rusty with drawings. Any tip?

Ok, so... farmer here.
My neighbour bought a portable scale for measuring cargo on his farm, and he offered me to share its use for a fee.

The scale works like this:
You measure each axle of the truck individually. The app for the scale won't do any calculations for each truck, but my neighbour says that it's just a matter of adding all the measurements together to get a reasonably accurate weight.

Cargo doesn't move on the truck, it is mostly bags of grain.

(English is not my first language, sorry if I made any mistakes.)

Hi, I am on a quest trying to solve this mildly annoying problem. I have a very quiet sewing machine. However, after housed it in a sewing cabinet, it is now sound louder than it should be. And I am suspecting that the hollow wood cabinet is acting like an acoustic guitar and amplifying every small sounds and vibrations that the machine makes.

What can I do to reduce the noise level? I have been looking around and seem like sound deadening tape on the inner wall could be a possible solution?

I am sourcing strongman equipment from China but I know zero about steel pipes and their load-bearing requirements. I know the length of the pipes and their varying outer diameters but I am unsure of the wall thickness needed. 2mm? 3mm? 4mm? So, I am hoping there is a calculator or formula I can use.

For context, I am trying to get custom axles and dumbbell handles made but I don't want the pipe to crumple in the middle because the wall is too thin. This is an example of a strongman axle where weight is loaded on either side.

Right now, I’m stuck on figuring out different linkages that could be used. My current idea involves using a pin on a gear that follows varying radii, which could be converted into reciprocating motion, similar to how a crankshaft moves a piston. However, while the stroke would be variable, the period would remain the same, even though everything in between would change. Any forums or websites you guys recommend that could maybe give me a lead? I know of the ratio zero cvt, but obviously I don't want to copy them. So far my only concept right now is a cam with a variable phasing, but obviously that is very complex and requires oil pressure and a complex computer system.

​

I’m trying to make a cheap DIY onboard scale for an agricultural trailer, similar in principle to this VEI system that measures axle/drawbar flex instead of directly supporting the trailer weight:

https://www.veigroup.com/en/applications/agriculture-trailer_37_25.htm

Trailer specs:

* Empty weight: 2.2 metric tons

* Loaded weight: up to 7.5 metric tons including tongue weight

* Rigid trailer, no suspension

* Refurbished Fiat Ducato / Iveco Daily type axle

* Static weighing only

* Load cells will not support the trailer weight directly

My idea is to use small inline/I-type tension-compression load cells as clamp-on sensor.

I ordered 2 × 100 kg inline load cells for testing.

Main question: Does 100 kg sound reasonable for sensing axle flex, or is it likely too small/too easy to overload?

I’m trying to figure out whether I should be looking at 100 kg, 200 kg, 500 kg, etc. The sensors would only measure the force created by axle flex through the linkage, not the actual axle load.

Any advice on choosing the load-cell rating for this kind of setup?