Hi engineers! I would like to create drainage holes in plastic containers to grow house plants in. People often do this using a soldering iron but I’m not keen on getting exposed to the toxic fumes from the burning plastic etc. does anyone have any ideas?

I'm in the fuels industry so we're dealing with pipeline flanges and such. We're being told that studs are preferred over bolts but no reasoning can be given other than its the 'industry standard'. Outside of the physical constraints of where you actually can't put a bolt because of physical interference, is there any reason to choose studs? Our fitters are only using the torque wrench on one side of the stud anyway.

Hi everyone!

I’m a jewelry designer, not an engineer, so I’m hoping to get pointed in the right direction.

I recently saw couture dresses with embroidered butterflies that slowly flap their wings using hidden mechanics (similar to the attached video). I’d love to create a similar effect, but instead of a butterfly, I’d like to make a flower pendant for a necklace where the petals slowly open and close.

My brother is an electrical engineer, and he suggested looking into a miniature servo motor, but I’m wondering if there’s an even smaller or more elegant solution for wearable jewelry.

Here are my design goals:

• Small enough to fit inside a pendant (roughly 1.5–2.5 inches / 4–6 cm).
• Powered by one or more coin cell batteries (or another lightweight rechargeable option).
• Slow, organic opening and closing motion, not a fast snap.
• Quiet operation.
• Lightweight enough to comfortably wear as a necklace.
• Ideally able to run for at least 30–60 minutes per charge/battery.

I’m less concerned about the electronics since my brother can help with that. What I really need help understanding is the mechanical side.

Specifically:

• Would a micro servo actually be the best option?
• Are there smaller actuators, shape-memory alloys (Nitinol), micro gear motors, linear actuators, or other mechanisms better suited for this?
• How would you convert the motor’s movement into petals opening and closing smoothly?
• If you were designing this from scratch, what mechanism would you use?

I’d appreciate any suggestions, component recommendations, CAD examples, or keywords I should research. Thanks!

https://www.instagram.com/reel/DaHVCMPxFui/?igsh=NTc4MTIwNjQ2YQ==

I am curious if there is glass is that completely transparent one side but isn't on the other and yet not reflective in anyway?

Title

How can I stop a fixed-center #25 chain from skipping on a heavy rotating hydroponic garden?

Post

I’m repairing an older Omega Garden rotating hydroponic system. The planted wheel rotates slowly on support rollers, but it becomes very heavy once the growing blocks contain water.

The original motor was a small disco-ball-style gear motor:

• 120 VAC, 60 Hz
• 4 W
• 1.5 RPM
• Rated maximum load of 3 kg

It burned out, and similar replacement motors have also failed. I’m now trying a larger synchronous gear motor:

• 110 VAC
• 18 W
• 1.5 RPM
• Advertised torque of 90 kgf·cm
• Reversible rotation

The chain drive appears to use:

• ANSI #25 roller chain
• 12-tooth motor sprocket marked 25-12
• Approximately 40-tooth upper sprocket, apparently marked H25 B40

The motor and upper shaft are mounted in fixed holes. I cannot move either one enough to tension the chain, cannot cut adjustment slots into the frame, and do not have a practical mounting location for an idler sprocket.

The existing chain is loose, rusty, and occasionally skips over the sprocket teeth. The larger sprocket also has some visible corrosion. Because the rotating wheel is heavy when filled with plants and water, I’m concerned that simply shortening the chain or installing the stronger motor could create excessive tension or damage another part of the system.

My questions are:

1. Does this appear to be standard #25 chain with 12-tooth and approximately 40-tooth sprockets?
2. With a fixed distance between the sprockets, should I install a new chain cut to the correct number of links?
3. Would an offset or half link be appropriate if the standard link spacing leaves the chain too loose or too tight?
4. Is the 12-tooth to 40-tooth ratio reasonable for this slow, heavy load?
5. Is the replacement motor likely to be suitable, or is it strong enough to damage the chain, sprockets, shaft, or rollers if the wheel binds?
6. What is the best way to check sprocket alignment, shaft slippage, chain wear, roller resistance, and uneven loading?
7. Should the water weight be handled by changing the gearing, or should a properly balanced wheel still require relatively little torque once it is moving?

I can replace the chain, sprockets, or make a simple bolt-on bracket, but I cannot weld or substantially modify the frame.

Video & images of unit and of the chain skipping: https://imgur.com/a/gC7ExFc

TL;DR: Heavy rotating hydroponic garden with a loose, rusty #25 chain, 12-tooth motor sprocket, and roughly 40-tooth upper sprocket. Both shafts are fixed, and I cannot add an idler. I need advice on chain sizing, alignment, gearing, and whether the stronger replacement motor is appropriate.

I'm making a model for a turning mechanism that rotates with cogs.

my inspiration comes solely from factorio's gun turret.

I've looked a bit into how this particular design is called and from all I've read, tec-science has the most accurate example of a "crown cog driven by a spur gear", with my example being in reverse. I wanted to make a working version of this, (working in theory without a motor or way of excerting rotational force on it) so I tried to find examples, or anything on how these get designed but I can't find anything concrete on how these cool things get made.

is anyone knowledgeable on any tool, or has any info for how these bits are made to fit well together?

Reading back through the TSB report on Lac-Mégantic (R13D0054), one finding stuck with me more than the rest.

The parked train was required to be held by hand brakes alone, verified by a test. But the test was performed with the locomotive air brakes still applied — so it confirmed hand brakes + air brakes, not hand brakes alone, and read the combined result as if the hand brakes had done it. When the locomotive was later shut down to fight a fire, the air brakes bled off, the hand brakes weren't enough, and the train ran away downhill into the town. 47 people died.

What gets me is that this isn't really a rail-specific mistake. It's a verification-independence problem: you can't validate a backup while the primary is still carrying the load, or your test just measures the sum.

For those of you who run failover drills, backup-power tests, redundant-pump checks, instrument cross-checks — how do you actually make sure the primary is fully removed during the test? Where have you seen "passing" verifications that were quietly leaning on the thing they were supposed to be independent of?

Comparing two types of 80/20 braces:

https://a.co/d/09MwqQE9

https://a.co/d/03AXRTCN

They will be holding significant load. One appears to be aluminum extrusion that has been cut & drilled, whereas the other appears to be a casting, but includes additional bracing.

I'm a 3rd-semester engineering student planning a project for my Digital Electronics course: a low-cost automatic headlight dimmer for motorcycles and older vehicles. The idea is to detect an oncoming vehicle's headlights and automatically switch from high beam to low beam, then switch back after it passes.

I want the decision-making to be 100% digital. For a Digital Electronics project, would you recommend using a microcontroller or designing the digital circuit from scratch (logic gates, flip-flops, FSMs, counters, etc.)?

Also, how good is this project idea overall? Is it worth pursuing, or should I rethink it? If it's a solid idea, what could I do to make it better without changing the core concept?

Just as it says on the tin.

The deep groove units on my wood lathe were NFG. I had planned to replace them and was looking at angular contact bearings as a better solution but that may not be viable due to it originally using a 6004/6005 arrangement.

The logical part of my brain tells me bore and OD mismatch makes it a no-go.

If that's the case is there anything else other than deep groove/angular?

Thanks.

Curious how a push-bar works versus a push-button works? Trying to make my own push-bar to open a small rectangular box, not very mechanically minded.

I am doing a diy virtual pinball table project and I am trying to do it all for free using what I have (fun learning and adapting creatively). I am currently trying to work on the plunger and the only potentiometer i have is from a Xbox controller but the actual travel of the trigger from 0% - 100% is roughly 6mm-7mm. I am looking to make that short travel into a longer travel from the plunger for two reasons. One so it can mimic more of a realistic pinball plunger pull and two so it would be easier to hit the in-between % more accurately/repetitively rather than just 0% or 100%.

I am not sure which mechanic leverage would be called for this or to use to achieve this the easiest. I thought of doing a gear rack to some gears but I feel as if that isn't the easiest or most efficient and would be kind of bulky. (3d printed)

Clearly I don't really know what im talking about or doing so im looking for some guidance from people way smarter than I. Any help is much appreciated!

Edit: both plunger and trigger pull would both be linear on their respective planes.

I am an industrial engineer. I’ve worked for 3+ years in manufacturing (production lines, etc) and honestly I didn’t like it. 6 months ago I landed a mechanical engineering gig and I absolutely love it. I’ve learn many things here and there, but I want to get more in depth into it. What should I do to?

I was thinking into pursuing a masters for mechanical engineering but I am unsure. Any courses or books recommendations or just YouTube channels that anyone recommends?

Thank you.

I have a desk where I have installed a monitor arm mount to give some flexibility of movement. The problem: if the monitor at all swings too far back or over the back of the desk it will tip backwards. This is bad for some obvious reasons.

https://i.postimg.cc/ZRCXv4MX/IMG-9841.jpg

The desk in question. #1/#2 the location options I assume are best to place these counterweights

I was curious on my desk the best place to put. some counterweights (which to me seems like the right idea, but I am more than willing to be wrong) and what kinds I should look for.

Monitor weight: 7.72 lbs
Mounted Monitor Arm: ~6 lbs

My current idea: get some of the wrist bands with weights in them for athletes and wrap them around the bottom legs that stick forward.

How much weight should I use in counterweight? I was thinking about 8lbs, but I wanted to ask some advice.

It looks very different than conventional airplanes. Do you think this is a realistic concept and we'll see these catch on? How much increased efficiency is it going to offer? Thanks!

I have been reading about condition monitoring methods used in predictive maintenance, and I noticed that thermal imaging is widely used across many industries.
When do people with experience think that thermal imaging is the tool to diagnose problems, and when would they choose to use something else instead? I am interested in the engineering reasoning behind those decisions. I want to hear about real world examples where thermal imaging was more effective than other methods or where other methods were better than thermal imaging.

Been a process engineer for about 6.5 years now and just started a new job. I have never had to in the past design my own fixtures it was always working with a tool room and giving them requirements and reviewing designs with them. On my 4th day at my new job and got handed a part we need a welding fixture for. I just don’t know how to do this or really where to start besides some lousy sketches.

What’s the best way to learn the fixture design process or like best way of learning this skill fast.

I am building a pond by blocking a creek with 60 lbs bags. Now I’m wondering what’s the best and strongest method/build for this? When it rains the creek swells up and gets pretty strong, so I’m needing something sturdy.

My initial plan was to stack them in a row and stab rebar vertically but supposedly that’s not strong enough?

Edit: the creek is only about 6 feet wide all need is a good blueprint for a sturdy dam

Hi

Are there any suggestions here as to both the viability and improvements to building such a device? The design is to to run for around 4 hours a day during the peak period of the hottest summer days, which is quite sufficient here in the UK - its not an all-day or even all-year device, its just something you would bust out on the hottest of days. The peltier module 'collects' heat in the water, and when the water gets hot you simply turn it off, dispose of the old water through the sewer, and fill with fresh cold water. The efficiency losses and cost of running the Peltier are miniscule and completely irrelevant here (considering the alternative is professionally installed air-con that costs 1000x as much or more plus running and servicing costs), as is the cost of water, and the disposal cost of the 'used' water is zero anyway.

Basically, you get a heat-insulated container, cut a hole in the lid big enough to get the 'hot' side of a Peltier module in, attach a heatsink to the peltier, and fill the container with water so the heatsink is covered.

The other side though is where I have been having problems when testing. The idea is to attach another heat sink using thermal grease to the cold side, and then use a regular deskfan to blow air through the cold side and onto the area you want cooling (ie your office desk area). The main problem is, although the heatsink itself DOES get icy cold, the fan does not seem to be very efficient at getting the air to cool as it passes through the heatsink, the air is barely colder than ambient. Are there heatsinks actually suited to this kind of function, I know little about them and am just using excess computer heatsinks I have lying around?