• If it’s steel it’ll harden. The most common failure in tempering springs (or heat treating in general) is not keeping them at temperature long enough.

You’ve got to temper the to give it proper springiness.

• As an engineer and the owner of an industrial equipment manufacturing firm I can say with absolute certainty that refusing the metric system is madness and spells doom for any technical career aspirations. I’m not exaggerating when I say I simply cannot hire someone who is not capable of using the US customary as well as metric systems. We only see US units in legacy work and repairs. All new work is designed and produced using the metric system. There are fewer and fewer US unit machines every year and that means fewer job opportunities for anyone not at the late stages of their careers. There are countless technical justifications for using the metric system, but the simplest reason is that the money is in its mastery.

• It’s worth noting that your motor is designed for intermittent use, not sustained operation. If you slow it down electrically it’s going to run hotter than designed so the duty cycle is going to be reduced. You’ll have to adjust your design to suit the new duty cycle.

Use pulleys. There’s no reason to get into actual gearing or complex frequency modulation. The nice things about pulleys is they are inexpensive, available everywhere with belts of any size and very forgiving of misalignments.

• This is great! Congratulations! Complicated, and often dangerous, projects have always been the heart and soul of engineering and it’s fantastic to see people pursuing their ideas. Well done! No safety lecture from me, just a reminder to stay aware. The inevitable technical difficulties will manifest where you don’t anticipate them at the worst time possible, try to stay one step ahead.

• Irritable_Badger commented on sbtroy's instructable The Chaos Machine (Double Pendulum)5 months ago

The experiment is designed to illustrate that mathematical modeling cannot precisely predict the motion of the pendulum due to variables prior to initiating motion. You can perform the experiment in a vacuum using a robot to replicate the starting conditions and you will still have unpredictability in the motion of the pendulum elements. You can certainly increase the accuracy of predictions by decreasing the number of variables (as in my example above) but there is always a level of unpredictability present. Which is what it’s all about :)

• Irritable_Badger commented on Mrballeng's instructable Make a Ring by Melting Pennies. 9 months ago

Nothing has value beyond what it’s perceived to have (perception). In the case of currency or something you are using as trade the item has to have equal perceived value on both sides of the trade. I don’t trade Bitcoin because I perceive it as having no value, therefore it’s worthless to me, regardless of what the other person says it’s worth. Government currency simply tells the user how much value the government ascribes to it.

• Irritable_Badger commented on aspirescience's instructable MAGNETIC LEVITATOR9 months ago

Two won’t work. You can’t hold something between two constant magnetic fields, one will always overcome the other. See Earnshaw’s Theorem for more information. For multiple magnets to work one, usually the lower, uses multiple electromagnets, Hall sensors and a simple circuit to quickly switch the electromagnets to balance the forces.

• The process isn’t intended for bronze. It’s for mild steel, which must be greased, oiled or otherwise coated with something to stop it from rusting almost immediately. For the color change to be uniform you have to remove the grease, oil, paint etc... or it looks blotchy.

• The magnet rotates because the motion is constrained in every other direction. It wouldn’t be levitating otherwise. The difference in energy between what the object needs to levitate and what the maglev supplies is to be translated into rotary motion. It has no option. Even if you built a maglev system with extremely high sampling and response speeds you’d still get some variation in the field as electrical things in the room are switched on and off. You’d probably get variations as the sun moved across the sky. The energy difference has to happen and it has to go somewhere. You could probably hold something larger than few atoms entirely still, but you’d eventually have a heat issue somewhere. In magnetic linear motion systems and magnetic linear accelerators the suspended objects als...

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The magnet rotates because the motion is constrained in every other direction. It wouldn’t be levitating otherwise. The difference in energy between what the object needs to levitate and what the maglev supplies is to be translated into rotary motion. It has no option. Even if you built a maglev system with extremely high sampling and response speeds you’d still get some variation in the field as electrical things in the room are switched on and off. You’d probably get variations as the sun moved across the sky. The energy difference has to happen and it has to go somewhere. You could probably hold something larger than few atoms entirely still, but you’d eventually have a heat issue somewhere. In magnetic linear motion systems and magnetic linear accelerators the suspended objects also move around, but the motion is largely lost across the length of the suspended object (they also have bumpers to accommodate that motion).

• 12 months ago
• Irritable_Badger commented on Make_Things's instructable Table Saw Blade Gauge1 year ago

At such a small scale a bigger concern than random indentations in the gage is consistent feed speed and downward pressure on the stock. At slower feed speeds the depth of cut is deeper and at higher feed speeds the depth is shallower. Practice helps with that. Power feeders are also a solution, unfortunately they’re expensive, but the expense is a good indicator of how important feed speed is. Downward pressure will also introduce depth variations larger than what you’re concerned about. A feather board mounted to the fence fixes that. The tool in the Instructable is a good solution and if you make it accurately it doesn’t really need improvement. If you’re looking for greater precision and accuracy there are other factors to address.

• “It’s a waste of time to build something that can be bought for the same price”. That’s possibly the most shortsighted thing I’ve read in 2018. That’s the kind of attitude that makes it so difficult for everyone in the industrial engineering and machine design business to find employees. Knowledge of how to do something and the ability to do something are wildly different things, but the best people I hire take both of those elements and combine them to create solutions to complex challenges that have never been faced before. The only way to develop the skills to do something and the ability to tie skills and knowledge together is by doing things. I’ve yet to meet anyone in the machine design industry who doesn’t have endless stories of their successes and failures in projects they’ve u...

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“It’s a waste of time to build something that can be bought for the same price”. That’s possibly the most shortsighted thing I’ve read in 2018. That’s the kind of attitude that makes it so difficult for everyone in the industrial engineering and machine design business to find employees. Knowledge of how to do something and the ability to do something are wildly different things, but the best people I hire take both of those elements and combine them to create solutions to complex challenges that have never been faced before. The only way to develop the skills to do something and the ability to tie skills and knowledge together is by doing things. I’ve yet to meet anyone in the machine design industry who doesn’t have endless stories of their successes and failures in projects they’ve undertaken just for fun. Rampant consumerism is dangerously naive, destined to fail, offers no intellectual value, imparts no skill and is simply no fun.

People have a tendency to misunderstand the learning process. People rarely just do something, they’re actually combining individual nuggets of knowledge they pick up in the process of countless experiences. If you could look back at a persons life you could see where they actually acquired the knowledge to just do something; even if they don’t realize it. It’s a huge problem in complex technical fields. Kids graduate college with their mechanical/electrical/materials engineering undergraduate degree but they don’t know how to actually do anything. Bruises, cuts, burns and trashed tools and equipment are the most important things in someone’s tool chest. Keep up the good work!

• Irritable_Badger commented on JLGG_3D's instructable WIRE CUTTING MACHINE 1 year ago

This is well done. Tc

This is well done.

• Irritable_Badger commented on tomatoskins's instructable Make a Wood Tap From a Bolt2 years ago

Assuming an appropriately slow speed, tapping soft materials, like wood, the problem with the drill press is the spindle return spring trying to pull the tap out. Letting the tap "self feed" isn't an issue. On consumer drill presses the return spring is usually a flat wound coil inside a housing on the feed handle shaft on the opposite side of the head than the handle. Just take it off. If you can't slow your drill speed enough use a ratchet and socket to turn the spindle manually using the nut that holds the forward pulley. It doesn't need to be perfect. With few exceptions, wood has enough movement to cover the entire range of thread tolerances in any given 24 hour period. You don't actually want it to be too perfect. If you make it too tight the wood will end up splitting a...

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Assuming an appropriately slow speed, tapping soft materials, like wood, the problem with the drill press is the spindle return spring trying to pull the tap out. Letting the tap "self feed" isn't an issue. On consumer drill presses the return spring is usually a flat wound coil inside a housing on the feed handle shaft on the opposite side of the head than the handle. Just take it off. If you can't slow your drill speed enough use a ratchet and socket to turn the spindle manually using the nut that holds the forward pulley. It doesn't need to be perfect. With few exceptions, wood has enough movement to cover the entire range of thread tolerances in any given 24 hour period. You don't actually want it to be too perfect. If you make it too tight the wood will end up splitting around the fastener as it moves throughout the seasons.

• Irritable_Badger commented on tomatoskins's instructable Make a Wood Tap From a Bolt2 years ago

Yes. It just gets the tap crusty with wood. The relief in the tap isn't designed to self clean very soft chips. Just brush it out with a toothbrush or it'll rust.

Use a hacksaw to cut the bolt. Cut between two threads and you not only don't beat up the threads, you're left with a nice sharp "tooth" that makes initial alignment much easier when you start taping and it leads in much easier.Put paraffin wax on the tap to lubricate the tool. Just rub the block across the threads. It's about \$3 for a box of 4 blocks of wax and you'll lose it before you ever run out. It's in every grocery store and in the US it's usually sold under the "Gulf" brand. You can also use it on drawer runners in furniture if you've got sticky drawers.

Tapping a hole in wood using a drill or drill press isn't a problem unless you're using very small screws (smaller than #4) or high speeds. The wood is softer than non-rigid "flex" tapping collets. In naturally oily woods you don't even need to predrill the hole. You can make the hole and cut the threads simultaneously with the tap. In rigid tapping operations in metal it's a different story because chips and heat are the enemy. Insufficient coolant, misalignment of the tool with the hole or simply excess speed will lead to broken taps almost immediately.

• You can also get iron shavings with a piece of rebar and a bench grinder. Put a rectangular plastic bowl of water, or vinegar, (I got one from Walmart for less than \$2) under the grinding wheel and start grinding away. You'll be surprised how fast it accumulates. Using the rebar also results in far faster chemical reaction and a more robust acetic acid because it's iron, not steel. That little bit of carbon that went into making the steel has a tremendous effect on the final product when you're using it in an application that calls for iron.

• Irritable_Badger commented on mikeasaurus's instructable 9 Easy Ways to Distress Wood2 years ago

A dirt and gravel road is a great distressing tool. Put the sides you want to distress on the road then walk around on the boards. You'll have to experiment with it, but it's really easy and the results are instant. If you don't weight a lot and want more distressing you can bounce up and down in places, but don't jump. It's too much and looks fabricated. If too much dirt/clay/mud gets packed on that's ok. Just scrape it off with a little muscle behind it. Practice with your road surface is key.What you are doing is replicating barn/southern farmhouse entryway flooring without the centuries of walking normally required. We figured this out replacing irreparably damaged planks in a barn my friend converted into a house. It looks authentic because it is! You're just doing it backwards.

• Irritable_Badger commented on hackmattr's instructable Copper Torch3 years ago

New motor oil works fine for darkening hardware. Used motor oil used to be better, but after 1984ish everything that produced the high carbon content in the used oil was removed from the equation. The gas, the oil and high wear engine parts like piston rings and bearings share little with mid-80's and older equivalents other than their name and generally similar appearance.

• Does a turners cube count as captive? I'm glad I asked. I did not know some 3D printers leave pockets in the parts. The tiny spools of filament I've seen make a lot more sense now. Just by eyeballing the spools I thought there wasn't a lot of material to use.Thanks for the info!

Nice work on the step-by-step. Out of curiosity, as a traditional machinist with no real 3D printing experience, what is the purpose for the nut; embedded or otherwise? If the part design requires internal threading why not bore the two holes to depth then cut the threads in the part itself? Or insert the nut from the end and capture it with a circlip? Variations are endless. I'm not taking a swipe at your design or execution, I'm genuinely curious. Thanks!

• Irritable_Badger commented on kludge77's instructable Gummy Bear Axe3 years ago

You'd be surprised/disappointed at how little protection is provided by general use respirators. There's a strong argument supporting the potentially lethal false sense of security afforded by an inappropriate respirator may be more dangerous than no respirator. Many people think that if they can't smell the (whatever) they are protected. The fact is the hazardous elements of (whatever) and the odorous elements of same are often entirely different things. Many urethanes are a great example. Positive pressure respirators are often the only things that actually work. Most respirators only block the urethane smell, not the urethane hazards. It's entirely possible to fall over dead when using urethanes all the while wearing serious respiratory protection. The moral of the story is that you...

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You'd be surprised/disappointed at how little protection is provided by general use respirators. There's a strong argument supporting the potentially lethal false sense of security afforded by an inappropriate respirator may be more dangerous than no respirator. Many people think that if they can't smell the (whatever) they are protected. The fact is the hazardous elements of (whatever) and the odorous elements of same are often entirely different things. Many urethanes are a great example. Positive pressure respirators are often the only things that actually work. Most respirators only block the urethane smell, not the urethane hazards. It's entirely possible to fall over dead when using urethanes all the while wearing serious respiratory protection. The moral of the story is that you must know and understand what the safety equipment you have is capable of. A variety of filters for a variety of chemicals should be on hand be in any workspace. Expired filters should be tossed out, even if never used. Same with filter duty cycle. If the manufacturer says two cumulative hours is the max then the filters get tossed at the two hour mark. Safely being safe is a big deal. Don't put yourself at risk being safe in an unsafe way.

Yes, most of the two part PMMA resins sold directly to the retail consumer aren't suitable for this project (most are actually repackaged resins used in the artificial flower arrangement market). But PMMA comes in many, many flavors and quite a few would be perfectly suited to life as an axe handle. It's worth investigating the various PMMA resins that are available. Not only can you find resins exhibiting most any properties you require, they're often less expensive than the standard stuff targeting the individual consumer.

• Irritable_Badger commented on kludge77's instructable Gummy Bear Axe3 years ago

I feel quite confident in saying someone capable of making it has sense enough sense to know it's only useful for Human vs Gummi combat. The fixing a broken hammer handle with electrical tape crowd have automated security protocols that prohibit them from doing much beyond buying a bunch of stuff. Bulk polymerization of the resin, potentially liquefying the Gummies and/or starting a fire is the only risk here. Casting with anything in the acrylic monomer category creates the potential for bulk polymerization. Assuming the mixing instructions are followed, bulk polymerization is typically initiated by contamination in the mould. Metal reinforced duct tape (not fiber reinforced duct tape), metal shavings, oxidized tooling, etc... can all initiate the process. - Old Mechanical Engineer Who...

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I feel quite confident in saying someone capable of making it has sense enough sense to know it's only useful for Human vs Gummi combat. The fixing a broken hammer handle with electrical tape crowd have automated security protocols that prohibit them from doing much beyond buying a bunch of stuff. Bulk polymerization of the resin, potentially liquefying the Gummies and/or starting a fire is the only risk here. Casting with anything in the acrylic monomer category creates the potential for bulk polymerization. Assuming the mixing instructions are followed, bulk polymerization is typically initiated by contamination in the mould. Metal reinforced duct tape (not fiber reinforced duct tape), metal shavings, oxidized tooling, etc... can all initiate the process. - Old Mechanical Engineer Who Understands Risk Assessment

Dead is dead, the important part is how you get dead. "Man Killed by Axe Head Thrown by Gummi Bears" beats stroke or something normal.

• Irritable_Badger commented on djpolymath's instructable Electrolysis Bucket4 years ago
• Irritable_Badger commented on JackDavies's instructable DIY Spot Welder From Microwave4 years ago

Although it's not terribly likely, discharging a capacitor via dead short can result in catastrophic failure of cap itself, and potentially your shorting bar. Exploding caps blow really hot and nasty stuff in every direction and the slag melts right through most synthetic fabrics (including carpet and clothes). It's really not much fun. More likely is your shorting bar ends up welded to the terminals on the cap and/or you burn the bejesus out of your hand with the now very hot screwdriver, wrench, etc..We have a piece of railroad track behind the shop and we push caps for discharge into the track by taping then to the fat end of a broken fishing rod (Anything metal will work the track was just here when we moved into the shop). Like I said, the likelihood of an catastrophic cap failure ...

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Although it's not terribly likely, discharging a capacitor via dead short can result in catastrophic failure of cap itself, and potentially your shorting bar. Exploding caps blow really hot and nasty stuff in every direction and the slag melts right through most synthetic fabrics (including carpet and clothes). It's really not much fun. More likely is your shorting bar ends up welded to the terminals on the cap and/or you burn the bejesus out of your hand with the now very hot screwdriver, wrench, etc..We have a piece of railroad track behind the shop and we push caps for discharge into the track by taping then to the fat end of a broken fishing rod (Anything metal will work the track was just here when we moved into the shop). Like I said, the likelihood of an catastrophic cap failure and injury/property damage is low, but you can eliminate the risk all together by taking an extra two minutes to discharge the the capacitor in a safe way.

• Irritable_Badger commented on 32Tudor's instructable How to fix cloudy headlights4 years ago

All headlights used to be glass. They got foggy too. It was easier to polish them with abrasives, and the work lasted longer, but the only way to have truly fog free transparent stuff on the front of a car is to not drive it. Windshields used to get foggy too, but that was long ago before modern safety glass. Styling is the big reason for polycarbonate/acrylic headlight lenses. Even very strong glass like borosilicate and kodial treated silicate glass has a very limited shaping options that can stand up to the abuse a car headlight takes. Once you start compound curves or acutely angled edges glass of all sorts starts losing its strength. Glass wants to be flat and going too much against the wants of any given material is simply poor engineering. As far as long lasting solutions to clea...

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All headlights used to be glass. They got foggy too. It was easier to polish them with abrasives, and the work lasted longer, but the only way to have truly fog free transparent stuff on the front of a car is to not drive it. Windshields used to get foggy too, but that was long ago before modern safety glass. Styling is the big reason for polycarbonate/acrylic headlight lenses. Even very strong glass like borosilicate and kodial treated silicate glass has a very limited shaping options that can stand up to the abuse a car headlight takes. Once you start compound curves or acutely angled edges glass of all sorts starts losing its strength. Glass wants to be flat and going too much against the wants of any given material is simply poor engineering. As far as long lasting solutions to clearing poly headlights there aren't any and there will never be (not driving the car aside). Poly breaks down under UV light and once the process starts it can't be stopped long term. It's just the nature of the material. The material in headlight lenses is pretty impressive as far as using polycarbonate outside. Lesser variants get foggy, brittle and turn yellow (look at the gas pump volume display next time you're getting gas).Choose the solution you find easiest and simply repeat when the lenses get foggy again. Don't go overboard fighting chemistry the sun.

Wine glasses do indeed want to be flat. As I noted above, glass can be shaped, but it loses strength the further away from flat it gets. Not flat glass can take shapes that exhibit phenomenally strong attributes for a given characteristic, but only at the expense of other attributes. Using your wine glass as an example: A wine glass can support enormous amounts of weight if the weight is evenly applied squarely across the rim of the glass when it's standing normally. The same glass can support far less weight it's turned upside down. At the same time the wineglass cannot withstand striking or side loading. Annealed glass is not suitable for any automotive application. Annealed glass is great for making wine glasses and some optics because it has less distortion than heat strengthened o...

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Wine glasses do indeed want to be flat. As I noted above, glass can be shaped, but it loses strength the further away from flat it gets. Not flat glass can take shapes that exhibit phenomenally strong attributes for a given characteristic, but only at the expense of other attributes. Using your wine glass as an example: A wine glass can support enormous amounts of weight if the weight is evenly applied squarely across the rim of the glass when it's standing normally. The same glass can support far less weight it's turned upside down. At the same time the wineglass cannot withstand striking or side loading. Annealed glass is not suitable for any automotive application. Annealed glass is great for making wine glasses and some optics because it has less distortion than heat strengthened or tempered glass, but annealed glass is not very strong.