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  • corradini commented on bananafred's instructable Non-PV Solar Power1 month ago
    Non-PV Solar Power

    Couple of thoughts on economics:(A) I'm wondering (although I don't think so) whether it's not just cost-per-watt when comparing to PV, but also dealing with area. If you need more square (feet/meters) to generate the same wattage, that's also a possible 'cost' to factor in. (B) More significantly, you'd for sure have higher up-front (capital + installation) costs. Not only would lenses (or parabolic mirrors) have significant mounting requirements, but they'd need to track the sun - which means motors and joints and things. Not a criticism - I love the idea and understand that your point was just a general experiment! - just an observation.(C) Finally - a Peltier module is not a Seebeck module - you want a "TEG", not a "TEC" (thermoelectric generator vs. cooler), mor...

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    Couple of thoughts on economics:(A) I'm wondering (although I don't think so) whether it's not just cost-per-watt when comparing to PV, but also dealing with area. If you need more square (feet/meters) to generate the same wattage, that's also a possible 'cost' to factor in. (B) More significantly, you'd for sure have higher up-front (capital + installation) costs. Not only would lenses (or parabolic mirrors) have significant mounting requirements, but they'd need to track the sun - which means motors and joints and things. Not a criticism - I love the idea and understand that your point was just a general experiment! - just an observation.(C) Finally - a Peltier module is not a Seebeck module - you want a "TEG", not a "TEC" (thermoelectric generator vs. cooler), more or less. Peltiers aren't as efficient when run 'backwards' to generate power from heat. (Quick info here - and I have no connection to this company: http://www.europeanthermodynamics.com/news/difference-between-TEC-and-TEG)

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  • corradini commented on ASCAS's instructable Mini Peltier Air Conditioner (Plans)1 month ago
    Mini Peltier Air Conditioner (Plans)

    There's also size, complexity, and capital cost (vs. operating cost). For larger-scale operations, traditional cycled A/C is generally more appropriate; for smaller, portable, and/or other applications a peltier often makes good engineering and/or economic sense.

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  • corradini commented on Mjtrinihobby's instructable Making a Beefy Peltier Cooler! 1 month ago
    Making a Beefy Peltier Cooler!

    VERY interesting point that higher voltage takes longer but gets colder. (Makes you think about what "efficiency" means, from both a thermodynamics and a practical standpoint. :-) So it seems it'd be smart to start out with a lower voltage, to get a quick drop in temperature (and save power), then up the voltage somewhat - if you want things colder. You could do it manually, or for the extra points (and expense) throw a 'duino or similar into the mix. (I'd be curious as to whether it'd then stay at the lower temp if you reduced the voltage again. That'd obviously depend greatly on the real-world properties of the cooler and system, but not sure whether it's just ultimately the heat-loss-proportional-to-voltage factor anyhow.)

    Not quite accurate. I don't know about felony vs. misdemeanor vs. civil violation, but it IS true that collecting rainwater was generally illegal in Colorado. (Link to article in Denver Post - which I presume is not fake news - below). This has been modified, VERY recently, but historically Colorado - in its state constitution! - held that water in the air was owned *collectively* by the people of the state and that if an individual collected rainwater that it infringed on any senior rights of people "downstream". Water rights in the American West is a VERY complicated, touchy, and much-litigated issue.http://www.denverpost.com/2015/03/16/rooftop-rainwater-collection-bill-easily-clears-colorado-committee/

    >>...buy the true compressor type...That sounds like the voice of experience, and probably valuable to the guy who may need to seriously rely on one. OTOH, this *IS* Instructables... >;-)

    Now THAT (thermal transfer from walls) was a clever insight that nobody else picked up on. I had to think about it for just a sec, but yeah - the more air circulation is going on the more you're using the walls of the box as kind of (really poor, but still) 'heat sink fins'! The walls are inherently warmer than the contents of the box, so moving air around must increase the speed of external heat transfer into the box. You want the inside air nice and still.

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  • corradini commented on TheCuriousCreator's instructable Curved Wood Laptop Stand4 months ago
    Curved Wood Laptop Stand

    VERY nice! How do you keep the laptop from sleeping while it's closed - (I'm guessing you have to go into power management and disable that)?There are a couple of other ways to do this, as I'm thinking about it. You could bandsaw some thin strips instead of buying veneer. And rather than using a mold (sorry, American spelling ;-) - actually I'd call it a form anyhow - you could just use a couple of stop-blocks nailed/clamped to a board or workbench (like this: n_________n ), and arch the strips between them while gluing 'em up. They'd naturally form what's called a 'catenary' arch, like a suspension bridge. You could steam the strips first - there's lots of stuff online about doing that with a PVC pipe or similar, or maybe just put in an oven for a while with a big pan of boiling water ...

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    VERY nice! How do you keep the laptop from sleeping while it's closed - (I'm guessing you have to go into power management and disable that)?There are a couple of other ways to do this, as I'm thinking about it. You could bandsaw some thin strips instead of buying veneer. And rather than using a mold (sorry, American spelling ;-) - actually I'd call it a form anyhow - you could just use a couple of stop-blocks nailed/clamped to a board or workbench (like this: n_________n ), and arch the strips between them while gluing 'em up. They'd naturally form what's called a 'catenary' arch, like a suspension bridge. You could steam the strips first - there's lots of stuff online about doing that with a PVC pipe or similar, or maybe just put in an oven for a while with a big pan of boiling water - as long as you get them to the form reasonably quickly.Nice work!

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  • corradini commented on Aperition's instructable Make a Candle From Cheese 5 months ago
    Make a Candle From Cheese

    This reminds me of the old story about someone who was presented with a report and said "you could've said this in way fewer words" to which the author said "yeah, but I didn't have the time". It's clever and funny - mostly - but not *THAT* clever and funny. Aperition: TAKE THE TIME. Less is more. And more funnier. And useful-er :-)

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  • corradini followed Gifts & Wrapping, Survival, Canning & Preserves, Kitchen and 11 others channel 8 months ago
  • corradini commented on cfcubed's instructable A Small DIY Home Hydroponics Setup 8 months ago
    A Small DIY Home Hydroponics Setup

    Nice improv - very Macguyver! I'd suggest lining the walls with reflective film. I used a mylar "space blanket" - they're like 3-5 bucks in the camping section of a Target or Walmart! Huge sq.ft., cheap, and very lightweight - so easy to stick on with spray adhesive, glue stick, etc. Helps with both light and heat retention - the heat's key for my super hot Carolina Reaper peppers. Helps with germination, too, and can signal many plants that frost is past and it's time to flower/fruit (or bud - I'm not judging. Hey, that's legal here in CA now anyway. :-)

    Also, for lighting I bought 2 packs of 5 LED ribbons from Amazon - I think ~$15 w/ power brick- with a red/blue ratio (green wavelengths are wasted for reasons that become obvious with a few seconds' thought. ;-) I curved a sheet of thin plywood a bit - sprayed w/ warm water and tied loops of rope to hold the curve in place through more wettings until it stayed. Then spray-adhesive'd some mylar space blanket as a reflector, and stuck the led strips on. They're adhesive-backed but it's lousy adhesive and mylar's slick, so I used narrow strips of duct tape to help. Works great, really lightweight and low power per lumen, very little wasted as heat.

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  • Easy Build Heat Treat Furnace - No Power Tools Required.

    Also: metal burns - quite literally. Oxidation can be slow, i.e. "rust", but there're faster processes too: heating the heck out of iron/steel in the presence of oxygen will eat it. (That's (more or less) what scale is.) Whereas: ceramics, pretty much by definition, are metal oxides. Meaning they've been, well, "pre-burnt". That's why fireplaces are built out of firebrick, potters use ceramic liners in kilns, and so many bread/pizza ovens are built with mud, clay, and stone. It's not the cost or effort of making things from metal (although those are also prohibitive!), or insulation issues (although that's relevant too) - it's that the fire will eat the metal.And then you don't have an oven, fireplace, kiln, etc., anymore.

    Concrete has enough water content, even after a long cure, that it will often not just spall/crack but actually explode, in contact with high temperatures. It's also really dense. The "certain types of white bricks" you're referring to are firebrick, which is a bit specialized. For extremely high heat in kilns and temp ovens, it's even better to use specialized bricks that are almost like ceramic sponges. (Fortunately, they're cheap, easy to cut with anything more than a butter-knife, and fantastically good at keeping crazy heat on one side from passing through to the other.)

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  • corradini commented on kai.h's instructable Heat Treating 1084 High-Carbon Steel8 months ago
    Heat Treating 1084 High-Carbon Steel

    Sounds nice, but it REALLY depends on the steel. What you described might make a fantastic, sharp, tough knife with one type of steel - and a lousy one with another. Steels are complicated.

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  • corradini commented on TITANIUMTAINE's instructable Mini Cleaver Build10 months ago
    Mini Cleaver Build

    VERY nice - not only "for a 13-year old" but for anyone. (I made my first knife - a nice marking knife for woodworking, out of a reciprocating saw blade and rosewood - when I was like 40, and it was tricky, and I'm real good at making all kinds of things, so I'm impressed!)A few comments, meant very constructively! Remember that an Instructable is not just to show what you did, but to guide someone else to make one, too. The the fewer basic questions people have to ask, the better.Looks like you decided to do an instructable after the blade was already shaped and beveled. I get it; I've gotten to that point with lots of projects and thought "dang!, I really shoulda been shooting pix of this.". But if you're doing that, you might want to be more specific on those step...

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    VERY nice - not only "for a 13-year old" but for anyone. (I made my first knife - a nice marking knife for woodworking, out of a reciprocating saw blade and rosewood - when I was like 40, and it was tricky, and I'm real good at making all kinds of things, so I'm impressed!)A few comments, meant very constructively! Remember that an Instructable is not just to show what you did, but to guide someone else to make one, too. The the fewer basic questions people have to ask, the better.Looks like you decided to do an instructable after the blade was already shaped and beveled. I get it; I've gotten to that point with lots of projects and thought "dang!, I really shoulda been shooting pix of this.". But if you're doing that, you might want to be more specific on those steps. A key example would be how you put the bevel on the blade - that is a tricky step where a lot of folks use an improvised jig, or a method with a sharpie, etc. And what bevel angle you put on is interesting info too.One other point: you mention briefly "I used a homemade grinder" - WOW, man, that's impressive all by itself! As a big fan of Matthias Wandel (check out woodgears.ca or his stuff on YouTube) I can (mostly) get how you did it from your pic, but that itself is a project worth showing at least more pix of here!Best wishes, and keep it up! Oh, yeah, one last question - why a mini-cleaver? :-)Cheers,Andrew

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  • How to make a custom bow grip using a balloon and some flour

    How do you actually CAST the balloon full of flour, so that it keeps its shape? Do you mean something like gesso, rather than farina? Or do you add water at some point? This is confusing.

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  • corradini commented on misko13's instructable Homemade Pork Lunch Meat10 months ago
    Homemade Pork Lunch Meat

    Stan1y - as Wolfgang Pauli put it: not only is that not right - it isn't even wrong. Yep, salt is a chemical. And so is dihydronium oxide (also known as WATER). And oxygen. And carbon. You want "chemical-free" food, you'll need to go Star Trek and subsist on pure energy. And you're griping about the narrow definition of the word "natural" - we can substitute celery powder for Prague and end up with substantially the same "chemical" - as the industry now disingenuously does with "no added nitrites" bacon. Saying that salt and nitrite are "considered by some" to be "the problem" is a wildly vague straw-man statement - who's "some", and what's "the problem"?. It's hard to see what your point is that cured pork ...

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    Stan1y - as Wolfgang Pauli put it: not only is that not right - it isn't even wrong. Yep, salt is a chemical. And so is dihydronium oxide (also known as WATER). And oxygen. And carbon. You want "chemical-free" food, you'll need to go Star Trek and subsist on pure energy. And you're griping about the narrow definition of the word "natural" - we can substitute celery powder for Prague and end up with substantially the same "chemical" - as the industry now disingenuously does with "no added nitrites" bacon. Saying that salt and nitrite are "considered by some" to be "the problem" is a wildly vague straw-man statement - who's "some", and what's "the problem"?. It's hard to see what your point is that cured pork needs Prague powder but it's an additive - so are salt, sugar, and spices; what's the point? Seems like you're just nitpicking terminology here.(And NO idea what the point is to bring up two other preservatives only to point out they're irrelevant here.)I'm trying to be "nice and respectful" -- I'm just responding to the oddly non-relevant critiques you made - or didn't - here. It's cured ham. Cured ham uses nitrite (as you pointed out!) Other than being pedantic, it's not clear what you were trying to accomplish.

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  • corradini commented on mikeasaurus's instructable gentleman's ski poles11 months ago
    gentleman's ski poles

    A) I LOVE the concept, and nifty Making skills. I've been skiing for 40+ years; old-skool was "Bota Bags", the 'hip-flask of skiers' if I can coin a phrase.B) Saw the comments below on safety of the vinyl -- funny timing, as I was just commenting on another Inst'ble about using "vinyl" (=PVC) gutters for hydroponic gardening, which I think is just fine. But: I'm gonna have to disagree, here.I won't/can't say this is 'unsafe' -- but it concerns me, and I wouldn't do it. (Just FYI, I have a patent in hydrocarbon chemistry and some relevant knowledge.) Here's the point: phthalates are used as plasticizers in PVCs to make them flexible. This vinyl is clearly (ahem) quite flexible. And while polar solvents (i.e. water) don't tend to leach phthalates (which are not bound, ...

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    A) I LOVE the concept, and nifty Making skills. I've been skiing for 40+ years; old-skool was "Bota Bags", the 'hip-flask of skiers' if I can coin a phrase.B) Saw the comments below on safety of the vinyl -- funny timing, as I was just commenting on another Inst'ble about using "vinyl" (=PVC) gutters for hydroponic gardening, which I think is just fine. But: I'm gonna have to disagree, here.I won't/can't say this is 'unsafe' -- but it concerns me, and I wouldn't do it. (Just FYI, I have a patent in hydrocarbon chemistry and some relevant knowledge.) Here's the point: phthalates are used as plasticizers in PVCs to make them flexible. This vinyl is clearly (ahem) quite flexible. And while polar solvents (i.e. water) don't tend to leach phthalates (which are not bound, that's important) from PVC -- apparently alcohols are more efficient at that. Link to actual science journal article below. I have no axe to grind (or commercial/employment interest) about phthalates, but they are possibly linked to estrogen-like effects in mammals, which is why we don't use BPA in baby bottles any more, for example.And which makes the name "Gentleman's (Ski) Poles" somewhat amusing, potentially. Or potently. Or not-potently.... >;-) There's just way too much meat in there - oh, dang, there I go again - to chuckle about.-------------------------I think it'd just be far easier and possibly significantly safer to just plug the bottom of a ski pole so that the libation won't leak out, and use the crafty shampoo-bottle-thread solution from this Inst'ble at the top. Ski poles are aluminum and, well, I'm pretty sure beer cans are too, so probably safe enough, after a few good rinses just for fun. I'd imagine that pouring in some food-grade silicone rubber would work just fine - better yet, just pull off the ski-pole tip and squeeze in a bunch of clear silicone sealant from the bottom; let it cure for a long time, more rinses. Added bonus: more volume. :-)--------------------------P. Chatonnet, S. Boutou, A. Plana. Contamination of wines and spirits by phthalates: types of contaminants present, contamination sources and means of prevention. Food Additives & Contaminants: Part A, 2014; 1 DOI: 10.1080/19440049.2014.941947

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  • corradini commented on seamster's instructable Impossible Nail in Wooden Block11 months ago
    Impossible Nail in Wooden Block

    I've got a pretty good amateur woodworking & metal shop (including some CNC stuff) - and I've done a lot of fabricating parts that included some threading & tapping. And I have a set of rather tiny taps & dies, too, probably small enough to do that w/ a - fairly large - nail.That said - I think you're way underestimating the difficulty of machining that. To drill the hole - well, you could use a lathe, but it'd be a trick to chuck the nail with its head, unless the jaws on your 3-jaw chuck were short enough, and your (small) lathe was really, really well-aligned. (And a few other inevitable gremlins.) Or you might be able to use a mill, but again the setup and precision would be crucial. And then there's the tapping/threading ops on each side - we're down to almost watchmaki...

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    I've got a pretty good amateur woodworking & metal shop (including some CNC stuff) - and I've done a lot of fabricating parts that included some threading & tapping. And I have a set of rather tiny taps & dies, too, probably small enough to do that w/ a - fairly large - nail.That said - I think you're way underestimating the difficulty of machining that. To drill the hole - well, you could use a lathe, but it'd be a trick to chuck the nail with its head, unless the jaws on your 3-jaw chuck were short enough, and your (small) lathe was really, really well-aligned. (And a few other inevitable gremlins.) Or you might be able to use a mill, but again the setup and precision would be crucial. And then there's the tapping/threading ops on each side - we're down to almost watchmaking precision if you want the nail to be straight, the threads to not cut through the sides, etc. etc. etc.It'd actually be a lot easier to just drill a hole in each half and stick a pin in it with some good epoxy. You'd have to epoxy it anyhow - otherwise someone could just unscrew the threaded nail - why bother with threads? Another easier solution might be to just do a half-lap joint (nah, would probably break under stress), or an epoxied "X" joint you could cut with a dremel disc or slitting saw? Remember the joint will be hidden. Heck, you could possibly even just use a thin sleeve rather than a pin - no concentricity issues with the hole drilling.But wait one sec, here - all these solutions, going back to Cleareye10.'s original suggestion, rely on a 90° adapter that fits into the big holes, in order to drill the center hole for the nail. The OP's holes are 2½"Ø - my right-angle drill head (a Milescraft Drill90) is way larger. Ditto the right-angle drills from Ryobi, Milwaukee, Bosch, and DeWalt, which are smaller but still too large. Let's just go back to the original idea: simply breaking & re-gluing the wood is WAY EASIER. And works. Occam's Razor, sorta - why pick a much harder way to do something, when it doesn't really get you anything more?

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  • corradini commented on LinkG4's instructable Aquaponics Vertical Garden11 months ago
    Aquaponics Vertical Garden

    hreid - excellent points. (Wish I'd read farther down before posting my long bit above responding to timzebo.) - Absolutely agree on alumin(i)um and galv'd steel. Aluminum has virtually no biological role despite being the 3rd most common element on Earth! After a few billion years for life to figure out something to do with Al, it's decided not to. It doesn't seem to be super-toxic to humans (otherwise we'd skip beer & soda cans - the protective formation of Al2O3 is helpful there), but you're right that it's quite reactive in acidic environments and it's probably not smart to eat a lot of whatever you get from that. (I will not get into the Alzh. debate.) And while Zn is biologically essential, a whole lot of it ain't good.- That said, your points on rigid PVC, the rat ≠ human ...

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    hreid - excellent points. (Wish I'd read farther down before posting my long bit above responding to timzebo.) - Absolutely agree on alumin(i)um and galv'd steel. Aluminum has virtually no biological role despite being the 3rd most common element on Earth! After a few billion years for life to figure out something to do with Al, it's decided not to. It doesn't seem to be super-toxic to humans (otherwise we'd skip beer & soda cans - the protective formation of Al2O3 is helpful there), but you're right that it's quite reactive in acidic environments and it's probably not smart to eat a lot of whatever you get from that. (I will not get into the Alzh. debate.) And while Zn is biologically essential, a whole lot of it ain't good.- That said, your points on rigid PVC, the rat ≠ human biology issue (fully agree!), and the monomer issue are (ahem) dead on. (Bows.)

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  • corradini commented on TheHomebrewGuru's instructable Fusion Jr. Home Energy Reactor1 year ago
    Fusion Jr. Home Energy Reactor

    You mean Seebeck - which is exactly the inverse (but basically the same thing) of the Peltier. Look them both up on Wikipedia.

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  • corradini commented on JessaG1's instructable Simple Hydroponic Strawberries 1 year ago
    Simple Hydroponic Strawberries

    I don't mean to criticize, but I don't understand your statement that strawberries "are happy with" only water. Plants need nutrients to grow - this goes beyond even botany to basic thermodynamics! >;-) Putting it simply: you can't make a strawberry out of water, no matter how good the setup. A strawberry has mass; that mass comes from somewhere, and it's composed *mostly* (but not totally) of "CHON": carbon, hydrogen, oxygen, and nitrogen. O2 can come from atmosphere (remember photosynthesis?), but plants do NOT get nitrogen from air; it has to come from N2 compounds, through the roots. They also need phosphorous and potassium (hence the "NPK" ratios on fertilizer labels). And trace minerals. This is why hydroponics 'food'/nutrients are supplied. Saying...

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    I don't mean to criticize, but I don't understand your statement that strawberries "are happy with" only water. Plants need nutrients to grow - this goes beyond even botany to basic thermodynamics! >;-) Putting it simply: you can't make a strawberry out of water, no matter how good the setup. A strawberry has mass; that mass comes from somewhere, and it's composed *mostly* (but not totally) of "CHON": carbon, hydrogen, oxygen, and nitrogen. O2 can come from atmosphere (remember photosynthesis?), but plants do NOT get nitrogen from air; it has to come from N2 compounds, through the roots. They also need phosphorous and potassium (hence the "NPK" ratios on fertilizer labels). And trace minerals. This is why hydroponics 'food'/nutrients are supplied. Saying you don't need to feed strawberries, or any other hydroponics crop, is provably false (and silly, but I'm being polite).

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  • corradini followed Audio channel 1 year ago
  • 3D home printer with Arduino

    Aha - thought so. For English readers - indeed, it is a stainless-steel cup used for making custard, or 'flan'. :-) Muchisima gracias, se~nor!

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  • 3D home printer with Arduino

    Que es "the custard rate" en espanol? No se tradujo también en Inglés - que suena como "natillas-tasa", cuando pienso que quería decir "taza" tal vez?(If so, for English readers, I think he means basically "measuring cup" - probably a Google Translate issue... :-)

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  • corradini followed Arduino channel 1 year ago
  •  Weather Forecasting and Interfacing DHT11  Sensor With Mediatek Linkitone Board

    Am I missing something? Like: the header file and code?

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