Is this Nuts (& Bolts)?

What kind of assembly do you think off? Don you want to disassembly and reassembly or not?

That is the question !

A teleportation beam?

Scotty?....Any time now.....

Oh crap, he knows about the trans-dimensional sewing machines! We're doomed!

OMG!

What I'm really worried about is ripping holes in REALITY!

Question: Does anyone know if this coincide with the end of the Mayan Calendar (on 12/21/2012) by chance, when the invading hoards of Gigantic Alien Locusts descent upon the Earth and eat all of us for breakfast?

You can relax. If you had plans for the end of the world in 2012 you're going to have to wait for a new date because according to the Mayan Calender the destruction of the world has been delayed and no new date set yet.

Ok lets limit the discussion to reversible bonding.

I would have expected reversible adhesives, magnetics, interlocking mechanisms (with reliability) etc. that would have made these screws obselete.

Looks like there is no ROI for innovating in this arena so we are stuck with a million screws to open up a laptop :-(

ZIP...

ZIP...

This person is showing up at doctor with golden screw in belly button. he says I wanna have screw taken out! The doctor unscrewing the golden screw and then horrible thing is happenning- This peersons buttocks fall off. Hiiiii!

Lynlynch is right, GA

We have wonderful glue today, with amazing bonding power and some are reversible, but when talking about the supposed problem you also have to look at economic feasibility, and we have really refined screw production. so whats the point or is this just a mental exercise?

Yes, glues could be wonderful alternates, except on the condition of undoing the joints simply, as we do with bolts & nuts.

Sorry, I forgot the image of the cleko fasteners in my last post so better late than ever.

"Then you have a fastener that is not only extensively used but even older than the screw. I'm talking about nails which in the construction of houses and small building are probably used even more often than screws. However, while nails can be removed they are generally not as reusable as a screw and also prone to working loose if there is any sort of vibration or flexing."

Good info but before nails, we used pegs wooden pegs into holes in joints and they could be removed depending on the type of wood used for the peg or the beam. Pegs can be made to stand both vibration and flexing and are still used in Boat,furniture, and house construction today. Hope this helps.

This is a sore point with me.... literally. My brother has been putting together a drive shed/barn and I've helped him a couple of weekends. We have an air nailer, even with spiral nails, but he insists on using 3" and 4" screws to put it all together... and it is a much harder and longer job as a result.

Does anyone else think that woodscrews are a significant advantage over spiral nails?

Chris

Is your brother a masochist or what?
You have my Kris's permission to slap him.
Del

thanks... I might just have to.

to add a little more info... more specifically we are mounting the trusses and stringers with screws. so working 15 feet in the air, balancing on one foot, etc.

chris

Having just completed replacing much of the wood on my roof, I will offer this as a compromise between nails, and screws. Galvanized ring shank nails. And of course a pneumatic nail gun.

Another consideration is the building code that must be delt with. There was not any words that were left to use to try to convinve the building inspector that I wanted to use wood screws to secure wood to the roof instead of the ring shank nails. His standard comment was hire a structual engineer to certify that screws are at least as secure as the required nails. That means that I would first have to determine the holding power of the spec nail system, and then perform the same test using screws.

building code? whazzat?... this is bumfu* saskatchewan..... farm land... I don't even think he got a permit. it is largely undeveloped land.. no existing structures, except the converted shipping container for a camp dwelling.

Thanks Masu,

Saskatchewan is known for the wind... it is flat prairie. (and cold) but it is pretty dry and quake free to my knowledge. I think the wind is the key factor. He used big posts for the lower part, (10$ each) and came up with some trusses at an auction (although I suspect they are factory rejects).. but the top plate is all 2x8 qty4 screwed together with a 2x10 on top...and then all the trusses and stringers are screwed.. and he is putting 90 degree brackets to solidify the truss to the plate (although they are also cross-toe-nailed with 6" spiral spikes)

but he will have a durable shed when complete...

Chris

Yeah, that does look like it might want to fly, does Boeing know you are building this?
Started as a barn, ended up as the Spruce Goose
Del

it is 'special' alright. . He says he made a cad drawing... but we never saw it. it is all custom fitting on the job. one end is 4" wider than the other, so the trusses are not true to the building...

but it is only to shelter his farm equipment...

chris

Perhaps you should have delivered envelops to the decision makers. It seems to be a common practice here in So. Fla.

Ingenious! I think you could develop that for use in hurricane and tornado zones, for a variety of building types. ga.

Do the blow out panels in your drawing also allow air to enter? From my angle, it would seem that if air was blowing directly from the side, the area over the center of the roof would become low pressure. Just my opinion though.

When the panels let air through you end up with what effectively is a venturi or in aviation terms an aerofoil. As the air passes under the roof the area it has to pass through is decreased by the reduced height of the roof and it therefore has to travel faster. This results in a drop in the air pressure below the roof and therefore the air above pushes it down into the truss structure not up.

On a gable roof the opposite is true. The air travelling over the roof has to accelerate and this reduces the pressure above the roof. The air below then pushes upwards and if the roof is not secured strongly enough it starts doing an aeroplane interpretation.

I've noticed that nail which have rusted are much more difficult to remove than new ones: has anyone thought of designing a nail with a "fast rusting" coating. Or perhaps a way of getting nails in position with some kind of glue coating.

That's an interesting concept.

Here's a question for all of you budding CR4 people.

What forces are at work holding that rusty nail in place?
HINT: Think fundamentally.

As iron/steel rusts it expands and will thus grip better.
Next!
Del

Yes, but what holds it in position, why doesn't the nail just get pushed back out of the hole as it expands.

Now before you say friction yes but what causes the friction? What forces are at play here?

It expands radially and the jagged rusticles dig into the wood itself as they form and react with the wood creating wroost which is a hardened oxided form of the wood.
If you just keep asking why, why, why like a demented kid, I'll just invent more rubbish, now leave me in peace.
Del

splarf! (wroost)

Rust doesn't form evenly, the surface becomes rough, and the little bits which swell the most dig into the wood.

Ok, at a fundamental level there are four forces that make the universe work, the weak nuclear force, the strong nuclear force, gravity and the electromagnetic force.

Now the first two only come into play when you start messing about with the nuclei of atoms so in this situation they don't count.

That leaves gravity and the electromagnetic force and in this case the force that holds the nail in place is the electromagnetic force.

This comes to play in two ways:

1. Chemical interactions where electrons are transferred or shared between atoms. When this happens the total electric charge on an atom becomes nonzero and as a result atoms bond together to form chemical compounds. This is what happens with the formation of the rust.
   
2. Friction, which comes about when you try and push one atom past another. The friction is due to the outer electrons from one atom being repelled by those from a nearby atom which on irregular surfaces like the rusty nail can trap sections in electromagnetic pockets and thus prevents the nail from moving.

So, in the real world where nuclear reactions are for the most part irrelevant it all comes back to either gravity or the electromagnetic force. Gravity is an attractive force between to masses but is an extremely weak force so unless you are talking about planetary type masses it all comes down to the electromagnetic force.

There are nails sold for use with pneumatic nail guns that are coated with adhesive. The heat generated from the insertion melts the glue. once in place it cools allowing the adhesive to bond between the nail and wood.

Adhesive coated nails usually have a dark coating that is intended to make them stay where they are driven.

interesting!

This begs the question: What are thumbscrews? Are they for using your thumb to turn them? I tried and found I have to use at least one of my fingers as well. What's the deal?

thumbscrews are torture devices applied originally to thumbnails...

Originally? What are they applied to now? The examples shown in the link seem impractical, you would need someone else to apply them.

"you would need someone else to apply them"

probably the original DIY self-torture instructions have worn off...

yes, they were originally tools of the Spanish Inquisition I believe, along with a whole pile of other "tools of the trade"

So, they were invented by Mel Brooks?

oh no... just popularized in the modern era by brooks.

I've seen similar application in chemical laboratories, used for pinching the rubber hoses. Also, lock smiths uses similer hand vices to hold smaller objects like keys.

G'day Unredundant,

You asked:

• "What are thumbscrews?"

Do you mean Dzus fasteners like the ones shown in the image below?

Anyway, regardless of that they are another form of reversible or reusable fastener. They are a quarter turn overclocking fastener that are used extensively in the aviation and car racing industries usually to hold things like engine covers and access panels in place.

Regards, masu

I twisted my share of Dzus buttons as an aviation electrician. I am referring to these:

And the fact that you have to use more than just your thumbs to turn them. So the name "thumbscrew" is misleading.

Ok, now I know what you're talking about and your right, you can't do them up or undo them with your thumb alone. Actually if some gorilla fisted assembly worker has done them up, which from my experience is the norm, you can't undo the darn things no matter how many fingers you use. You can also bet your bottom dollar that the ones that are over tightened don't have screw slots and are strategically located so that it is impossible to reach them with a pliers.

"I twisted my share of Dzus buttons as an aviation electrician."

You'll be familiar with cable lacing (see image below) then. Which is a bit off topic but brings up the subject of cable fastening methods.

Cable ties (image on rignt) have become very popular over the last decade or more but my experience has revealed a particularly nasty potential fault. When they are trimmed if you don't trim them right back to the nickel you can end up with an extremely sharp edge that I have seen open up somebody's arm like a knife that required a considerable number of stitches to repair.

Cable lacing isn't as versatile as cable ties and can take longer to do but when done properly is far neater and more effective.

Hi all,

screws are much older than 17th century!

In ancient Greece and Rome screws were used in pressing grapes in winemaking and oil from olives.

The earlyest known used only big logs of wood 10 to 20 m long as levers to increase the available force.

RHABE

I saw this Dardanelles Gun on display at the Tower of London, The breach screws into the barrel. I guess if you got hit with one of the 1200Lb stone balls it shot, you would be screwed!

Thanks for the inputs. I dont deny that the screws do their job and pretty well, and just because of it being old, I am not saying that they are dumb.

Call it a mental exercise if you will.

But when you get sensitized (for a week, think of screws as a problem) and then look around.. boy they are everywhere

Then you feel the urge to figure out something better or run to CR4

The original method does have some interesting new twists. Check out

http://www.fastorq.com/zip_nut.aspx

Inventions and radical evolutionary changes come about in response to "problems" or a "need" (Thus "necessity is the mother of invention".)

There are numerous alternatives to screws, which are used according to need. A computer case, for example, could be snapped together with the sort of integral snap fasteners used on many cheap electronic products. Plastic removable rivets (like those used in car interiors) could be used. Velcro straps could be used. But typically, screws are used because they work so well.

For a relatively low turning torque, a screw can supply hundreds or thousands of pounds of clamping force. In an assembly like the cylinder head of a car engine to its block, the resulting connection is almost as secure as welding would be, but permits disassembly. In this case, the head bolts have evolved into very specialized single-use fasteners, with special techniques for tightening, but the helical inclined plane feature remains. But for many applications, the standard screws that can be found at a hardware store work very well.

A similar question to yours would be why are wheels still round after all these centuries?

If you imagine that there is a problem to be solved regarding screws then the first step is to identify and clarify the problem. Then search the common alternatives to screws, and see if any of these can be used instead -- a great many applications use some of these (50 or so classes of?) common alternatives. In some assemblies, nails can be used instead of screws, and they are faster and cheaper to use. In piping, PVC pipe can be assembled with pipe threads to bolted flanges, making a relatively complicated assembly... or a simple glued push-in coupling can be used, for a fraction of the and assembly time and cost. Why then is a bolted flange used? It depends upon the need, doesn't it?

So, what do you need in a fastener that cannot be found in the alternatives? If you look at cases for electronic devices you will see snap-together cases that can be pried apart for service, integral rivet posts that are melted at assembly (and which make service difficult), solvent-welded cases that can not be disassembled, Dzus fasteners or similar where the clamping force required is low, conventional rivets, pop rivets, integral plastic posts with press-on spring clips, semipermanent glues, etc. The decisions made regarding fasteners are made for many reasons, with parts and assembly cost being key drivers. You will find that high-quality test equipment, is very likely to be put together with conventional threaded fasteners, usually with full depth nuts, rather than the cheaper sheet metal press on versions (speed nuts). Most of the alternatives are cheaper, but not better.

So define the problem with screws that you want to overcome, and you are on your way to developing yet another alternative. Perhaps your invention will become as ubiquitous as the integral plastic hinge, which is remarkably simple, adds essentially no cost, and (time has shown) works very well.

"A similar question to yours would be why are wheels still round after all these centuries?"

snort, splarf, choke ... I wish I'd said that...

Wheels used to be square, but over the centuries, the corners wore off.

Interestingly (or maybe not) if you take woodscrews you will see that over recent years they have undergone radical improvement with fine pitch starting threads, double helix fast threads, nacked shanks, self countersinking heads etc. You no longer need to drill piolt holes and can just power drive two pieces of timber together without them jacking appart as you break into the second bit of wood. They can save vast amounts of time over old style screws.
I recently used some with 'torq'? head, a driving bit was included in the box of screws...brilliant for working in a confined space, no cam out.
Del

Speaking of cam out: has anyone ever come across/seen/heard of/thought of a flat head screwdriver with a tip which tilts slightly when you push.

The "hinge" is a bit like the ones you get in good pliers; the two things at the sides are supposed to be little springs: I'm sure there are other ways of keeping the head straight when no pressure is applied.

The automotive industry is one of the largest users of threaded fasteners. They are always looking to find a low cost substitute for them. If there is a way, they will find it. There are some applications where there is no substitute for the lowly nut and bolt. They will be around for a long time to come. Finding low cost substitutes for threaded fasteners is part of an engineers/designers criteria. This is true in most product design. If a manufacturer of electric drills can knock a few cents off each tool, he can save enough to make him more competitive. If there is a nut/bolt used, you can bet it's there for a good reason.

"Ok maybe Paper is also another survivor."

Had to ask - remember when the '90's were going to "Intoduce the age of the paperless revolution?"

I should have bought IP or GP stock back in the time, eternal skeptic that I am, but...

But a better way than the inclined plane - I mean than screws? Consider the options (invent them, there are none; reasonably-priced and readily-available adhesives notwithstanding).

How about a better way than the wheel, given sliding friction and the relative ease of creating rotational motion?

How about a better oxidizer than oxygen?

Regards.

Maybe off topic but..

This was in 2007..

"The demand for paper used to outstrip the growth of the U.S. economy, but the past two or three years have seen a marked slowdown in sales--despite a healthy economy, according to The Christian Science Monitor. In the early to mid-90s, the booming economy and improved desktop printing helped boost paper sales by 6 or 7 percent annually."

Our company has virtually cut all paper usage, except for contracts etc. Bet that is the case at most places. so yes there is a trend towards a paperless office.

"yes there is a trend towards a paperless office."

I would have to agree with that, at least for me and the way I do things.

I'm retired, but I still to lots of engineering related work. Now I use a notebook computer which with its portability means I can use it for just about everything like notes, drawings, communications, calculations, etcetera that I hitherto used paper for.

Not only has my computer drastically reduced my consumption of paper but having the power of a computer has dramatically changed the way I go about things.

When I started working as an engineer in the 1970s having a computer that can be carried in something that is smaller than a briefcase but works as a drafting board, programmable calculator, word processor (typewriter & secretary for old geezers like me), dark room, filing system, audio visual system, entertainment system, telex machine, video phone, etcetera, etcetera, etcetera is something that I wouldn't even have phantasized of in my wildest dreams.

How about a better oxidizer than oxygen?

Try Chlorine!

Chlorine will go to everywhere and play havoc there,

try iodine, it is still more corroding and more likely to stay in place if temperature is low.

I use epoxy-glue mixed with silicon-carbide (grit 180 to 800 depending on specs) for optimised gluing of metal to anything else. This is giving distance - needed for acceptable shear strength if temperature coefficients of expansion don't match and is not only giving strength by enhanced friction but predominantly gripping into the material by small contact areas and thus ploughing if slided by brute force.

RHABE