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Simple Machines


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In doing some research, simple machines kept coming up.

A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines which were defined by Renaissance scientists: 

Lever, Wheel and axle, Pulley, Inclined plane, Wedge, and Screw

 

We use them every day without realizing it. 

Axe when chopping wood is a wedge. If you use a cross cut saw it is an inclined place to cut the kerf. Once the notch is cut and the back cut is made a wedge is used to encourage the tree to fall.

A block and tackle (pulley system) is the wheel and axle, and pulley.

Pitting pipe under a heavy load so it will move easier is the wheel and axle or roller.

Give us some ideas as to how you used simple machines to solve your problem. Additional points for photos. 

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5 hours ago, ThomasPowers said:

I once loaded a 60# powerhammer into my pickup by myself using levers, (cribbing), rollers, come along (pulley + lever)

I moved a 1cwt aldays and onions power hammer last year using the exact same method, it's simple and it works, why complicate things!

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The thing I use most is the truckers hitch knot (pulley). Probably the most useful knot to cinch loads to your truck, but can also be used to lift heavy objects into your truck, as long as you don't exceed the weight limit of the rope and NEVER stand underneath the object

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There is a truckers hitch and  truckie hitch. Both are similar in use.

The truckers hitch can be difficult to undo after a load or when wet, where as the truckie hitch unties easily. 

 

 NEVER stand underneath any object that is suspended. Rigging can fail, many times without warning.

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Used a slate bar to put my 250 pound anvil on a stump.  two planks to form an inclined plane enough room between them to put the slate bar (lever) anvil on the planks with the face on against the slate bar and the foot facing up the plane.  jammed the slate bar in the ground and leaned into the anvil.  actually moved up quite easily.  just had to keep it where it was when taking another bite.  the wife quit watching thinking I was soon going to hurt myself. 

 

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Not precisely a machine as defined here, but while installing a new toilet this morning, I slid the old one out of the bathroom, down the hall, and out through the garage on a piece of heavy cardboard. Reduced the friction significantly, thus making it easier to slide, and kept it from damaging the floors. 

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Your right Glenn, both knots are great. The truckie hitch works wonders but I use mostly the sheepshank variant of the truckers hitch with a half hitch to bind the loop. I like it because you can put it in the middle of the rope if you have too much slack, without untying the rest of the rope. I have had ropes fail from the force I put on them without the hitch getting to tight to untie... Back on subject, you can also use the object itself as a simple machine. A 55 gallon drum tilted on edge(lever and fulcrum) to roll it to where you need to go(wheel & axle)

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Mr. JHCC said,

"I slid the old one (toilet), out of the bathroom,  ... out through the garage ... on a piece of heavy cardboard ..."

Great idea.

For real heavy, recalcitrant items. a little spray of silicone will help additionally.

If silicone residue is a problem, spray the cardboard bottom surface with 'Pam', (lecithin) . Available in most kitchens.

Use the spray sparingly. Don't soak the surface.

There is an additional benefit to using lecithin  it's edible!

SLAG.

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"Trucker's hitch?" How about posting a pick of what you're using. Dad called it a "binder knot" and we used it mostly for hauling hay but tied all loads with them. Not much good though unless you anchor with a bowline. Dad was pretty adamant about it was called till I showed him a virtually identical knot drawn in the rigging of a Phonecian sailing ship AND in the Boyscout manual for shortening ropes and securing loads.

I use virtually all the simple machines in daily life levers and wheels especially. 

Frosty The Lucky.

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Here is a picture of what I have been told is called a truckers hitch, though when I looked it up yesterday I now see it is a sheepshank variation of the truckers hitch. I also tie the top loop in a half hitch around the line with the load to stop it from untying. I use it mostly for hauling hay, but also use it for all types of hauling. I have seen it used for lifting a load in a barn high enough to back a truck under, though I will admit I haven't used that method personally. One can use multiple knots on a single load and run the loose end through the loops to a final hitch to compound the leverage when tightening. 

Truckers_hitch.jpg

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Knot I had drilled into me was the bowline on a bight. Had to learn to tie it one handed: dominant hand, off hand and one handed behind your back: dominant hand and off hand---the mountaineering class wouldn't take you outside the building till you could tie the "rescue knot" one handed. off hand, behind your back,  lets see that was around 1977...yup I still remember it but am not nearly as flexible as then.

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Yeah, that looks like Dad's binder knot alright but we'd throw a half hitch in the loop on top to lock it. Just in case you know. ;)

Darn you Thomas! I used to be able to tie a bowline one handed but not sure if I still remember how it feels, now I'll have to go get a piece of line.

Frosty The Lucky.

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What you are calling a truckie hitch is called a teamsters hitch in the books that I have.  I use it every time I tie any load. As Frosty said I always put an over hand knot on the upper loop otherwise the loop can fall over, untying the hitch,   In north Georgia where there were truck loads of chickens being transported for processing it was called a "Chicken Knot".  Now the main replacement is webbing and ratchet.  

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I know this type as a 'sheeting hitch', well not exactly the same knot, a variant that does the same task. I've used it in place of a block and takle to move a ton and a half of stone slabs to rebuild a ancient footbridge in a remote area of the North Yorks Moors only accessible by a long climb down a steep bank......Jobs like those demant a limit of gear to be hauled and carry most of it inside your head where it's no weight at all!

 

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I believe the general category for this type knot is a "bend" a sheet bend is one kind.  At one time Dad gave me a book of knots and there must've been 50 pages of bends a couple per page. It was one of those books it takes a special tall shelf or you have to lay it down and then people use what's hanging over the shelf as a shelf itself. 

And yes, I've doubled them up like a block and tackle, friction starts being significant when you triple them. 

Frosty The Lucky.

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