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How much does it weigh?

How many times is this question asked? What type of items? What do you use? A bathroom scale great for

100+ pounds, but poor for that pocket tool that weighs a few ounces or even a 10 to 15 pound pack. A

cheap dieters scale the operative word here is cheap. Most Ive seen are junk that I wouldnt trust. Someoutside source the post office, the grocery store meat/ produce scale or the nail scale in the local hardware

store. Yeah right! Walk in with 20 or 30 items to weigh. Unless your buddy works there if you are luckyyoull get thrown out on your ear. If not the nice men in the blue uniforms will either take you to the gray

bar hotel or introduce you to the men in the white coats. Who will be glad to fit you with the long sleeved

sports coat with the buttons in the back.

Why not build the most accurate scale available? This is the balance beam. This device is easily

constructed from simple materials under even the most primitive conditions. Depending on the materialsused they can measure from a few ounces to tons. A balance beam scale consists of a bar/beam, a pivot

point/fulcrum, and a means of attaching weights to the ends. The beam can be anything from a simple

piece of wood to a heavy steel rod depending upon the range of measurement that is desired. The fulcrum is

what the beam balances upon. The finer/smaller it is the more accurate the system will be. Thats why high

precision scales advertise that they have a knife-edge balance point. The means of attaching weights to the

ends of the beam share the same criteria as the fulcrum. The smallest size that is practical for the rated

amount.

Accuracy of scales is usually based on a percentage of the scales range. In a perfect world the balance

beam scale works on the principle that Force times Distance equals Force times Distance. [FD=FD] Thatmeans that a 1-lb. [Force] 1-ft. [Distance] from the pivot point equals 1-lb. 1-ft. on the opposite side of the

fulcrum. This equation shows that you can get some additional range for a set of weights by moving the

pivot. A 1-lb. weight 2 feet from the pivot will balance a 2-lb. weight 1-foot from the pivot. Although you

will need to compensate for the difference in weight for the different lengths of the beam. Also the

difference in apparent weight of the object and weight holding assemblies. This is easily done by adding

weight to either side to an empty scale until it balances.

Well we dont live in a perfect world. The real world has things like buoyancy, friction and geometry. Airlike water is a fluid. This means that a small fraction of the objects weight will be supported or float on air.

The amount depends on shape and density. That is why most high accuracy scales use pans on the same

size on each end to compensate. Friction also adds a small inaccuracy factor. The geometry of the parts andtheir relationships has the largest effect.

For the balance beam to work, a set of fixed known weights is needed. Muzzleloading enthusiasts and

reloaders have these in balls or bullets. These are measured in grains. For those that dont have these items

there are coins. Im only going into US coinage. Those that use others will need to find out the weight fortheir own.

These weights are approximate due to wear and tear or contamination.

Penny = 2 Grams = 38.5 = 1/11[.09] Ounces or 11 pennies = 1 ounce

Nickel = 5 Grams = 77 Grains = 1/6 [.176] Ounces or 6 Nickels = 1 Ounce

Dime = 2 Grams = 34.6 Grains = 1/12 [.08] Ounces or 12 Dimes = 1 Ounce

Quarter = 5 2/3 Grams = 87.3 Grains = 1/5 [.2] Ounces or 5 Quarters = 1 Ounce

There are s and Dollar coins but who has them regularly.1 Ounce = 437.5 Grains = 28.35 Grams = 16 Drams

1 Gram = 15.4 Grains1 Gram = 1000mg.

Weight Conversion Factors

Ounces to Grams. Ounce X 28.35 = Grams

Ounces to Grains. Ounce X 437.5 = Grains

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Grains to Ounces. Grains X .002286 = Ounces

Grains to Grams. Grains X .064935 = Grams

Grams to Ounces. Grams X .035273 = Ounces

Grams to Grains. Grams X 15.43 = Grains

Well you have built your scale. Weighed all your gear. Trimmed the ounces. But what can this informationbenefit you in the field? You caught a fish. How about showing off for your camping buddies? Weigh their

gear around the campfire. What ever you can think of that you may want to know how heavy it is. The first

reaction is, do you think Im crazy enough to carry the extra load of a scale? Because you know how it

works you dont have to. A simple scale can build one on the spot. Take a stick and find its balance point.

Tie some string around this point. This is the pivot. Use the string to suspend the would be scale. Hang

what you wish to know on one end. Hook known weights on the other until it balances. Add up the total ofthe known weights. There is your answer. Just a minute what weights? The gear you are already carrying.

At the start you weighed your gear at home. If you carry a list in your wallet of these weights you have

your fixed weights. Suppose that the object weighs more that your gear. Weigh rocks. Once you know their

weight you now have more known weights for your scale.

Do you regularly carry a hiking staff or walking cane? It can be made into a handy all round measuring

device. Most know that it can be made into a ruler by adding dimensional markings. It can also be easily

modified to act as the beam of a balance beam scale. To start find the natural balance point. This may ormay not be the exact middle because of the difference in diameter between top and bottom. The options are

to drill a hole to string cordage through, cut a notch or draw a ring. This will be the pivot. Measure equaldistances from the pivot to near the ends of the staff. Mark these the same as the pivot. This is your 1 to 1

scale. Select on end as the fixed and the other as a variable. On the variable end split the distance in half

and mark. Do this again. Depending upon the length of the staff it may be practical to do this once and

possibly twice more. When the distance between the pivot and the variable hole get to close together you

can have 2 problems. First is due to measuring inaccuracies the multiplication factor can cause large errors.

Second too many holes or notches closely spaced could weaken the staff.

Using the force to distance formula. The cutting the distance in half can effectively double or halve thescales measuring ability. For example: Using a 1-lb. weight and 2 additional divisions. Hanging the known

weight [1-lb.] at the fixed end it will balance 1-lb. at the end. 2-lbs. at the middle hole. Finally 4-lbs. at the

hole nearest the pivot. Conversely using the same 1-lb. weight on the variable set of marks and theunknown on the fixed end. You can balance 8ozs. 4ozs. or 2 oz. Different fractions other than halves can be

used but this is the simplest math.

The maximum the staff scale can weight depends upon the strength of the staff and cordage or other

supporting devices. Accessories that can be pre-made and carried along:Wire hooks: To use as the pivot and to hang the weights.

Stuff sacks: Normal sacks that are carried can be used to hold loose material for weighing.

Slings or nets: These can be made to hold the material or to hold normal cookware [pots or plates] that can

act as places to put the material to be weighed and the know weights.

Note: Prior to weighing anything you need to balance the system to compensate for any difference between

the supporting methods used. This is especially important when using the extra leverage of the variable

lengths. This is easily done by adding weight as necessary to pre-balancing before the actual job ofweighing of objects.

Here is a page that has detailed plans for building an accurate one for home use.

http://www.nakka-rocketry.net/

http://www.nakka-rocketry.net/http://www.nakka-rocketry.net/