How to Build a Homemade Weighing Scale

You can build a portable homemade weighing scale that can be used to measure things with a good degree of accuracy and that is compact enough to fit into a pocket. This scale is simple and measures in grams. It is perfect for precise weighing up to 51g. This is perfect for gold panners who don't want to carry a scale around with them to measure small amounts and has many other applications when you're working with gram scale measurements for a quick estimate.

Things You'll Need

• Street sweeper bristle (1/16inch x 1/8 inch x 26 inches)
• Dremel or drill
• Small cutting disk
• 1/16-inch diamond-tipped drill bit
• Spool of sewing thread
• Duct tape
• Spool of dental floss
• Five pennies
• Eight nickels
• One paperclip
• A scale for calibration

Instructions

1. Get a street sweeper bristle from the gutter next to the sidewalk after a street has been scrubbed. Use a hot glue gun to glue a lid from a soda bottle on the thin edge of the bristle at one end. Glue the cap so it faces away from the bristle and make sure that the cap has the Styrofoam or plastic seal removed from the inside.

2. Tie a little loop of sewing thread around the bristle and slide it to the middle of the bristle, just off center toward the cap.

3. Test the bristle to see if the bristle stays balanced while you hold the string. If the lid falls, move the string closer and closer at each test until you find the center of balance. Once you have found this center of balance where the cap neither rises nor falls, mark it with a pencil.

4. Tape the bristle on a block of wood so that the block protects the surface underneath. Make sure the lid you hot-glued to one side of the bristle is not damaged. Use duct tape on either side of the location where you will be drilling into the bristle. Make sure that the tape is wrapped all the way around the block and that the block is held in place by a vise. Drill into the bristle at the center of balance mark using the 1/16-inch diamond-tipped drill bit in your Dremel tool or drill. Tie a piece of dental floss to the scale at the hole in the center of balance where you drilled it.

5. Get five pennies and eight nickles that were made after the 1980s. Since each penny weighs 2g, use the lightest sewing thread you can find and cut a section of string 1/3 of an inch long for each coin. Use the smallest smear of superglue that you can to attach the very ends of one of these strings to a coin so the loop is big enough to slide over the end of the bristle. Repeat the process with all of the other coins. If you can, take the coins to a scale that is known to be calibrated and file off just enough to make the coins exactly 2g for the pennies and 5g for the nickels. Get a paperclip and trim it at the inside loop until the paperclip weighs exactly 1g and throw this in the collection with your coins.

6. Put one penny in the cap. With a 2g penny still in the cap, put a penny on the other side of the bristle and slide it around until it balances the other penny. Use your Dremel cutting disk to cut a notch where the penny on the loop balances out the penny in the cup.

7. Dangle the string from a door knob using a slip knot in the end so that you can get your scale off again (with the door open for safety). Put the sample that you are going to weigh in the bottle cap and hold the bottle cap gently so that it does not tip over. Add weights until the bottle cap feels balanced. Gently let go of the bottle cap, but be ready to grab it again if it is not balanced. Add or take away weight until the two sides balance out.

8. Count the weight in grams from any coin or modified paperclip used to counter-balance the sample. Again, a penny is to weigh 2g, a nickel is to weigh 5g, and the modified paperclip should weigh 1g.

9. When you have finished weighing the sample, dump out the sample and rinse the cap for the next use. Dry the scale well before the next use.

Tips & Warnings

• You can calibrate the scale as occasion requires by adding a dab of glue or scooping it away with the hot tip of a glue gun on either side. Make sure that the glue dabs do not get in the way of scale operation.

• Do not tie the string around any body parts. Do not use this scale in any improper or immoral way. Do not use this scale to weigh dangerous substances. Do not use this scale to measure anything else until you are confident in your abilities to use this scale without spilling the contents. Do not use this scale in wind. Use care as you measure with this scale and check your accuracy often.

Resources

• Weights Of American Coins (US Treasury)
• Dremel Tool Diamond Tip Bits
• Simple Scale Measuring 2 Gram Weights Only