Jump to content
I Forge Iron

How to weigh things without a scale


Glenn

Recommended Posts

Let us say you are thinking about buying an anvil but do not know the weight. Put the anvil on a board (say 2x6 for strength) and place a fulcrum (piece of pipe) under the board. Measure center of the anvil to the center of the fulcrum which is say 3 feet. You know the weight of a blacksmith to be 150 pounds. (ok, he has missed a couple of meals for sure). The blacksmith has to stand 6 feet sway from the fulcrum for the teeter-totter to balance. That means 150 pounds times 6 feet equals 900. Move the anvil side distance to the blacksmith side of the equation and divide it into the 900, or 900 divided by 3, which should be a 300 pound anvil. No wonder you could not lift the thing by yourself (grin)

 

Link to comment
Share on other sites

It's easier to calculate than that Glenn, simply divide or invert and multiply. Say the balance point is 2' from the fulcrum and the smith is 4'. 2/4=1/2, the smith weighs half as much as the anvil 300lbs. OR invert and multiply smith = 150 x 2 = 300.

It's the same way you figure gear ratios and is in fact exactly the same, a gear being a lever that goes all the way around.

Frosty The Lucky.

Link to comment
Share on other sites

Steel is 40 lbs per sq ft and 480 lbs per cu ft. Easy math. When it comes to scrap or stock, most steel suppliers have data sheets (free) of weight by cross section and shape per running ft. There's probably a PDF for that list and there is also the "metal calculator app" which is free for the less mathematically inclined. 

Link to comment
Share on other sites

Thank you Jerry, lol. 

Displacement is another way, if you know what it is made of (steel) and one puts, say 20 inches of water in a 55 gallon drum (22-24" depending on the drum) but of math (pi R squared depth) so 3.14x1.66 squared (multiply the sum by it's self) times 2 (1.83 for a 22" drum) now plug in the weight plug in foot (480#) thank you Ivan.

 

#%$!! Won't let me edit! 

You are only looking at the displacement, as in the difference between 24" ( 2') and the depth after you drop in your anvil 

Link to comment
Share on other sites

Why not use a photoscale virtualization weights and measures app for your phone? Simply place an object of known size in the picture and select material. Viola, done! You guys really like doing things the hard way.. :)

J

 

Link to comment
Share on other sites

9 hours ago, j.w.s. said:

Why not use a photoscale virtualization weights and measures app for your phone? Simply place an object of known size in the picture and select material. Viola, done! You guys really like doing things the hard way.. :)

J

 

How accurate is it? Is there an entry for alloy? I know I'm old and kind of worn but I find sorting through the all too often useless bells and whistles somebody  living in Mother's basement thinks are must have is more work than just using a bathroom scale.

If it's a viable app, I'm all for it but to many aren't even good wastes of time.

Frosty The Lucky.

Link to comment
Share on other sites

9 hours ago, j.w.s. said:

Why not use a photoscale virtualization weights and measures app for your phone? Simply place an object of known size in the picture and select material. Viola, done! You guys really like doing things the hard way.. :)

J

 

You're  someone's leg aren't you? I actually looked for the app and didn't find it so either there's some leg pullin or I'm lookin for the wrong name lol.

Link to comment
Share on other sites

Must be a typo Steel is zero pounds per sq foot as a square foot is 0 in thickness;  and so 12x12x0 x density per CUBIC inch is of course zero.

I would just do a simple ratio using a simple fulcrum say 1' between anvil and fulcrum and then you find how far out you have to stand to balance it; Not being 150 lbs I figure a 6' piece of 2x12 would handle *anything* I was likely to run into and a piece of angle iron with the legs down would make a decent fulcrum.

Link to comment
Share on other sites

1 hour ago, ThomasPowers said:

Must be a typo Steel is zero pounds per sq foot as a square foot is 0 in thickness;  and so 12x12x0 x density per CUBIC inch is of course zero.

I would just do a simple ratio using a simple fulcrum say 1' between anvil and fulcrum and then you find how far out you have to stand to balance it; Not being 150 lbs I figure a 6' piece of 2x12 would handle *anything* I was likely to run into and a piece of angle iron with the legs down would make a decent fulcrum.

sq foot has no weight ... you beat me to it!  

Link to comment
Share on other sites

10 hours ago, Frosty said:

How accurate is it? Is there an entry for alloy? I know I'm old and kind of worn but I find sorting through the all too often useless bells and whistles somebody  living in Mother's basement thinks are must have is more work than just using a bathroom scale.

If it's a viable app, I'm all for it but to many aren't even good wastes of time.

Frosty The Lucky.

The best I've found is from Yoyodyne Propulsion, Inc. They have a Spacial and Dimensional Research department that's putting out some interesting things on the engineering front. It's one of John Whorfin's projects and he's sort of a tyrant for perfection so you know they're going to get it on the money before they release it from alpha testing.

J

Link to comment
Share on other sites

10 hours ago, ThomasPowers said:

Must be a typo Steel is zero pounds per sq foot as a square foot is 0 in thickness;  and so 12x12x0 x density per CUBIC inch is of course zero.

 

 

9 hours ago, J said:

sq foot has no weight ... you beat me to it!  

12"x12"x1"=40lbs (sq ft) each sq ft by 1/8" incriments of thickness=5 lbs

Cubic foot = 12" x12" x12"=480 lbs

 

 

Link to comment
Share on other sites

  • 2 weeks later...
On March 7, 2016 at 8:11 AM, Crazy Ivan said:

 

12"x12"x1"=40lbs (sq ft) each sq ft by 1/8" incriments of thickness=5 lbs

Cubic foot = 12" x12" x12"=480 lbs

 

 

Mathematically speaking an Area, in our case "square foot", has zero thickness therefore zero weight. That's true if we're talking about steel, brass, or bananas.  Its not until you give it a thickness like 1" , 1/4" etc... Then it becomes Volume, which given the density, becomes weight....

And I think steel is closer to 490 lb/CF 12"x12"X1/4" = 10.2 lb ish

now...what were we talking about... :)

Link to comment
Share on other sites

  • 3 months later...
On March 7, 2016 at 0:35 PM, j.w.s. said:

Why not use a photoscale virtualization weights and measures app for your phone? Simply place an object of known size in the picture and select material. Viola, done! You guys really like doing things the hard way.. :)

J

 

 How does the app measure size. Or does it require input from user?

 

Link to comment
Share on other sites

On 3/17/2016 at 0:45 AM, J said:

And I think steel is closer to 490 lb/CF 12"x12"X1/4" = 10.2 lb ish

12 inches x 12 inches by 1/2 inch is 20 pounds. Easy for me to remember as it is all 12 12 12 and 20.

Link to comment
Share on other sites

If ya don't like a pint's a lb, the world around, Frosty...

Came in the railyard with some Mexican Kansas City Engines the other day (don't ask, I haven't figured it out either), and the main tower asked for a fuel reading.

So I tie up a couple of handbrakes, go look, and tell them the first engine has xxxx many thousand liters and the second has yyyy many liters. Long pause.....

The tower, where they have computers, and calculators, and google... - "ummm, how much is that in gallons?"

Me - Well, my electronic devices are turned off and stored in an out of reach compartment in accordance with company policy and the FRA rules, but a liter's kissing cousins to a quart, so if you'll divide by four...."

"Oh. Ummm, okay."

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...