Mechanical Advantage vs. Lever vs. Human Error

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BMR
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This is my first post here, so pardon if forum guidelines/criteria require this to be designated elsewhere.

I am designing a clamp mechanism utilizing lever mechanics, and I am getting conflicting info regarding Mechanical Advantage and the Law of 1st Class Levers. Regarding MA, knowing that
300px-Lever_mechanical_advantage.png

e4516522ccaaa831010fc757760110894929d202


If:
FB = 40,000 lbs
FA = 1,000 lbs
Then: b = 40, a = 1, and the MA is 40:1

In regards to Levers (Specifically 1st Class Levers)
torque_lever.png

F2 = F1 L1 / L2

If:
FB = 40,000 lbs
FA = 1,000 lbs

Then:
40,000 = 1,000 (32.174 ft/s2 [gravity constant]) (L1 / L2)
40 = 32.174 (L1 / L2)
L1 / L2 = approx. 1.243 or 1.243:1.

So for 1,000 lbs to lift 40,000 lbs., either a 40:1 or 1.243:1 lever ratio is required. Am I simply wrong for factoring in a gravitational constant?
 

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BMR said:
Am I simply wrong for factoring in a gravitational constant?
Yes. You get the same mechanical advantage whether the lever is on the Earth, the Moon or in free space.

On Edit: Assuming that F1 and F2 are either both pushing forces or both weights, that is.
 
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BMR said:
So for 1,000 lbs to lift 40,000 lbs., either a 40:1 or 1.243:1 lever ratio is required.

@kuruman gave you the correct answer. But to amplify, if you move the whole apparatus to a planet with one half Earth's gravity, then the same weights would weigh 500 lbs and 20000 lbs, but the ratio 40:1 remains unchanged and the MA remains unchanged. That is why you don't need G.
 
Another way to say the same thing as @anorlunda: If the number 1000 is a mass, then you multiply by g to get a weight which is a force. Here you have 1000 lbs which is already a force (the mass has already been multiplied by g) so it would be wrong to multiply by g again.
 
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