Looking to calculate the mechanical advantage of a toggling lever (t-shirt press)

[Cake of Doom]

I'm sure there is a spring calculation spreadsheet on this site. Using this, could you not calculate the size/spec of the spring to deliver the required force at full compression and then calculate the minimum length of lever required to aid in the compression?

What is it you are looking to clamp?

Ignore this^^^

Again I will refer you to Destaco. They have made these things for decades. No one knows them better. We could give you theoretical forces just based on geometry, but the actual real world force output near the final clamping point is mainly affected by miniscule deflections and bending in the individual components. They eat that stuff for lunch. Ask for Application Engineering assistance.

Do this ^^

[Kelly_Bramble]

So going back to the OP- who has the engineering chops to determine the force generated by this lever? General formulas, links to similar problems, or precise calculations; all will help.

Let's think this thru... You're asking for a displacement vs resultant force analysis on an unknown fixture. Without springs the stiffness of the mechanism as well as the item you intend on clamping would need to be understood. This is more than chops - this is a major analysis effort based on the selected geometry and engineering materials. Seriously, there is a good reason that there are springs in the design.

For the kinematic/static analysis you could model the fixture in your CAD software for the desired displacement. For the stiffness you will need to make some assumptions or measurements. I’m guessing that if you have FEA software and apply about 3-5 hours of effort on an existing fixture you will have an analysis that might be close to actuals.

For simplicity, you might consider a pneumatic cylinder design approach. You will be able to achieve a known force at an unknown displacement by controlling the applied psi to the cylinder and mechanism.

Simplicity is your friend.