Mechanical advantage question

[Rrsinness]

Hello all,

I am fairly new to the realm of mechanical advantage, but i have a fairly decent grip on how simple, compound, and complex pulley systems work. Do gear ratios compound the mechanical advantage of pulley systems? I have a set of fours (block and tackle pulley system) that has the ability to create a 5:1 MA. I also have a Dutton-Lainson worm gear winch that has a 40:1 MA. If i use the winch to pull the 5:1 pulley system, will I really have a, theoretical, 200:1 mechanical advantage?

Thank you in advance for taking the time to read this, and any help that is given.

 

[3DDave]

Friction is a component that reduces the practical application of mechanical advantage. As a result you will not be able to pull with 200 pounds using only exactly 1 pound of force. Elasticity reduces mechanical movement, so that one foot of output motion will require more than 200 feet of input motion.

But, in a frictionless universe with inelastic materials on test questions, then sure, they multiply.

 

[Compositepro]

Mechanical advantage in a pulley system refers to force multiplication, whereas gear ratio applies to torque or rpm, which are not the same as force. So it is not quite so simple as multiplying the two numbers. How you couple the gear box to your rope will affect the actual mechanical advantage of your system. The output of the gearbox might be a capstan that the rope wraps around. What is the diameter of the capstan? What is the length of crank driving the gearbox?

 

[Rrsinness]

@compositepro, The drum of the winch is 1 1/2". I have a jam nut on the input so I can have any size input lever that I want. The factory length crank handle is 7", however, I have breaker bars and ratchets that are 7", 11", and 17 1/2". The particular winch that I have is a 2" strap winch, so I would attach some sort of rope grab (a prusik or midline loop) and attch the winch strap at that point. This may be more of an idea than practical application, but since I have the items available for use, I am curious.

 

[Rrsinness]

I finally got the strap for the hand winch. Attached are pictures of the idea that I have. At the picture taking end would be the "anchor", and the concrete wall end is the "load". Does this picture help with estimating mechanical advantage?