You are here:

Physics/Mechanical advantage


Sir, I've been looking at the simple, common examples of mechanical advantage, such as 2 unequal hydraulic pistons (1 skinny & long piston connected to 1 wide & short piston) and also of seesaws (lever & fulcrum). What those have in common is that, although they're of unequal sizes to provide mechanical advantage, they have a 1:1 movement ratio.

What I'm projecting to do is: have 2 fixed wheels of the same diameter, connected via a chain, turn at the same RPM (1:1 movement ratio) but with an increase of torque on the output wheel.

Any ideas on how this could be done? I'm limited to using chains and cannot use a moving pulley (as with some examples). Also can't use meshed gears. When compared with the hydraulic piston examples, I would guess the input of the chain would have to go a longer distance? Could wrapping the chain numerous times around the input wheel's plane (helically) increase the torque on the output wheel?

Any help is appreciated.
Thanks in advance,

You don't have a 1:1 movement ratio on the pistons you mention.  You have a movement ratio equal to the ratio of the areas of the pistons.  Therefore your problem is invalid.  You can either reduce the movement of the output wheel at increased torque, increase the movement at reduced torque, or keep them the same at the same torque (minus losses to friction).  Perhaps you can be more specific about what this is for, and then I can be of more help.


All Answers

Answers by Expert:

Ask Experts


Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

©2016 All rights reserved.