Designing a Pulley System to Increase Weightlifting Force

AI Thread Summary
A user is designing a pulley system for a weightlifting machine that increases the force required to lift a load, specifically to make a 50kg weight feel like 100kg. They seek simple modifications to their pulley design to achieve this effect, suggesting a configuration where the rope is attached to the ceiling and runs under a movable pulley. The goal is to create resistance that simulates lifting a heavier weight without actually increasing the load. The user has received several ideas and is considering them for implementation. The discussion highlights innovative approaches to pulley design for resistance training.
Monkey
Messages
9
Reaction score
0
Hi,

I am building a simple pulley for a weightlifting machine. In most cases pulleys are designed to lift heavier loads easier, I want to actually make it harder to lift the load… So I don't have to put so much weight on the end.

Can I amend my simple pulley design in a (simple) way to increase the force required to lift the load at the end?

In my example I want to lift the 50kg load… How would I make it double the load, so it feels like I am lifting 100kg?
 

Attachments

  • Screen Shot 2015-02-05 at 6.17.54 AM.png
    Screen Shot 2015-02-05 at 6.17.54 AM.png
    2.3 KB · Views: 555
Engineering news on Phys.org
Look at schemes that make a weight easier to lift and interchange the person pulling with the weight being lifted.

For example, end of rope attached to ceiling. Rope goes under a movable pulley attached to pull-handle and then over a pulley attached to the ceiling and then to a weight attached to the other end of the rope.
 
For instance, look at the drawing
 

Attachments

  • image.jpg
    image.jpg
    11.1 KB · Views: 478
Thank-you very much for your replies. Have got a few ideas in mind now about how to make it work.

Best regards.
 
How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...
Back
Top