I in working out forces in a real mechanism

In summary, the conversation discusses a mechanism that controls the movements of multiple assemblies in the X, Y, and Z directions. The mechanism has a wobble issue during fast X travel and the team is looking for solutions, possibly including calculations to prove their effectiveness. They are considering adding vertical restraint, adjusting the pivot position, adding dampers, and using scheduled starts for rapid movements. They also mention the importance of representing the forces acting on the mechanism and possibly using different types of linear rails with higher moment stiffness. A better CAD view is requested to provide more information about the cam and rails.
  • #1
MeesterDave
1
0
I have a mechanism that controls the movements of multiple assemblies in the X Y and Z directions.
The mechanism has been built and suffers from a wobble on a fast X travel. We have a few suggested solutions but it would obviously be a good idea to get some calculation to help prove a solution.
We all (a small team of 4) are scratching our heads and trying to recall force vector diags and torque diags.
75dc1de358.jpg

the Yellow dot is the COG
The orange squares represent rails and carriages stopping (ideally) X and Y movement
The orange square in the middle is a linear cam that is used to raise and lower the assembly that is driven towards the viewer. Consequently all the weight is on this cam and follower and pivots about the cam.
hence the wobble shown by the red arrows.

Im looking for a way of representing the forces acting on this and so use the same method to show forces on proposed solutions.

Thanks in advance!
 
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  • #2
Problem : Inertial torque + inadequate restraint .

Solution : Add outboard vertical restraint + move notional pivot position + add dampers + use scheduled start for rapid movements
 
Last edited:
  • #3
Do you have a better CAD view which shows more about your cam and linear rails? What kind of linear rails are they, and can you buy ones with higher moment stiffness?
 

FAQ: I in working out forces in a real mechanism

What is meant by "working out forces" in a real mechanism?

"Working out forces" refers to the process of determining the magnitude and direction of forces acting on different parts of a mechanical system. This is an important step in understanding how the system functions and how it can be optimized for efficiency and safety.

Why is it important to consider forces in a real mechanism?

Considering forces in a real mechanism is crucial for understanding how the system will behave under different conditions. Forces can affect the stability, motion, and overall performance of the mechanism, and failure to account for them can lead to malfunction or even accidents.

What are the common methods for working out forces in a real mechanism?

Some common methods for working out forces in a real mechanism include free body diagrams, virtual work, and computer simulations. Each method has its own advantages and limitations, and the choice of method will depend on the specific goals and constraints of the project.

How do material properties and geometry affect forces in a real mechanism?

Material properties and geometry can greatly influence the forces present in a real mechanism. For example, a material's stiffness and strength can determine how it will deform under load, while the shape and size of components can affect how forces are distributed throughout the system.

What are some challenges in accurately working out forces in a real mechanism?

One of the main challenges in working out forces in a real mechanism is accounting for all the variables and factors that can affect the system. This can include external forces, friction, and non-linear behavior of materials. Additionally, obtaining precise measurements and accounting for potential errors can also be challenging.

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