×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

(OP)
I need an approach to come up with the longitudinal load induced by acceleration/deceleration of a car body mover in an automobile plant.  The capacity of the mover is 3000 lbs and runs about 450 ft/min.  I would the time to reach this velocity is about 1 sec.

Here's an attempt at some long lost dynamics skills:

v = v (init) + a * t

450 = 0  + a * 1sec

so, accel = 450 ft/min^2

Then, F = ma

My English units skills are limited (lb force vs lb mass), so I'll pass the torch to the next contributor...

Try this (working in ft, second units only) -

The final velocity is 450/60 = 7.5 ft/sec.

That gives a = 7.5/1 = 7.5 ft/sec^2, which is approximately 23% of gravity. (7.5 ft/sec^2 = 27000 ft/min^2 - the time in trainguy's post should have been 1/60 in minutes).

I don't know the total mass of your mover (including its 3000 lb load), so I will assume that it weighs 4000 lb. in all.  Then the mass = 4000/g, where g is approx 32.2 ft/sec^2.

Thus the average force over the 1 second duration = 4000/32.2*7.5 = 932 pounds force.

Were this my project, I would add a healthy 'ignorance allowance' so that the mechanism had sufficient capacity for the peak acceleration.

OOPS...

I KNEW the math seemed way too easy...

Maybe I should stick to Sum(F) = ma where a=0 (statics).

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each personâ€™s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now
White Paper - Medical Device Design Control
Medical device product development is a highly integrated and regulated process. Implementation of a requirements tracking solution requires attention to a variety of nuanced topics. When presented with the task of tracking the many concept relationships in a project of this type, the initial software solution of choice tends to be a two-dimensional text systems. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!