×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • 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.

Students Click Here

How to prevent this item from rotating while at the time of assembly ?
5

How to prevent this item from rotating while at the time of assembly ?

How to prevent this item from rotating while at the time of assembly ?

(OP)

RE: How to prevent this item from rotating while at the time of assembly ?

This looks like you're connecting electrical bus work. There are requirements related to the maximum current-carrying capability of a joint based on the contact cross-section and the size of bolt used. My guess is that if this is an electrical connection, you REQUIRE a minimum of two bolts (and probably more contact surface between the large bar and the smaller U-shaped one). The other alternative would be to permanently join the two (e.g. weld or braze).

Converting energy to motion for more than half a century

RE: How to prevent this item from rotating while at the time of assembly ?

(OP)
Hi Tudor,

Thats a good thought, but unfortunately we cannot remove the material as you mentioned. Since it will affect the conductivity.

Regards,
Anand, G

RE: How to prevent this item from rotating while at the time of assembly ?

Weld 2 small plates on the sides of the L shape bracket

RE: How to prevent this item from rotating while at the time of assembly ?

What eventually attaches to the top hole?

Insert the bottom bolt loosely (let the bracket flop around), insert the top bolt into whatever gets assembled next (positioning the bracket wherever it wants to be), tighten both.

RE: How to prevent this item from rotating while at the time of assembly ?

If all you care about is rotation during assembly (and only assembly), a simple fixture in the shape of a very shallow 'U' that takes up the space between the two brackets will prevent rotation. Once assembled, remove the fixture.

Dan - Owner
http://www.Hi-TecDesigns.com

RE: How to prevent this item from rotating while at the time of assembly ?

A small upstand o the L shaped bracket at the edge of the big plate.

Or a temporary thing (piece of wood maybe) which fits between the big plat and the vertical bit of the upstand. This could have small pins to locate the bracket.

Or a simple T piece with the top part held against the big bar and the bracket prevented from rotating by use of some pins or upstands pointing down. Then lift off.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: How to prevent this item from rotating while at the time of assembly ?

something like this to be removed

RE: How to prevent this item from rotating while at the time of assembly ?

2
This design is perfect.

If you want this connection to become loose and fail in service.

Holding it straight during assembly is the least of your worries.

RE: How to prevent this item from rotating while at the time of assembly ?

If you can machine one of the parts, you can add an edge or a groove on one of them that will fit the other one, thus aligning it.

But because such alignment methods must also include clearances for assembly, they will always work themselves loose - unless you use two screws. No matter what you do, one screw is always a natural pivot point. And even if the inevitable relative rotation between parts in use is only .0001 degrees, it will always grow.

I am ALWAYS uncomfortable when I see ANY two parts joined by only one screw in ANY application. No matter what you do it will ALWAYS work itself loose. If you use only one screw, a loose connection is in your future, period. It is inevitable. Remember this advice from a white-haired old man when that joint finally does fail. I told you it would.

RE: How to prevent this item from rotating while at the time of assembly ?

(OP)
Hi MR. Little Tech

Thank you for the reply. Nice thought.

RE: How to prevent this item from rotating while at the time of assembly ?

(OP)
Hi Robyeng,

I have used your thought for my work.

Thank you for your time and reply.

RE: How to prevent this item from rotating while at the time of assembly ?

The reason that you see so many fasteners used in buss work isn't the rotation issue.
It is because the Cu is so soft compared to the fasteners. Even with Cu alloy bolts.
This is why you see lots of fasteners with large washers (or flanged heads), in order to maintain contact area.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: How to prevent this item from rotating while at the time of assembly ?

And Belleville washers used in attempts to head-off the loss of preload from embeddment, compensate for thermal expansion, etc.

On the whole, brazing is a much better choice for connecting.

However, if you must use threaded fasteners, many small fasteners are far better than one large one.

RE: How to prevent this item from rotating while at the time of assembly ?

This is an extremely common issue in just about any mechanical assembly, and is rarely an issue worth thinking about. Just assemble everything loosely until all the bolts are in place and then tighten every bolt. What does fixturing help with, except for adding complexity and tolerance problems?

RE: How to prevent this item from rotating while at the time of assembly ?

(OP)
HI Composite,

The issue here is, i have shown only the one sub assembly, this assembly will not have a easy access once we put other assembly in the cabinet.

Thus loosely placing the bolt and torqueing after the everthing will not work here.

regards,
An

RE: How to prevent this item from rotating while at the time of assembly ?

If you can bend the bar downwards first before bending upwards it could be mounted so that the bent bar sits tight against the edge of the bus bar and that will keep it from rotating.

Sorry, finger sketch. Red is bus bar, blue is 90 degree tap, gray is bolt.

RE: How to prevent this item from rotating while at the time of assembly ?

(OP)
HI Tugboat,

Thank you for taking time and reply to my query.

Much appreciated. BTB sketch is good and i can able to understand :).

Regards,
An

RE: How to prevent this item from rotating while at the time of assembly ?

It will still come loose. Trust me.

RE: How to prevent this item from rotating while at the time of assembly ?

Maybe like this, can go straight also depends on what width do you need :

RE: How to prevent this item from rotating while at the time of assembly ?

In the competition for low-tech sketch -

This part could be laser-cut and press-brake formed.




I don't see the point in designing the assembly in such a manner that two fasteners could not be used, however.

RE: How to prevent this item from rotating while at the time of assembly ?

@Jboggs
I believe you.

RE: How to prevent this item from rotating while at the time of assembly ?

Pre-drilled hole (or drilled on installation) and a 5 cent spring pin should do.

Precision guess work based on information provided by those of questionable knowledge

RE: How to prevent this item from rotating while at the time of assembly ?

Quote (TudorM)

Maybe like this, can go straight also depends on what width do you need:
That's an extremely weird way to do it.

If you want to deal with the collision between the rectangle part and the bend radius, it's 10 times easier to make a chamfer on the rectangular part than it is to create that notch you drew on the sheet metal part.

RE: How to prevent this item from rotating while at the time of assembly ?

Scuka ,extreme is to cross the polish border right now. An idea no matter what sort of, will/can bring new ideas.

RE: How to prevent this item from rotating while at the time of assembly ?

if one does not do it the proper way in the get go, then this will be a problematic problem after the assembly is completed. the op says there is no access to torque the bolt after assembly. then what if it becomes loose then what. add two smaller bolts, and Loctite into place as to prevent becoming loose.

RE: How to prevent this item from rotating while at the time of assembly ?

and yes to keep square use a shop aid during assembly of the flange. to maintain square while torqueing then remove

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.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. 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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close