Clamp design

[keitheng]

Hi,

I have had you guys machine a piece of camera equipment. the craftsmanship is amazing and the piece looks great.

However, it doesn't work the way i intended because the metal is too hard. I used aluminum 6061.

There are two holes in the piece i made. they are connected by the center cut-out hole. There is a thread-tap hole on the top of the piece which is suppose to bend and clamp the two holes on to rods when a screw is tightened.

the metal i picked is way too strong and there is no clamping action when i tighten a screw in. Which type of metal would you guys suggest that is the most cost effective?

i have included my project file.

[Tech2]

The problem is in the design, not the material. Unless you have a reason not to, you would be better off with separate screws for each of the two clamps and breaking the bridge with a gap. Currently the structure is counter-productive to the intent.

[keitheng]

if i understand correctly, you are suggesting i approach the design like the first image i have attached.

I did try a design like that with you guys, but the program said something about the thread and tap not being allowed on the sides and the top at the same time. Perhaps this was a glitch? A thread/tap hold on top is necessary for me because it will attach another piece of equipment to it.


the second pic i have attached is another company's design that I was trying to improve upon. their approach is the same as mine but their's works. can you help me figure out what it is about mine that isnt working?

as you can see, theres also has two holes for double rods to go through. a thread/tap is located on the top to screw and clamp down on the rods to hold them in place.

[Tech2]

Yes the first image is one variation of a more conventional clamp that should work better. About the error you got you would need to post the design for assistance. The single screw approach might work with very close tolerance on the shaft holes but generally it's advisable to minimize high tolerances. Another approach is a two part assembly as shown although it's not as strong.

[keitheng]

Thanks tech 2, but the latest design you suggested may not work, because when you screw the bottom piece to clamp on to the bars, it may not land exactly flush with the top piece.

do you have a suggestion how you may be able ensure it landing in the exact right spot?

Also, won't two pieces be more expensive?

I created a quick mock up of a design close to the first suggestion you made.
Do you think this will work with Aluminum 6061? I'm really concerned that it wont bend enough to clamp tightly on to the bars.

[Tech2]

Yes, one piece is more economical usually. You want to modify your latest design so there is less material around the hole so that the material can bend when the screw is tightened.

[keitheng]

ok I will make the eadge around the holes thinner so they can bend. i will try to do that tonight.

My next question is, do you think Aluminum 6061 will also bend back in to place when the screws are released?

Also, do you have a recommended measurement for the thickness of the edge around the hole to ensure that it will bend?

[keitheng]

any ideas regarding the questions in my last post?

[Tech2]

The degree of bend is minimal so 6061 should be fine IMO. I would guess around 0.1" to 0.2" thickness.