clamping force on 1/2" dia rod
clamping force on 1/2" dia rod
(OP)
thread404-396097: Required Clamping Force on a Column
sounds like i may have a similar question to this previous inquiry.
Am working with a 1/2" dia smooth rod that runs thru the center-line of a compression spring. In compression, the spring is exerting a nominal 450N force.
I need to restrain the rod with a clamping device, open/close via a cam action on clamp. Clamp width (contact with rod) is nominal 1/2". The rod dia would be reduced by 1/16" where it would contact clamp. Hence a 1/2" wide notch running circumferentially is created in rod to inhibit slipping.
If this design is realistic, then I assuming the force required to open the cam and release clamp could be controlled by the length of a lever arm on the cam, which would snap the clamp open or closed.
sounds like i may have a similar question to this previous inquiry.
Am working with a 1/2" dia smooth rod that runs thru the center-line of a compression spring. In compression, the spring is exerting a nominal 450N force.
I need to restrain the rod with a clamping device, open/close via a cam action on clamp. Clamp width (contact with rod) is nominal 1/2". The rod dia would be reduced by 1/16" where it would contact clamp. Hence a 1/2" wide notch running circumferentially is created in rod to inhibit slipping.
If this design is realistic, then I assuming the force required to open the cam and release clamp could be controlled by the length of a lever arm on the cam, which would snap the clamp open or closed.





RE: clamping force on 1/2" dia rod
... except that you have provided only a small sample of the information required to solve whatever your actual problem is.
Mike Halloran
Pembroke Pines, FL, USA
RE: clamping force on 1/2" dia rod
1. notch the rod
2. don't notch the rod
3. add a hard rubber coat on the inside of clamp to improve static friction.
this site is basically what I'm trying to do, but totally different application & size:
http://www.fitnessbodyequipment.com/images/bars_co...
RE: clamping force on 1/2" dia rod
WRT to the image provided,
I think I've seen similar clamps, used by gaffers.
... except not with over-center cams, but with relatively large half or full wingnuts, so that a pretty fair amount of clamping force can be generated.
I'd bet they'e expensive.
I've also had occasion to buy connecting clamps for building laboratory frames.
Most of them are garbage, sold to idiots who will buy anything shiny.
The best/least_awful of them comprise nickel-chrome plated zinc saddles, heavy stainless steel half-circle saddle clamps, and ridiculous poorly made wing-screws that can be easily replaced with stainless socket head screws. Even those clamps cost ~$15 each, 20 years ago.
But 450N, if I'm converting it correctly in my head, is a lot of force to be restrained by a friction clamp of any kind. If the rod were threaded, you could use a nut. If the rod were machined with a series of grooves, like a thread with zero pitch, you could use a sort of half-nut clamp, closed by an easy to operate toggle if you wish. I'm not aware of any such thing for sale now, but it seems achievable.
How many will you need?
Mike Halloran
Pembroke Pines, FL, USA
RE: clamping force on 1/2" dia rod
yes, i see your point. good idea. i'm probably looking at having to fabricate something like this. Am prototyping an idea (better mouse trap concept)and this clamp would also have to RELEASE quickly. Didn't mention before, since didn't want to add confusion. So the clamp would be functioning as a "trigger release" mechanism.
probably looking at fabrication of say 4 initially.
Know any fabricators in south Florida? I'm in Sarasota.
RE: clamping force on 1/2" dia rod
It won't snap open but they clamp tightly and release quickly.
I am thinking of the QR seat post clamps and such.
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P.E. Metallurgy, Plymouth Tube
RE: clamping force on 1/2" dia rod
I'll check if he's still alive and in business.
Mike Halloran
Pembroke Pines, FL, USA
RE: clamping force on 1/2" dia rod
RE: clamping force on 1/2" dia rod
RE: clamping force on 1/2" dia rod
RE: clamping force on 1/2" dia rod
RE: clamping force on 1/2" dia rod
RE: clamping force on 1/2" dia rod
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P.E. Metallurgy, Plymouth Tube
RE: clamping force on 1/2" dia rod
RE: clamping force on 1/2" dia rod
He does a lot of prototype machining in most materials.
Mike Halloran
Pembroke Pines, FL, USA