Low force application

[ray2625]

We are currently working on a low force application that would require 0 lbs to 30 lbs of force applied to a part. The system will be mounted vertically. The currect design utilizes a pneumatic cylinder with tooling attached. We utilized two electronic pressure regulators (SMC) to regulate the Rod an Cap end of the cylider to achieve the required differential force. The issue is the lower forces as we expected. It turns out that the cylinder O-rings have a high enough frictional effect and requires too large a breakaway force to get the load moving. This in turn compromises our ability the achieve extremely low forces. I am entertaining the idea of switching to a small motor of some sort and using current/torque control to apply the required forces. Does anyone have any suggestions or experiences working down in these low force ranges?

 

[itsmoked]

Look into linear actuators. I believe they could easily help in your application. We used them to clamp molds at Signetics eons ago and they are certainly more capable now.
You can run feedback control and totally profile your force.

 

[ray2625]

Thanks for the input, I will be looking into the linear actuators as long as I can get them down to the physical dimensions that are required. They have definitely come a long way....

 

[sreid]

Go to Airpot.

http://www.airpot.com/

The cylinders they make are essentually friction free. Selective fit carbon pistons in a honed glass cylinder.

 

[MikeHalloran]

OR,

rebuild your current air cylinders, using Bal-Seals instead of o-rings for the piston and rod seals.



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA