On Wed, 07 Mar 2012 02:40:18 -0500, Tom Gardner wrote:

I have a flow control valve like this:
http://www.grainger.com/Grainger/PAR...l-Valve-4A789?
Pid=search
It controls the speed of a 2x10 cylinder and the movement of the
cylinder and mechanism is making the adjustment knob move so the
cylinder gets faster and faster. It does have a set screw that will
lock the adjustment knob but the operator needs to change it often and
during the stroke. Is there a simple way to stiffen the knob without
locking it? (Yes, I could get a new one.)

If the suggestion to straight-knurl and spring-keep the knob doesn't
float your boat, how about making a splined shaft and dog clutch
arrangement, so the operator pulls the knob to disengage the clutch,
turns it, then lets go to let it settle back onto the clutch.

It's way more work than a knurl and a spring, but it's way more positive,
too.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com