Let the Record show that "Buerste" on or about
Thu, 4 Mar 2010 14:31:33 -0500 did write/type or cause to appear in
rec.crafts.metalworking the following:

Is works perfectly and fast! By varying the pressure in the cylinder that
presses the gears together, the wire is gripped very well at 60 lbs air
pressure and will slip through the gears easily at no pressure.

The only problem I have is that the gears over-run and feed too much wire.
I've considered lightening the gears by drilling a bunch of holes. Also, a
drag brake on one or both gears with screws pressing brass pucks against it.
Another idea is an air limit switch that is struck at the end of the stroke
by the crank. This switch would unload the pressure on the clamping
cylinder and let the wire slip between the gears when they over-run.

Sounds like a "delay" between when you say "stop" and it does
actually stop. Reminds me of a story about teaching a bunch of
farmers to use small boats. They were used to tractors, which only
turn when the steering wheel turned. Turn the wheel hard over, make a
90 degree turn, then straighten the wheel, "plow on". Small boats,
otoh, keep turning. One needs to stop 'turning' before completing the
turn, so that the boat is going "straight" when it gets to the new
heading.

So "re-calibrate". That is, if X amount of time produces Y amount
of wire, shorten X. Seems to me the air limit switch is an idea for
doing just that. Cut off the air so that the "overrun" produces the
last amount of travel needed to get the right amount of wire. That
"over travel" is not a bug, it is a feature.


pyotr

-
pyotr filipivich
We will drink no whiskey before its nine.
It's eight fifty eight. Close enough!