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Brian Lawson Brian Lawson is offline
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Default Timed relay control

Hey Tom

OK. Got the street address. I'll send some. How soon do you need
them? Actually, no doubt about it, better if I send them from
Michigan late Friday or early Saturday. I have to go to a meeting for
NAMES in Ann Arbor, so it's very easy for me to get them across the
border rather then the goofing around with US Customs Forms sending
from here. So, forget I asked.

I'll box up a few and send them..how?? USPS, USPS Priority, UPS,
DHL, Fedex.........whaaaaaatttt???? Lemme know soonest.

Take care.

Brian Lawson
ps...they are free to you. I got a bunch I didn't even bid on at an
auction a week or so ago. Didn't even realize there were any of this
type in the drawers until I was sorting through all the crap I got. We
used these same ones on older elevators, so they were a surprise but
familiar type.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

On Wed, 14 Nov 2007 14:31:38 -0500, "Tom Gardner"
wrote:


"Brian Lawson" wrote in message
.. .
On Wed, 14 Nov 2007 12:33:41 -0500, "Tom Gardner"
wrote:

Our newest machine has a logic problem. The machine has two nail guns
that
assemble a handle onto a wooden block brush. The operator loads a handle
and brush into the fixture and presses two palm switches. The palm
switches
energize a relay that latches and energizes the solenoid valve that
controls
an air cylinder that lifts the fixture to the nail guns until the fixture
hits a limit switch. The NC contacts on the limit switch then open and
the
relay unlatches. The NO contacts close and energize a solenoid valve that
supplies air to the triggers on the nail guns. (There is also a limit
switch
at the bottom of the stroke that powers the palm switches only at the
bottom
position.)

The problem is that when the fixture hits the limit switch it reverses
direction immediately. The gun trigger air solenoid only gets that quick
hit and doesn't have enough time to build up enough pressure to trigger
the
guns. I need to delay the fixture at the top of the stroke long enough to
fire the guns.

A few tenths of a second should be enough. An off-delay timed relay
should
do it, right? As I look through the Grainger catalog and McMaster-Carr I
get a bit confused.

What is a "Off delay Retrigerable, one shot" relay? I don't think that
this
is what I want but I'm not sure. I think I want just an "Off Delay"
relay.

Hey Tom,

Always a problem to get anything electronic to "delay" AFTER the power
is removed. But an air-check armature type will. I have a handful of
Allen-Bradley 115 VAC, if you want to give me a snail-mail and you can
wait long enough for them to get there, they will be free.

I think if it was me, I'd be leaving the air on to the nail-guns and
setting the nail guns to "bump-fire".

Take care.

Brian Lawson,
Bothwell, Ontario.


Thanks, I graciously accept your offer and will gladly trade you some
brushes. I can't bump-fire as we have eliminated the safeties and modified
the noses to fit in between rows of wire.
see: http://www.ohiobrush.com for an address. I'll need yours.