On Wed, 17 May 2006 02:45:24 GMT, "Tom Gardner"
wrote:
"F. George McDuffee" wrote in message
.. .
On Tue, 16 May 2006 13:42:53 GMT, "Tom Gardner"
wrote:
I just recieved a mandate to automate a fastening opperation. We have to
drive two #10 x 1-3/4" SMCs to hold this handle. This has become a
full-time job, so it's a high priority and high budget because the job is
menial and high risk of repetitive motion injury.
http://www.bettymills.com/shop/produ...FS4067600.html
================
From your responses to the follow-ups it may be time to
re-evaluate your product. Is there any need to remove the
handle? If not, your best bet may be to eliminate the screws and
use what are called drive screws.
see:
http://www.hansonrivet.com/w58.htm
http://www.smithfast.com/udrivescrew.html
http://www.instockfasteners.com/PROD...rivescrews.asp
and a bunch more.
Depending on your production levels you can go several ways.
(1) slide fixture that operator loads brush, handle and screws.
(2) slide fixture that operator loads brush and handle with drive
screws fed from syntron hopper
(3) shuttle table with two fixtures with automatic screw feed --
load one while the screws are driven on the other
(3) rotary index table with automatic screw feed.
Given that you want the operator to pack 12 to a box start with
the slide fixture [keeps operator's hands/fingers out of danger]
with manual drive screw insertion -- magnetic holders should work
fine.
If this works out (and production requires) you can upgrade to
automatic drive screw feed with little problems.
If you go this route and use pneumatic cylinders to seat the
drive screws I strongly suggest a enclosure and lock for the air
pressure regulator. For some reason the operators/foremen always
set the pressure as high as possible and start breaking things,
possibly because the machine seems to cycle faster.
Be careful of all pinch points and use double button [two hand]
controls with anti-tie down to prevent any accidents and/or OSHA
problems.
Unka George
(George McDuffee)
I remember drive screws, we used to attach a steel scraper to a brush 30
years ago and haven't used them since but what a GREAT idea! They should
work for the wood and plastic handles too. Now, what do I drive them with?
Many of the same people that sell the screw inserter equipment
also sell drive screw inserters. Also the drive screw suppliers
should either sell the equipment or know who does.
Hydraulic and pneumatic drive is available. Compressed air will
cost more than the electricity for the hydraulic over the long
run but the initial cost of the pneumatic drivers is lower. I
have seen long stroke electric solenoids used, but it is
difficult to control insertion speed. (too fast can cause
splitting and stripping in wood and plastic)
Production volumes, cost and difficulty of set-up/change-over
will determine how much automation you want to invest in.
Gunner's idea of using a hand operated arbor press (or even a
kick press if you can find one) is a good idea for initial
testing and evaluation, and can be a real life saver when you
need a 1/2 dozen of something and you are in the middle of a long
run of another part number on the automated equipment.
It may be worthwhile to phase in the amount of automation in the
assembly operation. For example, automatic feeding of the drive
screws will be expensive, and you may want to have the operator
manually load the drive screws in addition to the other parts to
start.
You may well wind up with several assembly stations and machines
for different production levels, from Gunner's arbor/kick press
for short runs/specials, to a rotary table or shuttle fixture
machine with automatic screw feeding/insertion for the high
volume items.
On drive screws, not only is the insertion pressure critical but
also the insertion rate (especially in wood and plastic), thus
you generally need both pressure regulator and flow control
valves. As indicated before, the air pressure regulator and flow
control valves will need to be secured from operator/foreman
"adjustment."
Most likely you will want to press to a positive stop. You may
also need to include "cycle complete" circuitry to insure that
the press cycled to the full depth to seat the drive screws.
It is good to see that we can still make things here in the USA.
Do a "Paul Harvey" and let us know the rest of the story....
Unka George
(George McDuffee)
There is something to be said for government by a great aristocracy
which has furnished leaders to the nation in peace and war for generations;
even a democrat like myself must admit this.
But there is absolutely nothing to be said for government by a plutocracy,
for government by men very powerful in certain lines and gifted with the "money touch,"
but with ideals which in their essence are merely those of so many glorified pawnbrokers.
Theodore Roosevelt (1858-1919), U.S. Republican (later Progressive) politician, president. Letter, 15 Nov. 1913.