In a message dated 3/5/99 8:28:56 AM Pacific Standard Time,
[log in to unmask] writes:
<< My apologies if this gets duplicated but I've had problems sending and
wasn't sure if it went the first time.
I'm looking for a rotary lead trimmer for trimming through-hole component
leads after soldering. I'm aware of Q Corporation, but would like to know of
others that may be available and what positive or negative experience people
have had in using them.
Thanks in advance.
Rick Thompson
Ventura Electronics Assembly
2665A Park Center Dr.
Simi Valley, CA 93065 >>
Hi Rick!
I've been having problems this last week as well...not sure if my posts
are getting out to the group or not...sometimes I get a confirmation message
sometimes I don't, and sometimes I get a message about the resources my
message took, and again sometimes I don't...
Myself, I've not used rotary trimmers before, but Paul Klasek
([log in to unmask]) has, and he know em' pretty well. There was a thread
last year that brings up an issue with using them trying to trim leads to
.020" and how Paul dealt with it. If ya' ask me, that's not trimming leads,
that's shaving them! hehehe...
Send a note to Paul and ask him about them...or Paul? Ya' There? Give this
gentleman the lowdown...
-Steve Gregory-
From: Chris_Smith[SMTP:[log in to unmask]]
Sent: Friday, 17 July 1998 4:39
To: [log in to unmask]
Subject: [TN] Lead Trimming Question ?
All,
I have a lead trim operation that uses a Q-corporation LOM II trimming system
with a vacuum fixture. We are using the standard cutting rings with a 30
degree angle. The Vacuum fixture being used is quite snug and there is very
little vacuum loss in the process. The issue I have is the height requirement
we're trying to meet is .020" max length. This strict requirement is
resulting in pcbs being cut into and damaged, some flagging, and some solder
fractures. This seems to be a very operator dependent operation and costly if
not done correctly. I have tried varying the speed the cutter is moved across
the board, having Q-corp sharpen the blades instead of us doing it and using a
QB-1 PCB brusher which was purchased for this product. Is there anyone out
there with a similar trim height requirement and what types of things do you
perform to insure a repeatable process? Also anyone with suggestions please
let me, I need to get this resolved if at all possible.
Thanks
Chris Smith
Manufacturing Engineer
-----------------
From: Paul Klasek <[log in to unmask]>
Subject: Re: Lead Trimming Question ?
Hi Chris ( & the rest of us on this issues )
On one of my previous projects I've got just that requirement = almost flush
base cut . Tried all sorts of tungsten blades , super thin grinding disks on
hyperspeeds with vacuum take off ; costly, unsafe, unrepeatable , you know it
all .
What we finished up with was in-house build rig consisting of a high speed
diamond blade with >polished< top (Teflon coat if you feel extreme) gliding on
geared time feed (or lever if you have a girl with feel, don't give it to a
guy) below few chrome steel separating wires (.020 gauge in your case) on
which the pcb is resting (in a nest ; unless you designed tool holes for top
clamp fingers) . Both top touch clamp and bottom blade mounted with silicon
foam suspension to ensure positive but gentle action. If you design the top
clamp on grid you can change the fingers position according to your top
geography ; say if you have 8 slits running from a center to glide & lock
clamping fingers easy to a free spot on board . The wires we >tensioned< with
cam lock lever ( piano wires & mechanics may do you ) Again, keep the cams
sliding so you can adjust wires in between the bottom topography on different
boards . Check the status of separating wires periodically , the constant
polishing kills them eventually If you have them on reels, just unlock the
cams , pull fresh length in, lock again .
Let me know if get stuck .
See you
Paul Klasek
http://www.resmed.com.au
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