Had you any real experience, you'd be using a vacuum chuck Jon.
It's not possible to "squeeze" a part identically in a vice every time you
change over.
Here is a machining "Tit" for ya'.
There is not reason to change out a vice and waste time mounting a
vacuum chuck if you don't need to and a vise will work fine!
If anyone is interested I'd be happy to post pictures of our numerous
vacuum-holding systems some of which are made by IBAG and many of
which we make ourselves.
Jon Banquer
San Diego, CA
No kidding.
You just clamp the chuck in your vice.
You can even use that fancy and useless five axis stop you swear by to
locate the thing.
By doing so, you can make your chucks in advance if something custom is
necessary.
Otherwise, you buy standard stock and change out O-Rings. You can do that in
sewconds if the guy generating the set up documents and code knows what he's
doing. Ask him.
Why don't you let the quality of your work dictate the level of interest
Jon?
Put up something you have done yourself.
You took someone else's original art, changed it a little and posted
it to your blob as if you came up with the idea.
Clue: It's not plagiarism if you credit your sources!
Tom
[
I then mill a .030 deep step with a 1/2? 3 flute carbide end mill on
both jaws. Next I insert a dovetail cutter and mill a dovetail in both
the fixed and moveable jaw. I then come back and cut off the burr that
the dovetail cutter leaves making sure to push the burr away from the
edge of the dovetail.
]
You're saying you have machined an edge that will cut into and/or
dimple the plastic blank?
[
Finally I use the end mill to create ?teeth? in the dovetail so that
the plastic part can?t slide.
]
Why would the part slide when the dovetail you milled on the jaws are
cutting into the plastic blank and putting downward pressure
(hopefully) holding the part on the step you milled with the 1/2" end
mill?
[
I frequently machine plastic parts and don?t wish to waste time
machining two sides parallel so I can hold the material so the part
won?t move while it?s being cut.
]
You have to mill off all the dimples you made in your plastic blank
when you clamped it in your serrated jaws, so how are you are saving
time in your operation?
[
The whole process can be done in less than ten minutes and results in
a cheap way to hold and mill plastic parts.
]
Ten minutes, under what conditions?
When do you start & stop the clock?
Are you assuming you have the correct end mill 1/2" to mill step add
deburr, 1/8" end mill to create "teeth", dovetail cutter and all
holders already in the machine?
Are you including changing vise jaws to aluminum soft jaws?
You going to mill a stop into the soft jaws or do you have to install
one?
[
It?s so fast I don?t even bother to save the aluminum soft jaws and
instead just make them whenever I need them.
]
If this is as repetitive as you say, why not make a set or two of
precision quick change hard jaws and do away with having to machine
jaws over and over and over again?
Why are you cross posting machining tips to comp.cad.solidworks?
Tom
Yup, there you have it!!
Good response there Jonnie,
If you have to do that routine, say 30 times a year, and you toss the
jaws, as you say, AND, it only takes you 10 minutes MAX.
Then 30 X 10 =3D 300 minutes / 60 =3D 5 hours X 75.00 P/Hr =3D $375.00
Not counting cost of jaw blanks
I can buy several sets of jaw blanks from US Shop Tools and make the
dovetail once for that kind of money.
It probably doesnt take 10 mins. more like 30 mins, unless as said
earlier, all the tools just happen to be in holders, in the turret or
carosel and the alum jaws just happen to be in the vise, and the part
is the same size as the last one you made, and the tools in the turret
were'nt used on 304 or 17-4 or O-1, in other words damaged or worn, in
the REAL world 10 mins goes by real quick.
Have a nice Saturday, I gotta go make real parts that go real fast!
"D"
Tom:
I have one of the original Mr. Clampys that was sent to me probably 8
years ago. It was a pretty neat idea, especially for fourth axis work.
What holds your part are a couple of 1/2" dia. pins that stick up some
.100, the dovetail self-centering clamps just hold the part down on the
pins which resist the machining side loads.
I used it a couple of times just to do it. I haven't used it in
probably 7 years. To use the Mr. Clampy (or Technigrip as they changed
the name), requires you to mill a couple of .500 holes in your stock as
well as dovetail the edges. Plus if you have to drill through your
part for some tapped holes or whatever you might hit the hardened pins
or the Mr. Clampy body.
I wonder if they're still in business.
Bob, I'm pretty sure they are still around. It really is a fantastic
idea for certain types of parts. I don't think the product will ever
get huge though, because really, who wants to do a prep-op on every
single part they make? You have to weigh the benefits of increased
metal removal, against the cost of additional logistics, handling, and
machining of the blanks.
For some parts though, the idea is almost unbeatable.
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