Wire EDM Machine Operation Chapter 8
Copyright November, 98 Page 8-3 Sodick Inc.
being machined must be finished to the proper size in the (straight) land area of the die.
Then the taper angle must be machined. If several trim passes are necessary, this could
almost double the production time for the die. By using our recommended method, the
taper angle is cut first (with roughing conditions), leaving only a very small area to be
machined for the land area of the die. The necessary trim passes may be reduced, but
even if not, the surface area for machining this area is reduced to the point that the trim
passes will occur much faster.
Say for example that you are machining a .25 degree taper angle and the thickness of the
die land is to be .125 inch. In this case, if the clearance angle is machined first, the
amount of stock left for the land to be machined is only .00054 inch, and one trim pass
would easily remove this stock. To calculate the amount of stock for the die land area
simply multiply the tangent of the clearance angle times the thickness of the land.
However if the taper angle were 5 degrees and the land thickness were .25 inch, the
amount of stock would be .0218", which is greater than the wire diameter. In this case, if
you tried to use our recommended method the wire would actually be creating a slug as
you machined the die land. This slug would cause problems during cutting and in this
case you would be wiser to machine the die land first.
If the stock left in the die land area after machining the clearance angle is greater than
about half the wire diameter, then you must cut the die land first. If not, you can save a
great deal of time by cutting the taper angle first.
There is one exception to this rule. If you are machining within extremely accurate
tolerances (.0001 or better), you may be wiser to machine the die land first in all cases.
But for general-purpose applications, use our general rule.
H
H
O
O
W
W
T
T
O
O
P
P
R
R
O
O
G
G
R
R
A
A
M
M
T
T
A
A
P
P
E
E
R
R
Now that you know the theory of taper cutting, you can decide for yourself which method
of taper cutting is best for your particular application. We will give you the information
to do it any way you wish.
As with wire radius compensation, there are three steps to programming taper:
1) Initialize taper (G51 for left, G52 for right)
2) Make machining motions
3) Cancel taper cutting mode (with G50)
(Notice the similarities to wire radius compensation. These commands should be easy to
remember!)
To Next Page
Loading...