Re: [CAD_CAM_EDM_DRO] EMC, ISA and other Questions...

Hi:

I just noticed some questions on the rotary capabilities of EMC and Mach1.
In EMC, the rotary axis is designed to follow the X,Y Z axis in their time
frame. That is to say a move like G1X1A360 will try to "fit" the A move into
the time necessary to move the X 1 unit at the present Feedrate. This causes
a runaway rotary axis and usually lost pulses. If you try a G1X.1A360 you'll
find it races away in the A axis.

I have redesigned that section to recalculate the feedrates for the
rotary move by applying a ratio of feedrate necessary to maintain the feed
at the proper speed. This is done by setting the diameter of the rotary
stock. The feedrate is then calculated as a function of the circumference of
the item beingn machined taking into account the movement in the Z axis for
the move.
It can be used 2 ways. Either tell the machine the diameter is zero( or
close to zero) .0001 or so in diamter in which case the Z must be set to the
distance from the center, or tell the system the actual diamter of the stock
and set the Z to zero as it touches the stock. The circumference is adjusted
on each move to be an average of the Z position during that move. The
feedrate is then recalculated onh each move to take these varibales into
account. Internally, the feedrate of an F60 move may be changed to F.034 for
example to allow the X to complete its move in the time frame of the rotary
axis instead of the other way around. The recalculations are not very
complicated but do necessitate adding new information inputs such as
diameter of stock to the input screens.

The rotary axis center is assumed to be from the Z axis in both the A and
B and no correction is yet applied to the C, but in the end it will be
corrected as a function of the X,Y offset from center. The A and B are
designed to be XZ and YZ axis while the C is rotational in the XY plane.
Ideally, a selection will be aded to allow for reconfiguration of the axis
planes in a per session basis.

Hope this information helps,
Art
www.artofcnc.ca