Re[10]: emc really needs a copyleft cad/cam package

Terry wrote:

>before i go off assuming the wrong idea
>does roll == a, pitch == b, and yaw == c?

Terry,

In the CNC world, A,B, and C are ROTARY axes which rotate AROUND X,Y
and Z, respectively. I also covered this in previous posts.

The DIRECTION of travel (for these rotary axes) is defined by
the "right hand rule". Which boils down to: Look at the rotation
FROM the PLUS direction of the UNINVOLVED axis to determine if the
rotation is clockwise (plus) or CCW (minus).

Roll, pitch and yaw also define rotational movements. In aircraft,
these are related to the direction of travel. So if we are sitting in
the pilots seat, looking forward: we ROLL onto one side or the other,
we PITCH downwards or upwards, and we YAW to the left or the right.

If the direction of travel (Normal flight direction here, we'll leave
Sean Tucker out of this! :-) ) is assumed to be X axis travel, then
your assumption is correct.

Be aware that some machines on the market are mislabeled (according
to the published "axis naming standards for the machine tool
industry"). These are usually calling the X axis (by standard
definition) Y. One example is the Super Tech machines and their XYYZ
controller. Properly, this would be XXYZ (they use two "sync'd"
motors on the longest axis of their gantry machine)

By definition, X is the longest axis. Or the axis which can "carry"
the longest dimension of work.

So you can have an open-ended "billiards table" type machine whose
travel is "wider" than "deep". And the X axis is still properly the
depth, (towards and away). Left and right are the Y axis.

By definition, Z is the "tool carrying" axis.

Now a mill table, like a bridgeport, can carry the longest work from
left to right (which also HAPPENS to be, in this case, the longest
TRAVEL as well) and this is properly called the X axis.

I realise this is more than you asked for, but it seemed a good time
to bring this up again. (there was a recent post mis-stating the axes)

Hope this helps.

Ballendo

P.S. Sean Tucker is an aerobatic "airshow" pilot. If you ever get the
chance to see him, DO SO! The things he does with an aircraft
(propeller) are amazing...