RePost: Encoder resolution (1st post had lathe axis error!)
Posted by
ballendo@y...
on 2000-09-02 18:20:40 UTC
Reposted (I had the lathe axes wrong!) see CORRECTION: below
Dennis,
The Microkinetics Software Package(s) all use their Instep motion
library, which is available as a separate product(requires you to
use/buy their PCcard, though!). This library contains the code to
carry out all the requests for motion needed by the motion
application.
For those familiar with EMC, these are the equivalent of the
canonical functions.
The library procedure isThreader performs threading in microkinetics
software.
Description(from the docs) "Threader allows you to perform externally
synchronized... moves in which the external pulses are interpolated
with the steps of the move. By attaching an encoder... the Threader
command can be used to lock up to 4 axes to the incoming signal."
So what is happening is: for a given number of pulses from the
encoder, the motor(CORRECTION: Z axis in our lathe example)will step
a certain
number of steps. It is the RATIO of the (spindle)encoder steps to the
(CORRECTION:Z axis)/motor steps which create the thread.
Note that if we include steps to move the CORRECTION:X axis, we will
get tapered
threads.
Ballendo
P.S.
Someone mentioned using mill software to drive a lathe. Piece of cake
as long as threading is not involved. Swap the axis cables at the
drivers so x feeds the CORRECTION:Z motor,y feeds the CORRECTION:X
motor, and leave z disconnected or disabled. Draw the bottom half (as
shown on the screen)of the part outline, including any roughing
passes. If you set part/program zero to the centerline of the part,
your displays will read the current RADIUS of the part. BE CAREFUL OF
MOVES TO 0,0!,
they will try to cut to the lathe centerline ADDITION: and chuck
face!!!
P.S.S. For those unfamiliar with lathes, the CORRECTION:X axis
carries the tool in and out from the center(making different
diameters) and the CORRECTION:Z axis oves the tool left and right
along the workpiece. Y (very seldom used) raises and lowers the tool
height (in relation to the spindle centerline)
Dennis,
The Microkinetics Software Package(s) all use their Instep motion
library, which is available as a separate product(requires you to
use/buy their PCcard, though!). This library contains the code to
carry out all the requests for motion needed by the motion
application.
For those familiar with EMC, these are the equivalent of the
canonical functions.
The library procedure isThreader performs threading in microkinetics
software.
Description(from the docs) "Threader allows you to perform externally
synchronized... moves in which the external pulses are interpolated
with the steps of the move. By attaching an encoder... the Threader
command can be used to lock up to 4 axes to the incoming signal."
So what is happening is: for a given number of pulses from the
encoder, the motor(CORRECTION: Z axis in our lathe example)will step
a certain
number of steps. It is the RATIO of the (spindle)encoder steps to the
(CORRECTION:Z axis)/motor steps which create the thread.
Note that if we include steps to move the CORRECTION:X axis, we will
get tapered
threads.
Ballendo
P.S.
Someone mentioned using mill software to drive a lathe. Piece of cake
as long as threading is not involved. Swap the axis cables at the
drivers so x feeds the CORRECTION:Z motor,y feeds the CORRECTION:X
motor, and leave z disconnected or disabled. Draw the bottom half (as
shown on the screen)of the part outline, including any roughing
passes. If you set part/program zero to the centerline of the part,
your displays will read the current RADIUS of the part. BE CAREFUL OF
MOVES TO 0,0!,
they will try to cut to the lathe centerline ADDITION: and chuck
face!!!
P.S.S. For those unfamiliar with lathes, the CORRECTION:X axis
carries the tool in and out from the center(making different
diameters) and the CORRECTION:Z axis oves the tool left and right
along the workpiece. Y (very seldom used) raises and lowers the tool
height (in relation to the spindle centerline)