How can I ramp off....

[gogego]

a part feature in an exact mirror of how I ramp on...I have a deep slot that I have to run a .006 radius tool .125 deep in. I have the tool ramping in at a 45 deg angle with comp on...we always have to manually pick ramp points, then need to go in and modify the g code to get the comp to stay on while ramping out...we are using X5 and X9 and er um MC3 yes 3 since that is the only post we currently know how to work, I don't really understand how to modify points in a finished mill contour without messing up the toolpath.
Any advice or suggestions appreciated.
CHEERS!

[Superman]

You haven't mentioned the slot dimensions or tool size

2D contour will only RAMP in the Z- direction
- use a lead in / out
- can have comp the entire way down, comp turns OFF on the lead out section

the only ops that may allow Z+ ramping would be circlemill or threadmill ( not entirely sure of the circlemill ) but they also tend be on circles, never tried different geometry yet

[psychomill]

Your post will likely need to be modified if you want the comp on before/after Leads (unless your post has a switch for it).

You could also just draw your ramp on/off lines and toolpath it with your slot...

[gogego]

We tried drawing the toolpath.. but then finish contour wants to ramp on/off more than once because of the overlapping entities I guess. is there a way to swap the order in lead in/out of the arc/line movement? I want to ramp onto the part feature in a line movement not arc onto it.
would like arc move above part feature to turn comp on
ramp at 45 deg onto part feature - entry
fin contour....overlap entry point
ramp off at 45 deg - exit
arc move above slot to turn comp off
Am I overlooking a toolpath option..or is this a posting issue?
CHEERS!

[Superman]

I think we have a "language" problem

RAMP - to cut in a spiral motion whilst keeping the tool "in the cut"

LEAD IN / OUT - linear or arc motion to bring the tool "into the cut line", can be used to turn ON or OFF the cutter comp,

note!! cutter comp on most CNC machine must be taken up while doing a linear move. The linear lead distance must be grreater than the offset size being applied to the tool ( in the machine control registers )
eg. if using "control comp" the line length must be greater than the tool radius,
if using wear comp, line has to be greater than zero,
but, say
if you need to comp the line 0.100" then the lead in /out liength must be greater than 0.100"--but this is extreme and there are other restrictions ie ( size of internal arcs Vs the tool radius )
-normally a distance of 0.01"-0.04" or greater would suffice ( it is your choice, shorter is efficient, but you can put larger sizes to suit the situation, same goes for the rad sizes and sweeps )

this is why the lead in/out has a linear move as it's first and last movement---it is on this feature that comp is adjusted,,,,the arc is to give smooth movement to & from the cutting of the contour wall
the overlap ( if used ) is to avoid dwell marks on the wall ( -is sometimes used when higher feedrates are applied )


Never have a tool take-up or cancel comp in a internal corner
either-
- break the 1st entity into 2 pieces
- start at midpoint ( in the Lead in/out tab )

this can give unexpected NC code results ie no comp cancel move is applied on the operation
( some posts need a little biult in error detetion for such a situation )


Try using a 2D contour,
-select lead in/out
-check start at midpoint--ON or OFF ( your choice, depends on the chained geometry )
- overlap = 0 ( leave OFF unless you need it, complicates other functions from working correctly ie subs, ramping multipasses etc)
-set line tangent , length 0.01"
-set arc sweep 45° , radius 0.01"
copy Left side to Right ( upper middle arrow )


now, if you are RAMPING a shape,
use the same settings , now change the contour type pull down from "2D" to "Ramp", and set the options for the angle, pitch or step size

[gogego]

Isnt that ramp definition the description of a helix ramp?
I need a ramp motion that ramps from say
(toolpath of ramp is parallel to part feature)

initial lead in motion of straight line then arc
ramp on
x.65 y.10 z.01
x.65 y.00 z-.05
machines contour
then ramps off
x.65 y.00 z-.05
x.65 y-.1 z.01
lead out motion arc then straight line

When I choose contour ramp in parameter page I get the initial motion I want
But then it leads out at my final z depth which would destroy part features
I do break the contour line where the ramping occurs... and I have been using toolpath editor to move my z points but that is a time consuming hassle since it requires Ii change many endpoints z level.
I still want another option Y the heck wont it ramp off exactly like it ramps on but in reverse.

Just to help visualize this, we recently milled features with .067" spacing .125" deep using a .006" rad tool @12 deg
there isnt a ton of space to play with and our tool comp has a fairly small range too.

CHEERS!

[txcncman]

Draw in a 3D toolpath of your choosing and use 3D Contour.