MastercamX5 Contour ToolPaths

Please let me understand the following:

In McX5, Contour Toolpath / Cut Parameters we have under compensation type several choices but I always choose “Computer”

Then we have Compensation Direction and the options are Right or Left

My understanding is in the "Left" the endmill will cut on the outside of a line and the "Right" will cut on the inside of a line.

So if I want to cut a square 4"x4" if I use the left I will get a 4x4 square and if I use the "right" I will get a smaller square (endmill diameter x 2).

Is this correct?

Thank you

No...
Left means ... the cutter follows the contour on the left side.. this is "climb" milling (if cutter is rotating CW)
If the chain went CCW then left comp is placing tool inside.
If the chain went CW, then left is placing tool on outside..

Ie the big and small arrows when chaining... big arrow is the profile direction... small arrow is the cutter side
Chaining direction is taken the from closest endpoint to the other end onto the next contacting entity.
It pauses if there is a branch that a choice of direction is to be made by you.

Hint... do not start contours in a corner as lead ins & outs will either be omitted or may cross over your profile ( if you cancel gouge checking), you can set to start at the midpoint of your 1st chain entity.. found in "lead in/out" settings of that toolpath operation.

If the start of chain moves from your pickpoint, then you have errors on the chain ( branching, double entities, breaks, endpoints too far away to chain)

Another hint... in toolpath parameters, the "geometry" item, you can modify, add, change startpoint etc) by r-clicking on the chain... you get another "editing" menu

Have to study what you say Superman, very interesting and answers a lot of my questions

You explain what Left will do to the cutter but how about the Right? What happens if I select the Right?

Thanks

Forgot you're a wood worker... lol

Right.... it will place the toolpath on the right side of the chained profile... so for a CW spindle rotation, you will be "up-cutting" (conventional machining)
When using the XY offset, a positive number makes the tool stay FURTHER away from your profile, negative makes the cutter edge cut into the chain.
This XY offset principle works for all comp types, positive being the direction the smaller arrow points (my previous post)
Another hint... cutter comp OFF & zero offset & lead in/out OFF.... makes cutter path ON TOP of your profile...

Very happy I learned what the 2 arrows mean when you chain an object, many thanks Superman.

So you are saying “….Right.... it will place the toolpath on the right side of the chained profile... so for a CW spindle rotation, you will be "up-cutting" (conventional machining)…”

Does this change if the chaining is CW or CCW?

Quote:

---

Originally Posted by kolias

Very happy I learned what the 2 arrows mean when you chain an object, many thanks Superman.

So you are saying “….Right.... it will place the toolpath on the right side of the chained profile... so for a CW spindle rotation, you will be "up-cutting" (conventional machining)…”

Does this change if the chaining is CW or CCW?

---

I wanted to correctly state the operation when most times you use a standard cutter that is rotated CW when cutting.

Now, going back to your "4x4 square". I want to upcut all item (right comp)
I will pick on the r/h entity(line), break that line into 2 pieces, and also place a 3" circle inside the square.
Go... 2d Contour, select chain(pick r/h entity above break point) (it should chain CCW, from the breakpoint), accept that contour. Select a tool, don't worry about other settings, as it is only an example.

If toolpath parameters(comp type) is left, toolpath should calculate on the INSIDE going CCW.
If comptype is right, path will be OUTSIDE going CCW...
Remember, you chained CCW.

Now.... select the geometry parameter of that toolpath...
It should open the select window, r-click, and ADD chain, select the circle at 4 o'clock position, (it will chain CW)
Accept the addition and regen the operation...
If comptype is right, you now have toolpaths outside the square, and inside the cicle

Next exercise... open that geometry parameter, in the window l-click drag the top chain to below the second...
This puts the circle cut to occur before the outer square...

Note... circles start points are initially at 3 o'clock position

So, still wanting to learn ?..... ;-)
You have just scratched the surface. So keep experimenting

Thank you Superman for the education, very interesting.