Need Help!- FACETED ELLIPSE

[cncstephen]

I'm not fully trained on the Mastercam X I'm using. How do I get a smooth ellipse? I drew the shape with the ellipse icon. The post processor spits out G01 points which doesn't make for the prettiest parts. Any help would be much appreciated.

[cadcam]

Are you useing the filtering option that helps with splines look at Arc Filter/ tolarences option.

[cncstephen]

Thanks for the reply. Where do I find that filter for arcs?

[Superman]

Any geometry that has splines will generate point to point G-code
- the distance between these points is controlled by the "Filter", the value represents how far the toolpath can stray from the profile before looking to go to the next point
a large number gives large facets ( good for roughing )
use a smaller number for a finishing path

Point to point code can make your machine seem like it's going to walk out the door, but it depends on the machine type & control and what feeds you are doing it at.

Another trick is to "Simplify" or replace the spline/s with a series of arcs, this will eliminate the point to point code on those items that are not splines

[cncstephen]

Thanks Superman,

I have tried to Simplify but that didn't alter the G code. I get a G03 approach and exit. In between it's all G01. There must be a way to convert the lines to arcs, I'm sure. I just haven't found it yet.

Thanks again.

[cncstephen]

Hi CADMAN,

I found the filtering option on the Contour Parameters page. I tried any and all options (including one way filtering) and processed the first tool machining the outer ellipse. it came out with G01 code yet again.

Any more suggestions? I'm sure I must be missing something obvious.

[cncstephen]

Hello,

I may be on to something. I've just tried increasing my filtering tolerance from the .025 default to .5 and generated a much different G code. I think I'm heading in the right direction. I hope.....

Please comment,
Stephen

[Superman]

Originally Posted by cncstephen Hello, I may be on to something. I've just tried increasing my filtering tolerance from the .025 default to .5 and generated a much different G code. I think I'm heading in the right direction. I hope..... Please comment, Stephen

You have headed in the wrong direction.....U' turn

See if I can explain what happens when you make the value larger
-if you have a circle and then turn it into a spline, you will get point to point code instead of arcs.
-now by increasing the filter tolerance, you are allowing Mcam to (un-conditionally) adjust the geometry away from the desired shape ( but to stay within the set tolerance range ), in fact if you make the value large enough, you'll end up with a rectangle

If you want arcs, then you have to "Simplify" or replace the spline with arcs.

simplify works by replacing an entire spline by arcs, it will only replace a spline if an arc can be drawn within the deviation size (on the upper toolbar ).

HINT----break the spline into shorter lengths, it is far easier to fit a series of arcs on a horse-shoe shape, than trying to get 1 arc to fit the whole shape

change your drawing colours before simpliying to see the new entities

usually an ellipse can be made from a minimum 4 arcs, so I'd break it into 8 peices, & go from there

[cncstephen]

Thanks ever so much Superman. I'll give it a try now and get back to you.

[cncstephen]

You are indeed a Super Hero. I think things are okay now. Many Thanks. I do like Mastercam when I understand it a a little.

[spy008]

When you create your ellipse in MCX you have the option to create using splines or arcs. Use the arc option.

[RalphWilson]

The more I use MasterCam , the more I seem like I don't know what I'm doing.
Simple statement.
MasterCam has rules I don't like.

A simple arc can be expressed simpler in code some times rather than in mastercam.
the info was taken and now giving credit to :
formula for ellipse { google search
mathwarehouse dot com.


Just how fussy you are about the true nature of the output of the ellipse in standard form, graph and formula of ellipse in math.

An ellipse is the set of all points in a plane such that the sum of the distances from T to two fixed points F1 and F2 is a given constant, K.

TF1 + TF2 = K

F1 and F2 are both foci(plural of focus) of the ellipse.

In a fanic : ie. Fadal controler.

You can have the controller do the ellipse for you.

set up a loop and have the formula in verables on point at a time then do the mirror and mirror again.


you can do some interesting things with tool paths.

to make a ellipse on the fly.

Just draw a circle in top view the dia would be the length of the ellipse.
switch to side view and xform rotate the circle to a angle.

Switch back to top view , your looking at a ellipse now.
Same as before , make a tool path and remove all the z moves out of the program.

Good luck.


Or you can do it twice in mastercam.

Draw the ellipse and put a contour tool path to it.
Set the tolerance to .0002" in the tolerance box.
back plot the toolpath without the tool visable.
Mastercam allows you to save the tool path as geometry.
Do that and save to a difernt level.
At 2 tenths you will have the best ellipse on the planet or a million short lines.

Put your real tool path to the one you just made in backplot.






Then