View Full Version : witness marks

11-09-2007, 07:08 PM
This may seem trivial ,but here it goes....How in the hell do you make the
the toolpath overlap on the lead in lead out moves, I can't figure it out driving me crazy!!! I keep leaving witness marks, I've never had this problem in
mastercam, also how do you start a contour in the center of a hole? I've been using it for about a week so bear with me...is there a circle mill routine i'm missing or is there a formula?

Cam Nerd
11-12-2007, 09:30 AM
Just use 2 axis contour to machine the hole, after you chain it, select "plunge" from the top toolbar and select the holes center. This will allow the cut to start at the center of the hole.

If you have several holes and do not want to select each center point, use the Lead in move, and set it to Line on all, the change the lead in length to the holes radius. You will need to set the leadin amount from "tool radius" to "constant"

As far as overlap, I guess your not using truemill, since this feature has an "overlap" amount, If your using contour, then the best way I know is to use the Lead In/Lead out controls to build in overlap.

11-12-2007, 11:32 PM
I thought true mill is only for roughing at least that is was the guy at work told me, He's not very skilled on the Cam system.. is there a way to overlap on the perimeter of the part? Having the same problem there as well, is there an overlap for that? I have found that at 45 deg entrance with an ovelap keep these marks to a minimum. can I change this to enter at an angle

Cam Nerd
11-13-2007, 08:09 AM
Truemill can be used for wall finishing, and does work quite well. The last pass of a truemill toolpath looks the same as any other finish pass, the only differences is that it maintains constant feedrate around the corners. You will really only see a speed benfit if truemill is roughing out an area. If your simply just profiling the part, there is only one way to do that.

In truemill there is an overlap, however, in the pocketing and contour there is not. You can use the leadin/leadout controls to adjust the angle and length of the move, so if you set these up correctly, you can sorta get the same result