Best programming method

[TERRYH 439]

I am working on a check fixture for a part we made the trim die for, it has a 6mm wide groove around the OD I need to do it with a 6mm ball and go 3mm deep to maintain the 6mm width. what would be the best method to do this so there is less hand work after its done if I did it vertical where I could and then at locked angles on the rest to try and get away from leaving cusps in the bottom and make sure I am maintaining the 6mm width all the way around. in the top pic the green line is what I have to cut and the second one is a close up of one area. will be doing this in 2019. 

[JParis 212]

I'd create a 2D contour above the geometry...toolpath with a 2D contour using the 6mm Ballmill and then project that 2D contour down onto the surfaces

[Newbeeee™ 3,659]

8 minutes ago, JParis said:

I'd create a 2D contour above the geometry...toolpath with a 2D contour using the 6mm Ballmill and then project that 2D contour down onto the surfaces

+1.

It works like a charm.

[5th Axis CGI 4,252]

You already have the cutting edge defined which is the perfect tangential intersection of the side of the endmill. Grab that top intersecting edge and use 3D contour. Then in your incremental depth setting using -3mm and call it a day. You should be able to use Pencil and grab the 3mm radius and I think that should work. John's way is another way. May ways in Mastercam to do this on a 3 Axis machine.

[Redfire427 75]

5th Axis suggestion will work, however, if the groove is important, then his suggestion won't work due to steep and shallow areas. The best way would be to offset the edge geometry to create a centerline and then project the toolpath onto the solid/surfaces. This will maintain proper depth of the contour.

Upon closer inspection, I see your contour is a full radius, so 5th axis suggestion will work just fine.

Carmen

[AMCNitro 208]

IF the cross section of the groove is important you can flowline it with a smaller ball endmill

[5th Axis CGI 4,252]

8 hours ago, Redfire427 said:

5th Axis suggestion will work, however, if the groove is important, then his suggestion won't work due to steep and shallow areas. The best way would be to offset the edge geometry to create a centerline and then project the toolpath onto the solid/surfaces. This will maintain proper depth of the contour.

Upon closer inspection, I see your contour is a full radius, so 5th axis suggestion will work just fine.

Carmen

The beauty of the suggestion is the ability to do depth of cut and even a finish pass leaving .005 to finish. No other toolpath will work as slick and do the job he is needing IMHO. Have made many trim tools over the years and I use 3D contour for finishing complex shapes and all kind of things that when people see how I use it the way I use it they wonder how is it even possible. Geometry is a known and when you know the knowns then using it this way just becomes second nature. 

[TERRYH 439]

thanks guys for the help and suggestions 

[JHyder2 0]

23 hours ago, AMCNitro said:

IF the cross section of the groove is important you can flowline it with a smaller ball endmill

For what it's worth, if the geometry/dimension was critical, (assuming you're cutting into a solid and the groove is not established/roughed at all), I would use an equal scallop, set to counterclockwise spiral, using the groove perimeter as containment, and containing the center of the tool to that boundary.  Probably using a 4mm 2-flute ball.  

 

That would start the tip of the ball tangent to the top edge and make passes around the perimeter, spiraling inward toward the bottom until the groove was complete.  This would be better/simpler motion for the machine with less deceleration/acceleration/direction change while also not being so hard on the tip of the tool.  And, if I had to guess, it would be a faster operation also.  

[AMCNitro 208]

That's another option

[Joe777 1]

Try, Surface finish pencil, save tool path as geometry, delete unwanted geo and contour 3d.

[5th Axis CGI 4,252]

11 hours ago, Joe777 said:

Try, Surface finish pencil, save tool path as geometry, delete unwanted geo and contour 3d.

wHy create extra work when it is not needed?

[jlw™ 2,095]

Recently ran similar.  Did exactly as JP suggested with project.  I use project quite often actually.