Can anyone explain toolpath filtering?

[Bob W.]

I have a surfacing roughing operation and I turned on filtering (1:1) and the NC program shrunk by 70%. What exactly is happening with filtering? Also, what do the different values mean - 1:1, 2:1, 3:1, etc...? My Mill doesn't have high speed machining activated (Haas Mini Mill) so what setting will allow the mill to run more efficiently? I'm sure it is obvious that I am somewhat new to this stuff and I appreciate the help :-)

 

Thanks,

Bob

[medaq]

Best way to explain, The machine is looking for arcs on different planes, and or looking for straight lines it can join. So if you have a arc in the z plane the machine will have to break it into many many pieces of code to do one arc. With filtering it breaks that huge amount of code, by switching the plane to write a arc. Accomplishing what it would of done in 100-200 lines of code in one line. by using g18,g19 and making a g2-g3 move instead of a g1.

 

Jim

[cadcam]

Filtering Toolpaths

Filtering toolpaths is a great way to reduce the size of the G-code file used to produce complex 3-dimensional surfaces. When you filter a toolpath, the CAM system replaces toolpath moves that lie within a specified tolerance, in a straight line, with a single toolpath move. This is contrary to the purpose discussed above of setting the cut tolerance to a small value, but if you set the cut tolerance and the filter tolerance to the same value, you will get very little reduction in the amount of code produced. Now, we can set the arc filter to reduce the amount of G-code without reducing any accuracy.

 

With the toolpath filter you can replace multiple linear tool moves with a single arc move of a specified minimum and maximum radius. You can choose to create arcs in the XY, XZ, and/or the YZ planes, but the tool motion must be parallel to a machine axis to get the arc output. Setting the arc filter parameters allows you to smooth the faceting that is typical of linearized surface toolpaths, and create a single arc move out of several linear moves to reduce the amount of G-code produced.

[Bob W.]

Okay, than makes sense. How do the different ratios come into play? It also sounds like the machine will run considerably faster with filtering on. Is this correct?

 

Thanks for the info.

Bob

[Todd Tracey from Fastech]

Anoter source for a good explanation in the following link. The writer explains things and has diagrams that help.

 

http://www.haascnc.com/solutions_3D.asp#3D

[cadcam]

I agree John does a great job of explaning it.

[Todd Tracey from Fastech]

Hey Jay, how you doing on X2?

I played around at home today and loaded X+. Hole Axis, Mold+, Pro Drill, Catia Trans. all seem to run OK.