depth problem in Surface contour toolpath

[bucketbot]

Hi,

 

When I do a surface contour toolpath, the toolpath generated is made so the tool is always in contact with the surface which is what I want for finishing. My question is that if I use this toolpath directly on stock, I will be at a higher depth when I do my last pass and the tool will be very deep.

 

Is there a toolpath or an option in surface contour that remove the stock in front of the surface with a Z step down so that I do not go to deep?

 

thx.

[uncle_dolan]

Could you post an image of what you mean?

[Jasond0530]

Surface rough contour has stepdown!

[Jon H @ In-House Solutions]

Surface rough contour has stepdown!

And stock to leave, if I'm understanding your problem correctly...

[bucketbot]

Ok look at the picture I attached. You will see that the tool at position 1 is less deep then the tool at position 2.

Consider that I do from top to bottom which is position 2 comes after position 1. Therefore, there will be more material to the left of the tool in position 2 than in position 1.

 

So is there an option or a toolpath that takes away the material on top of the surface and in front (at least a diameter thick)? Or is there something I'm missing with mastercam because I'm still learning this software?

[Millertime]

It looks like you need to rough that first before you run youre surface finish contour.Surface finish contour and surface rough contour does not have stepovers.you will prob want to hst surface rough rest mill that first or opti rough it??

[Rotary Ninja]

Depending on the stock you are taking off, I usually drive around the 2d Contour of the part first, staying away from the surfaces .025" or so.

 

Then if I need to rough the actual surface I use a Surface Finish Contour toolpath using a bull or flat endmill. I'll set the stock to leave on drive surfaces to .025" there as well. In the finish contour parameters tab there is a check box for "Order cuts bottom to top". I use that a lot. Especially if I am not doing a rough pass on the surface and I am going straight to the ballnose (which I do a lot). Cutting from the bottom to top prevents the center of the endmill from doing any of the rough work and leaves a nicer finish in my opinion.

 

If you do create a pass for rough and one for finish just copy the rough toolpath down, set the stock to leave on drive to .0" and change the tool and stepdown amount. This method works for me. I am sure there are other ways to do this. Hope this helps.

[Rotary Ninja]

I forgot to mention - On the finish countour parameters tab there are a couple things I use to get a good blend. One is "Cut depths" and the other is "Shallow". I always use these because the default settings don't give a good blend. On the cut depths I switch to absolute. Right-click in the text field for minimum depth and click on the highest point of your drive surface. Right-click in the Maximum depth text field and select the lowest point of your drive surface. Then click to the right of your entry for the maximum depth and subtract the radius of your ballnose or bullnose.

 

So, if the top of your part is Z-0-, and the radius of your surface contour is .500" and your ballnose is .500" you should have 0.0" in the minimum depth and -.750" in the maximum depth.

 

For the Shallow settings I select "Add cuts to shallow areas", Minumim stepdown to something like .0005" and limiting stepover to whatever my stepdown is. I uncheck "Allow partial cuts"

[Mick]

On the subject of Surface Rough Contour, and Surface Finish Contour, I recall a while ago that some people had issues with Surface Rough Contour, where it gouged the part quite often. Does anyone recall this issue, and wether it was addressed or not?

 

I haven't used Surface Rough Contour since then, so I can't comment but I would be interested to here of any outcomes.

 

 

Quoting RotaryNinja,

 

"For the Shallow settings I select "Add cuts to shallow areas", Minumim stepdown to something like .0005" and limiting stepover to whatever my stepdown is. I uncheck "Allow partial cuts" "

 

I use the same settings. Surface Finish Contour works really well.

[Rotary Ninja]

On the subject of Surface Rough Contour, and Surface Finish Contour, I recall a while ago that some people had issues with Surface Rough Contour, where it gouged the part quite often. Does anyone recall this issue, and wether it was addressed or not?

 

I haven't used Surface Rough Contour since then, so I can't comment but I would be interested to here of any outcomes.

 

 

I never use surface rough contour. I will create multiple finish contour paths leaving less stock on the drive surfaces with each pass, and change the settings in cut depths before I use the rough contour toolpath. It's a little more work in the end, but it gives me what I want.

 

What I wish they would come up with is a setting to allow the same stepover across the radius of the contour. It would be more of a degree setting rather than a stepover or stepdown - if that makes sense. The shallow setting sort of helps, but on really large radii you still see variations in the stepover when shallow takes over. If there is another way to do this I have not found it. I realize this type of setting would generally only work on a static radius that stayed the same size around the contour. But it would come in handy.

[uncle_dolan]

If you use the surface high speed Waterline, you can set the maximum stepover as well as the step down which can help to keep the surface fairly consistent.

[LaszloK]

I'm just going by the picture you posted, but I would use a different tootpath to finish that part. In either case you would need to rough out the material on the left of the finished part. I only use the surface contour toolpath when the finished part has undercut walls.

[Rotary Ninja]

Which toolpath do you use?

[bucketbot]

Hi, thanks for your advice with surface contour finish and the shallow thing, it's really gives a good blend.

 

As for the roughing part, I decided to use Cut3d from Vectric instead. It's very quick to generate toolpath and it does exactly what I need for roughing. Because this program does only raster, the finish is not good enough so I do that part with Mastercam.