Cutting 3" deep pockets - no finishing pass?

[baudot]

I'm looking to cut an aluminum mold with pockets nearly 3" deep. Try as I might, I'm not finding narrower endmills to perform a finishing pass long enough for this.

I'm starting to think now that the way to do this is to not have a finishing pass, but to use the full size endmill for the entire cut. So I'd have to find a CAM setting to have the mill follow the path of the wall, to get a smooth finish on it.

Is this a good approach to the problem? Anyone know the setting to get this style of toolpath out of VCarve Pro or Cut3D?

[philbur]

I might be missing something but isn't this the basic function of all CAM applications?

Any slight step, due to a DOC that is less than the total depth, will have to be blended by other means.

You can have a finishing pass for each pass which will reduce deflection and therefor the size of the step to be blended.

Phil

So I'd have to find a CAM setting to have the mill follow the path of the wall, to get a smooth finish on it.

[baudot]

The CAM software I've used so far (VCarve Pro) has plotted a toolpath that moves in rows across the surface being milled, more like a dot matrix printerhead than a plotter, if you will.

[philbur]

I think you may have the wrong CAM program for creating molds with pockets 3" deep. VCarve Pro appears to be for engraving.

Phil

The CAM software I've used so far (VCarve Pro) has plotted a toolpath that moves in rows across the surface being milled, more like a dot matrix printerhead than a plotter, if you will.

[baudot]

I think you may have the wrong CAM program for creating molds with pockets 3" deep. VCarve Pro appears to be for engraving.

Which programs do you recommend?

[hoss2006]

baudot,
When you setup your pocket toolpath enter a value in "pocket allowance" like .015
to leave .015 material.
Then create a profile toolpath, inside machine vector and set your selected tools "pass depth" to 3.0.
That will take the .015 material off in one pass.
That's hella deep so chances are it's gonna chatter though you didn't say what diameter tool you're using.
Maybe set the pass depth to 1.0 or 1.5 to have less lines to blend.
Also, in future you'd be better off asking in the Vectric forum than here.
Vectric - CNCzone.com-The Largest Machinist Community on the net!
Hoss

[Dennis Rech]

The CAM software I've used so far (VCarve Pro) has plotted a toolpath that moves in rows across the surface being milled, more like a dot matrix printerhead than a plotter, if you will.

Under "Pocket toolpath" select "Offset" instead of "Raster".
You will then get a toolpath that traces around the perimeter instead of back and forth.

Also, you can draw a very narrow offset inside the pocket boundary and make a separate clean-up path. You can use Profile- cut inside of line for a 0.001 or so finish cut.

For any cut in metal, be sure and ramp your cut entry.

Dennis

[Gundawg]

Can you post a picture or a file? I use Vetric Aspire for my CNC router table there are several ways to accomplish your pocket and a finishing pass the use of leads to enter the cut and ramping is another method depending on the part geometry. You can save a offset vector on a different layer in the cad drawing and tool pathe that vector there is a bunch of ways to accomplish your finish pass. How large is the pocket and how big is the bit (length & diameter)?

Mike