Issue - Milling a rounded bottom model , at finishing pass leaves a flat area.

[ChrisGalmiche]

Hi There,

I've been following this forum since a couple of years, now I need som help to solve an issue I have when milling round parts.

As you can see at the following pictures I'm having some issues with the finishing pass. The bottom is suposed to be round but at the finishing pass an almost flat area appear (not totally flat, but with a much higher radious than it should)

I use Rhino for CAM and Rhinocam as CAM. Milling machine is a Syil x4 speedmaster and I'm using Mach3,

Any clue about whats going on?

Thanks!!



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[Ican]

What tool are you using?? It looks like perhaps the tool radius is too large for the part radius???? Can't really tell. Is your CAM package showing a good path? A path without the flat spot? Is that recessed?

[ChrisGalmiche]

Thanks for your Help Ican. I'm Using a 3mm ball endmill, but happens also with other tools, doesn't matter how small they are or how big is the radius, it's always the same thing... The CAM shows a perfect path, no flat spot at the bottom. It looks like there is still material to be removed, the endmill doesn't get down enough

[Spurry]

Have you checked for wear in the feedscrews?
From the picture it looks as if the error comes with a change of direction up/down or down/up, so any wear in the screws is exaggerated with the change of direction.
Pete

[Ican]

Thanks for your Help Ican. I'm Using a 3mm ball endmill, but happens also with other tools, doesn't matter how small they are or how big is the radius, it's always the same thing... The CAM shows a perfect path, no flat spot at the bottom. It looks like there is still material to be removed, the endmill doesn't get down enough

Odd. Since it isn't showing in your path in your CAM program, I would look at the tool description and make sure the CAM has the correct tool information to path from. As well, path the part wit a little different path...say on an angle with a little X in the movement. like this ///////// instead of all Y moves. It could be machine wear but if that is the case, I'd think it would show up in other parts being cut as well. One last thought... in the image, it looks like the tool is cutting...but at a different height as far as I can tell. Look at the code where the tool passes over that area, see if there are any Z moves. The way it looks, IF there are Z moves there will be a pattern you might be able to spot. That part is thin.... is it flexing?? Doesn't look like it but you gotta get this fixed....it's driving me nuts!!! Good Luck