770 user surface finish problems on interpolation moves


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Thread: 770 user surface finish problems on interpolation moves

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    Default 770 user surface finish problems on interpolation moves

    770 user surface finish problems on interpolation moves-image1-jpg
    anyone experience this? my machine is fairly new with only maybe 80hrs tops on it. any ideas please.

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    Default Re: 770 user surface finish problems on interpolation moves

    Are you using Fusion360? If so, that looks a bit pronounced but fairly typical for 2d adaptive clearing. Adaptive clearing is primarily a roughing strategy and it should be followed by a finishing strategy like 2d contour. Make sure you leave a bit of stock in the adaptive so that you have enough to clean up. You can also adjust the tolerance and add smoothing to your contour operation. Here is a short article that explains smoothing.

    https://www.nexgencam.com/hsm-tips-t...ing-tolerances



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    Default Re: 770 user surface finish problems on interpolation moves

    You can also get something similar at the CAD stage if you ungroup or breakdown (maybe twice depending on you cad package) a circle or arc or other curved object, it goes from a smooth curve to a series of straight lines that are not always obvious on screen unless you zoom in.

    Phil



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    Quote Originally Posted by jonniemac View Post
    Are you using Fusion360? If so, that looks a bit pronounced but fairly typical for 2d adaptive clearing. Adaptive clearing is primarily a roughing strategy and it should be followed by a finishing strategy like 2d contour. Make sure you leave a bit of stock in the adaptive so that you have enough to clean up. You can also adjust the tolerance and add smoothing to your contour operation. Here is a short article that explains smoothing.



    https://www.nexgencam.com/hsm-tips-t...ing-tolerances
    Thanks for the reply, I'll look into that when I get home. Tormach responded to my email also. Pretty damn quick, less than a day. I'm still very new to fusion and adaptive clearing. Didn't realize it was only for ruffing. I just duplicated and unchecked stock to leave. Thought would be good. I hope I can save this piece. Lol.



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    Quote Originally Posted by philbur View Post
    You can also get something similar at the CAD stage if you ungroup or breakdown (maybe twice depending on you cad package) a circle or arc or other curved object, it goes from a smooth curve to a series of straight lines that are not always obvious on screen unless you zoom in.

    Phil
    Thanks for the input. Much appreciated. An thanks for not flamming my noobness to. Lol



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    Default Re: 770 user surface finish problems on interpolation moves

    Adaptive clearing threw me too when I first switched to Fusion :-)



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    Default Re: 770 user surface finish problems on interpolation moves

    Looks to me like whatever you programmed it with cut a bunch of lines instead of a circle.

    What did you use to generate tool path for this part?

    You can buy GOOD PARTS or you can buy CHEAP PARTS, but you can't buy GOOD CHEAP PARTS.


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    Default Re: 770 user surface finish problems on interpolation moves

    That also looks the sort of faceting that you get with an STL file. Did you ever mention which CAD and CAM software that you are using?



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    Default Re: 770 user surface finish problems on interpolation moves

    Quote Originally Posted by MichaelHenry View Post
    That also looks the sort of faceting that you get with an STL file. Did you ever mention which CAD and CAM software that you are using?
    I'm using fusion 360. i'm trying to play with the tolerance, stock to leave, and smoothing. still can't seem to get rid of the faceting on the simulations.



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    Default Re: 770 user surface finish problems on interpolation moves

    Quote Originally Posted by C*H*U*D View Post
    Adaptive clearing threw me too when I first switched to Fusion :-)
    how did you get rid of it? i played with the tolerance, ran 2d contour finish passes, ran a spring pass, left more on the stock to leave, smoothing, and i can't seem to get rid of the faceting in the simulations.



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    Default Re: 770 user surface finish problems on interpolation moves

    Quote Originally Posted by fashionrider712 View Post
    how did you get rid of it? i played with the tolerance, ran 2d contour finish passes, ran a spring pass, left more on the stock to leave, smoothing, and i can't seem to get rid of the faceting in the simulations.
    I thought you were just using adaptive clearing, but if you're following it up with a 2D contour pass, I'm not sure exactly what the problem is.

    If you're able to share your Fusion file here, I'd be happy to take a look at it. Actually I'd be very curious to see what's going on.



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    Default Re: 770 user surface finish problems on interpolation moves

    Just looking at the thickness of the chips laying around your part, it looks like you are simply making to deep of a cut with each go-around of your end mill. When the cutting flute of the end mill catches the metal stock it tends to suck the end mill in for a just long enough to give you this series of short flat surfaces/facets. If possible, you might try a similar cut path with the radial depth of cut reduced a bit.

    You still want to leave enough material for a finishing path and even on that finishing pass you will want to reduce the depth of cut as well. It may take longer to finish milling part but if it's only the finish quality we're addressing here, a little extra time may be a non-issue. By the way; you never mentioned what cutting tool you are using for actually milling this part pictured.

    I use a 770 mill and I've been told more times than I can count that my Tormach mill doesn't have enough torque or rigidity to make any meaningfully deep cuts with each pass. Of course the folks making these statements are comparing my hobby mill to their industrial mills so, who can argue the point. My point is that if my 770 needs to be set up with tool paths with depths of cut that are shallower in order to get a decent finish then, the lighter weight 440 mill will almost certainly need to lessen those depths of cut even more so.

    MetalShavings



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770 user surface finish problems on interpolation moves
770 user surface finish problems on interpolation moves