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  1. #11
    Quote Originally Posted by magicniner View Post
    What you use for engraving depends on the required results, to get sharp corners on small letters you will need conical D-bit cutters and V-Carve type cutting paths
    The problem I get is chewed edges to the cut. This plate, for instance, Click image for larger version. 

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ID:	20024 had to be sanded and polished back to smooth. Is this ususal ?

  2. #12
    Quote Originally Posted by cropwell View Post
    How about a feeds/speeds/toolselection
    That's not at all a bad idea! ;-)

    - Nick
    You think that's too expensive? You're not a Model Engineer are you? :D

  3. #13
    I dont know what brass you are using? The brass i use is the best material ever i have used. I started to hate aluminum and mild steel . I dont know of a material thats easier to cut than brass.

    Engraving with 1 and 2mm tools is very nice in certain cases and generally sth entirely different from V carving. I like it much.


    Reasons for tools to break, not all but those that could concern us:

    1. Lack of rigidity of setup, machine or spindle runout. Its all the same. Results in very high wear due to friction combined with bad chip removal , leads to heating and tool brakes prematurely. This is a no brainer.

    2. Incorrect feeds and speeds that result in higher deflection than tool can accept. Tool stick out from collet also must be taken into an account.

    3. Incorrect geometry of tool and typpe of tool-number and angle of flutes, etc.

    4. all tools from <=2mm are in a different world where all should be carefully calculated and no rush.

    5. machine acceleration too high.


    I dont think we need to make a tool database. HSMAdviser or G-wisard are more than enough so no mistakes are made. I know i repeat my self but HSMAdviser is a Great program which is a must . i know via Exceoll sheet all can be calculated but using the program is such a breeze and flawless process. Believe it or not but 10 times more experienced than me people started to ask me on opinion on feeds and speeds with special and small cutters.




    I dont know what machine and cutters are we talking here but that below is how i do it and it works 100%. Suffice to say that i have in that range tools that each is 50-60 euro and i could rush them 200% faster from that below.

    Anyway, try always to use lower stickout if possible/ not so with the calc below as some clearance was needed due to deep channels. And have in mind i am using TiCn coated cutters so lower that a bit for uncoated carbide cutters.

    Click image for larger version. 

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    Now if you have a mill, thats what the same will look like:

    Click image for larger version. 

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    PS. Sorry above if you see its for edited ball nose cutters which i have the same size and type. But ball nose box is unchecked so its for straight flat end cutter. if Ball Nose are used, halve the depth of cut and double the feed
    Last edited by Boyan Silyavski; 18-12-2016 at 02:21 PM.
    project 1 , 2, Dust Shoe ...

  4. #14
    Quote Originally Posted by cropwell View Post
    The problem I get is chewed edges to the cut. This plate, for instance, Click image for larger version. 

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Views:	161 
Size:	130.9 KB 
ID:	20024 had to be sanded and polished back to smooth. Is this ususal ?
    Stiffness of machine plays big part to finish quality. So if you got spaggetti machine then yes this is usual.!!

  5. #15
    Quote Originally Posted by JAZZCNC View Post
    Stiffness of machine plays big part to finish quality. So if you got spaggetti machine then yes this is usual.!!
    not spaghetti - worse MD much wobblier, but I have to live with my mistakes until I get my own build done.

  6. #16
    'I dont know what brass you are using?' No Boyan, nor do I. I just bought it as .7mm sheet. Few metal suppliers seem to know what grade material they are selling.
    'I dont think we need to make a tool database' - I am not proposing that, just a place to discuss problems related to feed and speeds etc.

    Rob

  7. #17
    Quote Originally Posted by cropwell View Post
    not spaghetti - worse MD much wobblier, but I have to live with my mistakes until I get my own build done.
    Holy shite.!! . . You have MD and put brass in front of it.! . . .Are you crazy Man.

  8. #18
    Quote Originally Posted by JAZZCNC View Post
    Holy shite.!! . . You have MD and put brass in front of it.! . . .Are you crazy Man.
    Barking mate ! Woof woof, mad as a box of frogs

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