shiny milled surface sfpm
Close
Login to Your Account
Page 1 of 4 123 ... LastLast
Results 1 to 20 of 73
  1. #1
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    9,110
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2373

    Default shiny milled surface sfpm

    some milling insert cutters leave a very shiny mirror like surface if you take low depth of cut and run high sfpm.
    .
    kind of like burnishing or polishing the surface. anybody done any research on it ??

  2. #2
    Join Date
    Nov 2014
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    1,745
    Post Thanks / Like
    Likes (Given)
    2385
    Likes (Received)
    482

    Default

    Quote Originally Posted by DMF_TomB View Post
    some milling insert cutters leave a very shiny mirror like surface if you take low depth of cut and run high sfpm.
    .
    kind of like burnishing or polishing the surface. anybody done any research on it ??
    What materials? (cast iron ?) ? :-)

    Not exactly sure what your application is for this... But thought this might be of interest to you...



    ^^^ 3 mins in cogsdill * show a specific diamond burnishing tool that can be used on vertical or horizontal mill as a final pass.

    Ra 0.1 micron.

    What's interesting (at least to me) is that it's not a single point tool it has seven convex (domed) points but kinda reminiscent of a diamond tip as used in grinding to dress a wheel etc ?


    __________________________________________________ ______________________

    Not that it's any of my beeswax … In your day job you mill large castings, I don't know if your contact surfaces after milling are hand scraped or not, but was wondering if you don't scrape then does the texture (hills and valleys on a microscopic scale) provide a better 'Key" and contact surface (when bolted together final torque/tension) than a shinny flat surface..? I can't imagine if large contact surfaces can be wrung* together unless you have hyper precise lapping work + special stoning techniques (as used in the semiconductor industry and "peeps" that build air spindles etc.). ?


    ________________________________

    * No affiliation.

    ** Is the past tense of wringing , wrung ? (or wringed ?) … ? Or "they had been wrung " ?

  3. #3
    Join Date
    Jan 2012
    Location
    indiana, usa
    Posts
    125
    Post Thanks / Like
    Likes (Given)
    2
    Likes (Received)
    33

    Default

    Yes, speed, feed and depth of cut changes surface finish. Check your spreadsheet for more info.

  4. #4
    Join Date
    May 2005
    Location
    CA
    Posts
    980
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    196

    Default

    Most inserts I've used (on aluminum) are typically referred to as: "having a wiper". And yes, the geometry of the insert is such that just behind the cutting edge, the tool "drags" (burnishes) just a bit. The inserts used to cut the aluminum blank shown below were diamond (ultra fine grain PCD), but I have some highly positive rake, polished carbide inserts for a face mail that also have a wiper (or wiper "geometry" might be a better description).

    PM

    mirror.jpg

  5. #5
    Join Date
    Jul 2009
    Location
    Peoria, IL
    Posts
    11,210
    Post Thanks / Like
    Likes (Given)
    41
    Likes (Received)
    8469

    Default

    Jesus, can we ban this guy from posting on this topic? Or just ban him full stop?

    I guess when you're so good you can mill a surface to .00001/mile, you have time to obsess about "shininess".

  6. #6
    Join Date
    Jan 2015
    Country
    UNITED STATES
    State/Province
    California
    Posts
    565
    Post Thanks / Like
    Likes (Given)
    85
    Likes (Received)
    289

    Default

    why not just post in the other thread you made about this exact topic?

    sfpm for shiny surface with carbide tools

  7. Likes machtool liked this post
  8. #7
    Join Date
    May 2005
    Location
    CA
    Posts
    980
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    196

    Default

    Whoops... sorry guys: didn't mean to perpetuate a subject that has been covered before.

    PM

  9. #8
    Join Date
    Nov 2013
    Country
    UNITED STATES
    State/Province
    Utah
    Posts
    3,028
    Post Thanks / Like
    Likes (Given)
    849
    Likes (Received)
    1659

    Default

    Quote Originally Posted by precisionmetal View Post

    mirror.jpg
    THAT is BEAUTIFUL, no hand work. Damn!!

    I have Tom on my "do not read" list. It's so predictable, I don't even need to read his posts anymore to respond. BUT it was worth opening the Thread, just to see that Finish.

    R

  10. Likes cameraman, Mtndew liked this post
  11. #9
    Join Date
    Feb 2008
    Location
    MI, USA
    Posts
    620
    Post Thanks / Like
    Likes (Given)
    43
    Likes (Received)
    219

    Default

    Quote Originally Posted by thesidetalker View Post
    why not just post in the other thread you made about this exact topic?

    sfpm for shiny surface with carbide tools
    That wasn't the only one:

    shiny surface speed barrier

  12. #10
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    9,110
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2373

    Default

    Quote Originally Posted by precisionmetal View Post
    Most inserts I've used (on aluminum) are typically referred to as: "having a wiper". And yes, the geometry of the insert is such that just behind the cutting edge, the tool "drags" (burnishes) just a bit. The inserts used to cut the aluminum blank shown below were diamond (ultra fine grain PCD), but I have some highly positive rake, polished carbide inserts for a face mail that also have a wiper (or wiper "geometry" might be a better description).

    PM

    mirror.jpg
    .
    .
    not talking about a sharp honed edge wiper. this is more a dull acting insert under magnification it appears as a rounded bulge on the tip. if cuts at higher depth of cut and slower sfpm but when depth of cut in a narrow range and run at high sfpm it cuts and rubs surface shiny mirror like. the surface waviness drops from .0003" down to less than .0002 and often .0001"
    ..... i believe it makes surface red hot and material is pushed around like a burnisher. as picture shows a tape measure is seen in the milled surface reflection
    .
    the cutting parameters are more narrow to get a stable burnishing effect. i believe is it similar to diamond burnishing sometimes used on a lathe but its a carbide insert that can do both that is cut like a mill insert or cut and burnish under proper conditions
    .
    must be relatively new insert type. actually insert rated 400-820 sfpm but it gives a more stable shiny surface at faster sfpm and often will last longer at the higher sfpm. if not many have come across it not surprising i guess. i only seen it a few years now and maybe have tried 200 different cutting parameters. it actually works better at different cutting parameters than are recommended maybe have easily over 1000 feet milled by now. looking for 100% reliability and predictability and am close to that now just wondered if there was published research on it
    .
    just a observation works great on cast iron and steel but does badly on plastics that is if trying to hold a tolerance
    Attached Thumbnails Attached Thumbnails tungalloyinsert.jpg   shinymilling_cropped.jpg  

  13. #11
    Join Date
    Jun 2004
    Location
    Melbourne Australia
    Posts
    5,313
    Post Thanks / Like

    Default

    What's the end game? You already had 3 tries at shinny god.

  14. #12
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    11,641
    Post Thanks / Like
    Likes (Given)
    18326
    Likes (Received)
    6138

    Default

    Quote Originally Posted by machtool View Post
    What's the end game? You already had 3 tries at shinny god.
    R.E.M. - Shiny Happy People (Official Music Video) - YouTube

  15. #13
    Join Date
    Dec 2004
    Location
    uk
    Posts
    13,017
    Post Thanks / Like
    Likes (Given)
    3776
    Likes (Received)
    5936

    Default

    You do realize that any burnishing caused by the wipers will just build up tool pressure making your machining actually even less accurate.

    That said shiny does sell and everyone that pays always rates shiny!

  16. #14
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    9,110
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2373

    Default

    Quote Originally Posted by adama View Post
    You do realize that any burnishing caused by the wipers will just build up tool pressure making your machining actually even less accurate.

    That said shiny does sell and everyone that pays always rates shiny!
    .
    obviously it gets indicated and as picture shows you can see indicator in milled surface reflection which is a better finish than most grinders will leave.
    .
    it is more critical to get cutting parameters just right but usually can get it correct the first time. most likely 99% of machinist are not familiar with mirror finish milling yet. i was just asking if others were more advanced at mirror finish milling to .0002" or less tolerances.
    .
    its not a question if mirror finish milling can be done, its more can it be done with insert life at same or longer insert life than normal milling and how much of a speed increase in feed is possible. so better finish at tighter tolerances done at faster machining feeds with longer tool life and savings whats not to like. true is helps to have excel file on feeds and speeds recording settings and results. its well, a advanced process and more technically sophisticated. there is a learning curve.
    Attached Thumbnails Attached Thumbnails shinyhorzhead_cropped.jpg  

  17. #15
    Join Date
    Jan 2007
    Location
    s w NH
    Posts
    254
    Post Thanks / Like
    Likes (Given)
    163
    Likes (Received)
    87

    Default

    Quote Originally Posted by adama View Post
    You do realize that any burnishing caused by the wipers will just build up tool pressure making your machining actually even less accurate.

    That said shiny does sell and everyone that pays always rates shiny!
    funny memories thanks! used to make printing press parts in a jobshop of 50 people. sales manager was also in charge of scheduling what went first et al. he did have many years in one of the press companies. if something was out of tolerance but within reason, spend a lil time, even another cut or two, to make the part beautiful. same for something that was more than a little late. he's long gone now but god bless you Joe Sesin. not forgotten.

  18. #16
    Join Date
    Dec 2004
    Location
    uk
    Posts
    13,017
    Post Thanks / Like
    Likes (Given)
    3776
    Likes (Received)
    5936

    Default

    Quote Originally Posted by DMF_TomB View Post
    .
    obviously it gets indicated and as picture shows you can see indicator in milled surface reflection which is a better finish than most grinders will leave.
    .
    it is more critical to get cutting parameters just right but usually can get it correct the first time. most likely 99% of machinist are not familiar with mirror finish milling yet. i was just asking if others were more advanced at mirror finish milling to .0002" or less tolerances.
    .
    its not a question if mirror finish milling can be done, its more can it be done with insert life at same or longer insert life than normal milling and how much of a speed increase in feed is possible. so better finish at tighter tolerances done at faster machining feeds with longer tool life and savings whats not to like. true is helps to have excel file on feeds and speeds recording settings and results. its well, a advanced process and more technically sophisticated. there is a learning curve.
    Mill it, chuck your indicator in the dustbin and buy a optical flat, then compare it to a ground surface and get back to us. Let us know how well you do were each of your cutter stripes are. Stop mistaking shiny for flat, its not it just does not work that way and never has, oh and the indicator in the machine that just milled it proves only that your machine can repeat the same movement errors really well! Still does not nore ever shall make for a part thats actually milled flat to 2 tenths even if you could write the G code to do so!

  19. Likes cameraman, Mud liked this post
  20. #17
    Join Date
    Nov 2014
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    1,745
    Post Thanks / Like
    Likes (Given)
    2385
    Likes (Received)
    482

    Default

    Quote Originally Posted by adama View Post
    Mill it, chuck your indicator in the dustbin and buy a optical flat, then compare it to a ground surface and get back to us. Let us know how well you do were each of your cutter stripes are. Stop mistaking shiny for flat, its not it just does not work that way and never has, oh and the indicator in the machine that just milled it proves only that your machine can repeat the same movement errors really well! Still does not nore ever shall make for a part thats actually milled flat to 2 tenths even if you could write the G code to do so!
    Yup.

    "Shiny" is not a metric of anything.



    ^^^ Just to mess with people's heads a bit the work of Masao Yamaguchi …


    Ultra precise grinder but also the effect of structured patterns and cutter geometry. + Awesome coin trick on grinding machine.

    __________________________________________________ __________________________________________________ _


    Even a machine like a Mazak Variaxis (and many others) is capable of imparting a freakishly smooth surface (for example to aluminum) with a high degree of specular reflection from certain angles and has a freakish feel to it (almost ceramic / gloss like texture) when you run your finger nail over the surface. BUT that sure as hell does not mean that the surface is actually flat and does not have a significant wave in it also (like what Adama is saying) . A lot of modern CNC machines can do that routinely... It's not necessarily a surface property that is advantageous to surfaces whose surfaces are actually functional (i.e. they do something other than looking "pretty" or "Shiny" (in this case)) .

    I would have thought if one is building machines form cast iron and scraping and grinding is not used , then one would think that a surface that has accurate hills and accurate valleys (statistical distribution) , (as a result of face milling on an accurate stable machine), these micro hills and valleys comprising the exposed surface would be better for mating contact surfaces as the milled pattern will or could be made to "Key" better to each other, i.e. create a better more stable joint when bolted together and won't wander during service life from vibrations and bumps and crashes (as compared to a "slippery"/low friction surface) ?

    Even good grinding equipment will put a wave into a surface.

    __________________________________________________ ________________________________________________


    I still feel like I have 25 years of machining "technique" to catch up on but I don't understand why cutter geometry and coatings and materials are not "discussed" / mentioned (by OP/ Mr Tomb in this case)? [usually stuff has to be reduced (in some cases) to a single point cutter type problem. I thought the wiper technique for shell mills required also one of the inserts to be a "smidge" proud of the other inserts ? Which means the other inserts have to be set very carefully too and the mill trammed in perfectly (so you are not cutting a dish in the surfaces etc.)] ?

    Normally to analyze a surface in terms of flatness versus roughness and surface texture , best mathematical technique uses Fourier transforms
    , so flatness versus "Partical size" and frequency response can be determined over 100mm, 10 mm, 1 mm, 0.1 mm, 0.01 mm, 0.001 mm , 0.0001 mm etc. There's a whole range of ways to do that beyond the use of a profilometer.

    __________________________________________________ _______________________________________________



    Like what Adama says a wave plate brings a rather unforgiving reality to things … You can't BS a waveplate lol. Raw physics kinda trumps cherry picked data neatly arranged in paginated rows and columns stored on a computer.

  21. #18
    Join Date
    May 2008
    Country
    SOUTH AFRICA
    Posts
    1,448
    Post Thanks / Like
    Likes (Given)
    1047
    Likes (Received)
    593

    Default

    Quote Originally Posted by metlcutr55 View Post
    funny memories thanks! used to make printing press parts in a jobshop of 50 people. sales manager was also in charge of scheduling what went first et al. he did have many years in one of the press companies. if something was out of tolerance but within reason, spend a lil time, even another cut or two, to make the part beautiful. same for something that was more than a little late. he's long gone now but god bless you Joe Sesin. not forgotten.
    Yeah, was taught by an old timer too. If the part looks fantastic and it works where it is intended to then no one looks for any dimension errors. If it looks like crap then it is generally inspected EVERYWHERE.

  22. #19
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    9,110
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2373

    Default

    obviously most parts are also inspected in the inspection department.
    .
    newer cnc will probe part and create a inspection report which is compared to the inspection departments report to see if they agree. if they dont agree obviously we look into why.
    .
    i was just asking if anybody else knew of published reports on mirror surface milling which often produces parts to .0002" per 40" at often 150% or faster rates
    .
    i wasnt asking if anybody thought mirror finish milling was a good ideal or tries to find fault in the process. after thousands of parts made over the years i already know how well it works. its like 99% works ok and of course always looking into reducing the 1% of minor problems.
    .
    its fairly advanced technology and perhaps beyond the average machinist ability. surprisingly not much info in carbide insert catalogs. its difficult to get 100% reliability until you understand the cutting parameters. even after years i only get 99% reliability it can be fussy or sensitive to many things

  23. #20
    Join Date
    Nov 2014
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    1,745
    Post Thanks / Like
    Likes (Given)
    2385
    Likes (Received)
    482

    Default

    Quote Originally Posted by DMF_TomB View Post
    <snip>
    .
    i was just asking if anybody else knew of published reports on mirror surface milling which often produces parts to .0002" per 40" at often 150% or faster rates

    <snip>
    When you say 0.0002" per 40" do you really mean the profile bounces up and down +/- 0.0001 ('tenth) every 8 " ?


    What technical / academic journals have you researched so far?


    As I say "Shiny" is not a technical term or metric...


    For searching the past 70 years on the topic might require different terms that pertain to actual surface finish values?


    Is "Mirror machining" an actual accepted term ? (just asking) ? (most flat reflective surfaces that happen to occur (in various metals) that I know of are from single point techniques … The fact that surface is "reflective or shiny" is an artifact of a deeper technical requirement. [Not including hard turning/ dynamic annealing through the cut at high SF/M].


    Card carrying mold machines (even 5 axis) can produce high specular reflective surfaces on 3d contours ?

    __________________________________________________ __________________________________________________ ______________


    @ Mr Tomb Your basic thesis is
    : I have found a sweet spot where I can reduce tool life and increase surface accuracy and the surface happens to come out "shiny"... If I was not using spread sheets I would not have been able to nail this sweet spot with (claimed) 99% accuracy … Yay me, yay spread sheets, yay me again I need another raise 'cuz I routinely eclipse what a machinist of ordinary skill in the art is capable of.

    My takeaway: If people didn't raz mr Tomb about his Spreadsheets there would not be threads like this one. (Maybe).

    And what have we learnt today ?


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
2