Double disc ground MIC6 and post-grinding machining
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 24
  1. #1
    Join Date
    May 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    2,507
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    1637

    Default Double disc ground MIC6 and post-grinding machining

    I've got a customer in the design phase of some small (6" x 12") aluminum assembly machine pallets that need to be consistent above all else. 2 prototypes, 30 piece orders, up to about 100-120 or so total. The customer is asking me what is reasonable for a flatness callout, not providing a target. Thickness is up in the air, but I'm thinking 3/4" since MIC6 is spec'd .005" flatness at that thickness, but .015" flatness in anything thinner. Just seems like less hassle and more stiffness for a couple bucks more in material.

    Main question: If I get TCI to cut oversize and grind to .002" flatness for me (the tightest they will quote), what are the chances of me bolting this to a nice flat fixture, machining the pictured features, and the plate staying flat? I know I'd be in for a fight with 6061, less so with 7075, but what about MIC6? We'll be using sharp tools, taking it easy on the roughing, good coolant, etc.

    untitled-top.jpg untitled-bottom.jpg

  2. #2
    Join Date
    Sep 2017
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    719
    Post Thanks / Like
    Likes (Given)
    106
    Likes (Received)
    378

    Default

    Is there a hardness spec? Could you use tooling (jig) plate?

  3. #3
    Join Date
    May 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    2,507
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    1637

    Default

    Quote Originally Posted by Rick Finsta View Post
    Is there a hardness spec? Could you use tooling (jig) plate?
    Isn't that what MIC6 is?

    No hardness or any other material spec other than they are cool with whatever alloy, as long as it's hard anodized.

  4. Likes sfriedberg, Ox, wheelieking71 liked this post
  5. #4
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    7,737
    Post Thanks / Like
    Likes (Given)
    1807
    Likes (Received)
    5436

    Default

    3/4" sounds like a good choice, at least it "seems right" looking at the model. I think you should have a stable part when the machining is done, but you may want to rough first, remove the burrs, and check on a surface plate before final machining. You may see a little variation in remaining stress in the raw stock, but it's supposed to be stable.

    If there's enough money in the project, rough the plates in a vise, then make a vacuum fixture to locate and finish all the critical geometries. Low stress clamping for light machining, minimal distortion in the final part.

  6. #5
    Join Date
    Nov 2014
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    2,886
    Post Thanks / Like
    Likes (Given)
    3412
    Likes (Received)
    793

    Default

    Quote Originally Posted by [email protected] View Post
    <snip>

    Main question: If I get TCI to cut oversize and grind to .002" flatness for me (the tightest they will quote), what are the chances of me bolting this to a nice flat fixture, machining the pictured features, and the plate staying flat? I know I'd be in for a fight with 6061, less so with 7075, but what about MIC6? We'll be using sharp tools, taking it easy on the roughing, good coolant, etc.

    untitled-top.jpg untitled-bottom.jpg
    I don't have anything useful to add but just to say that there isn't anything in (predominantly) aluminum alloys that is dimensionally more stable.

    In terms of stability there isn't anywhere else you can go (up from that , that I'm aware of ? ).

    Beyond that double sided tape or a vacuum plate ? (I haven't tried the super glue thing yet ).


    Sounds like you know how to machine it.


    For precision optical stages there are specialists in aluminum grinding for micron level -ish flatness (but doesn't seem you need that).


    I'm being pushed / nudged towards aluminum castings simply for their stability.


    There may be some other alloys used by instrument builders (for long term stability) that are in the bronze and brass direction... [Probably not necessary / appropriate ].


    I believe Mic6 is relatively forgiving for further heat treatments and you can "Re-set" the alloy easily without leaving permanent "artifacts" in the metallic structure.

    I had no idea that the price difference between let's say 6061 and MIC6 was so close to be worth while ?


    Cool idea !

    ___________________________

    Now I see Milland beat me too it pretty much. (slowpoke).

  7. #6
    Join Date
    Aug 2005
    Location
    CT
    Posts
    7,780
    Post Thanks / Like
    Likes (Given)
    324
    Likes (Received)
    1844

    Default

    Quote Originally Posted by [email protected] View Post
    Isn't that what MIC6 is?

    No hardness or any other material spec other than they are cool with whatever alloy, as long as it's hard anodized.
    Matt, I have made tons of repeat fixtures out of MIC6 whenever the customer specified just a plane-jane "jig plate" or .750 plate, and never had any issues.
    I honestly did not know that they are specced at .005 flatness, just took it for granted that a jig plate is better than what I can achieve inhouse.
    Some of those fixtures were as large as 48 x 30, and they had to fit a mating receiver made 10+ years in the past, and they've all fit like a glove.
    No shrinkage, warp or flatness issues whatsoever.

    The nice thing about MIC6 is that it will anodize uniformly, and in some cases customers specified "aesthetics" on the print with either "color" anodize or black hardcoat.
    Though I have not looked into it for 10+ years now, but I have had one rejection due to blotchy appearance after anodizing.
    I was told that a "jig plate" is what it is, a cast plate that is milled to specs without care for the alloy, so there can be visual differences after plating.
    A MIC6 however is 6061 cast plate, and it should be uniform.

    (again, this is only what I was told, so since then all "jig plate" for me is MIC6 )

  8. Likes cameraman, doug925 liked this post
  9. #7
    Join Date
    Nov 2014
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    2,886
    Post Thanks / Like
    Likes (Given)
    3412
    Likes (Received)
    793

    Default

    Quote Originally Posted by SeymourDumore View Post
    <snip>


    The nice thing about MIC6 is that it will anodize uniformly, and in some cases customers specified "aesthetics" on the print with either "color" anodize or black hardcoat.

    Though I have not looked into it for 10+ years now, but I have had one rejection due to blotchy appearance after anodizing.
    I was told that a "jig plate" is what it is, a cast plate that is milled to specs without care for the alloy, so there can be visual differences after plating.
    A MIC6 however is 6061 cast plate, and it should be uniform.

    (again, this is only what I was told, so since then all "jig plate" for me is MIC6 )
    That's pretty valuable re: cosmetics of MIC6 … I just assumed that was the Achilles heel for MIC6... Good to know.


    20 years ago where I used to work we had this ultra thick hard coat that was almost like a salt and pepper / speckled grey finish that would hide a multitude of sins.

  10. #8
    Join Date
    Jul 2010
    Location
    corvallis,or
    Posts
    871
    Post Thanks / Like
    Likes (Given)
    89
    Likes (Received)
    365

    Default

    I've used Mic6 for fixture plates that we removed a whole lot more material than yours and hit .002 flatness without much trouble. Seemed very stable. We started with 1.5" and milled it down to somewhere around 1.25" with large pockets. We also used stuff called K100 (I think) which was mostly the same but maybe a little cheaper.

    Parts were nickel plated afterward for durability. I really liked the look.

    Sent from my XT1710-02 using Tapatalk

  11. #9
    Join Date
    Feb 2016
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    189
    Post Thanks / Like
    Likes (Given)
    436
    Likes (Received)
    99

    Default

    You can also look into ATP-5 plate. I found it for a job requiring a bunch of fixture bases and ended up using it over MIC-6. It was cheaper and ended working well for the project. I didn't design the parts, so i'm not sure what our flatness requirement was for them.

  12. #10
    Join Date
    Oct 2007
    Country
    SPAIN
    Posts
    3,547
    Post Thanks / Like
    Likes (Given)
    1995
    Likes (Received)
    1292

    Default

    Quote Originally Posted by SeymourDumore View Post
    A MIC6 however is 6061 cast plate, and it should be uniform.

    (again, this is only what I was told, so since then all "jig plate" for me is MIC6 )
    I thought MIC6 was a 7000 series material?
    And "general ally tooling plate" in the UK is 5000 material

  13. #11
    Join Date
    Nov 2002
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    3,270
    Post Thanks / Like
    Likes (Given)
    1864
    Likes (Received)
    811

    Default

    Quote Originally Posted by [email protected] View Post
    Isn't that what MIC6 is?
    Per Trident Metals, NO. It is not. (Ask me how much $$$ THAT lesson cost me.)

    Mic 6 cast plate, is just that. Mic6.
    Tooling plate AKA Jig Plate, (at least around here) is 6061-t6, but has different flatness & parallelism, and is also marketed differently.

    Doug.

  14. #12
    Join Date
    Nov 2002
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    3,270
    Post Thanks / Like
    Likes (Given)
    1864
    Likes (Received)
    811

    Default

    Quote Originally Posted by barbter View Post
    I thought MIC6 was a 7000 series material?
    And "general ally tooling plate" in the UK is 5000 material
    Per my suppliers here: Mic 6 is "whatever" scraps, bits, remnants they have left over, are melted down, cast, and ground flat.
    There is no uniformity from batch to batch. That is why Mic 6 anodizes blotchy, and is different with every HEAT.

    Doug.

  15. #13
    Join Date
    Jul 2011
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    34
    Post Thanks / Like
    Likes (Given)
    23
    Likes (Received)
    32

    Default

    Quote Originally Posted by [email protected] View Post
    I've got a customer in the design phase of some small (6" x 12") aluminum assembly machine pallets that need to be consistent above all else. 2 prototypes, 30 piece orders, up to about 100-120 or so total. The customer is asking me what is reasonable for a flatness callout, not providing a target. Thickness is up in the air, but I'm thinking 3/4" since MIC6 is spec'd .005" flatness at that thickness, but .015" flatness in anything thinner. Just seems like less hassle and more stiffness for a couple bucks more in material.

    Main question: If I get TCI to cut oversize and grind to .002" flatness for me (the tightest they will quote), what are the chances of me bolting this to a nice flat fixture, machining the pictured features, and the plate staying flat? I know I'd be in for a fight with 6061, less so with 7075, but what about MIC6? We'll be using sharp tools, taking it easy on the roughing, good coolant, etc.
    I believe that flatness spec is across the entire plate when it's manufactured. A 6" x 12" section will likely be flatter from the mill than you can easily achieve through secondary processes. Also, ATP-5 is spec'd at .005" flatness in all thicknesses.

    About 90% of the work I've been doing lately has been QC jigs in ATP-5 for a major 3D printer manufacturer, typically about 9" x 12" x 3/4 - 1 1/4" thick. We haven't observed any warping or creep measurable with our tools, even with sections milled as thin as 1/8". The customer verified the parts on their CMM and found that even with a 3-part assembly and the associated tolerance stackup, the critical features were parallel within .01 deg.

    These were run on a Haas Super Mini Mill, so it's not like we have some crazy equipment or anything. It's just very stable and consistent material. I wouldn't overthink it too much if I were you, at least give it a shot without grinding first.

  16. #14
    Join Date
    May 2005
    Location
    CA
    Posts
    1,130
    Post Thanks / Like
    Likes (Given)
    9
    Likes (Received)
    286

    Default

    I believe it's somewhat difficult to get good cosmetic results when anodizing MIC6. The nature of it being cast can cause acid being "trapped" in the typical small voids in casting. Also, I believe the silicon content is not "consistent" as it is in wrought plate, which can also cause issues. Finding an anodize shop with a good amount of experience may be key in getting good results.

    jmho

    PM

  17. #15
    Join Date
    Aug 2005
    Location
    CT
    Posts
    7,780
    Post Thanks / Like
    Likes (Given)
    324
    Likes (Received)
    1844

    Default

    Quote Originally Posted by doug925 View Post
    Per my suppliers here: Mic 6 is "whatever" scraps, bits, remnants they have left over, are melted down, cast, and ground flat.
    There is no uniformity from batch to batch. That is why Mic 6 anodizes blotchy, and is different with every HEAT.

    Doug.
    I don't know Doug, in my experience MIC6 anodizes uniformly and consistently.
    I thought MIC6 was just the trade name for ALCOA's tooling plate.

    Mic6(R) Aluminum Cast Plate

  18. Likes wheelieking71, DavidScott liked this post
  19. #16
    Join Date
    May 2004
    Country
    UNITED STATES
    State/Province
    California
    Posts
    2,507
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    1637

    Default

    Quote Originally Posted by precisionmetal View Post
    I believe it's somewhat difficult to get good cosmetic results when anodizing MIC6. The nature of it being cast can cause acid being "trapped" in the typical small voids in casting. Also, I believe the silicon content is not "consistent" as it is in wrought plate, which can also cause issues. Finding an anodize shop with a good amount of experience may be key in getting good results.
    Thanks Pete. I've been hearing that as well, but the customer doesn't really care about aesthetics with this, it's just in-house tooling.

    With that said, my anodizer would rather deal with K100 because of the reasons Doug brings up, consistency and quality. I've worked with K100 before and liked it just fine. Do any of your guy's answers change regarding flatness issues with K100 over MIC6? TCI doesn't seem to offer it, but DIX does. Anybody else I should talk to that can supply double disc or blanchard ground blanks?

    And don't get caught up in tooling plate / not tooling plate. It's a non-issue for this project. As long as it's stable and it comes from a reputable mil, nobody cares what it's called or if it's 5xxx, 6xxx or 7xxx series.

  20. #17
    Join Date
    Nov 2014
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    2,886
    Post Thanks / Like
    Likes (Given)
    3412
    Likes (Received)
    793

    Default

    Quote Originally Posted by [email protected] View Post
    Thanks Pete. I've been hearing that as well, but the customer doesn't really care about aesthetics with this, it's just in-house tooling.

    With that said, my anodizer would rather deal with K100 because of the reasons Doug brings up, consistency and quality. I've worked with K100 before and liked it just fine. Do any of your guy's answers change regarding flatness issues with K100 over MIC6? TCI doesn't seem to offer it, but DIX does. Anybody else I should talk to that can supply double disc or blanchard ground blanks?

    And don't get caught up in tooling plate / not tooling plate. It's a non-issue for this project. As long as it's stable and it comes from a reputable mil, nobody cares what it's called or if it's 5xxx, 6xxx or 7xxx series.

    https://www.clintonaluminum.com/wp-c...ison-Sheet.pdf

    ^^^ differences marked in red...

    Seems (at least according to these guys)… (VISTA).

    MIC6 is a 7000 series alloy.

    (K100 (s) ) seems to be 5083 alloy ? "Modified".

    Flatness

    K100s ---> 5/8” & Up Within .010

    MIC6 : 3/4" & up Within .005”


    Yield Strength


    K100s : 18 ksi

    PIC6 : 15 ksi


    tensile strength

    K100s : 41 ksi

    PIC6: 24 ksi

    Elongation over 2" ?

    K100s: 12 – 15%

    Mic6: 3%


    Micro-Structure :

    K100s: Virtually porosity free

    PIC6: Porous micro structure



    Anodizing

    K100s: Very Good

    PIC6: Special Procedures Req’d….


    __________________________________________________ ____________________________________________


    I can see why your anodizer would want K100...

    Hang on a mo'... flatness ?

    Personally I would try both but I would lean to k100. but Pic6 would probably have a smidge less distortion (as such) not from stress relief but the K100 appears to be more ductile (as far as any cast aluminium alloy can be … which is not very much.). If both carefully machined I think the K100 is a better quality material (zero porosity). 100 to 120 pieces I would think overall consistency of process would be better.

    What ever you do let us know how it goes ?

  21. #18
    Join Date
    Jan 2016
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    226
    Post Thanks / Like
    Likes (Given)
    73
    Likes (Received)
    99

    Default

    I designed a part (~1/4" thick, 18" x 12") that we made in MIC6 at my last employer. Most of the plate was removed to make the part (hence going with cast, bottom surface of the final parts were flat within 0.001"), and it was clear anodized. We never had an issue with anodizing, and in my experience people do refer to it as tooling plate, although I could never get everyone in the room to agree on whether it was "mike" 6 or "mick" 6.

  22. Likes [email protected] liked this post
  23. #19
    Join Date
    Jul 2019
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    7
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1

    Default

    Quote Originally Posted by barbter View Post
    I thought MIC6 was a 7000 series material?
    And "general ally tooling plate" in the UK is 5000 material
    Hey agreed! the McMaster Carr catalog says the mic6 is a 7000 series, additive zinc.

  24. #20
    Join Date
    Feb 2013
    Country
    UNITED STATES
    State/Province
    Idaho
    Posts
    689
    Post Thanks / Like
    Likes (Given)
    141
    Likes (Received)
    740

    Default

    Quote Originally Posted by Sjzona View Post
    Hey agreed! the McMaster Carr catalog says the mic6 is a 7000 series, additive zinc.
    The 7000 alloy designation on mic6 indicates that it was made with 7000 recycled beer cans per 5' by 10' sheet of 1" thick plate. The current designation is actually 7200 series alloy, because beer cans have gotten lighter and now weigh .5714285 ounces and it takes proportionately more cans per sheet. The blotchy anodizing and variability in machining properties result from vendors using multiple brands of beer cans.

    Glad I could help.

  25. Likes gkoenig liked this post

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
  •