How to make a reamer cut a little smaller?
Close
Login to Your Account
Page 1 of 3 123 LastLast
Results 1 to 20 of 53
  1. #1
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,011
    Post Thanks / Like
    Likes (Given)
    195
    Likes (Received)
    337

    Default How to make a reamer cut a little smaller?

    I have a project that uses 1/16" dowel pins in 6061, they're a couple tenths over nominal as usual.

    For some reason my 1/16" straight flute reamer is cutting big, the pins fit but just go right in. I've checked and don't see any burrs on the cutting surfaces, I've even run a stone down them to make sure. If it wasn't Sunday I'd just get a new reamer.

    Any way to make it cut a few tenths smaller?

  2. #2
    Join Date
    Feb 2018
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    76
    Post Thanks / Like

    Default

    Run a stone at about 45deg to dull a little. Don't ream any more than .005.
    run slow feed fast, use cutting oil.
    If that doesn't work run spindle backwards and hold a hard stone against it to make a little smaller.

  3. Likes thomj liked this post
  4. #3
    Join Date
    Jul 2012
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    2,745
    Post Thanks / Like
    Likes (Given)
    1047
    Likes (Received)
    1078

    Default

    After doing everything to make it cut smaller by how you use it then try as mentioned above stoneing a 45 on the cutting edges. I have only needed to do this on a 1/2" reamer on 6061 holes. It worked well but I was amazed at how much I had to stone the cutting edges to get it to cut smaller. This was for a finicky production job and it worked well, the reamed holes remained the same size to the end of the run.

  5. #4
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,194
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8251

    Default

    Quote Originally Posted by Terry Keeley View Post
    I have a project that uses 1/16" dowel pins in 6061, they're a couple tenths over nominal as usual.

    For some reason my 1/16" straight flute reamer is cutting big, the pins fit but just go right in. I've checked and don't see any burrs on the cutting surfaces, I've even run a stone down them to make sure. If it wasn't Sunday I'd just get a new reamer.

    Any way to make it cut a few tenths smaller?
    "Tenths"?

    I'd not bugger-up a reamer over ignorant shiney-wood when you can simply "put the squeeze" to it and make it shrink its own holes. And/or Loctite 'em.

    Not as if small steel pins in shiney-wood have all that much budget against stress loosening to begin with...


    Page Two:

    Put the shiney-wood in yer oven. Drill & ream it HOT. She'll cool tighter.


  6. Likes tdmidget, SamH liked this post
  7. #5
    Join Date
    Jan 2017
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    2,465
    Post Thanks / Like
    Likes (Given)
    442
    Likes (Received)
    1748

    Default

    Just in case you aren't doing this- stop the spindle at the bottom of the hole, and retract straight out.

    Running the reamer while retracting can oversize your hole.

    Also throw an indicator on the reamer and thump it in true before you run it down the hole, and drill as close to your finish size as you can..

  8. Likes tdmidget, BobRenz, Gordon Heaton, Mtndew liked this post
  9. #6
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,011
    Post Thanks / Like
    Likes (Given)
    195
    Likes (Received)
    337

    Default

    All good ideas guys, thanks! I was reaming about 0.010" and pulling it out of the hole while running so I'll try a smaller cut and stop at the bottom.

    I did try to dull it a little but it didn't seem to make much difference, maybe I need to go a little more as mentioned.

    The pins will be pressed in and out "in the field" so I want a mild press fit, now they just slid in and out. No slop but no press either.

    I think I was able to decipher your post Bill, thanks for the input. And good to have you back...

  10. #7
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,194
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8251

    Default

    Quote Originally Posted by Terry Keeley View Post
    I think I was able to decipher your post Bill,
    I don't "hate" shiney-wood, Terry - or I wouldn't have clocked a coupla million miles on airey-planes, prefer aluminium boat hulls, my 'loominum diesel-fuel tanks, nor love my all 'loominum rustfree (of course!) 2005 Jaguar.



    But WTH.. it is slightly less stiff or thermally stable than Bamboo, so I don't expect it to doo what it isn't good at.

    Even when you get this fit to come good... With a sensitivity of less than a thou?

    Your "mild" press fit of steel into raw 6XXX may not have a very long field-service life-expectancy @ a mere 1/16" diameter ++ the effects of the disparate chemistry of the two major metals.

    Then again, it may not NEED to?

    We've had no sight of the end-use nor how long it has to last, or under what conditions.

  11. #8
    Join Date
    Jun 2012
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    9,957
    Post Thanks / Like
    Likes (Given)
    3358
    Likes (Received)
    3567

    Default

    If you micrometer check the reamer it can not cut smaller than than that.
    Very often a reamer will cut .0002 over the micrometer size.

  12. #9
    Join Date
    Feb 2005
    Location
    Hatch, NM Chile capital of the WORLD
    Posts
    9,018
    Post Thanks / Like
    Likes (Given)
    13662
    Likes (Received)
    10663

    Default

    Get some hole shrinkers..

    I can't find them now, but Micro-Mark used to sell a set of "hole Shrinkers".
    Nothing but some ball bearings on a stick. Place bearing at top of hole
    and tap with hammer.

    This is of no use on a 1/16" hole, but when I make IN HOUSE (Not to ever leave this shop
    as a finished product.) fixtures and I need to dowel pieces together, I just use one
    reamer a, .2505, and then run a form tap down the ones I want to be a press fit.

    The spin it backwards and hit it with a stone works, or I use a diamond file, usually
    doesn't take long, or much to bring it in a couple tenths.

    Have you tried using an endmill? They are usually a little undersize, though if
    there is any run out, you're screwed.

    Also, how slow are you turning it.. Laugh all you want, but I generally toss all surface
    speed calculations out the window when I'm reaming.. Unless its a big reamer.. 450rpms
    max (unless its a production deal, but usually its not).. Seems to work pretty consistant
    that way. I'm not going to scrap an $800 part just so I can ream a hole 3 seconds quicker.

  13. Likes SamH liked this post
  14. #10
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,194
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8251

    Default

    Quote Originally Posted by Bobw View Post
    This is of no use on a 1/16" hole, .. and then run a form tap down the ones I want to be a press fit.
    Good stuff. And yah - it can, too, be of use, 1/16" and even much smaller.

    By this time of this century, most of us have Metric drills, reamers, taps around, as well as US/inch (also letter and number drills, etc.).

    Lotta times the solution is a crossbreed just a skosh off .. that you already own - just in the other drawer.

    Gotta love those wall-charts...


  15. Likes Bobw liked this post
  16. #11
    Join Date
    Apr 2005
    Location
    Beaverdam, Virginia
    Posts
    7,260
    Post Thanks / Like
    Likes (Given)
    613
    Likes (Received)
    3402

    Default

    Have you messed with the speeds and feeds yet? Sometimes dropping the rpms while increasing the feed can work. I also have had luck with grinding off half the cutting edges.

  17. Likes Bobw liked this post
  18. #12
    Join Date
    Jan 2017
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    2,465
    Post Thanks / Like
    Likes (Given)
    442
    Likes (Received)
    1748

    Default

    Might also try kerosene instead of cutting oil...

  19. #13
    Join Date
    Nov 2005
    Location
    Santa Barbara
    Posts
    283
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    88

    Default

    Are you choking up on it? I try to leave reamers hanging out much longer than drills, to let them float better. It needs to follow the hole that's already there, instead of trying to make it's own. On that same note, are you spotting the pilot holes? If the drill goes in crooked, the reamer will start out off center, making the hole big, and probably tapered. Also, make sure you're drilling deep enough. If the reamer bottoms out on the pilot hole, or on the chips, the reamer will wobble a bit. It doesn't take much.

    As others have already said, try a bigger drill, a lower speed, and a higher feed. I usually spot drill to .070 diameter, and drill to #53, as deep as I can get away with. Then ream at 10 SFM, feeding at .01" per rev, no pecking.

  20. Likes Hit&Miss_Tom liked this post
  21. #14
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,011
    Post Thanks / Like
    Likes (Given)
    195
    Likes (Received)
    337

    Default

    Thanks again guys.

    Hole is blind so burnishing with a steel ball won't do, never saw a ball that small anyway but I'm sure they exist.

    Tried different speeds/feeds, cutting oil/none, they all seem to cut the same. Will trying stopping at the bottom and pulling straight out as mentioned, also zeroing the runout. Tried plain old 1/16" drills, too tight.

    I'll figure out a solution and report back soon.

    Oh and Bill, although there's still lots of "loominum" on airplanes these days, lots of that is being replaced by carbon fiber. What's the old saying? Boeing's are built by beer guzzling union men with rivet guns, Airbus' are built by wine sipping Euro girly men with glue guns?

    But factor in the "Max" fiasco and I think I'd opt for the glue gun myself...

  22. #15
    Join Date
    Sep 2002
    Location
    People's Republic
    Posts
    2,960
    Post Thanks / Like
    Likes (Given)
    214
    Likes (Received)
    2055

    Default

    Not to be too obvious, but you could try using the correct size reamer.

    dowel pin reamer sets seem to only run down to 1/8, but they are half a thou or 2 thou under. Any size you want is available from L&I

    mcmaster stocks .0620, .0622. .0623

    less than 20 bucks ea

  23. Likes James H Clark, PegroProX440, 9100 liked this post
  24. #16
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    7,232
    Post Thanks / Like
    Likes (Given)
    1700
    Likes (Received)
    5004

    Default

    Quote Originally Posted by Terry Keeley View Post
    But factor in the "Max" fiasco and I think I'd opt for the glue gun myself...
    We have (had?) a thread on that, but Boeing's 787 doesn't share the MAX's issues with MCAS. So fly the glue gun 787 all you wish.

    On the MAX, idiot cost cutters won out over engineers. Nothing good happens after that...

  25. #17
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    26,194
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8251

    Default

    Quote Originally Posted by Terry Keeley View Post
    But factor in the "Max" fiasco
    Bad, one, that. But one can avoid - as I DID do for about twenny years whilst Scarebus was sorting THEIR hash. Proud member of the "If it ain't Boeing, I ain't going!" movement.

    The real scare, now, is that it was effing SOFTWARE! "AI" AKA Artificial Idiot.

    And we think self-driving cars and 18-wheelers are a good idea?

    How d'we avoid THOSE, then?


  26. #18
    Join Date
    Apr 2005
    Location
    Beaverdam, Virginia
    Posts
    7,260
    Post Thanks / Like
    Likes (Given)
    613
    Likes (Received)
    3402

    Default

    Quote Originally Posted by gustafson View Post
    Not to be too obvious, but you could try using the correct size reamer.

    dowel pin reamer sets seem to only run down to 1/8, but they are half a thou or 2 thou under. Any size you want is available from L&I

    mcmaster stocks .0620, .0622. .0623

    less than 20 bucks ea
    Something tells me he doesn't want to wait for something from McMaster to show up on Tuesday.

  27. #19
    Join Date
    Nov 2013
    Country
    UNITED STATES
    State/Province
    Utah
    Posts
    4,376
    Post Thanks / Like
    Likes (Given)
    1171
    Likes (Received)
    2400

    Default

    I realize this isn't "in the box" thinking. But have you considered buying a Reamer that will cut the size you want? As opposed to trying to manipulate the Tool to cut under what the OD of the Tools flutes are.

    R

  28. #20
    Join Date
    Oct 2005
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,011
    Post Thanks / Like
    Likes (Given)
    195
    Likes (Received)
    337

    Default

    Thanks for all the help guys, this place is awsome.

    Tried a few more "technique" based things but it didn't make a difference.

    So I chucked it in the lathe, ran it backwards and touched it with an India stone. It miked about a tenth smaller and wala, perfect fit!

  29. Likes Bobw, michiganbuck, Mtndew, metlcutr55 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
  •