Results 1 to 7 of 7

Thread: Tapping Problem

  1. #1
    Grinder Guest

    Default Tapping Problem

    This is my first post and hoping to see if anyone has some knowledge to share. Any comments appreciated.

    We are tapping 6 holes on 13-8 material and having a hell of a time. All holes are not thru. 4 holes are .1157/.1076", .315" depth (TAP .1380-32 UNJC-3B Thd, .250 min depth) and 2 holes are .1503/.1435", .322" depth (TAP .1380-40 UNF-3B) which later requires a helical coil insert later.

    Problem: We start the TAP on the CNC MILL (FADAL 4020), w/ the starting tap having no issues. The bottom tap is not working or going down. We made over 100 parts and had to "hand tap" each part to reach the bottom.

    We don't know what to do. Right now we are considering purchasing a different machine?!, like a Haas DT-1. But wanted to get your input first.

    Thanks
    Attached Thumbnails Attached Thumbnails img193.jpg  

  2. #2
    gabby Guest

    Default Re: Tapping Problem

    Have you tried using just the finish tap. Any tapping I have done on machines we only used one tap. Also spiral flute taps are best for blind holes. Use as big a drill as possible without making the core diameter oversize

  3. #3
    Join Date
    Oct 2009
    Location
    Old Saybrook, Connecticut
    Posts
    22
    Thanks
    0
    Thanked 1 Time in 1 Post

    Default Re: Tapping Problem

    I agree with Gabby's suggestions. It sounds like you are not using rigid tapping. If your machine does not have rigid tapping, that could be your problem. I use Haas VMCs with rigid tapping, and on holes that are problematic I sometimes tap half way down and then repeat the tapping code going to full tapping depth with the same tap. This allows for chip clearance and plenty of coolant. The spindle orients each time so as long as the tap is programmed to start at the same z point there is no danger of cross threading. The rigid tapping allows for a precise tapping depth. Also, slowing down the feeds and speeds often helps. I have never done tapping on a CNC without rigid tapping, so I don't have personal experience with problems encountered doing it that way. I hope this is helpful.

    Don
    Last edited by DRGergler; 11-07-09 at 07:57 AM. Reason: added suggestions

  4. #4
    Join Date
    Jul 2009
    Posts
    15
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default Re: Tapping Problem

    Both replies bake sense. If you use two taps, there will be no way for them to orientate. You will cross thread almost for sure. Only thing I might add, if you really need to go with two taps might be to try using a compression tap holder on the second tap. It's old-school, but whatever works

  5. #5
    Grinder Guest

    Default Re: Tapping Problem

    Thanks for the responses. We'll look into the problem today.

  6. #6
    Join Date
    Oct 2009
    Posts
    9
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default Re: Tapping Problem

    Hey Grinder,

    If these suggestions don't work, try thread forming taps instead of thread cutting taps. You will have to drill bigger holes but you will not have any chips to plug your hole. It is also a stronger tap for this kind of application.

    Hope it helps.

    YBMach

  7. #7
    JKvasnicka Guest

    Default Re: Tapping Problem

    What year is your 4020? If it is since 1994 or 5, it has a vector drive spindle and can do ridgid tapping. Are you using a compression-type tap holder in a rigid-tap scenario? Make sure you are using Fadal programming with Fadal parameters or Fanuc style programming with Fanuc-set parameters. Fadal took out the need to program in a margin of error a is done in fanuc programming -only if the programming parameter is set to "Fadal" vs Fabuc."

Similar Threads

  1. Makino seiki tapping problem
    By venuengg in forum Machine Repair & Troubleshooting
    Replies: 0
    Last Post: 09-22-18, 12:46 AM
  2. Problem during tapping process
    By angelito in forum Machine Repair & Troubleshooting
    Replies: 6
    Last Post: 02-13-12, 03:12 PM
  3. Tapping problem!
    By pdmjk in forum General CNC & Manufacturing Discussion
    Replies: 8
    Last Post: 03-11-09, 09:07 AM
  4. FADAL rigid tapping problem
    By andatek in forum Machine Repair & Troubleshooting
    Replies: 6
    Last Post: 01-16-08, 05:57 PM

Posting Permissions

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