Free 186 More Best Homemade Tools eBook:  
Get tool plans

User Tag List

Page 2 of 2 FirstFirst 1 2
Results 11 to 12 of 12

Thread: Slotting Saw Arbor for Unimat

  1. #11
    PJs
    PJs is offline
    Supporting Member PJs's Avatar
    Join Date
    Sep 2014
    Location
    Northern CA
    Posts
    1,844
    Thanks
    8,420
    Thanked 1,128 Times in 724 Posts

    PJs's Tools
    Definitely safer...a lot of spun mass there...wouldn't be pretty if something went hinky. Your new arbor is a beaut, and will be much closer coupled than the old way! Thanks for the comparison. ~PJ

    186 More Best Homemade Tools eBook
    ‘‘Always do right. This will gratify some people and astonish the rest.’’
    Mark Twain

  2. The Following User Says Thank You to PJs For This Useful Post:

    Paul Jones (Oct 24, 2015)

  3. #12
    Supporting Member mklotz's Avatar
    Join Date
    Aug 2015
    Location
    LA, CA, USA
    Posts
    3,515
    Thanks
    362
    Thanked 6,548 Times in 2,156 Posts

    mklotz's Tools
    Quote Originally Posted by Paul Jones View Post
    PJs,
    The only challenge with cutting metric threads on this lathe is that the split nut has to stay engaged and the motor reversed for each threading pass.
    Well, although it's the inherited wisdom, it's not exactly true, at least in some cases. Consider the following truism...

    If we disengage the half-nuts and move the carriage a distance to the right that is an integer multiple of the thread pitch AND also an integral multiple of the leadscrew pitch, we can reengage the half-nuts without losing registration on the thread we're cutting.

    Such a movement, once calculated can be accomplished accurately in a variety of ways including a DI and a "stick" cut to the correct length working against a stop fixed to the lathe ways.

    If you're interested in trying this, there's a program (STICK) on my site that will calculate the required displacement.

    Sometimes the required length is too long to be practical and one will have to resort to the "keep the half-nuts engaged" method but when it does work it's a real time saver.

    Here's an example output from STICK...

    THREAD CHASING OFFSETS

    Type of leadscrew thread (M)etric or [I]mperial? I
    Leadscrew pitch [8 tpi] ? 8
    Type of thread [M]etric or (I)mperial? M
    Pitch of thread being cut [1 mm] ? 0.5

    Move carriage 2.500 in = 63.5 mm to right to recapture thread

    2,000+ Tool Plans
    Last edited by mklotz; Oct 25, 2015 at 10:38 AM.
    ---
    Regards, Marv

    Experience is always far worse than pessimism

  4. The Following 2 Users Say Thank You to mklotz For This Useful Post:

    Paul Jones (Oct 25, 2015), PJs (Oct 25, 2015)

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

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
  •