Free 186 More Best Homemade Tools eBook:  
Get tool plans

User Tag List

Results 1 to 5 of 5

Thread: Straddle Knurler

  1. #1

    Join Date
    Oct 2012
    Posts
    9
    Thanks
    0
    Thanked 34 Times in 7 Posts

    jgedde's Tools

    Straddle Knurler

    Here are the fruits of my latest labors in the shop... This is a straddle knurl. For those who don't know what the advatages are, they create a knurl without putting stress on the cross slide and headstock bearings. In addition, it is autiomatically self centering. It also allows small or long pieces to be knurled without deflection.

    All the pieces were handmade by me except for the button head screws, spring, circlips and the knurling wheels.

    The goal was to produce a rigid tool with no perceptible slop in the hinges. This allows one to simply stop a knurl cleanly, although the convex wheels installed into the tool are designed for axial feed to a groove or off the end of the workpiece.

    The whole thing, except for the thumbscrew, is made from W1 tool steel... It all came out of either a 5/8 or 1.25 inch round stock scrap bin piece. The hinge and wheel pins were hardened and left untempered. They ended up so hard, a Carbide lathe tool did little more than polish it. In any event, I tried to break them to test brittleness and they held up.

    As a test of the assembled tool and to create the thumbscrew, I installed a simple hex nut onto the threaded piece and knurled the thumbscrew. Obviously, it works. More important though it that its performance exceeded my expectations! Why was I using a bump tool for all this time?

    The wheels installed are 64 DP (diametral pitch), M42 cobalt, TiN coated units from Accu-Trak. They are expensive, but worth it IMHO. They'll last a lifetime for an HSM and create supurb knurls. In any case, these beat the living heck of of the import jobs. The advantage to the diametral pitch knurls (as opposed to the traditional circular pitch knurls) is that they will simply track on any diameter which is a multiple of 1/64" (other DPs will track in 1/32" increments but are a bit fine for my tastes). This means no calculations of circular pitch vs workpiece circumference afre required to guarantee tracking. For those that choose to mash the knurls into tracking, I accept that... I've done it too...

    The knurl pins are held in by a retaining clip design which engages a groove in the pin. This is in lieu of a circlip. This idea came from Guy Lautard's Machinist's Bedside Reader book.

    Here are the pictures...

    Straddle Knurler-knurled.jpgStraddle Knurler-left.jpgStraddle Knurler-top.jpgStraddle Knurler-working-end.jpg
    John

    186 More Best Homemade Tools eBook
    Last edited by jgedde; Oct 18, 2012 at 04:37 PM. Reason: Fix photos

  2. The Following 3 Users Say Thank You to jgedde For This Useful Post:

    Jon (Oct 23, 2012), kbalch (Oct 18, 2012), Paul Jones (Aug 20, 2014)

  3. #2

    Join Date
    Oct 2012
    Posts
    15
    Thanks
    1
    Thanked 12 Times in 7 Posts

    ltlvt's Tools
    John for some reason I can't see the pictures. Just red x's in boxes.
    Terry

    2,000+ Tool Plans

  4. #3
    kbalch's Avatar
    Join Date
    Jun 2012
    Location
    Clermont, FL
    Posts
    5,034
    Thanks
    2,275
    Thanked 532 Times in 384 Posts
    Hi John,

    If you add the photos to your post, I'll be happy to include the knurler in our database. You can do so by editing your original post and then clicking the 'Insert Image' icon (indicated by the red arrow in the screencap).

    Ken

    Attached Thumbnails Attached Thumbnails Straddle Knurler-screenshot2012-10-12at115204am.jpg  

  5. #4

    Join Date
    Oct 2012
    Posts
    9
    Thanks
    0
    Thanked 34 Times in 7 Posts

    jgedde's Tools
    The pictures should now be working...

    John

  6. #5
    Jon
    Jon is online now Jon has agreed the Seller's Terms of Service
    Administrator
    Supporting Member
    Jon's Avatar
    Join Date
    Jan 2012
    Location
    Colorado, USA
    Posts
    26,438
    Thanks
    8,100
    Thanked 40,247 Times in 11,775 Posts
    Thanks again jgedde! This one went into our Metalworking category, and of course on your homemade tools page: jgedde's Homemade Tools. Your receipt:




    2,000+ Tool Plans

Thread Information

Users Browsing this Thread

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

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
  •