Free 186 More Best Homemade Tools eBook:  
Get tool plans

User Tag List

Results 1 to 4 of 4

Thread: Chain drilling remarks

  1. #1
    Supporting Member mklotz's Avatar
    Join Date
    Aug 2015
    Location
    LA, CA, USA
    Posts
    3,515
    Thanks
    362
    Thanked 6,546 Times in 2,156 Posts

    mklotz's Tools

    Chain drilling remarks

    Rick Sparber's chain drilling guide, detailed here...

    http://www.homemadetools.net/forum/c...ng-guide-73254

    provides a very clever way of laying out hole locations closely so that hole-to-hole breakout is avoided when drilling.

    I wanted to add some remarks but didn't want to intrude on his thread so I started this one.


    If laying out holes around a curved, rather than straight, contour, making a drilling guide may be more effort than is practical. In this case a spacing punch, such as the Starrett #118, photos here...

    https://picclick.com/Starrett-Spacin...176136104.html

    may be more practical. Building your own version of this is straightforward. On the rare occasions when I've chain drilled, I've used the beam compass I made...

    http://www.homemadetools.net/forum/t...-verburg-27353

    although far simpler designs are possible if only the hole spacing function is required.

    A row of holes can be drilled on the mill. One approach I've read about is to drill every other hole in the line using the spacing function provided by the accurate mill table screws. Then go back and drill a second sequence of holes between the first sequence. The idea is that, with a hole on each side, there will be less tendency for the drill to wander toward either. I've never tried it so I can't testify to its effectiveness.

    If I were to do it on the mill, I would use an endmill to make the holes. An endmill is much stiffer than a drill and consequently has less tendency to wander. Of course, if the workpiece can be mounted on the mill to chain drill a straight series of holes, why not just use the endmill to mill a long slot? Generally, chain drilling is a type of last resort for workpieces too large to fit into machine tools.

    186 More Best Homemade Tools eBook
    ---
    Regards, Marv

    Experience is always far worse than pessimism

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

    baja (Jun 5, 2019)

  3. #2
    Supporting Member jdurand's Avatar
    Join Date
    May 2019
    Location
    Krasnodar Krai, Russian Federation
    Posts
    1,467
    Thanks
    127
    Thanked 766 Times in 425 Posts

    jdurand's Tools
    I'll post a video on stitching cast iron which shows more chain drilling.

    2,000+ Tool Plans

  4. #3
    Supporting Member Frank S's Avatar
    Join Date
    Aug 2015
    Location
    Peacock TX
    Posts
    11,619
    Thanks
    2,176
    Thanked 9,112 Times in 4,361 Posts

    Frank S's Tools
    Quote Originally Posted by mklotz View Post
    Rick Sparber's chain drilling guide, detailed here...

    http://www.homemadetools.net/forum/c...ng-guide-73254

    provides a very clever way of laying out hole locations closely so that hole-to-hole breakout is avoided when drilling.

    I wanted to add some remarks but didn't want to intrude on his thread so I started this one.


    If laying out holes around a curved, rather than straight, contour, making a drilling guide may be more effort than is practical. In this case a spacing punch, such as the Starrett #118, photos here...

    https://picclick.com/Starrett-Spacin...176136104.html

    may be more practical. Building your own version of this is straightforward. On the rare occasions when I've chain drilled, I've used the beam compass I made...

    http://www.homemadetools.net/forum/t...-verburg-27353

    although far simpler designs are possible if only the hole spacing function is required.

    A row of holes can be drilled on the mill. One approach I've read about is to drill every other hole in the line using the spacing function provided by the accurate mill table screws. Then go back and drill a second sequence of holes between the first sequence. The idea is that, with a hole on each side, there will be less tendency for the drill to wander toward either. I've never tried it so I can't testify to its effectiveness.

    If I were to do it on the mill, I would use an endmill to make the holes. An endmill is much stiffer than a drill and consequently has less tendency to wander. Of course, if the workpiece can be mounted on the mill to chain drill a straight series of holes, why not just use the endmill to mill a long slot? Generally, chain drilling is a type of last resort for workpieces too large to fit into machine tools.
    Marv when it is necessary to drill overlapping or holes so closely spaced that the risk of break out to either hole side is not only possible but highly probable. When you can do is to drive in sacrificial dowels. once the holes are all drilled then unless they are blind holes just drive the dowels out.
    If the intent is to use the holes to stich repair a crack what I've done in the past was to drill a small hole at each end of the crack then drill out 1 hole then tap it but not tap all the way to full cleanout normally I would use a starting tap but not one that had a long starting taper just a taper of a few threads Plug taps work as well but the taper is too short for my next procedure which is to screw in a non graded non coated bolt until it twists off then dress down the surface and drill the next hole encompassing half of the bolt and repeat the procedure until the end of the crack. I've done it on aluminum as well using aluminum bolts. No fancy jig or special tools required other than a drill motor a few bits a tap, some bolts and a grinder.
    Never try to tell me it can't be done
    When I have to paint I use KBS products

  5. The Following User Says Thank You to Frank S For This Useful Post:

    baja (Jun 5, 2019)

  6. #4
    Supporting Member jimfols's Avatar
    Join Date
    Sep 2015
    Location
    Ontario Calif USA
    Posts
    853
    Thanks
    2,150
    Thanked 547 Times in 288 Posts
    If laying out holes around a curved, rather than straight, contour, making a drilling guide may be more effort than is practical. In this case a spacing punch, such as the Starrett #118, photos here...

    https://picclick.com/Starrett-Spacin...176136104.html

    I always enjoy learning about things I didn't know are available.



    2,000+ Tool Plans
    Jim

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
  •