Retrofit of a Vintage Craftsman Drill Guide (update)

I needed a machine that would give me the ability to make a specialized part for my motorized bike project. The part connects a 5/16" x 24 thread output stud to a 3/8" dia. driveshaft. It couldn't be found anywhere, so I needed to make it. I just happened to have an old craftsman tool with the right configuration to solve my problem, with some alterations and a mini lathe chuck I was able to build what I needed. The lathe chuck was the perfect addition to this machine because of it's ability to hold round stock or flat bar stock in perfect 90 deg. alignment with the drill chuck. This machine can now be used for boring, tapping inside threads and with threading dies for male threads. It can be powered by any drill for boring operations or operated manually for tapping and threading.

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Step 1:

The first step for this retrofit was to build and secure a mounting plate with a large pass through hole for long stock and four position holes that mate with long set screws attached to the back of the chuck. The lathe chuck simply drops into the position holes. I also flipped the beam over and where the original drill head attached, the top end of the shaft has been squared to accept a 1/4" socket extension.

Step 2:

Here we can see the pass through hole and the ends of the upright rods that have been extended down 1/2"  to mate with holes in my workbench plank. This adjustment holds the machine in place when force is applied.

Step 3:

In this picture we can see the machine completely assembled and setup for a drilling operation. The round stock mounted in the chuck is going to be center bored and threaded. When completed it will become a specialized coupler.

Step 4:

After twice boring the stock first with a 21/64" drill bit half the length and then using 17/64"  to complete the bore hole it is ready to be tapped. When finished it will have 1/2" of 3/8"x16 threads and 1/2" of 5/16"x24 threads. 
I can use a regular tap handle with a 1/4" short socket extension to spin taps.

Step 5:

So far I have shown boring and tapping operations. This step shows that threading dies can also be placed in the jaws of the lathe chuck. Stock up to 3/8" dia. can be held in the original drill chuck. Dies that are to small can be installed by first placing them in a die handle and then clamping the handle in the lathe chuck jaws.

Step 6:

In the following steps I am going to demonstrate the real versatility of this retrofited drill guide. Here I am adjusting the newly added work rest.

Step 7:

In this step I am showing that flat bar stock can also be drilled by clamping the stock in the chuck between the step ledges.

Step 8:

I also made the mounting plate supports with flush pegs so that the mounting plate can easily be removed. Here I am using it to hold the lathe chuck in my drill press.
  I think this tool would be great for any hobbyist or small shop with limited space. As you can see I built this in a limited space, my wife's kitchen table.

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    14 Discussions


    7 years ago on Introduction

    Obviously one can tap and thread on a lathe even if one can not single point the threads. Simply take a manual tap holder and let the handle rest on the ways.Use the back rest of the lath to push the die forward. The same is true for running a tap. Use a super slow speed on the lathe and the tap will advance itself after it cuts a bit. Use a lot of oil and think about where your hands are. You do not want the tap handle to crush your fingers against the ways. When you are only threading a few pieces this is a fast and efficient way to get the job done.

    Sorry! I really don't know what Sears called this thing. I have done a search, but haven't found the original tool anyplace else. I found this one at a yard sale a couple years ago. If anyone recognizes this old tool please post.

    The original tool that spawned the genre was called a Port-Align. I have one of the original Port-Aligns - it is very similar to the Sears tool you used except that the base piece is round.

    I found this instructable to very interesting. I see the old Port-Align leaving the drill box very soon!

    Here is a link to ebay with the exact tool I started out with. It was just recently listed and I just found it myself. Thanks.


    Reply 8 years ago on Introduction

    Looks like an older version of the craftsman drill guide before adjustable angle was added.


    8 years ago on Introduction

    very nice… and useful.
    I'll put it on my (way too) long list of projects.


    The tool in question is a tapping fixture. It's meant to align taps perfectly square with holes, the chuck holds the tap. It was missing it's handle.
    It's similar to this one from axminster

    Why couldn't you drill the holes using the tailstock chuck in the lathe? It would be allot more accurate than this fixture, and in this application any inaccuracy causes vibration. You can also tap and cut threads using the die in the lathe, making sure the threads are perfectly square that way too.

    Phil B

    8 years ago on Introduction

    I did something similar to this in step 4 of this Instructable, but with only a drill press and an adjustable wrench.  The difference is you are making the female threads, while I was making male threads.


    8 years ago on Introduction

    Very smart idea, and well executed and documented!