Tapping Machine / Apocalypse Drill Press




Introduction: Tapping Machine / Apocalypse Drill Press

This Instructable will describe how to build a machine to assist with tapping holes.

My inspiration for building this was a CNC router design that I am working on. My design calls for 24 tapped holes to be used for mounting bearings. The bearings will travel along a steel bar, thus forming my x, y and z axes. Any slop in this area will lead to inaccurate cuts so everything needs to align perfect.

I haven't started building the router yet but my tapping machine has already proven itself to be very useful. The images above show a couple of examples of what it is capable of. The brass pipe plug is for a Vapor Mod that I am working on. The threads were cut using a 7mm x .5mm tap. As you can see, the threads came out nice and straight allowing the tank to thread on easily and sit flush against the top face.

An old 3/8" inch drill (with a 1/2" chuck) is used and serves two purposes: Smaller taps can be mounted directly directly in the chuck. Larger taps with a 1/2" square end are easily accommodated by adding a 3/8" ratchet extension and 17mm socket. In addition, the drill's gearbox was retained, allowing the tapper to produce a lot of torque with minimal effort. 2 lbs of force on the handle will produce 10 ft lb of torque at the chuck. As a comparison, a 4" T-handle wrench would require 60 lbs of force (30 lbs per side) to produce 10 ft lb of torque. As I was tapping the brass plug I was able to turn the handle with a single finger!

The tapping machine was also beneficial for tapping a copper pipe to accept the brass plug's 1/2" NPT threads. The copper pipe was mounted using my Simple Inside Pipe Clamp. The gearbox in a typical 3/8" drill such as this is not made to handle the amount of torque required for a tap this size. However, I was able to get the tap started and finish up with a 3/8" ratchet.

Step 1: Materials

Most of the materials used in this build were laying around my garage. Feel free to modify the design to suit your own needs (or junk pile). The first step involves gutting the drill so a broken unit is fine. If you can find a heavy duty 1/2" drill cheap that would be even better as you will be able to develop a lot more torque.

1 @ 3/8" drill (non-operational)

2 @ 1" x 2" x 10" long angle iron

2 @ 1" x 1" x 4 3/4" long angle iron

1 @ 1/2" x 1/2" x 19" long square hot rolled steel tube

1 @ 1/2" x 3" long round hot rolled steel tube

1 @ 3/8" x 12" long hot rolled steel round

2 @ 1/2" x 1/2" x 1/2" long angle iron

1 @ 1/4" x 1" long hex head bolt with nut and washer

1 @ 6" paint roller

1 @ metal cabinet knob

2 @ small washers

2 @ 1/8" x 1" long machine screws with nuts and washers

Step 2: Prepare Drill

In this step we will prepare the drill for use.

Remove the screws from your drill and save them for later. Separate the two haves of the body. Remove the cord and all of the internal electrical components. These can be discarded or saved for another project.

Mark the location of the motor shaft on the plastic housing.

Carefully remove the motor and gearing. It might be a good idea to take a picture first so you can get everything back in properly. Clean the body with soap and water. We will be attaching hardware to the inside of the housing with glue so it is important to get everything clean. Remove the old grease from the gears. Carburettor cleaner and an old tooth brush work great for this.

Step 3: Attach the Handle

In this step we will construct a handle and attach it to the motor shaft.

With the internals of the drill still removed, place the two haves of the housing back together. Insert enough screws to hold it together. Drill a hole through the housing exposing the motor shaft.

Cut the paint roller as shown. Place the rear motor bearing and any washers on the paint roller. Carefully align the paint roller with the motor shaft and weld the two pieces together. Grind the weld to allow the bearing to slide back on to the motor shaft. Create a smooth transition between the two shafts to prevent stress cracks.

Cut the handle of the paint roller off approximately two inches from the 90 degree bend. Leave enough material to allow the knob to be attached.

Drill a hole through the metal knob. The hole should be large enough to allow the knob to turn freely on the handle. Weld a small washer above and below the knob to hold it in place.

Step 4: Attach the Front Support

In this step we will attach a steel bar to the drill.

The images show a stainless steel tube. This was later replaced with a 3/8" hot rolled steel round.

Drill two small holes through the underside of the housing. The holes should be large enough to accept two small screws. Use the screws to mark the steel round. Drill the steel round at the two marks.

Separate the housing into two halves. Insert the screws into the steel round, add two washers and two nuts. Use JB Weld to attach the washers and nuts to the housing. Put a long straight bit in the chuck. Measure the distance between the bit and the steel round both close to the housing and at their ends. Adjust as necessary to make sure they are parallel. Align the steel round with the bit by eye before allowing the JB Weld to set.

Step 5: Build and Attach the Stabilizer

In this step you will create a stabilizer to keep the drill body from turning during use.

The stabilizer consists of two 1/2" x 1/2" x 1/2" long pieces of angle iron welded to a bolt. Use a grinder to smooth the sharp edges of the angle iron. This will help it to slide along the rear shaft without binding.

Clamp the two pieces of angle iron to a small piece of 1/2" square tube. Tack weld the angle iron to the head of a bolt. Remove the clamp. The angle iron needs to be able to slide easily over the 1/2" square shaft so it may be necessary to pry them apart slightly. Complete the weld.

Remove the screws from the front support. Disassemble the motor housing being cautious not to disturb the nuts and washers. Put a washer and nut on the bolt at it's mid point. Insert the stabilizer into the hole formerly occupied by the electrical cord. Reassemble the housing. Replace the front support.

Step 6: Build the Stand

In this step we will assemble the stand.

Cut two 10" long pieces of 1" x 2" angle iron. Mark the center point of each. Tack weld the 1/2" x 1/2" steel tube to one of the pieces and the 1/2" round tube to the other. Both tubes will be perpendicular to the 2" face of the angle iron and touching the 1" face.

Move the assembly with the 1/2" tube to your drill press. Drill a hole through the 2" face of the angle iron where the 1/2" tube meets it. You should be able to push the 3/8" steel round attached to your drill body through the 1/2" tube without restriction. .

Set the two 1" x 2" pieces of angle on your work surface so that they are parallel and the supports are vertical. We need to test fit the drill body. If any adjustments need to be made now is the time to make them. Use a square to make sure both supports are at a 90 degree angle to your work surface.

Slide the stabilizer over the rear shaft and insert the 3/8" rod into the front support. Make sure you are able to raise and lower the drill body as far as the supports will allow.

You should be able to change the angle of your stabilizer bolt slightly at this point as we haven't glued it yet. Experiment with turning the stabilizer in or out or adjusting the angle to find the position that works the best. With everything completed, I am able to raise the drill body and let go and the stabilizer will hold it in place. If I lift the drill body slightly and press down on the stabilizer it will release, allowing the drill body to move downward. This allows me to position a tap over my workpiece and get everything lined up before tapping. Once I am tapping there is enough vibration between the stabilizer and vertical support to keep it from binding.

When you are satisfied that everything is aligned, remove the drill body from the stand, remove the screws and separate the two halves of the drill body. Remove the stabilizer. Apply JB Weld to the nut, washer and one of the drill body halves where the nut and washer were. Be careful not to get any glue on the bolt. Reinstall the stabilizer, reassemble the drill body and return it to the stand. Make sure everything still moves freely before the glue sets.

Measure the distance between the two pieces of angle iron. Cut two pieces of 1" x 1" angle iron and tack weld them to the 1" x 2" angle iron. Once again, make sure everything is aligned properly. Remove the drill body from the stand and complete all the welds.

The image shows the tapping machine outfitted with a set of Adjustable Welding Clamps. If you use this design you will want to align everything as follows: Align the front and rear supports between a pair of rails. This will allow a tap in the drill chuck to pass between the rails when fully lowered. Drill a hole approximately 1" from the end of both pieces of 1" x 2" angle iron. Again, mark the holes so that the clamp is between two rails.

Step 7: Using Your Tapping Machine

Step 8: Apocalypse Drill Press

This step will show you how to modify the tapping machine to serve as a drill press that doesn't require electricity to operate.

What good are all those zombie rounds without an operational firearm? Don't let a broken weapon stand in your way of zombie killing bliss. With a hand-operated drill press you will be able to perform repairs or fabricate new parts to keep your weapon in tip top zombie-killing shape.

While you could use the tapping machine as a drill press as is, the gear box is going to slow you down. The increased torque comes at a cost of increased rotations of the handle. Turning the handle 10 rotations will cause the chuck to turn once. This is great for tapping but not so good for drilling. In order to maximize efficiency, we need to mount the handle directly to chuck's shaft. I will describe a way to do so in such a way that the tool can be used for drilling or tapping.

The following parts are required:

1 @ 2" long 1/4" ratchet extensions

1 @ 6" long 1/4" ratchet extensions

1 @ 608 skate bearing

The 608 skate bearing will need to slide onto the shaft of the longer ratchet extension. Be sure to check the fit before you do any cutting or welding.

The red box in the image above shows the path that our additional shaft will take. Lay your long ratchet extension along the path shown and check for anything that might interfere with it. The cooling fan definitely needs to go. The iron laminations on the motor may need to be ground down a bit. One of the motor contact mounts will need to be ground down a little. We might be able to keep the top right screw but the plastic pillar will definitely need to be reshaped.

Mark the location where the shaft crosses the exterior of the drill housing. Drill a 7/8" hole through the drill housing at the location marked.

Cut the male end from the long ratchet extension and trim its length so that it will extend about 1" from the drill housing. Slide the 608 skate bearing onto the shaft of the ratchet extension. Make sure everything lines up and any restrictions have been removed.

Remove the motor and gears from the drill housing. The aluminium block and bearing insert will need to be moved to the new shaft before welding. You may need to reduce the diameter of your ratchet extension with a grinder before this is possible. Align the shafts and clamp them to your welding table. Weld the shafts. Grind your weld so the bearing and block can be slid back into its original position. Make sure your weld is smooth to avoid stress cracks.

Move the gear assembly back to the drill housing. JB Weld the skate bearing to one side of the drill housing.

Fabricate the handle as described in Step 3. with the following exceptions. Instead of mounting the handle directly to the motor shaft it will be welded to the male end cut from the ratchet extension. Cut the male end from a shorter 1/4" ratchet extension. Weld the shaft of this extension to the motor shaft.

When complete you will have two female connectors protruding from the drill housing. The handle can be attached to either depending on whether you are drilling or tapping.

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    6 Discussions


    5 years ago on Introduction

    It looks like you did a good job. I've been trying to construct one myself, except having it on its side. The drill has to go in horizontally to for proper installation, but it's hard to turn a drill bit on its side. I'll have to keep at it, but I like how you rigged it just right.



    Reply 5 years ago on Introduction

    Thanks DaveyH.

    I'd love to see a pic if you want to throw up a link. BTW, I have made one improvement that I have been meaning to post. The drill had a little too much side-to-side play for my tastes. I drilled a hole in the base where the 1/2 round tube is welded and welded another section of tube below. In all, its about 10 inches now.


    Two things to help your tapper:

    Use a countersink to put a lead- in chamfer for the hole to be tapped, it helps produce a cleaner, straighter thread.

    A small magnet inserted up into the socket will help retain the larger taps with out tape.

    Nice fixture, anything to relieve the boredom of tapping a bunch of holes by hand is always welcome.


    Reply 5 years ago on Introduction

    Great tips BeachsideHank. I have been looking for a simple way to square up the end of round pipe prior to threading. Using a countersink to chamfer the hole before tapping may help with this as well.