Cross-Slide Table Modifications

by Keith Brooke

October 2007

Frontispiece Photo


Change List
Dial Gauge Control for Table Movement
Table Locks
Thrust Bearing
Leadscrew and Nut
Dials and Handles
Table Stops
Z-Axis Micrometer Gauge
Appendix - Making the Lead Screw


It seems to me that all drill presses should have the same kind of work holding and positioning features as a milling machine. Recently the availability of inexpensive Asian devices has made this capability much closer to affordable.

X-Y Vise Photo

Photo 1: Popular X-Y Drill Press Vise

Cross Slide Table Photo

Photo 2: Popular Cross-Slide Drill Press Table

For several years I used a simple X-Y vise as shown in Photo1 because it was cheap and reasonably functional.  The cross-slide table as in Photo 2 was available but was a couple of hundred dollars and didn't seem worth it at the time. Then a small sale and a big moment of weakness coincided and I made the switch. I bought mine at Busy Bee in Canada but  everybody else's product looks pretty much the same.

This table was usable as delivered but  could never have been mistaken for a professional tool. I started nibbling away at its shortcomings and ended up with little of the original but the castings. Since it was done piecemeal, I wouldn't do everything exactly the same if I were doing it again as a unified project. But here's what I did and why for what it's worth.

All modifications were done with a Taig lathe and a Rockwell drill press.

Change List

As far as I can recall, the following changes are listed in pretty much the sequence in which they were made. 

The original gibs were steel and not suited to wearing in for that nice silky movement. I just made exact duplicates in brass. Over time they have improved the action noticably.

Dial Gauge Control for Table Movement
With the poor leadscrew dials it was just about impossible to move the table with any precision. Since I wanted to drill accurately located holes, this was important. I tried mounting dial gauges with magnetic bases and arms but found it surprisingly difficult to get them placed just right. Constant headache. So here's my solution.

Y Gauge Photo

Photo 3: Y-axis Dial Gauge Arm

X Gauge Photo

Photo 4: X-axis Dial Gauge Arm

Photos 3 and 4 show the mounting blocks and rods installed to hold dial gauges for measuring table movement in the X and Y directions. This eliminates any uncertainty because of  backlash, loose gibs or a sloppy lead screw.

Table Locks
Locating the table precisely is not much help if it's going to jiggle around whenever the tool hits the work. So locks are needed to make sure it stays put.

Y-Axis Lock Photo

Photo 5: Y-axis Table Lock

X-Axis Lock Photo

Photo 6: X-axis Table Lock

Photos 5 and 6 show the extra gib holes drilled and tapped to take the ball handled locking screws. Once tightened, these keep the positioned table perfectly stationary. Very accurately spaced holes can be achieved.

Thrust Bearing
I wanted to try light milling on the drill press since I didn't have a milling machine at the time. Experiments showed that there was just too much uncontrolled table vibration. For milling, the table should be as jiggle free under movement as when locked down. Once the gibs are properly adjusted, the only other component allowing uncontrolled motion is the lead screw.  I started with the thrust bearing where I assumed (incorrectly) all the backlash to be.

Ball Thrust Photo

Photo 7: Original and New Thrust Bearings

Mounted Bearing Photo

Photo 8: Mounted New Thrust Bearing

The original was just a steel disc with lots of non-adjustable backlash determined by how (not very) close to it  the outer sleeve was pinned to the shaft during manufacture. The new one carries a ball bearing and spacer so the backlash is determined by the precision of the ball/race fit. If I were doing it again, I'd make this block thicker and mount two ball bearings with a spacer between and some bearing preload. It's amazing how much play there is in a single ball bearing. I never thought of this until later but couldn't have done it originally anyway because I was fitting it to the original leadscrew and was limited to the thickness of the original thrust plate.  

The new plate had to be larger in diameter to make room for new mounting holes outside the bearing recess.

Leadscrew and Nut
The new thrust bearing helped but didn't completely eliminate the problem. The table could still be moved perceptibly back and forth. So I took the whole thing apart to have a look at the leadscrew assembly.

Old Leadscrew Photo

Photo 9: Original Leadscrew Assembly

The original leadscrew has a 1/2-10 Acme thread and a very loose nut. The second nut in Photo 9 shows how I tried to tighten up this fit by adding screws to bear on the leadscrew. It was a half-vast fix and didn't really work. Making an adjustable nut for an Acme thread is problematic and, anyway, the cost of a 1/2-10 Acme tap is close to $100.  So back to the drawing board.

New Leadscrew Photo

Photo 10: New Leadscrew and Nut Assembly

Here is the heart of all these modifications, a new leadscrew and nut. The leadscrew is 1/2-20 threaded rod and the thrust bearing end was machined completely on the Taig lathe. For some reason, at the time of making this particular part I made step-by-step photos which are in the appendix for those who are interested. The nut is adjustable following the practice of the Taig  CR mill and is somewhat larger than the original which is shown for comparison. Also shown is one of two spare blanks made in case of a screw-up along the way.

The new lead screw works like a charm and is as smooth as silk.While the thrust bearing could be improved, it's just not worth the trouble because the backlash is quite acceptable.

Dials and Handles
The original dials were intended for a 10 pitch leadscrew and were too small. The new ones have 50 divisions to suit a 20 pitch leadscrew and are the same size as the new thrust bearing carrier.

Dials Photo

Photo 11: Original and New Dials

Mounted Dial Photo

Photo 12: New Dial Mounted

The dial carrier was made the same length as the original pinned spacer. The new dial is held in place by a circlip which is bent and rides in a groove wide enough to let it press lightly on the dial so as to damp its rotation.   

The increase in leadscrew pitch  means more turns per inch table travel so rotating handles ease the wear and tear on fingers.

Table Stops
Adjustable table stops make certain kinds of repetitive operations much more convenient.

X Axis Stops

Photo 13: X-Axis Table Stops

Y Axis Stops

Photo 14: Y-Axis Table Stops

The stops ride in standard T-Slot Tracks (Lee Valley 12K79.22) used in tablesaw mitre gauge slots. The stops are just drilled aluminum blocks secured by 1/4-20 T-bolts and finger nuts. The stop posts are made as shown.

Z-Axis Micrometer Gauge
This section has nothing to do with changes to the cross slide table but adds the final axis control for drill press work and is included to complete the subject.

Depth Gauge Mount

Photo 15: Mount for Dial Depth Gauge

Mounted Depth Gauge

Photo 16: Mounted Dial Depth Gauge

Photo 15 shows mounted on the drill press head casting an aluminum mounting adapter which will hold a standard 4" dial caliper. Photo 16 shows such a caliper in place. This provides micrometer measurement of the tool movement along the Z axis. Full three-axis control is now available for all drill press work.

Appendix - Making the Lead Screw

Rod Bearing Photo

Photo 17: Making a Bearing for the Threaded Rod

The leadscrew is far too long to be held between centers on a Taig. To give the steady rest something to ride on, lock two 1/2-20 nuts together on a short length of rod and turn half of one of them to a nice round.

Rod Bearing in Use Photo

Photo 18: Rod Bearing as Tailstock Subtitute

Now cut a length of threaded rod about 1" longer than the lead screw to be made. Grip it in the three-jaw and support the outboard end with the just-made round riding in the steady rest, a kind of substitute for a tailstock dead center.

Starting Cut

Photo 19: Turning a Starting Diameter

Use the parting tool to produce a sufficient length of the required diameter so a regular left-hand tool can be used to continue.

Finishing Cut

Photo 20: Completing the Major Diameter

A normal left-hand tool is used to complete the major diameter for the thrust bearing, dial and handle.

Thread Diameter

Photo 21: Turning the Thread Diameter

Turn the reduced major diameter for the thread being used. Cut off the leadscrew to the required length.


Photo 22: Threading the Leadscrew

Mount the die holder in the headstock and lock a couple of 1/2-20 nuts on the other end for a hex socket ratchet. Run the thread. This completes the leadscrew.


© Copyright 2007 Keith Brooke. Queries and comments welcome. Please put the word 'Taig' in your e-mail subject to bypass my junk mail filter.

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