lathe rotary table free sample

A rotary table used in conjunction with a mill allows a machinist to produce virtually any part they can design. Sherline’s rotary table is a precision piece of equipment that has been designed to work with their vertical milling machines. However, it can be used on any mill whenever the small 4-inch size would be an advantage. The only limits are size, not complexity.

The table is 2″ high and 4″ (100mm) in diameter. The main components have been machined from solid bar stock steel, and the complete unit weighs seven pounds. The table has been engraved with a laser, giving sharp and precise lines every 5°, numbered every 15°. These lines are calibrated with the 72-tooth worm gear that is driven by the handwheel. The handwheel is divided into 50 parts, making each line on the handwheel 1/10°. This allows a circle to be divided into 3600 increments without interpolation. Seventy-two revolutions of the handwheel rotate the table one revolution.

The rotary tables can hold more weight when they are not under a continuous load. Click on the Video tab above to see examples of different weights and uses for our rotary tables.

The table T-slots are identical to those used on the Sherline mill and lathe, making the vast line of Sherline tooling available for use with this product. Two hold-down clamps and T-nuts are provided with the table. Also included is an adapter that allows Sherline’s 3- and 4-jaw chucks to be screwed directly to the rotary table. An optional right-angle attachment is available (P/N 3701) to mount the table in the vertical position to increase its versatility further. With the table mounted vertically, an optional adjustable right-angle tailstock (P/N 3702) can be mounted to the mill table. It is used to support and stabilize the other end of long work held in a chuck or otherwise attached to the rotary table.

This is a modification of our 4″ Manual Rotary Table. This modification came about after requests from our laser engraving customers. They wanted a rotary table that had a larger through-hole to which they could mount our chucks.

This version of the Sherline rotary table has a Nickel-Teflon plating on the tabletop because it was designed to be used in an everyday production environment. This gives the table a rust-resistant surface that is hard and has added lubrication qualities.

The table is 2″ high and 4″ (100mm) in diameter. The main components have been machined from solid bar stock steel, and the complete unit weighs seven pounds. The table has been engraved with a laser, giving sharp and precise lines every 5°, numbered every 15°. These lines are calibrated with the 72-tooth worm gear that is driven by the handwheel or stepper motor. The handwheel is divided into 50 parts, making each line on the handwheel 1/10°. This allows a circle to be divided into 3600 increments without interpolation. Seventy-two revolutions of the handwheel rotate the table one revolution.

NOTE: You can have your manual rotary table upgraded to CNC-ready, but this is done as a factory-only replacement. You will need to ship your manual rotary table back to our factory for the conversion.

Years ago, before I learned CNC, I owned a Phase II 8″ horizontal/vertical rotary table that I purchased from Kap Pullen’s Getmachinetools.com store. He has them at a good price, BTW, and he’s a darned nice fellow to deal with as well as being a frequent HSM contributor. Anyway, its a nice little table, but I hadn’t done a whole lot with it for quite a while after purchasing it. As is so often the case, one day, a project landed on my doorstep and I was glad to have it.

Before I could get started, however, I had to make some accessories for it. Basically, I needed some T-Nuts to fit the table, as well as a little fixture that makes it easy to hold a plate up off the table through a hole in the center so you can machine it. The latter, what I call a “plate machining fixture”, was inspired by something similar I saw the Widgitmaster of CNCZone fame using to make Dremel clamps for his mini-router:

I turned the round spigot using the 4-jaw on the lathe. I’m making the fixture out of MIC-6 aluminum plate, which is pre-ground very flat on the sides. This is a 5 inch by 3 inch piece. I’ve clamped it to the rotab using my T-nuts and the regular mill clamps and step blocks. It is sitting on parallels to make sure I don’t cut into the table. You can also see how I’ve clamped the rotary table to the mill table using a big cast iron V-block I have. You can never have to many blocks with precision faces hanging around!

Having a 4-jaw chuck on your rotary table is mighty handy! Because it’s a 4-jaw, you can dial in the workpiece by adjusting the jaws until it is perfectly concentric with the table’s axis of rotation. The best way is to make an adapter plate that attaches to the back of the chuck in the same way that your lathe does so you can exchange lathe tooling with the rotab. Here is an example:

For the example, the chuck is threaded onto the adaptor plate, and then the holes in the adapter plate’s flange are used to bolt down to T-nuts on the table.

In my case, I bought a 4-jaw from Shars brand new, and simply drilled some through-holes in the chuck to mount to the table directly without an adapter plate:

First, you want to make sure your part is properly centered on the table. To do that, I clamp the table down on the mill table (no special place is needed), put my Indicol indicator holder on the mill spindle, and find some round feature on the part to indicate on. For example, on the plate milling fixture above, indicate on the round boss, or on the center hole. Spin the table and bump the part in until spinning the table doesn’t move the indicator.

Second, locate the center of rotation directly under the mill spindle. You can simply use the X and Y table handwheels to do this. Use that Indicol to indicate off of a circular feature you want centered under the spindle. Turn the indicol around on the spindle and adjust the handwheels until the indicator stays put relative to the spindle position. A Blake Coaxial indicator will make this last even simpler.

When you’re rounding partially by cranking a part around on the rotary table, it’s really easy to go a little too far and screw things up. The answer is to drill the end points to make the exact stopping point on the rotab a lot less sensitive:

Centering with a Blake indicator is really fast, but what if you don’t have a Blake, or worse, what if your mill is too small to accomodate one? Here is a nice solution I found on a German site. This fellow has made an ER collect fixture for his rotary table, and has taken care that when installed on the table, the axis of the collet is aligned with the table’s axis. He can then place a dowel or other straight pin in the collet and line up until it will go into a similarly sized collet on the spindle. Nice trick! It’s similar to how Widgitmaster showed me to align a drill chuck on a QCTP to the lathe centerline with a dowel pin held in the lathe chuck.

CNCR turns a stepper motor controlled rotary table into a CNC controlled device. It makes it easy to accurately set the position, rotate an index step back and forth, move between two positions or run at a constant speed. An automated lock signal can lock the rotary table when it is not moving. Place the rotary table on the cross slide of a lathe and you can change tools by pressing a button.

CNCR is optimized to run on a small 7" touch screen. The supported controller is GRBL version 1.1 (or compatible grblHAL, grbl_ESP32), a free open source controller based on affordable Arduino hardware. The controller can be connected by USB, Bluetooth or a (wireless) network. If you ever wanted to CNC your rotary table, this is the easy and affordable way to do it.

A rotary table is a precision work positioning device used in metalworking. It enables the operator to drill or cut work at exact intervals around a fixed (usually horizontal or vertical) axis. Some rotary tables allow the use of index plates for indexing operations, and some can also be fitted with dividing plates that enable regular work positioning at divisions for which indexing plates are not available. A rotary fixture used in this fashion is more appropriately called a dividing head (indexing head).

The table shown is a manually operated type. Powered tables under the control of CNC machines are now available, and provide a fourth axis to CNC milling machines. Rotary tables are made with a solid base, which has provision for clamping onto another table or fixture. The actual table is a precision-machined disc to which the work piece is clamped (T slots are generally provided for this purpose). This disc can rotate freely, for indexing, or under the control of a worm (handwheel), with the worm wheel portion being made part of the actual table. High precision tables are driven by backlash compensating duplex worms.

The ratio between worm and table is generally 40:1, 72:1 or 90:1 but may be any ratio that can be easily divided exactly into 360°. This is for ease of use when indexing plates are available. A graduated dial and, often, a vernier scale enable the operator to position the table, and thus the work affixed to it with great accuracy.

Rotary tables are most commonly mounted "flat", with the table rotating around a vertical axis, in the same plane as the cutter of a vertical milling machine. An alternate setup is to mount the rotary table on its end (or mount it "flat" on a 90° angle plate), so that it rotates about a horizontal axis. In this configuration a tailstock can also be used, thus holding the workpiece "between centers."

With the table mounted on a secondary table, the workpiece is accurately centered on the rotary table"s axis, which in turn is centered on the cutting tool"s axis. All three axes are thus coaxial. From this point, the secondary table can be offset in either the X or Y direction to set the cutter the desired distance from the workpiece"s center. This allows concentric machining operations on the workpiece. Placing the workpiece eccentrically a set distance from the center permits more complex curves to be cut. As with other setups on a vertical mill, the milling operation can be either drilling a series of concentric, and possibly equidistant holes, or face or end milling either circular or semicircular shapes and contours.

with the addition of a compound table on top of the rotary table, the user can move the center of rotation to anywhere on the part being cut. This enables an arc to be cut at any place on the part.

Additionally, if converted to stepper motor operation, with a CNC milling machine and a tailstock, a rotary table allows many parts to be made on a mill that otherwise would require a lathe.

Rotary tables have many applications, including being used in the manufacture and inspection process of important elements in aerospace, automation and scientific industries. The use of rotary tables stretches as far as the film and animation industry, being used to obtain accuracy and precision in filming and photography.

A rotary table is a really nice accessory to have for your mill, but one that you can delay purchasing for a while until you master the basic milling operations. The rotary table is driven by a worm-gear and is accurately calibrated in degrees and fractions of a degree.

Finding a rotary table of the right size for the mini-mill has been a lille problematic. 8-inch tables are really much too big. Even a 6-inch is pushing the limits. I have one from Grizzly. It is well made and works well, but mounting it to the table was a little bit of a challenge.

The first rotary table I purchased was made in India and was of really poor quality. I returned it to the vendor for a refund. Unfortunately, the return shipping on a heavy object like this is not cheap, so be careful what you buy!

Sherline makes a beautifully finished 4″ rotary table which I got to see first hand at Cabin Fever 2001. I was very impressed by the high quality of this item, but It was a little small for my needs.

The table I currently use is a Grizzly G1049 6-inch model. As of 03/02 it sells for $199 plus shipping. It is well-made, and I have been very satisfied with it, although it is a little large for the mini-lathe as you will see in the photos below.

After cleaning off the packing grease with kerosene, a painbrush and a rag, I mounted it on the mini-mill table using 3/8″ carriage bolts that I also use for my 3 1/2″ Grizzly milling vise. The center hole is a #2 Morse taper.

The RT is really a little oversize for the mini-mill, but still provides enough clearance to be practical. I did not feel that the weight was beyond the capabilities of the mini-mill table.

Here’s a picture showing the table with a 12″ rule and a 1/2″ mill in an end mill adaptor. Mounting the mill in a collet would provide another 2″ or so of working room. The head is at the top of the column. Also shown is the 3″ chuck from the 7×10 mini lathe. As you can see, there is adequate clearance for most operations.

The casting has mounting lugs for both horizontal or vertical mounting. This makes it potentially much more flexlible, but the table of the mini mill is small compared to the RT which makes mounting the rotary table in the vertical orientation a little tricky.

One problem is that the lower edge of the handwheel for the RT is lower than the base of the RT, so it must be positioned off the edge of the table. If the RT is positioned perpendicular to the X-axis, the mounting holes in the RT are outside the limits of the T-slots in the mill table.

For the price, I was pretty impressed by the quality of the table. I would rate it somewhat lower in quality than the Sherline 4″, but much better than the Victor 6″.

The handwheel is satin-finish steel with cleanly etched divisions. Each full rotation of the handwheel rotates the table by 4 degrees. A brochure included with the RT illustrates an indexing plate accessory which can apparently be attached to the RT, but I’m not sure whether or not Grizzly sells this accessory.

An eccentric cam between the handwheel and the table permits you adjust the meshing of the worm-screw to minimize backlash. A screw with a T-handle locks the cam in place once it is set.

Here’s a nice little 4″ imported rotary table offered by LMS for $134.95. They offer several other models, including the Sherline 4″. I don’t have any first-hand experience with this one, so I can’t really comment on quality or capabilities.

When the Servo Control executes a G94, a 250 millisecond delay is required before starting the next step. This may cause the mill axis to move before the table rotates, leaving a flat spot in the cut. If this is a problem, add a 0 to 250 milliseconds dwell (G04) after the M-Code in the mill program to prevent mill axis movement.

By adding a dwell, the rotary unit and the mill start moving at the same time. It may be necessary to alter the feed rate on the mill to avoid timing issues at the end of the spiral. Do not adjust the feed rate on the rotary control; use the mill with its finer feed rate adjustment. If the undercut appears to be in the X-Axis direction, increase the mill feed rate by 0.1. If the undercut appears in the radial direction, decrease the mill feed rate.

If timing is off by several seconds, such that the mill completes its movement before the rotary and there are several spiral moves one after another (as in retracing a spiral cut), the mill may stop. The reason is the mill sends a cycle start signal (for next cut) to the rotary control before it has completed its first move, but the rotary control does not accept another start command until it finishes the first.