The Versa-Mil basic unit (Figure 9-1) has a powered machining head which moves vertically on four hardened ground guide posts by means of a precision-ground lead screw calibrated to 0.001 inch. Thirteen different speeds are available to the head through the use of different size pulleys to accommodate all types of machining and cutter sizes within the range of the unit. The circular T-slot on the face of the basic unit accommodates a variety of attachments. The graduation marks on the basic unit indicate the degree angle an attachment is to be positioned for various machining operations.
Figure 9-1. Versa Mil basic unit.
The external grinding head (Figure 9-2) bolts to the face of the Versa-Mil making the unit a precision external grinder. The head adjusts to 30 degrees range of angle to either side. A flat belt from the motor provides power to the head for smooth operation. Different pulley diameters allow matching spindle speeds to the grinding wheel size and rating. A wheel guard on the head offers protection to the operator from debris coming off the wheel during grinding.
Figure 9-2. External grinding attachment.
A wide variety of internal grinding jobs can be handled on a lathe with the Versa-Mil basic unit and the internal grinding unit (Figure 9-3). The internal grinding attachment bolts to the face of the basic unit and is driven by a flat belt from the motor. The internal grinder handles grinding wheels from 5/8 inch to 2 1/2 inches in diameter and grinds to a depth of 4 inches. Five different speeds are available to match the spindle speed to the grinding wheel diameter and rating.
Figure 9-3. Internal grinding attachment.
The heavy-duty deep-hole grinder (Figure 9-4) may be attached to the face of the Versa-Mil for deep internal grinding. The deep-hole grinder accommodates grinding wheels 3 to 5 inches in diameter and grinds to a depth of 10 inches. A flat belt from the motor drives the deep-hole grinder for smooth operation. Six spindle speeds are available to match the spindle speed to the grinding wheel diameter and rating.
Figure 9-4. Heavy-duty, deep-hole grinder.
Cutters held in the lathe chuck, collet, or between lathe centers can be ground quickly and accurately with the Versa-Mil unit equiped with an external or internal grinding head. The tooth stop rest (Figure 9-5) assures uniform grinding of cutter teeth because the finger on the gage ratchets over the teeth stopping each tooth in the exact same position. The tooth stop rest is completely adjustable for height and position.
Figure 9-5. Tooth stop rest.
The diamond dresser (Figure 9-6) is used with all Versa-Mil grinding attachments and clamps to the workpiece, tailstock, or lathe face plate to true the grinding wheel. A 0.35-karat industrial diamond mounts in either of two positions to dress the face or side of the grinding wheel. The cast-iron frame with V-notch clamps securely to round shapes up to 3 1/2 inches in diameter.
Figure 9-6. Diamond dresser.
The universal milling head (Figure 9-7) mounts to the face of the Versa-Mil and is driven by the spindle of the basic unit. This feature eliminates the need for special belts and permits the head to operate at any angle. The milling head and the basic unit have the same spindle taper and use the same arbors. With the universal head, machining can be performed along the side of the work, allowing the machining of much larger parts. Angular operations such as thread milling can easily be performed on large diameter material using the universal head.
Figure 9-7. Heavy-duty, deep-hole grinder.
This unit bolts to the face of the Versa-Mil and is driven by the basic unit spindle. The An internal keyseater and slotter (Figure 9-8) commonly called a “Versa-Shaper,” bolts to the face of the Versa-Mil Versa-Shaper operates in any angular position and in either direction of stroke for cutting internal keyways, slotting, or shaping. Thestroke length adjusts from 0 to 4 inches with a speed of 44 to 450 strokes per minute. Tool holders for l/8”, 3/ 16”, 1/4”, 5/16”, and 1/ 2” cutters are available for use in the Versa-Shaper.
Figure 9-8. Internal keyseater and slotter (Versa-Shaper).
For speeds higher than the basic unit can provide, a highspeed end milling and drilling head (Figure 9-9) bolts to the face of the Versa-M il. The head rotates 30° in either direction from center. Graduation marks on the face of the basic unit indicate the angle setting. Thirteen spindle speeds are available to the head directly from the motor through the use of a V-belt and pulleys. Arbors may be mounted in either end of the high-speed head. The spindle taper is the same as the basic unit. The high-speed head is used mostly for small diameter work such as end milling, drilling, or other related operations.
Figure 9-9. High-speed end milling and drilling head.
The indexing head (Figure 9-10) mounts in the lathe head stock spindle to index work held in the lathe chuck, collet, or between lathe centers. The indexing head mandrel locks into a 1 1/8-inch or larger spindle bore; however, adapters for other bores are available. Forty turns of the dividing head crank rotates the lathe spindle one revolution. The indexing plate has 18 circles of holes allowing for divisions to be made in degrees, number of sides, or the number of teeth on gears or splines.
Figure 9-10. Indexing head.
Versa-Mil units are furnished with an adapter (Figure 9-11) that fits the T-slot of the compound rest on most conventional lathes to lock the Versa-Mil unit to the compound rest with two hex-head bolts. Four holes in the base of the Versa-Mil unit allow mounting the basic unit in any of four positions 90° apart. Mounting the basic unit by this method permits the use of the compound rest for angular movement where low mounting of the Versa-Mil is not required. Any operation normally done above the centerline of the workpiece is usually accomplished by using the T-slot adapter and the compound rest. Such operations include milling keyways, slots, and splines, angle milling, and gear cutting. Other operations such as drilling or boring may also be accomplished if they are performed above the center line of the work.
Figure 9-11. Adapter plate.
When a lower mounting of the Versa-Mil unit is required, the compound rest can be removed and replaced with a special adapter base (Figure 9- 12) that mounts directly on the cross-slide. The base plates are semifinished and may require drilling two mounting bolt holes and a pivot pin hole. The location of these holes depends upon the lathe model and size. The base plate adapter should be used for operations on or below the centerline of the workpiece. Such operations include milling keyways along the side of a shaft, surface milling with a shell end mill, and drilling or boring on the centerline of the workpiece. The compound rest must be removed prior to mounting the base plate adapter.
Figure 9-12. Adapter base mounting.
Although not part of the basic unit accessories, the feed table may be found in some shop sets. Rigid accurate feed tables (Figure 9-13) make the Versa-Mil unit a portable machine tool by providing two additional directions of. travel. Precision finished ways, adjustable gibs. and accurate lead screws calibrated to 0.001 inch assure accurate positioning and feed for the most precise machining. Feed tables for Versa-Mil units are available in four different models and all feed tables can be quickly converted to reduce table height when only one direction of travel is required.
Figure 9-13. Feed tables.
Machining done on the lathe with a Versa-Mil allows the cutter to move along three different axes: vertical, lateral, and longitudinal (x, y, z). However, not all machining can be done using the lathe. Because the lathe allows longitudinal and lateral movement, mounting the Versa-Mil directly to a bench or piece of equipment would severely restrict its machining capabilities. Feed tables eliminate that restriction by providing those two additional directions of travel. Feed tables mounted directly to a bench or piece of equipment allow the Versa-Mil to perform machining in all three directions.
When the basic unit is to be used independently or with an attachment other than the grinding attachments, an arbor and cutter must be selected and mounted. The cutter should be mounted onto the arbor first. The arbor should be secured in a vise to properly mount the cutter.
This ensures a properly torqued cutter and prevents the arbor from bending or causing damage to the Versa-Mil basic unit. When tightening the arbor nut, the pressure applied to the wrench should always be in the direction of the operator in case of slippage. Listed in the following paragraphs are various arbor styles and some of their uses. Note that they are similar to, but smaller than those used on a milling machine. Refer to chapter 8 for illustrations not listed.
Taper arbors (Figure 9-14) are designed primarily for use with Brown and Sharpe, or Morse standard taper shank tools.
Figure 9-14. Taper arbor.
The fly-cutting arbor may be used for boring, facing, gear repair, keyway milling, and form milling. This type of arbor allows the tool bit to be positioned at either 45° or 90° to the arbor axis.
The side-milling arbor (Figure 9-15) is used with arbor-type cutters and slitting saws. This arbor is supplied with 1/8” and 3/8” spacing collars.
Figure 9-15. Side milling arbor.
The shell end milling arbor is used primarily for facing; however, milling a wide slot with a shell end mill can be accomplished.
This type of arbor is used for mounting chucks with a #3 Jacobs taper. The chuck itself is used primarily for drilling.
The straight shank arbor with setscrews (Figure 9-16) is used with straight shank drills of the correct size, end mills, and Woodruff key seat cutters.
Figure 9-16. Straight shank arbor.
The straddle mill arbor is used for milling splines on a shaft, milling hexagon or square shapes, and large keyways. Six spacers come with the Versa-Mil accessories, allowing milling of areas from 1/8 to 3 inches wide in 1/16 inch increments.
The threaded angle mill arbor is used for milling angular grooves and dovetails.
After selecting the arbor, select the desired cutter for the machining process, mount the cutter on or in the arbor, and mount the arbor in the Versa-Mil unit or attachment. Ensure the arbor and spindle are free of dirt and burrs.
This cutter has a l/2-inch straight shank and is used for cutting Woodruff keyslots in a shaft. This cutter may also be used for cutting straight keyways in a shaft or similar operations.
Side cutters are available in two basic styles. The stagger tooth side milling cutter should be selected for milling keyways and deeply milled slots, while the straight side milling cutters are usually used in matched sets for straddle milling or individually for side milling.
This cutter is used for slabbing or surfacing cuts and end or face milling.
Form cutters are manufactured in a variety of shapes. Selection of the cutter depends upon the desired shape or form to be machined.
Fly cutters are usually square tool bits ground with the proper clearances for boring, facing, or counterboring. Fly cutters can also be ground to particular shapes for special jobs such as gear repair or spline milling.
End mills are manufactured in a variety of shapes and styles and should be selected in accordance with the job to be performed. The two fluted end mills are recommended for cutting keyways and for deep milling while the multiple flute end mills are designed for end milling and routing work.
Slitting saws are manufactured in a variety of styles and sizes and should be selected in accordance with the job to be performed. Use slitting saws to cut deep slots in the work and for cutting slots.
When the external grinding head, internal grinding head, or deep-hole grinding head is selected and mounted on the Versa-Mil, a wide range of grinding operations is made available. The data books published by the leading abrasive manufactures should be referred to for proper selection of grinding wheels as the variety of grinding done by Versa-Mil is to great for complete coverage of wheels in this manual.
Use only abrasive wheels designed for the external or internal grinding heads that have been tested and found to be safe when operating at the speeds attained by these heads. Using incorrect untested wheels may result in breaking the abrasive wheel causing wheel fragments to be projected into the work area endangering personnel and equipment.
Straight abrasive wheels are furnished in 46 and 60 grit sizes. The 46 grit wheel is a general-purpose wheel and should be selected for rough-grinding cylindrical parts, face plate grinding, and so forth. Select the 60 grit wheel for finishing and for tool and cutter grinding where finer finishes are required.
Select a straight cup wheel for tool and cutter grinding, face plate grinding, and internal grinding of large holes.
Select a flare cup wheel for general tool and cutter grinding.
Select a dish wheel for tool and cutter grinding such as grinding flutes and individual teeth of milling cutters.