Dovetail-Base Headstock with 90-Volt DC Motor


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Spindle Options: 3/4-16 #1M taper or ER-16

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    Nickel/Teflon plating

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About the Headstock w/Dovetail Base

The Sherline industrial headstocks were developed based on the headstock used on the Sherline lathe and milling machine. The headstocks are made from extruded 6061-T6 aluminum and have a black anodized finish. They are available with your choice of a spindle (3/4-16 #1M taper or an ER-16*).

All Sherline Industrial spindles feature lifetime lubricated bearings with adjustable preload. The bearings are Class 5 for better accuracy, tighter tolerance, smoother and quieter movement, and cooler running. The bearings in all our industrial headstocks, except for the 3C headstock, are 6004-VV C3P5 – ABEC 5. The headstock bearings are rated for a continuous speed up to approximately 4,000 RPM with factory preload adjustment of .0002″. You may need a slightly looser preload setting of .0003” for operating speeds up to 10,000 RPM.

*NOTE: We do not sell the collets used with the ER-16 spindle. Those are available through MSC Industrial Supply Co. or other tool supply sources.

Standard Headstock Features

  • A brass gib on the dovetailed base fits Sherline steel dovetailed bed and column material
  • Includes a mounting point to attach a saddle nut on Sherline leadscrews
  • Spindle bearing dust cover washer
  • ER-16 collet nut ships with the ER-16 spindle headstocks

Mounting the Headstock

Lightly lubricate the dovetailed surfaces of the base or column material. Hook the angled edge of the dovetailed headstock base over the dovetail on the base or column. Attach the brass gib to the headstock using the three 10-32 x 5/8″ socket head cap screws provided. Tighten each screw until the gib is seated evenly against the dovetail, and the headstock slides evenly on the base or bed with no side-to-side play. Tighten the three set screws in the side of the headstock against the gib adjustment screws to lock them in place. (Do not over-tighten, or you can damage the threads of the attachment screws.)

Optional Nickel/Teflon Spindles

Most of our spindles are available with a Nickle/Teflon plating as a rustproof option for an additional cost. Check the option box above to add the Nickel/Teflon plating to your spindle order.

Spindle Precautions

These spindles should be considered light duty. A .405 (10 mm) through hole allows long stock to be passed through the spindle. This design provides a lot of versatility but was not intended for long or out-of-round parts to be rotated at high RPM. It is up to the operator to determine if the spindle and the setup are adequate and safe for the job being attempted.

The spindle is equipped with a dust cover, but it is not totally sealed. The presence of dust from grinding operations can shorten bearing life considerably. It was also not designed to be operated in a coolant bath. The spindle shaft should be shielded from coolant spray.

About the 90-Volt DC Motor

The powerful DC motor offers its maximum torque at low RPM, where you need it most in machining. This means it offers far more useable power than an AC/DC motor of equivalent or larger size. It also offers smoother and quieter operations than an AC/DC motor. The V-step pulley has two positions: A high-speed, low-torque position, and a low-speed, high-torque position. The second pulley position lowers the speed range down to about half that of the pulley position.

Standard Motor Features

  • 1/2 HP 90-volt high-torque DC motor (single direction)
  • 2-step “V” belt pulley (2nd position for more torque at low RPM)
  • Fiberglass-reinforced urethane drive belt
  • Variable speed electronic speed control: 70-2800 RPM
  • Load compensating circuit keeps RPM constant
  • Speed control accepts any input from 100 VAC to 240 VAC, 50 or 60 Hz, and automatically converts it to 90V DC output to the motor
  • Eight-foot, three-wire power cord (Select the correct wall plug or converter for your region)

The improper use of machine tools and their accessories can result in serious injury. Before using this tool, thoroughly read the instructions and make sure you understand its proper and safe use.


Always wear safety glasses when operating machine tools.

Download PDF Dovetail-Base Headstock with 90-Volt DC Motor Instructions

Instructions PDF Download

Headstock Specifications
Spindle base size 3.50″ long x 3.375″ wide (88.9 mm x 85.7 mm)
Spindle case height 3.625″ (92 mm)
Spindle centerline height above table 2.50″ (63.5 mm)
Hole through spindle .405″ (10 mm)
Spindle nose thread (Model 6517) 3/4-16
Spindle nose internal taper (Model 6517) #1 Morse
Spindle nose thread and taper (Model 6518) ER-16
Bearings (2) 20 mm, class 5, lifetime lubricated ball bearings with adjustable preload
Runout at spindle nose 0.001″ (Most are within .0005″)
End play (factory preload adjustment) .0002″ (.0051 mm)
Recommended continuous spindle speed 4000 RPM or less
Maximum spindle speed 10,000 RPM
Mounting provision Dovetail with brass gib
Motor Specifications
Type of enclosure Totally enclosed, non-vented
Duty rating Continuous–10 oz. in. at 6100 rpm, .85 amperes; Intermittent–30 oz. in. at 5500 rpm, 1.75 amperes (5 minutes on / 15 minutes off)
Output horsepower .06 KW (60 W) at 10 oz. in. / 6100 rpm
AC voltage (input) Normally 115 VAC, 60 Hz, Single Phase to rectifier (Sherline electronic speed control converts any input from 100 VAC to 240 VAC, 50-60 Hz.)
DC voltage 90V DC to motor (60 Hz)
Speed in rpm 6100 rpm continuous
Class of insulation Class A, 105° (C.) insulation system
Normal full load current .85 amperes
Starting current 1.7 amperes instantaneous starting current (<100 milliamperes). This is also stall current in True RMS
Max current at time of changeover from lower speed to higher speed Depends on load
Type of motor 3.00 inch (outer diameter) sub-fractional horsepower brush-type permanent magnet motor
Temperature rise at ambient 50° C. Less than or equal to 45° C.
Motor frame size 3 inches
Headstock Parts List
Part No. Description Quantity
40160 Preload Nut 1
40230 3/4-16/#1 Morse Spindle (used on P/N 6517) 1
40320 Bearing Dust Cover Washer 1
40330 0-32 x 5/8″ Socket Head Cap Screw 5
40420 Class 5 Headstock Bearings 2
40440 #2 x 1/4″ Self-Tapping Phillips Head Screws 2
40600 10-32 X 1/4″ Flat PT Set Screw 3
40670 10-32 x 1/2″ Socket Head Cap Screw 2
43230 2-Step V-Belt Pulley (used on P/N 6517, 6518) 1
65011 Headstock Case, Dovetailed Base 1
65012 Industrial Headstock Spacer 1
65013 Saddle Nut Attachment Plate 1
65014 Industrial Brass Gib 1
65023 ER-16 Spindle (used on P/N 6518) 1
65026 ER-16 collet nut (used on P/N 6518) 1

Click the P/Ns below to download a zipped version of the IGS 3D CAD file. You will need to extract the zip file before viewing the IGS file.
6517 3D IGS model
6518 3D IGS model
You need an IGS viewer to view .igs files. CLICK HERE to download a FREE IGS viewer.