Instructions for installing the mounting plate

Remove chips, dirt, etc. from the spindle and mounting plate. Nicks, burrs, etc. should be removed by careful honing either the spindle or
mounting plate. Install as follows:

THREADED SPINDLES: Screw mounting plate tight against the shoulder of the spindle.

LONG TAPER KEY DRIVE SPINDLES: Align keyway in mounting plate with the key on the spindle. Tighten the nut on the spindle securely on the mounting plate. Do not wrestle, this will cause nicks.

A & B TYPE SPINDLES: Install mounting plate with screws furnished, tighten equally and securely. The back mounting plate should seat on
the spindle face. Do not use the hammer on the wrench or cheater.

CAMLOCK TYPE SPINDLES: Install mounting plate on the spindle. Turn cam clockwise locking mounting plate in position. If reference the line on cams does not fall between “V” marks on the spindle, you must remove the mounting plate from the spindle and adjust cam lock studs by turning in clockwise or out counterclockwise one full turn. Reference line “MUST” falls between “V” marks on the spindle to ensure that the mounting plate is properly secured to the spindle. Tighten clock cams with the wrench provided. Each spindle has a reference line “I” at 12 o’clock and a “V” at 3 and 6 o’clock. When the mounting plate is properly tightened, reference line “I” should be between the “V” markings. Try each cam separately. Cam studs in the mounting plate ARE adjustable. If reference line “I” does not locate in position, adjust cam as follows: Remove cap screw beside cam stud, turn stud out if the reference does not go beyond “V” at 3 o’clock. Turn stud in if the line goes beyond “V” at 6 o’clock. When properly adjusted, secure all cams. The mounting plate should seat on the spindle shoulder.

ALL SPINDLES: When the mounting plate is securely installed, use the dial indicator to check the O.D. and face of the mounting plate. If more than a .0005″ error, take light truing cut, then install chuck with screws provided.

DIRECT MOUNT: Follow the above instructions for the type of spindle. Truing cut is not necessary.

CAUTION Never use more than hand pressure with the wrench furnished to tighten pinion or adjust screws or you will destroy the decision of the chuck.

FOR MOST WORK this chuck operates like any other scroll chuck; the stock is centered in the chuck quickly and with reasonable accuracy by turning the chuck pinion with the wrench furnished until the jaws grip work securely. Be sure to rotate work when tightening jaws- It will assure a firm, accurate grip. (see picture above right) FOR PRECISION ACCURACY, use the four opposed adjusting screws on the O.D. of the chuck body.

1. After work is gripped, use an indicator to determine which part of the work runs high and which runs low.
2. Chuck mounting bolts should only be snug, not tight when adjusting chuck.
3. Note the screw or screw numbers nearest the high point and unscrew slightly to release pressure.
4. Turn the chuck to the opposite screw or screws and tighten to take up half of the indicated error.
5. Keep making such adjustments until all screws are of the same tightness and the indicator dial hand stands still as you rotate the work,
This means dead zero precision.
6. Retighten chuck mounting bolts and confirm the adjustment.


1. Chuck workpiece as far back into the chuck jaws as possible, rotating the workpiece as the jaws are tightened – it will assure a firm accurate grip.

2. Whenever possible, tighten the jaws around the solid part of the workpiece.

3. DON’T OVERLOAD YOUR CHUCK – Do not chuck work larger than the outside diameter of the chuck. (See catalog for capacities.)

4. USE THE WRENCH FURNISHED – it is designed to provide sufficient leverage to tighten the jaws. NEVER use a larger wrench or pipe over the end of the wrench to increase leverage.

5. DON’T POUND OR HAMMER THE JAWS – Never use force if jaws seem to jam. Find the cause of obstruction or take chuck apart. It may need cleaning and lubricating. Be sure to remove chips and dirt which may have worked into jaw slots or scrolls.

6. Never straighten work in the chuck.

7. Avoid extending jaws beyond the outside diameter of the chuck.

8. When checking stock in the chuck, make sure jaws are tightened securely.

9. 6-jaw chucks must be cleaned more often than 3-jaw chucks as there is twice the number of jaw openings.

10. Never Start/Stop machine without gripping a workpiece, as jaws can migrate outwardly with fast start/stops without
pressure on the part.

Parts of True Chuck
If your chuck has master jaws with soft tops or solid soft jaws, be sure to align O.D. of chuck true before machining soft jaws. If you have several jobs using soft jaws or soft top jaws which have been hardened, they can be realigned in your chuck without returning or regrinding by making use of the adjusting screws.

A) Jaws
B) Scroll
C) Pinion
D) Front
E) Back
F) Adjusting Screws
G) Operating Wrench