Craftsman 103.24531, 103.24521 Adjustments, Types of Bits, Drill Sharpening, Operation

ADJUSTMENTS:

The following adjustments may be necessary to keep your drill press at its most efficient operation.

If the automatic feed return fails to return the chuck to the top of the stroke or if the return action becomes sluggish, the tension may be adjusted as follows; Lock the chuck at the top of its stroke using the quill lock handle. Hold the feed return adjusting knob firmly and release the feed return adjusting knob lock screw, Fig. 1. Turn the adjust- ing knob counter-clockwise and re-tighten the lock screw. Release the quill lock handle and run the chuck down. If spring tension is still not sufficient repeat the above adjustment until it is.

FIGURE 3

To change the locked position of table lock handle or headstock lock handle (Fig. 1), remove handle and rotate table lock, item 67, or headstock lock, Item 51, 180°. Re-insert and tighten lock handle.

CAUTION: Headstock or table assembly should be securely supported when changing locked position of handles.

The Quill Lock Handle, (Fig. 1 ) for greatest ease of operation should point down when locked. To change the position of the handle, loosen the set screw, remove handle from hex head screw and ro- tate to correct position. Replace handle and tighten set screw.

Belt tension adjustment is made by loosening the motor mount lock screws and moving the motor mount away from the tool. Excessive tension short- ens bearing life, causes excessive belt wear and robs the motor of power. Tension should be just enough to prevent slippage at normal operating speeds and feeds.

Tighten pulley set screws after a few hours operation.

TYPES OF BITS:

A variety of bits are available for use in your drill press.

For metal drilling the standard twist drill will prove adequate for the home -work shop. If exten-

sive commercial operations are to be performed, high speed steel drills although more expensive, will prove to be the better tool as higher operating speeds are possible plus longer cutting edge life.

The solid center wood bit has a single flute turn- ing around a solid center but carries two spurs.

The fluted bit is an excellent all purpose wood bit. It has two flutes each terminating in a cutting edge and spur.

The best bit for high quality machine drilling in wood is the spur machine bit. It is the stiffest drill, tracks nicely and produces an exceptionally smooth hole.

For larger holes, a hole saw is available for either metal or wood. This bit has a center drill for pilot and teeth around the outer rim similar to a saw blade.

Also, for large holes in wood an expansion bit may be used. When the expansion bit or any hand wood bit is used in the drill press, the screw point must have the threads removed from it so that it will not enter the wood too rapidly. These threads

may be filed off. (See Fig. 3.)

Countersinking in wood may best be accom- plished by using the double lip style. It will give the cleanest cut and will not gum up under con- tinuous operation.

Length of Cutting lips	Heel of
must be equot	Cutting Lip

FIGURE 4

DRILL SHARPENING:

When grinding twist drills, in order to maintain the efficiency of the drill, extreme care should be exer- cised. The dead center of the point must be main- tained, that is, the cutting lips must be the same length, Fig. 4. Also their angle in relation to the center line of the drill must be equal. The angle should be approximately 60 degrees, 120 degrees included, for metal and 35 degrees, 70 degrees in- cluded, for wood. The cutting lip should be relieved gradually behind the cutting edge so that the clear- ance at the heel is about 1 2 degrees.

OPERATION:

Chuck removal;

If at any time you wish to remove the chuck merely loosen the chuck holding collar and continue to turn it. This will force the chuck from the spindle taper. Do not attempt to drive or wedge the chuck off as you may damage the spindle or bearings.