Drill chucks

Glass surfaces which must fit closely are usually ground to shape. The most common example is the cone-and-socket joint the surfaces are first worked to an approximate fit with fairly coarse carborundum (about 100 mesh) which is put between them and wetted. The cone is rotated by hand or in a lathe or drill chuck, or by a special machine, until the smfaces meet closely—the carborundum must be kept moist all the time. The coarse abrasive is then washed off, and the grinding continued a number of times with progressively finer abrasive. Various possible abrasives are mentioned on p. 39. 

Drills and similar tools with parallel shanks are held in a drill chuck, Fig. 8.4. Many different types of chuck are available, each being adjustable over its complete range, and give good gripping power. 

Electric drills are probably used most frequently of all electrical tools. They may be used to drill metal or wood. Wire brushes are made which fit into the drill chuck for cleaning the metal. Variable-speed electric drills, which incorporate a vibrator, will also drill brick and concrete as easily as wood when fitted with a masonry drill bit. 

Bohrfutter drill chuck Bohrmaschine drill Bohrung (ProzessA organg) drill, drilling, bore ... 

The only flat machining required is slotting and milling a flat on the slider assembly. This can also be done w/a file or hand grinder or by clamping the piece in a horizontal feed unit on a drill press. The work is fed into a grinding stone mounted in the drill s chuck. 

The harder grades of glass may be drilled with metal drills that have been super-tempered by bringing them to a red heat and plunging them into a solution of salt water that has been previously boiled. A three-cornered file can be broken off and used to drill glass when it is placed in a chuck. The end of the file should be ground to a point on a grinding wheel. 

In bolduog gmall drilla made of steel wire or twist drills a driU chuck must be fitted to the bit stock. 

A solid chuck is to be made to fit this, and drilled with a quarter-inch hole to ht the smaller sized ehanka This solid chuck will also fit the chuck for the lathe. If barrel boring tools quick boring reamers, be made with the larger sizod shank, they can be used both in the latbe and with the bit stock. 

Drill guard - provided to protect the operator from contact with the revolving chuck and drill while still retaining visibility of the operation. These guards range from simple acrylic shields to a fully telescopic metal construction with acrylic windows. A typical pedestal drill guard is shown in Fig. 8.3. 

By rotating the outer sleeve, the jaws can be opened and closed. To ensure maximum grip, the chuck should be tightened using the correct size of chuck key. This prevents the drill from spinning during use and chewing up the drill shank. 

A hazard in the use of chucks is the possibility of leaving a chuck key in position. When the machine is then switched on, the chuck key can fly in any direction and cause serious injury. When you remove a drill from the chuck, always remember to remove the chuck key. Never leave it in the chuck for even the shortest time. 

Where a cutting tool or chuck has a Morse taper smaller than that of the spindle, the difference is made up by using a sleeve. For example, a drill with a No. 1 Morse-taper shank to be fitted in a spindle with a No. 2 Morse taper would require a 1-2 sleeve, i.e. No. 1 Morse-taper bore and a No. 2 Morse taper outside. Sleeves are available from 1-2, 1-3, 2-3, 2-4 and so on over the complete range. 

The tailstock can be moved on its guideways along the length of the bed and locked in any position. The quill contains a Morse-taper bore to accommodate centres, chucks, drills and reamers and is graduated on its outer top surface for use when drilling to depth. It can be fed in or out by... 

Drilling is carried out on a lathe by holding the drill in a chuck or mounting it directly in the quiU of the tailstock, which contains a Morse taper for this purpose. As with all drilling operations, some guide is required to enable the drill to start central, and a centre drill. Fig. 9.26, is commonly used. 

There are, however, certain features that are desirable in any drilling operation, including instrumentation, feed control, long feed and chucking, circulating pumps, and core bits and barrels. 

Drills are available with Morse-taper shanks which fit directly into the spindle without the need for a chuck. The size of Morse taper depends on the drill diameter, and the range is shown in Table 8.1. 

After the flats have been milled or filed, clamp the piston in the V-block, then locate, drill and ream the. 251 hole. Chuck the piston in the lathe using a 3-jaw chuck and turn the 45 degree tapered end 1/16" back. The tapered end is important because it will help the piston enter the injection cylinder smoothly. 

Remove the heater block from the chuck to layout the location for the. 501 cylinder bore and the. 374 bore for the heater cartridge. Reposition the heater block in the 4-jaw chuck and step drill the cylinder bore to 31/64" diameter. TTien ream through with a. 501 chucking reamer. Set the compound rest on the lathe and turn a 45-degree chamfer edge on the cylinder bore 1/16" deep. 

Reposition the heater block in the 4-jaw chuck. Center drill then step drill the bore for the cartridge heater to 23/64", 3" deep. Then ream the bore with a. 374" chucking reamer. 

Remove the heater block from the 4-jaw chuck and locate, drill and tap the 6-32 hole, 3/16" deep centered in the front of the block. Be sure and set the drill stop on tlie drill press to prevent the hole from being drilled through the cylinder wall. This hole will be used to attach the thermometer. 

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