Grizzly G7948, G7947 instruction manual Changing Speeds, To change speeds

Page 30

Changing Speeds

The belts in the head of the drill press must be rearranged to change speeds. A chart under the belt cover shows the belt positions needed to make the drill press run at the desired speed.

To change speeds:

1.UNPLUG THE DRILL PRESS!

2.Loosen the belt tension lock knobs (shown in Figure 26) on both sides of the headstock, so the motor is free to move.

Figure 26. Loosening lock knob (both sides).

3.Rotate the belt tension lever counterclock- wise, as shown in Figure 27, to take tension off the V-belts.

Figure 27. Using the belt tension lever.

-28-

4.Locate the desired speed on the speed chart under the belt cover and move the V-belts to the desired V-grooves on the motor, idler, and spindle pulleys.

For Example: As indicated in the speed chart for 670 RPM (Figure 28), a belt combination of A-1.2-2creates 670 RPM.

•The “A-1” refers to the belt position between the spindle pulley and the idler pulley.

•The “2-2” refers to the belt position between the motor pulley and the idler pulley.

Note: Both belts may have to be removed before certain speed changes can be made.

A-1.4-4

 

 

BELT:B-2.4-4

 

 

BELT:

630

6 RPM

670

7 RPM

4

D

4

 

 

 

 

 

4

D

 

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

C

3

 

 

 

 

 

3

C

3

 

 

 

2

B

2

 

 

 

 

2

B

2

 

 

1

A

 

 

 

 

 

1

 

 

 

1

A

1

 

 

 

 

B-2.3-3

 

 

BELT:A-1.2-2

 

BELT:

1650

10

RPM

2050

11 RPM

4

D

 

 

4

 

 

 

 

 

 

4

D

4

 

 

 

 

3

C

3

 

 

 

 

 

3

C

 

 

 

3

 

 

 

2

B

2

 

 

 

 

 

2

B

2

 

 

 

 

 

 

 

1

A

1

 

 

 

1

A

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 28. Pulley combination for 670 RPM for

example.

5.Rotate the belt tension lever until the belts are tight. Tighten both lock knobs.

6.Close the cover before plugging in the machine.

G7947/G7948 12 Speed Floor Drill Press

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Contents Model G7947/G7948 G7947 G7948Page Table of Contents Warranty and Returns Introduction ForewordContact Info Machine Data Sheet Other Related Information G7948 Machine Data Sheet 17-1/2 Identification Table Height Crank Raises/lowers tableColumn Lock Lever Locks table height Safety Safety Instructions for MachineryAlways Lock Mobile Bases if Used Before Operating Machinery Safety for Drill Presses Amperage Draw Circuit Requirements110/220V Operation Circuit Requirements110V Operation GroundingExtension Cords 220V OperationItems Needed for Set Up SET UPSet Up Safety UnpackingInventory Hardware Recognition Chart Floor Load Clean UpSite Considerations Working ClearancesTable Support To install the table supportColumn and Base Components and Hardware Needed QtyHandles and lock levers installed Assistance when moving HeadstockHeadstock is Very Heavy. You Must Drill Chuck & Arbor To assemble the drill chuck and mount it toSpindle To install the downfeed handles Downfeed Handles Belt Cover KnobTo install the table To install a light bulb in the drill pressLight 110V Only Test Run Floor Mounting Mobile Base MountingRecommended Adjustments Factory adjustments that should be verifiedTo make and use the base plate Operations Operation Safety Installing/RemovingTo install a drill bit To remove a drill bitUsing the Drill Bit Speed Chart Choosing SpeedsLubrication Suggestions Changing Speeds To change speedsDrilling Table Rotation Depth Stop Adjusting TableTable Height Table TiltArbor Removal To remove the drill chuck and arborAccessories G5753-Drill Press ViseG3640-Power Twist V-Belt 1⁄2 x H1300 H1298 G7984 H2347 H0736Maintenance Troubleshooting ServiceAbout Service Motor & ElectricalPulley is loose Remove pulley Drill Press Operations Depth Stop Feed Shaft Spring Calibration Loosening cover and jam nut Power and light switch assembly Electrical ComponentsG7947/G7948 Wiring Diagram G7947 Stand/Table Breakdown G7947 Headstock Breakdown G7947 Parts List DescriptionPVA26 G7948 Stand/Table Breakdown G7948 Headstock Breakdown G7948 Parts List PVA29 Warranty and Returns Warranty Card CommentsGrizzly INDUSTRIAL, INC BOX BELLINGHAM, WAPage Call Today For a Free Full Color Catalog

G7947, G7948 specifications

The Grizzly G7948 and G7947 are powerful, professional-grade milling machines designed for precision metalworking. These models cater to the needs of machinists and hobbyists alike, combining innovation with robust features ideal for various milling tasks.

The Grizzly G7948 is a vertical mill with a large working table, allowing users to handle bigger workpieces efficiently. It features a 2 HP motor, providing a spindle speed range from 50 to 3,000 RPM, enabling operators to tackle a wide range of materials and applications. The G7948’s dovetail column ensures stability and rigidity, minimizing vibrations during operation, which is crucial for achieving precision in milling tasks.

On the other hand, the Grizzly G7947 is a versatile combination of a lathe and a mill, perfect for those looking to maximize functionality in a smaller workspace. It also boasts a robust 1 HP motor, allowing for smooth operation with adjustable spindle speeds, enhancing its versatility. The G7947 is particularly user-friendly, featuring a quick-change tool post that facilitates faster tool swapping and changeovers, which is a significant advantage when working on multiple projects.

Both models come equipped with advanced features such as a digital readout (DRO) system that aids in precision measurements. The DRO provides real-time feedback on the machine's positioning, helping eliminate guesswork and ensuring accuracy. Additionally, the machines' power feed for the table enhances efficiency, making it easier for users to execute repetitive tasks without the strain of manual cranking.

Another notable characteristic of the Grizzly G7948 and G7947 is their user-friendly controls, designed with ergonomics in mind. The intuitive layout ensures that operators can easily navigate through the machine’s settings, allowing for quicker setup times and smoother workflow.

Lastly, the sturdy construction of both milling machines means they are built to withstand rigorous use, making them reliable choices for both industrial applications and serious hobbyists. These models exemplify Grizzly's commitment to quality and performance, making them exceptional additions to any workshop.
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