LED |
|
Speed |
|
Display |
|
| Depth |
Speed control | stop |
| |
handwheel | On/Off switch |
Figure 2. Operating Controls
Depth Stop
A drilling depth stop (refer to Figure 3) is provided on the right side of the drill head. The depth stop consists of a threaded rod with depth setting jam nuts. The front side of the threaded rod has a depth scale. The jam nuts are loosened and moved to the desired depth on the scale. The upper jam nut is then tightened against the lower nut.
Operating Precautions
The following operating and safety precautions must be observed in order to avoid harm to the operator or damage to the drill press.
1.The head assembly must be locked to the column so the thrust produced by drilling will
not | force the head assembly up the column. |
2.The work table must be locked to the column so it will not be forced down the column.
3.Be sure the belt is tightened to the proper tension.
4.DO NOT start to drill the workpiece until making certain the workpiece is held down securely.
5.MAKE SURE THE DRIVE MOTOR IS RUN- NING BEFORE turning the speed control handwheel in either direction.
6.Point of operation protection is required for maximum safety. This remains the responsibil- ity of the user/purchaser since conditions differ between jobs.
7.Make sure the drill is secured in the spindle or check before attempting to use the drill press.
8.Make sure the spindle taper is clean and free of burrs, scoring, and galling to assure maxi- mum gripping.
8
Jam nuts
Depth scale (on threaded rod)
Figure 3. Depth Stop
Drilling Recommendations
Speeds for Drilling
The speed of a drill is usually measured in terms of the rate at which the outer periphery of the tool moves in relation to the work being drilled. The common term for this is Surface Feet per Minute (SFM). The relationship of SFM is expressed in the following formulas:
SFM = 0.26 X rpm X Drill Diameter (in inches) RPM = 3.8 x ________SFM__________
Drill diameter (in inches)
In general, the higher the speed the shorter the drill life. Operating at the low end of the speed range for a particular material will result in longer life. The most efficient speed for operating a drill depends on many variables:
1.Composition and hardness of material.
2.Depth of the hole.
3.Efficiency of the cutting fluid.
4.Type and condition of the drilling machine.
5.Desired quality of the hole.
