Introduction: Changing Speeds on the 12 Speed Drill Press
The twelve speed drill press can go from 250rpm to 3000rpm in twelve steps. This many speeds is more than most of us are ever going to use or need.
3000rpm is too fast for any drilling operation. (You cannot use a drill press as a router, no matter who wrote that it’s possible!.) 250rpm may, at times, be too fast for drilling metal. But it is certainly too slow for any wood drilling operation you are likely to encounter. (Our shop has three drill presses. Only use the bench-top drill press for metal.)
For most drilling operations in wood, you will use a speed in the area of 1200 to 1500 rpm. When using “hole saws”, spade bits, or Forstner bits over 1-1/4” in diameter, you should slow the drill press down to 700rpm or less depending on the bit’s diameter (larger = slower).
Step 1: Let's Change Our Speed!
Turn off the drill press (duh!) To be perfectly safe, you should unplug the machine too.
Lift the cover at the top of the drill press. (Small black knob on the right/center of the cover.)
You’ll see that there are three sets of pulleys. The rear brings power from the motor. The front drives the drill chuck. And the center is an idler pulley.
Check to see at what speed the drill press is set by looking at the position of the belts and comparing their positions to the chart on the cover. (This first picture shows the speed is set at 3000rpm.)
We’re going to change the speed to something very slow (360rpm). This will necessitate removing both belts.
Loosen the two black knobs (one on each side of the machine) that are just forward of the motor mount. These knobs lock the motor mount slides in place so the belts stay under tension & don’t slip. (2nd pic)
Next pull the large chrome handle on the right clockwise towards the front of the machine. This will bring the motor mount forward and release the tension on the belts. (3rd pic) (Note that on two of our drill presses this lever doesn’t work. It will be necessary to pull the motor mount forward: Grip both sides of the motor mount and, bracing against the front of the upper casting, pull the motor forward.)
Remove the upper belt (The front belt in this instance) by turning the idler pulley while pushing down on the rear of the front belt. You are trying to force the belt into a smaller diameter groove. Watch your fingers! It’s easy to get pinched. Slip the belt off the front & idler pulleys. The rear belt comes off easily once the idler pulley is free to swing towards the back.
Remove the rear (lower) belt.
Step 2: New Speed Ahead
Now check the chart and find the speed you want. Note which belt is shown lower. We’ll put that belt on first.(1st pic)
In our case, we’re setting the speed at 360 rpm – suitable for large hole saws or for drilling into plastic or aluminum – so we put the front belt on first. (Both belts are the same size, so there’s no worry of getting them mixed up.)
Slip the belt over the idler pulley and engage the second to bottom groove.
Next, slip the front of the belt over the chuck’s pulley and engage it in the second to bottom groove. The belt should be level. (2nd pic)
Now slip the second belt over the top most groove of the idler pulley. Push the back end of the belt and rotate it over the drive pulley and fit it in the top groove. (3rd pic) (My image shows me doing just the opposite. It works because I’m fitting the belt in the top grooves.) Again, the belt should be level. (4th pic)
Now tension the belts by pushing the chrome lever counter clock wise. Hold it in place and tighten one of the locking knobs. Tighten the other knob.
Close the cover, plug in the drill press and you’re ready to go!
When you start drilling holes; if your bit stops rotating, then the pulley belts are slipping. You’re either applying too much downward pressure (drilling too fast) or the belts are too loose. Try going slower at first. If that doesn’t help then apply more tension to the belts.