Introduction: How to Change the Speed of a Drill Press

Picture of How to Change the Speed of a Drill Press

Changing the spindle speed for a manual drill press requires physically adjusting belts between pulleys.  In this example, we have three pulley sets two belts on a JET drill press.  The original speed is 540 and we will be changing it to 1840.

I made this at TechShop Detroit (www.techshop.ws).

Step 1: Unplug the Drill Press

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This critical first step is to unplug the drill press.  This is to ensure that while your hands are in the dangerous area of spinning pulleys, an accidental machine start does not harm you.

Step 2: Open the Belt Access Panel

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The top of the drill press holds a panel that can be flipped open to show the three pulley sets.

Step 3: Loosen the Locking Screws

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There are two locking screws on either side of the drill press.  Loosen both screws to allow for the motor to be moved.  The screws are located beneath the panel on either side.

Step 4: Pull Motor Lever

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Pulling the motor lever brings the motor closer to the pulleys and the pulleys closer to each other.  Note the difference when the belts are not pulled taut.

Step 5: Determine Belt Position for Desired Speed

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To change the speed to 1840 from 540 both belt positions must be changed.  The "left" belt will change to a position second from the bottom.  The "right" belt will changed to the bottom position.

Step 6: Remove First Belt

Picture of Remove First Belt

The first belt to be removed is the belt on top, which in this case is the "right" belt in the picture.  Lift the belt on the pulley set where the pulleys decrease in size from bottom to top.  Carefully lift the belt while rotating it on the pulley.  Keep your fingers on the outside of the belt to minimize the chance of your fingers getting caught.  Once the belt is loose, move it so that it will not be in the way when you remove the "left" belt.

Step 7: Remove Second Belt

Picture of Remove Second Belt

Repeating the same process, lift the belt on the pulley set where the pulleys decrease in size from bottom to top.  Carefully lift the belt while rotating it on the pulley.  Keep your fingers on the outside of the belt to minimize the chance of your fingers getting caught.  Once the belt is loose, move it so that it will not be in the way

Step 8: Put First Belt On

Picture of Put First Belt On

In this case, the "right" belt will now be on the bottom position since we are changing to the speed of 1840.  Put the belt in the correct position on the pulley set where the pulleys increase in size from bottom to top.  Then put the other side of the belt in the correct position on the other pulley set.

Step 9: Put Second Belt On

Picture of Put Second Belt On

The "left" belt will now be on the second from the bottom position since we are changing to the speed of 1840.  Put the belt in the correct position on the pulley set where the pulleys increase in size from bottom to top.  Then put the other side of the belt in the correct position on the other pulley set.  Verify that both belts are in the correct position.

Step 10:

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Pull the motor lever back in place.  The belts should now be taut.

Step 11: Tighten the Locking Screws

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Tighten both the locking screws on either side of the drill press to keep the system in place.

Step 12: Close Belt Access Panel

Picture of Close Belt Access Panel

Close the belt access panel.

Step 13: Plug in the Drill Press

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Plug the drill press back in... and you're ready to go!  The speed has been changed from 540 to 1840.

Comments

judypalmer (author)2015-09-07

Thank you for this nice instructable! I have an old Grizzly G7943 and couldn't find a pulley chart on line - the one in the lid is hard to access because of the position of the drill in my shop. I managed to pry it off and made a copy. I've uploaded here in case a Grizzly owner happens on your instructable.

mrbreezeet1 (author)2015-05-23

yeah, some only have 2 pullies, and 1 belt, only 4 speeds usually.

this kind is 12 0r 16 speed.

mrbreezeet1 (author)2015-05-23

does that press use a 3L belt, (3/8") or a 1/2" wide belt?

audreyobscura (author)2012-10-10

that's a rad system of gearing. i never really thought to look, but now i have a reason to open the panel of the press here in our shop!

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