I'm building a drill press and I'd like to be able to turn it on with a momentary switch on the handle, but sometimes I need both my hands free while it's running. Ideally, I'd use a "lockable" momentary switch if I could find one, or even build one (ideas welcome) but so far no luck. So what I have now is :

  • A wall outlet to plug the drill in ;
  • A regular on/off switch ;
  • A momentary switch (the - big - PCB type)
  • A small 3-way toggle switch (to toggle between momentary and on / off, and yes I know it sounds clumsy and somehow counterintuitive) and ;
  • A mosfet module to connect the switch(es) but I'm not sure they're of the right type / voltage, I use them in my 12V builds, should I use a different module for alternative current?

The only thing left is the diagram... How would I go and wire this ?

  • 1
    \$\begingroup\$ To latch the momentary switch you'll need a relay with a spare contact to form the latch. Have you got one? \$\endgroup\$
    – Transistor
    May 20, 2020 at 20:11
  • \$\begingroup\$ @Transistor I'm pretty sure I haven't ; can you please post a link to some info about it, like pics and specs? Thanks for your quick answer \$\endgroup\$
    – yPhil
    May 20, 2020 at 20:16
  • 1
    \$\begingroup\$ Craigslist -> actual drill press -> done. You'll spend twice as much trying to hork-a-dork it this way. Also you're playing with mains power, why do that when you don't have to? Also, when using a drill press, one hand is on the plunge bar, and the other hand is on the oil can. There's no holding a switch; to stop it just raise the plunge bar. Or a foot pedal would do. \$\endgroup\$ May 20, 2020 at 20:24
  • \$\begingroup\$ There are slide switches available with ON-OFF-MOM positions. Whether they're available for the ratings you need, I don't know. \$\endgroup\$
    – The Photon
    May 20, 2020 at 20:29
  • 1
    \$\begingroup\$ @Harper-ReinstateMonica, if you're working wood, you usually don't use an oil can. \$\endgroup\$
    – The Photon
    May 20, 2020 at 20:30

1 Answer 1


Here's one way to do that using a 12V= relay and a foot switch.

enter image description here

The control is to be housed in a protective enclosure with a socket for the power tool and one for the foot switch.

The foot switch is to be housed in its own enclosure and located on the floor.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.