The Inexpensive Dremel Foot Switch

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Intro: The Inexpensive Dremel Foot Switch

This is a very easy to make, inexpensive, durable foot-controlled on/off switch that can control the power on any small tool or appliance, such as a Dremel or other rotary tool, a "Leslie" rotating organ speaker motor, lights, or anything really. We're going to cut the extension cord partway along the length, and add in the switchbox, so that the outlet or outlets at the end of the extension cord are switched on or off when the foot switch is actuated.

Step 1: So Why?

So... Why Do I want to make a foot switch that lets me turn a 110v appliance on and off- specifically a dremel?


I do a lot of project work on motorcycles and motorcycle-shop-related electronics, namely cordless phones which do not survive well in a shop environment. I use my dremel for a veriety of things, at several different speed settings, but the tool has a simple slider on the body to control on/off and speed, and it's aggrivating to have to reach up and slide it all the way off because i need to use that hand to hold something else, and then have to try and get the speed right again 10 seconds later. This way I can just tap a switch with my foot, needing zero hands free to control the power- AND the Dremel can be left at a specific speed setting, with no fiddling around needed to get back to that setting later.

Step 2: Parts and Tools Needed

Parts Needed:

  • Extension Cord (New 7' extension cord) $3.97
  • SPST Pushbutton Switch (Guitar Pedal Switch, DigiKey #432-1212) $3.56
  • 4x4x1.5" electrical box $1.18
  • 4" square electrical box cover with 3/8 center blank $0.77
  • 5/16" flat washers (2) $0.32
  • 3/8" NM Electrical Box Cable Connector $0.38

Total cost: $10.18 + tax&shipping if applicable

Tools Needed:

  • Needlenose Pliers
  • Phillips Screwdriver
  • Soldering Equipment (Pencil, Solder)
  • Shrink Wrap and/or Electrical Tape
  • Box Cutter / Razor Knife
  • Wire Strippers
  • Optional: Duck Tape

For the most part, you should be able to actually spend less then I did to make this. I had to buy an extension cord but most people have one or two kicking around in a drawer somewhere- many people will also have the washers, and possibly even the electrical box gathering dust in some corner. Almost any pushbutton switch can be used, I just happened to have this switch ordered from DigiKey for another project, and decided to use it. It's a good switch to use, though- not too expensive, it's rated for 5A@125VAC so it's good for most small tools, and it is designed to be hit with a foot so the switch top is metal and quite sturdy.

Your washer sizing will need to correspond to what size the mounting hole for the switch you are using is. The washer needs to have a center hole just large enough for the switch mounting threads to fit through, and have a large enough diameter to completely cover the hole in the 4" square cover top plate.

Step 3: Determine Length & Cut the Cord


The first thing you need to do is find out how long of an extension cord you are going to need. Keep in mind that the cord needs to be long enough to reach from whatever outlet you are using, down to the floor beneath your feet, and over to a place that the tool you are plugging into it can reach the outlet. Wiring the box itself should use about 8" of the total length of the extension cord. You'll also want to have some extra length from the plug to the switchbox, so you can reposition the switchbox to be near your foot as you work. I ended up making the first 5ft or so of the extension cord the "plug" side, and only about 1.5ft the "outlet" side.

Once you have found where on the cord you want to put the switch box, mark it with a piece of tape.

The next thing you need to do is determine which of the two wires in the extension cord you need to cut. Most extension cords are "zip cord", they look somewhat like speaker line and have 2 individually insulated wires joined by a thinner section of plastic. One of these wires is the hot ( +110VAC ) wire, and the other is neutral/ground.

The best way to determine which wire is the hot wire is to look at the plug. On American 110-volt plugs, there is a wide and a narrow blade. The narrow blade is the hot conductor, and the wide blade is the neutral conductor. If you lay the plug out flat with the narrow blade on the left, the left insulated wire is probably the hot wire.

Go back to your taped spot on the extension cord, and carefully slice the thin plastic joiner between the two wires on the zip cord, for about 3". Then cut the "hot" wire. You can check to ensure you cut the right wire with a multimeter's conductivity tester. If you cut the wrong wire, you can either solder that wire back together and cut the other wire, or discard that extension cord and use another.

Step 4: Solder Time!

Take that cut you just made, and make sure there is about 2" of separated length of zip cord on either side of the cut. Then, bend the cord in half at that point, so that the uncut wire makes a loop and the two cut pieces of wire line up side-by-side. Place a zip tie on the cord, just behind the point at which the cord is separated- this will help reinforce things and keep the cord from separating more later.

Now, take the NM Flat Cable Connector junction box clamp and loosen the clamp, and then slide it over the looped end of the extension cord, past the zip tie.

WARNING: Do you see that thin finger nut on the inside (threaded) part of the clamp? Take that off! If you don't take that off you'll end up having to unsolder things later and you won't be very happy, will you?

Okay, now pull the bottom loop of continuous conductor away from the cut ends, strip them back, and tin the wires. If you don't know how to do this, there are Instructables to help you out.

Step 5: More Soldering, and What Not to Do


Okay, now pick a 3/8 punch-blank in the side of the 4"x4" electrical box, and punch it out with your needle nose pliers ( or other generic tool ). Slide the tinned wire leads through the hole, and thread the cable clamp's threaded nut over the tinned ends, so it is against the inside wall of the box. Pull through a few more inches of cable, to give you some working space.

Now, go ahead and solder on your switch- but DO NOT forget to put your shrink wrap up the wires first, or you will end up having to unsolder and resolder the switch!

Now, if you've done everything correctly, you should have the wire running through a hole in the electrical box, and a switch soldered and shrink-wrapped or otherwise insulated. If you did what I did the first time, and screwed up, you will have something like what's in the third picture- a switch, with no way to fasten the cable clamp to the box. Get another beer, cut the shrink-wrap, desolder the wires, and fix it. After all, it's not like you haven't done this before.

Step 6: Mounting the Switch, Finishing Up

If you haven't yet, punch out the center blank on your cover plate. Put one washer on the switch, and put the switch through the hole in the cover plate. Put the other washer on top of the plate, and thread in the top nut of the switch. On my switch there is a bottom nut that is adjustable, and i set it so the switch sits slightly higher then the minimum above the top plate. Tighten the top switch nut with a pair of pliers.


Now, push the excess extension cord back through the hole in the junction box, leaving a few inches of play to install the top plate with. Thread the clamp nut on the clamp threads, and tighten by finger and then with a pair of pliers, until the clamp will not rotate against the junction box. Line up the two pieces of extension cord that go through the clamp, and tighten the clamp down just enough to hold the cords where they will not slip.

Slide the top plate onto the screws in the junction box, and snug down the screws. You're done!

Be sure to test the footswitch with a multimeter or by plugging a light into the extension cord's outlet and pushing the switch. The light should turn on and off as you push the switch.

Hook it up and go do another Instructable!

Step 7: Final Thoughts

As this is my first instructable, and my first scratch-built concept project in a while, there are a few improvements that could be made, as well as some possible permutations.

  • To make a much longer plug / outlet cord, you can use 16-gauge solid-color insulated speaker wire or replacement lamp cord wire, and buy a replacement plug and outlet. The cost of a replacement plug and outlet is similar to what a standard extension cord costs, however.
  • Adding duck tape or some other form of tape to the bottom of the junction box helps to keep it from shifting on a concrete or hard floor, and also keeps it from scratching the floor
  • A momentary contact switch could be used instead of an on / off switch, providing a "dead man"-type of safety, as well as an even easier method of switching for fast on/off power situations. I decided to use an on/off switch because I tend to shift in my seat a lot as I work, and having to keep one foot in exactly the same place would be inconveniant.
  • A grounded (3-prong outlet) version of this could be made, you would just need to pass the ground wire through a screw in the junction box to ground the box as well. Also, most 3-prong grounded style appliances draw several amps, so a heavy-duty switch is called for.
  • you could use a standard wall light switch instead of a pushbutton switch, or even a regular toggle switch. However, this would require that you remain in stocking or bare feet for the duration of using the switch. In using this switch I find I can comfortably actuate it sitting or standing, wearing shoes or in stocking or bare feet.
  • A larger actuation surface would be nice for bare-foot uses, as the small area of the switch head tends to cause my toe to slide off to one side and not actuate the switch. This is a minimal issue, however, and could easily be rectified.

So there we are, then. I suppose if I don't get too much flaming or death threats from this, I may well post another.

Cheers! ~Bilby~

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77 Discussions

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BilbyDIY Dave

Reply 7 years ago on Introduction

Hey, looks great, man! Did you ground the metal chassis as some of the comments suggested? How do you like it so far?

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DIY DaveBilby

Reply 7 years ago on Introduction

I think I grounded the chassis (it's been a while since I made it). So far its worked great. The switch I used was a light up switch, but I dropped it and the light quit working.

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lorraineknit

10 months ago

How about using a sewing machine foot? Any thoughts on how connecting that might be different?

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jcroyle29

1 year ago

Nice ... thanks

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Joker972

2 years ago

Very easy to make, but has anyone made a foot pedal for a power strip? Seems like it would do the same job, since it's a matter of cutting off the current to the machine itself??

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Ricardo Furioso

2 years ago

Sensible.
Useful.
Carefully explained.
Thank you for your generosity in sharing your work.

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skiprlg

2 years ago

I'll try it

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Mike63

3 years ago on Introduction

Here's what details I can give: https://www.instructables.com/id/25-Year-old-Dremel-Foot-Switch/

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smelo1980

3 years ago on Introduction

Hi there. Great instructable. This was my first instructable I ever did and spurred me to start an account. Anyhow, I have one question for anyone out there as I am a notice when it comes to electronics. Can you or someone tell me how to add an led light to this switch so that the light turns on when the switch is turned on. It would be greatly appreciated!

Thanks again

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jherncal

6 years ago on Introduction

How the Switch. Live in Caracas Venezuela, and do not get the respuesto original, so I'm looking for ways susituirlo by adapting, but for that I need, you know how it works. Your input is 110 volts, but do any measurements with the multimeter and No. Y723 MOSFET device, I have 12 volts, but it is damaged. Also I have a glass thermistor smd capacitor, contacts, and other component, which is covered with black resin. Thank your help with this I leave the image.
Dremel 300 Series

Como Funciona el Switch. Vivo en caracas Venezuela, y no consigo el respuesto original, por lo que estoy buscando la manera de susituirlo mediante una adaptación, pero para ello necesito, sabe como funciona. Su entrada son 110 Voltios, pero realice una medidas con el Multimetro y en dispositivo tipo mosfet Nro. Y723, tengo 12 voltios, pero el mismo esta dañado. Asi mismo tengo Un termistor de vidrio un condensador smd, los contactos, y otro componente, que esta cubierto con resina negra. Agradecer su ayuda con esto les dejo la imagen. Dremel 300 series

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itsme.justin

7 years ago on Step 5

You could just use your dremel cutting tool to cut that nut off.....just saying. prooly easier and quicker

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oddmidge

8 years ago on Introduction

On small change, use a plastic project box. Incase you have wire issues, you don't want to shock yourself, it can be potentially fatal.

2 replies
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Either that or you should of used a 3 prong cord into the box to ground it. Just because the dremel is 2 prong doesn't mean you should use a 2 prong cord on the switch box. The dremel is 2 prong because it doesn't have any metal parts that could ever become live.

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chuckr44oddmidge

Reply 8 years ago on Introduction

I've been shocked by 110vac plenty of times, and I'm just fine-ine-ine-ine. *smack*


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sdallesasse

11 years ago

Very good job, but you should have a grounding conductor in the cord as well. If the feed side of the cord were to touch the box you could really get hurt. By having a cord with a ground does not always mean that you need to use a higher rated switch.

4 replies
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Bilbysdallesasse

Reply 11 years ago

True, and grounding would be a good thing for this. Where I am using this, there are no grounded outlets available, so I simply eschewed the extra cost and complexity and did without. When I said that you should use a higher rated switch with a grounded cord, i was talking about for devices that have a grounded plug themselves- many of which ( in the hobby / shop world ) draw more power then this switch is rated for. Thanks for the comment!

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DerinBilby

Reply 10 years ago on Introduction

grounding is simple just punch a aliminum rod about 10" in the ground and voila

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BilbyDerin

Reply 10 years ago on Introduction

Thanks for the suggestions ;) Of course all houses have grounded breaker or fuse boxes, and most water pipes are grounded as well. The problem I had (At the time i wrote this) was that none of the outlets were grounded- they didn't have the third prong on the outlet socket, nor were the electrical boxes grounded. The area of the building I was working with originally predated electricity and the electricity was wired in in the 1950s or 1960s, when grounded outlets weren't in common use.

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DerinBilby

Reply 10 years ago on Introduction

however we need to use the rod because our pipes are plastic.If your sockets are not grounded you can rewire the plugs.