Most mini drills have a switch in their body activated by hand which is ok for most applications.
When drilling pcb though, the constant on-off needed for the holes to be drilled accurate and with minimum damage to the cooper this can became tiring to the hand, so the purpose of a foot activated switch emerges. Although this is made with pcb drilling in mind it is not obligatory to have this only use, afterall is a foot activated switch waiting for you to find more uses for it.
Step 1: Materials
We had some spare acrylic glass so we used that but you can also use wood, aluminum or any other material you can find with ease and suits you.
To start you need a mini drill along with its power supply.
A switch to activate the drill, one from guitar pedals would be perfect but anything else with a strong spring to hold the upper plate and give a feeling to your feet is ok.
Two plates of 10mm acrylic glass 21cm long and wide enough to feel comfortable with your foot size.
4 smaller pieces to make some casing for the switch and allow cables to pass through, dimensions here are not crucial, any spares or leftovers will do.
A couple of hinges to connect the 2 plates, some M3 screws to mount them and some longer M4 to mount the switch assembly to the plate.
If you go with acrylic glass for the switch assembly, some glue for it will give a better aesthetics instead of using screws but it's up to you.
Step 2: Pedal
Mark the hinge holes and drill the plate. It is better to use countersunk screws so that they don't limit the pedal movement.
After fixing the hinges in base plate, place the upper plate perpendicular to base and mark the hinge holes on it. Drill, screw and your pedal is done.
Step 3: Switch Casing
One uppper plate for the switch to mount on it, a thicker one to house the switch and 2 smaller ones acting as spacers to allow cables pass through. The syringe is used to apply the acrylic glue to hold them together, the pieces can also be bolted but glueing gives a better opticall result.
Piece dimensions are determined form the switch you have so no need to be exact, just be sure the switch fits and cables can pass easily underneath.
Step 4: Put Them All Together
First we make the electrical connections to the switch, cut the positive wire of the drill power supply and pass it through the switch, that's all.
Drill 2 holes in the switch casing and use them as template to mark the holes in the base plate of the pedal.
Drill the base plate holes and using screws long enough fix the switch casing to the plate.