Rework power tool pedal switch

Went to yard sale, seller had a brand new power foot pedal switch. Several years old in the box, picked up to add to my drill press. $5-score! Its small plastic box-retails for bout $25. (Since found H/F has them for $14-don't know if internals are same) Cool!. My drills switches are on the side-awkward especially in panic to turn off. I had previously add a switched receptacle that drill plugs into that I can more easily reach and kill power while using.
     
New power foot pedal.                                                       Existing switched outlet

Soon as I got home I plugged drill press into new pedal switch then plugged switch into wall, Stepped on the pedal -nothing switch on drill needs to be in on position. Turn on drill then step on switch varoom...NICE. Then I turn on light--again nothing- step on switch light comes on, hmmm I don't want the light going on & off with foot pedal.
Easy enough fix, my drill has single power cord but separate switch for motor and light. I'll just disconnect existing wires to light switch, run a separate power feed so light is independent of drill...this is where it all failed.

THE FAIL...

Unplugged everything-double check wiring, paths look correct. Then I actually look up inside drill head....crap. The red and black wires are the end of power cord-I assumed internal wiring was from junction box where color & wire changed-nope. Stuck multi meter on wire ends and checked plug end...Black is Hot, red is ground, good grief. I wired a dead short when both are on. Turns out though I should have checked and verified first, that other than color assumption the motor switch breaks the hot to motor, the light switch breaks the ground to light. Err bells should have gone off when I noted black & red but they didn't. I hooked up new feed hot to ground, ground to hot- double whammy.

Rewired light (as I should have in the first place) disconnecting both leads from light fixture, ran new power cord hot thru switch, ground to directly to light. Now light is completely isolated from motor feed & switch. Turn light on/off it works, timidly with my hand on the main outlet switch I cautiously turn on drill....nothing. Played with drills switch-new pedal nothing. Unplugged pedal, plugged in drill directly-wala it works.

So I fried new pedal- . Disassembled pedal- yep micro switch fried. Dead short it acted as fuse.

NEW SWITCH IS IN THE MAIL...

Decided try to find a switch and to fix this pedal, plus I want to make some other upgrades to it. Also decided I want option to use pedal or drill normally without unplugging cords so make some changes to outlets.

The pedals factory micro switch is a Cherry D45LR1MD. Its rated at 15 amp - 1/2 HP, normally open, 3/16" connectors. Looking around either retailers had a minimum qty or min order charge.
Somehow I ended up at Newark.com site. They've a bazillion switches-no minimum. I identified switch I needed but noted higher amps available. Checked my drill its rated 15 amp 1 Hp. Ended up ordering a Newark 01N5051 (Honeywell V15H22-CZ100A03-K), its rated at 22 amp & 1 HP!. The trigger lever arm is bit longer, has 1/4" connectors but otherwise right switch, in stock and $2.14. Cool-higher ratings so it won't be weak link, I might have found one with identical configuration but I can cut the lever. Be here in a few days.

Old 15amp/1/2 HP verses new 22amp/1 HP internal micro switch.

MODIFYING THE PEDAL...

Used simple conduit plug to cover old hole, romex connectors for new end mounted cord. I cut a slot on pedal pivot hex head screw once I finally got it out, hex just spun out recess in plastic. I have a pilot light on main power outlet, I've seen others wish they had pilot on pedal. So though I'm not, I will note that the internal micro switch is wired normally open (off), but in the off position the other (unused) terminal is hot. Would be perfect for adding a pilot light, when foot is lifted from pedal the pilot would come on alerting that pedal /drill is energized.

Switch came in, has 1/4" terminal, one of the original wires spade is 3/16" had to change. The lever I cut a bit shorter but I also moved it closer to snap switch. Looking at the switch there are 2 positions for lever pivot, moving pivot closer to snap switch it reacts quicker. Very carefully pry with thinner side up, just enough to pull lever out and insert to hole closer to snap button. Minor but again could be ordered with desired configuration.

Modified pedal

ADDING SWITCHED OUTLET...

WORKS slick. New outlet switch lets me use the drill with new pedal or drills side switch for just quickie stuff. I've added a hook on post next to drill to hang the pedal when not in use. New cord is long enough I can use pedal with floor grinder that sets next to drill.

New switched outlet

New drill switched outlet box plugs into to original overhead power outlet. The main overhead switched outlet is over top of drill-easily reached. This switch controls all outlets on that circuit, outlet for drill , one for grinder, one exterior plug and another that's used for charging. Working outside I can reach the switch if needed.

Had the opportunity to re-drill moms 24 kitchen cabinet doors for new hinges, painful but so much easier being able to have both hands free with the 'new' foot pedal. I like it. Like it a lot HOWEVER....

Wiring of new outlet, oops...

REV 1 using stock drill switch

Ok fixed the back feed...As noted this is only a problem if drills cord is not plugged into pedal and prongs are exposed (like using pedal for grinder) but needs to be fixed. I was thinking relay-diode or some other electrical shamancy wazoo mechanism that Im unaware of. Writing this disclaimer, looking at diagram realized that if I simply replace the drills on/off SPST switch with a SPDT on/off/on (or actual any thing other than SPST) gets rid of any back feed potential. Eliminates any potential of having male plug energized.

When in drill mode still acts as on/off but when turned on -it disconnects/isolates form pedal line. It would select which line is hot but still function as on/off switch for drill-disconnects the other line not energizing both...why didn't this occur to me while I was in there? Got focused on back feed instead of eliminating the reason...
Here's a good explanation of switch definitions SPST SPDT DPST & DPDT switches if unfamiliar with the options..

Knew there was a reason for documenting this... Other than to share the availability of better micro switch for your foot pedal. Now to find switch that fits and rated high enough....

UPDATE!! couple years later. Rework/repair of drill, I needed to unwire hardwired power-again. Second time, so rewired with a plug and added second receptacle (which I was too lazy the 1st time). Shown on Table lift bracket replacement page, but also adding here.

Functionally the same, just for my own documentation- drill plugs in verses hardwired.

Replaced drill press switch

Found an 15 amp SPDT switch on/off/on at radio shack. The 3 position switch effectively selects which power source feeds motor and isolates them from each other. When switching drill on/off at press it doesn't energize pedal line now and vise versa as wanted, but with the center off position also allows me to turn off input from the pedal in pedal mode without reaching for main power outlet switch. Nice when Im standing there-need to reposition work & not accidentally hit pedal.

DONE...

Cool-though my $5 dollar yard sale find ended up more like $35. May seem a convoluted approach-it was...but now that its done it works well. Have switched power outlet that sends power to drill to use normally or to energize pedal without unplugging cords. Have new switch on drill that allows normal on/off from either power source or interrupts input from pedal. Have power pedal control that's rated for 22 amp, has a fuse and a pilot light. If I choose I can unplug drill from pedal and use pedal for grinder.

Conclusions:

What I would have done differently...now that its done. I realized the fuse I added to protect the pedal micro switch also protects drill, but there is nothing on the hardwired input. So should add another fuse (or maybe small reset able circuit breaker) to the hardwired input wire at switch. Yours may already have something, this drill doesn't. Seems silly to have fuse on one input and not the other. So I'm going to add another fuse & holder on the direct feed side of new drill switch so both inputs are fused.

The new switched outlet box, though I needed another plug for light, by changing the drills switch to SPDT this switching function may have been accomplished more simply., but I briefly think might require a DPDT switch.

I do highly recommend at minimum adding a fuse to your foot pedal-the internal micro switch will otherwise be weakest link and blow if there is any issue. I would also upgrade the internal micro switch as its probably rated at 15amp, unless your drill is rated less (and what ever else you might use pedal for) and could use a smaller fuse. Having pilot on the pedal is also nice. All the other convoluted wiring/outlet boxes unnecessary but does allow use of drill with or with out pedal at the flick of switch. New SPDT switch allows control regardless of input. You could accomplish what I did by simply adding another pigtail to feed drill directly to SPDT on/off/on switch. One plugs into foot pedal, the other into wall outlet. SPDT switch determines which source to use, either manually at switch or from pedal.

Silly stuff I call fun...enjoy

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