June 24, 2012
Adding a Switch Box to Model 61 & Older Saw Filers
Adding a front-mounted switch box will make your Model 61 and earlier filer easier and safer to operate. The 1725 rpm motors used on saw filers have a tiny space for a toggle switch and wiring. This space is usually too small for a new switch and power cord. However, many motors also have a front knockout sized for ½ inch electrical fittings. This makes it possible to attach a full-sized electrical box with plenty of room for wiring and your choice of a switch. The required parts listed below are readily available:
Rectangular steel box with ½ inch knockouts
½ inch box spacer
16 or 14 gauge stranded insulated wire rated for 110-120 volts
Crimp style terminals
Toggle switch of sufficient amperage
16 or 14 gauge 3 wire power cord with oil resistant cover (the cord from an old power strip or surge protector may be ideal and cheap)
The steps are:
1. Be certain that you have all required knowledge and skills necessary; otherwise use an electrician. In addition, I recommend that your filer be connected to a GFCI receptacle or breaker at all times. Disconnect the power cord.
2. Drill the center of the blank cover for the switch you selected. Install the switch in the cover.
3. Pry out the knockout on the motor and remove the side cover which holds the old switch. Disconnect the switch and remove the old wiring and power cord, noting which terminals are hot and neutral. Many of the nuts are an odd size, 11/32 inch, so a nut driver this size helps (Sears has them).
3. Remove the nuts from the box spacer and screw it into the motor’s knockout. Do not over-tighten. If your motor lacks female threads, use the nut furnished with the box spacer.
4. Turning to the new box, punch out the rear center knockout and a side knockout for the power cord. Install the grounding screw and a clamp for the power cord.
5. Use the stranded insulated wire and ring terminals to make connections from the switch to the motor. The power cord black wire connects to the switch. Another black wire goes from switch to the motor’s hot terminal. The power cord white wire goes to the motor’s neutral terminal. The power cord’s green wire goes to the ground screw in the box, with another green ground wire going the motor housing (not shown in photos). All connections should be made with ring terminals of the correct size for wire and terminal posts.
6. After double checking everything, assemble the cover to the box, making sure no bare connections are touching each other or a ground. Replace the original cover on the side of the motor. Ideally this hole should be plugged. Notice the plug on the left side of the box I used (the box was already on hand).
Posted by Mark Stansbury