Add 110v light to bench grinder-
After burning up the 12v light

Part 1 : FAIL
Replacing the very small low voltage light on my old Craftsman bench grinder with reading light that uses small projection bulb. Would have been ideal but... grinder light

The light on my grinder never really worked as you had to have a few inches away from wheel. Very small 12v bulb in a very small directional housing, shown on the left. On the right is the old brass 12v projection fixture from an RV that's been laying around forever.

. grinder light

Some rewiring and a of fiddling around got the fixture mounted to the flexible rod.

grinder light

Added the wood handle as this thing gets pretty hot but the light output is awesome. Light is perfect. Mounted to grinder, turned it on and bulb snapped. Assuming because it's so old then me handling while reworking old bulb just gave up. Tried another bulb- turned it on and it super nova'd before winking out while at the same time I realized its seeing full voltage. Its an RV light (automotive) chassis ground...mounting to the grinders frame ties the low and high voltage together- duh

Easy fix, made an isolator to go between light mount and grinder frame. Tried another bulb- nada, zip. Metered the light socket, its only showing fluctuating 1 to 2volts. Previously was putting out 14v. So whatever or however grinder generates the low voltage for light is toast. Bummer-just dumb. Had I made the isolator to begin with I'd be styling.

Now I have NO light- just pure ignorance. Well not ignorance, simple failure to see what was in front of me. Looking at the old light the bulb holder and mount is all plastic.Pretty obvious, totally isolated. Grinder has a separate return wire coming from motor that was connected to light. As the hots are all tied the low voltage was limited by the return wire. Which my new light is internally connected to chassis-. just dumb

Part 2: Adding a new 110v lamp

grinder lightKicking myself some more - ordered new 110v lamp..I found source for small machine lights, shipping was virtually same for 1 or 4 so ordered 4. Brought the per light price down to less than $10 each.

Easy modification. Abandon/isolate the low voltage circuit. Connect new 110 v light tapping grinders power cord connection at switch.

Using the new lamps switch, turn light on /off regardless of grinder on/off will be nice. Never liked the previous light not coming on till after grinder up to speed. However going on/off automatically with grinder also has merit. Could take opportunity to wire in a SPDT switch for light to grinder. Adding an on/off/on switch, tap incoming power to one side, grinders out put switch to other side. Allows light to be manually turned on/off with grinder on OR off. Or have light come on/off automatically with grinders switch...could. But I don't have switch on hand and this re purposing light project already costing more than the 'free' upgrade it started out to be.


grinder light

Lights arrived!

grinder light

Nice, shade is small but perfect for machine light. Laying out I pulled the plastic sheath off one. Surprised to find the 90 bend in the stem, wasn't expecting that. Not really an issue but just need to address for mounting.

grinder light

Actually not a bad thing having stand off. I could use washers or make another flat bolt on mount because hole in grinder base is too large.

grinder light

Or, if I was to keep the 90 bend, is drill smaller hole off to side. I have extra lights so I actually, if drilling, could add/convert to 2 lights! But not. I'm going to try to straighten one of the lamps stem and reuse grinders existing bolt on mount piece.

grinder light

Un wire as I want to heat tube to straighten.

grinder light

Spent a few minuets getting perfectly straight. Then ended up back bending as mount sets at a bit of angle.

grinder light

Added brass 3 way tabs to switch to plug in new lamp.

grinder light

For a bulb I sprung for an R16 LED. Cute little sucker. Cost more than the fixture though! But worth it. Several reasons, mostly I don't want a glass incandescent above grinder, just too many times have had stuff go flying. Certainly don't want a CFL. The LEDs are supposed to be a bit more vibration resistant than filament bulb. Instantly light up when switched on and run a LOT cooler. Bulb gets hot but tolerable- the shade barley gets warm so no problem directing. However centered without moving I am just amazed at the light output. Both rests are fully illuminated.

grinder light

Must have taken a dozen pictures trying to capture the lighting. LED just wigs out the camera. grinder light

Pretty stoked, real light! For my re purposing project that failed ended up spending about $25 to accomplish what would have been free. The end results worth the exercise. Been twisting that little 12v light around for years. No more waiting for grinder to come up to speed before light comes on. Back to top of this page

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