How to wire the switch up on a dewalt dw758 bench grinder

Mmmm... that's a little more complicated. If you have a continuity / resistance meter, we can noodle it out, though.

First, are the two white wires the ONLY wires coming from the motor? I suspect they are - that's not in conformance with any accepted color code, but it'll work. For the rest of this, I'll assume that the two white wires are the only ones from the motor.

You'll need to meter the switch itself, with no wires connected to it. In the OFF position, you shouldn't find continuity between any of the four switch contacts. In the ON position, you should find continuity between two pairs of contacts.

The black wire from the power cord should go to ONE of the two switch contacts in a pair that have continuity with the switch turned ON. One (either) of the white wires from the motor should go to the other switch contact IN THAT PAIR.

That leaves you with one more pair that has continuity with the switch turned ON. The white wire from the power cord goes to one of those, and the second white wire from the motor goes to the other one.

When you have it all wired up, plug it in & turn it on. If it's not right, it should immediately pop your circuit breaker. If it IS right, it should run fine.

If it pops your circuit breaker, open it back up and swap one wire from the power cord and one wire from the motor.

http://www.searspartsdirect.com/partsdirect/user-manuals/DW756TYPE1-Dewalt-Parts-BENCH+GRINDER-manual

The link should connect to the manual for DW 756. If the link does not work, go to the Sears parts web page and look up the grinder.

Maybe wrong color wires used connecting over the (capacitor)start winding giving a wrong rpm, or just only a worn stator coil.

Replace capacitor

You could connect the wires of the switch together inside and bypass the switch. Then I would connect in the power cable a switch rated for 1 hp. You can use surface mount electrical box, with two cable connectors (one for the cable going into the grinder, the other for the cable going to the male cord end of the cable. Install a 120 volt switch inside the box (similar to the light switch in the wall). Make sure that the switch is rated for 1 hp. I would install the switch under the bench, under the grinder.

Joe

Yes, the wobble can be fixed. First, remove both wheels and check the shaft bearings/bushings for wear. Make certain the grinder is unplugged and mounted securely. Try moving the shafts up, down side to side; there should be little or no noticeable movement. If there is movement it is a major(time and money) problem. I'm not familiar with what the shafts ride on. It could be, ball bearings(the best-long lasting, least friction, most accurate, but expensive), sealed bearings(almost as good as ball bearings, with many of the same attributes) and bushings(least expensive to produce and fit and cause the most friction. If excessive up,down side to side movement is present a decision must be made as to how much money/time you want to invest. If the shaft exhibit little movement; check if the shaft is running true/straight. Turn the grinder by hand while observing the shaft for bends. If none are seen by eye use a magnetic base micrometer to check run out(deviation from straight). If a micrometer isn't available; bend a short length of wire(coat hanger works nicely) with a small hook on one end and then put a pointer end on the other. Put a screw thought the end with the hook to mount it to the base of the grinder. Then bend the pointed end so it just touches the shaft. Rotate the shaft and notice if the distance changes between the point of the wire and the grinder shaft. Repeat for the other side. A couple of thousands won't hurt. However, any more and the cost effectiveness of tearing the grinder apart straightening the shaft must be considered. The most common cause of grinding wheel wobble is the wheels becoming out of true and/or unbalanced. This is easily cured with a wheel dressiing tool. The tool grinds the wheels in place. By gringing the wheels on the grinder they balance the wheel, true the wheel to the shaft and clean it of imbeded soft materials, aluminum, wood and so forth.

The neutral line should never be switched--only the hot wire (black). If there are only two wires that went to the switch, you should be able to tie them together and the motor will run when plugged in. The switch should be a common SPST type either toggle or rocker to fit. Hope this helps!

My experience of bench grinders suggest 15 amp will be enough, certainly at 240 volts . If you are 110 then I think it will still be enough but you dont make clear what the wattage of your machine is.

I had the same problem with a Northern Tools bench grinder. These are made in China and parts are hard to come by. I had enough room after removing the old broken on/off switch to install a single pole 15 amp light switch like you use in your home. I simply installed it horizontally and then put the switch cover on. It works perfectly. If you do not have enough room then look for any 15 amp or larger switch that will fit in the housing. Any on/off switch will work. You could even mount the switch on the bench in a switch housing and run the wires from the grinder to the switch and back if need be. Just be safe and make sure there are no exposed wires. As a last resort you could remove the switch connect the wires, eliminating the switch and use a plug in wall switch such as this.

our bench grinder can be used to keep your chisels, knives, gouges and other similar cutting tools sharp, which every woodworker knows is vitally important. Also, bench grinders are handy for sharpening lawn mower blades, drill bits, gardening shears and more. Additionally, a bench grinder can be used for honing and shaping metal objects when modifications are needed. For instance, perhaps you need to modify a door hinge to make it fit in a certain application. No tool is better for this task than a bench grinder.