What is motor starting capacitor of GB800 Bench grinder

SOURCE: Bench Grinders Safety issues

Goggles or safety glasses need to be worn to protect the operator's eyes from the sparks and metal filings that result. Depending on the workpiece and time of exposure, hearing protection may also be required, the dust produced is also potentially hazardous. The toolrest (or workrest) should be mounted slightly below the center of the grinding wheel with less than 3 mm clearance from the wheel. This prevents the work from jamming between the toolrest and the wheel. Grinding wheels designed for steel should not be used for grinding softer metals, like aluminium. The soft metal gets lodged in the pores of the wheel and expand with the heat of grinding. This can dislodge pieces of the grinding wheel. Wire brushes require particular attention for the safety of the operator and bystanders as the metal wires may become dangerous projectiles as they could bind with the object being brushed and so throw it away with great energy. The machine needs to be securely mounted to a pillar or a bench to be used safely and effectively, often with an emergency stop switch or pedal fitted close by the machine, for use in emergencies.

SOURCE: Given a bench grinder which did not work. How to test/fix?

I cleaned all the wiring connectors etc and used a 4-way extension cord with an i/o switch and thermal/arc breaker surge protector thingy. I had a piece of thick cable with a molded three prong plug which I had removed from a dead paper shredder (I think??) and connected the ground to the case (previously not connected) the black to the black and white to the white. I taped the connections and plugged the test cable into the extension thingy with its switch off and plugged it into the wall outlet. Then, with the grinder switch on, I gingerly switched on the extension thingy and the grinder (sans all moving parts) ie just the motor case and spindle (held securely in the B&D workmate) and viola(!) it worked fine and built up to very fast. I switched off the grinder switch and the motor slowed, taking an age to come to rest.
Then, I fitted a grinding wheel on the left hand thread end, tightened everything and retested, using the grinder switch to start it and it spun really fast.
Soooo, I guess the secure ground is an essential feature of a capacitor induction motor. I checked some old furnace motors that were "maturing" in the basement and they had no capacitor but only 2 wires...
I am now trying to remember which parts came off last and put it all back together. I plan to test it each time I put a part back...just in case. I hate it when you fix something on the bench and when rebuilt, it won't work...don't ask about the electric starter on the snowblower..not a happy puppy!
Please, pretty please and then some, do tell me if my "fix" is wrong and I could risk all kinds of nastiness.
Thanks,
Jenni.

SOURCE: switch and capacitor crapped out on 1/2 hp Sears bench grinder

Replacement should be simple. Just do a one for one hookup with the new part, after you unplug it first.
For a diagram go to;

http://www.searspartsdirect.com/partsdirect/getSubComp.pd?modelNumber=397.1949&productCategoryId=0721000&brandId=0247&modelName=CRAFTSMAN-1%2F2-H.P.-GRINDER&diagramPageId=00001&documentId=00023041&pop=flush

SOURCE: bench grinder, 110/220?? wired up properly

LIKELY the capacitor which is usually in the base is bad.

The capacitor shifts the phase angle in one of the two windings which creates a pseudo rotating field to start rotation.

SOURCE: Need part numbers to replace eyeshields on Dayton bench grinder

Your grinder is listed on page 3085 of the Grainger catalogue. The part number for the eyeshield is 00281.00 and the number for the lower eyeshield bracket is 00280.00. The right hand upper eyeshield bracket is number 25188.00 and the upper left hand bracket number is 25177.00. All of this can be ordered through Grainger at 1-800-323-0620. Marvin T.

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