Nutool bench grinder/sander is it possible to get a manual for this machine it is a NTG6L-4.

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: 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.

Testimonial: "This was very helpful. I have ordered parts from Grainger. Thank You."

SOURCE: I am looking for a Dayton Bench Grinder Manual

I would try and call Grainger parts to see if they have one. I know they deal with and sell Dayton equiptment. If no luck let me know and I will try and find another source.