No grinding Motor runs but the grinding blades don't

The nut that holds the blade on May gave come loose. Or motor is shot

If your Bosch 3915 compound miter saw is making a grinding sound when it slows down, it could be an indication of a few different issues. Here are a few things you can try to fix the problem: Clean the saw blade: A dirty saw blade can cause the saw to make a grinding sound. Use a brush or compressed air to remove any debris or sawdust from the blade. Check the blade for damage: A damaged or worn blade can cause the saw to make a grinding sound. Check the blade for any chips or missing teeth, and replace the blade if necessary. Check the bearings: The bearings on the saw's motor and blade can wear out over time, causing a grinding sound. Try to move the blade side to side to check for any play or looseness. If the bearings are worn, they will need to be replaced. Check the motor brushes: The motor brushes on the saw can also wear out and cause a grinding sound. Check the brushes for wear and replace them if necessary. Lubricate the saw: Lack of lubrication can cause the saw to make a grinding sound. Use a lubricant designed for power tools to lubricate the blade and other moving parts of the saw. If none of these steps solve the problem, it's best to take your saw to a professional for repair. Grinding sounds can be an indication of serious issues, and it's important to address them before they cause further damage to your saw

YOU PROBLEPLY WORE OUT THE WORM GEAR.ALWAYS KEEP YOUR BLADES SHARP. I HAVE THE SAME SAW AND THE ONLY PROBLEM I HAD WAS I BROKE THE DUST BAG OFF, MY FAULT.

While I don't have this brand or model of grinder, (coffee beans, spices?), I use a small elec. grinder for grinding coffee beans and unless the grinder and cover or perfectly lined up and locked in place, it willnot grind, a safety feature. Check and make sure everything is lined up so it closed with all the lines in place and the grinder is also put into the lock position.

I've long ago lost the manual that came with my grinder (I actually don't remember if it even had one), but I don't think it listed grinding times. You just grind a few seconds and check, then grind a little more if it's still too coarse. Unlike a burr grinder which is adjustable, in a blade grinder the same grind time may result in different consistencies as you change beans. By now I've just learned how long to hold the button for the different beans I buy, and the first few times I try a new blend or varietal I have to adjust the time. I think you'll just need to experiment and then you'll know what works best for your tastes.

Have you ever heard of the saying: A penny on the rail will prevent a locomotive from starting, but a locomotive will run over the same penny at speed.
This is what I think you have here. A coffee bean is preventing the blades in the grinder from grinding. Just like a garbage disposal, turn the blades (UNPLUG THE MACHINE) backwards to free up the blocked or binding blade, then try again. Depending on the age of the unit and frequency of use, the grinder motor may have failed and needs replacement.
Good luck.

This can be caused from a broken by a brken grinder motor or even broken grinder sensor.
However this can be cased by a stuck grinder from grinded coffee to the grinder bledes. So you try from the last posible problem by removing all the coffee beans from the machine and by the use of a vacum cleaner try to **** all the remainings both beans and grinded coffee. If you can remove the top panel then you will have access more direct to the grinder and by the use of painting brush and vacum cleaner you will be able to clean the grinding blades mere intesive. Try to rotate the blade manualy to be sure that they can run after the cleaning.
So now you will be able to add some beans and try the machine again. If the probelm remains then you will need a new motor.
Good luck.
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I am assuming you refer to the spinning of the motor, but not the grinding mechanism? Often times, the blade, grinder, or whatever does the actual work is on a shaft from the motor. There is a 'shear pin' through the blade, &tc which not only holds it on the shaft, but causes it to turn. If something jams the cutting part, the pin 'shears' off, to protect the motor from burning out. It sounds like that is what has happened to your grinder. The shear pin bits must be removed from the grinder and the motor shaft and a new one inserted. Usually, a common 'roll pin' will make a suitable substitute. Just make sure it is the proper diameter for a tight fit.
The motor shaft spins, but the blade, &tc does not turn.

The blade will spin automatically when the motor runs because it is connected to the main shaft. If it is not cutting, it will have to be removed and sharpened with a grinding wheel