I took off the grind settings knob on my Bunn G2 grinder... and now it won't grind!

Check bunn.com for a free download of your model's manual.
You should contact your vendor for service.
*** the following is for information only. Service should be performed by a qualified tech.***
* Most Bunn grinders usually have an adjustment screw in the middle of the burr plate housing.
* LPG is under the bottom chute. It's hard to see and you may need a mirror. Take a stubby flat blade screw driver in the slot and turn as needed, but go a quarter turn at a time!
* G2/3 have a large dial with the grind sizes clearly marked out. There is an adjust/calibration screw in the center of the knob.
* G9 have a large bolt in the center of the burr with a slot that could fit a quarter coin in it. You must un tighten the locking nut to turn it. Make sure you lock it down again after the adjustment.
* Final; if there any loud noise or grinding metal sounds or the motor hums and stops. Then turn off grinder right away. Back off whatever you did last and try again. If it's still making noises then unplug and call your vendor for service.
Aloha, ukeboy57

You should call your vendor for service.
*** The following is for information only. Service should be done by a qualified tech.***
* Check bunn.com for a free download of the G3 manual
* If turning the dial does not change the grind size then the inner burr spring is broken, stuck, of missing (it broke into small pieces to fall into someone's coffee grounds). Call vendor for service.
* If turning dial is very loose then the lock screw is loose. check setting then tighten down to lock into place. It's usually a small 1/4" hole on the side of the knob.
* The burr plate may be gummed up and stuck in place. Especially if oily beans or 'flavored' beans were ground in this machine often.
* It's possible the Grinder is WAY out of calibration. It's so far out of adjustment that the only setting is fine when the dial is set on course ground. This grinder was not assemble correctly. Check the parts diagram. Call your vendor for service.
Aloha, ukeboy57

Just replace the relay which drives the grinder.

Thats all
You are good to go

Thanks
Please rate my work

You will have to dismantle the grinder, removing the 2 bolts at front, then working your way back to the grind chamber, You can find the diagrams for the machine on bunn.com

Grind Adjustment Tools required: Large blade and medium Phillips head screwdrivers In order to adjust the grind, follow these steps (Refer to figure A): 1. Remove all coffee from the hopper. 2. Set selector knob to the finest setting (Espresso or Turkish) depending on the model. 3. Loosen both knob retainer screws in selector knob one turn only. 4. While pressing the bag switch, located behind the spout, press the START button so that the grinder will run during adjustment. 810 model - Press the ON or START button so that the grinder will run during adjustment. 5. With the grinder still running, turn the adjusting screw in the center of the selector knob slowly to the right until a slight clicking noise is heard. Immediately turn the adjusting screw to the left one grind setting. This is the finest grind obtainable. 6. Tighten both of the knob retainer screws. Once the ESPRESSO grind has been set (Turkish for Model 835, 875, 890), the other grind settings will automatically set correctly. 7. Press the STOP or OFF button. IMPORTANT: Always be sure the grinding burrs are not touching while the machine is running on the ESPRESSO/TURKISH setting. Otherwise serious damage to the motor may result.

It sounds as though your grind is out of adjustment. The grinder is probably set too fine. I have not worked on a G3 grinder but I would think it is like the Bunn G2. On the front knob you will find 2 small set screws and one larger adjustment screw (in the middle of the knob)
1. Set the selector knob to finest setting (Espresso or Turkish)
2. Loosen the 2 set screws about 2 turns.
3. Activate the start switch (you must activate the "bag switch" behind the chute)
4. With the grinder running, SLOWLY turn the center screw clockwise only until you hear a very slight whirring sound (this is the burrs touching).
5. Then, back off the center screw counter-clockwise about 1/8 of a turn, shut off grinder and re-tighten the set screws.
Check the grind in the "drip" setting by running a few beans through... the grounds should be about the consistency of sand. You should get a better flow through the machine with the grind adjusted properly. You may want to check the cleanliness of the hopper in the top... I have seen these dirty enough to impede the falling of the beans to the grinder.
Also, whenever you remove (for cleaning) the 2 larger screws that hold on the front "plate", be sure to put them back in evenly... kind of like one would with a wheel on a car- Finger-tight then slightly tighten each on a little at a time (back and forth) until tight.
Hope this helps.

sharpen it blade dull

That one is hard to explain but I will try. On the front of the grinder is the adjustment wheel, on the wheel is a small screw, if you put your hand on the wheel it might be about 1/4 inch from the front, back up screw about 1/2 turn or more then make sure the grinder is on 3 or espresso, make sure you can pull out front part of the wheel ONLY. If not back up screw a little more and try again, now that it can move freely without moving the numbers, pull it out and turn it to about 5 or 6 then turn grinder on and very SLOWLY, (This is the dangerous part do not go to fast or you could damage the grinder) turn towards trukish grind when you get close you will hear the burrs slightly touching. Back off the knob a little just before the touching part and turn grinder off. Then pull knob out and turn it to turkish and set screw.

First turn grinder to coarse setting and try grinding some white rice through it, that will clean out the coffee oils, if that does not work then the you will have to open the grinder and clean out the burr chamber and the spout for the grounds.

For this job, you will need detailed instructions. You can download a use and cleaning manual for this Grinder at this adress: http://www.bunn.com/pages/techdocs/manuals/grind.html