Metal shavings from grind chamber

#1: Post by **marriedman77** » March 7th, 2016, 10:51 am

Hello, I am in charge of the coffee at my church and we recently switched to whole bean coffee. We purchased a g9 coffee grinder for a bargain. I am now tasked with adjusting the grind and setting the timer. The problem is when I adjusted the grinder, I am now getting metal shavings falling out of the grind chamber. I have cleaned the hopper and grind chamber, there is nothing falling down into the chamber. Also the burrs are not touching. Talking with the tech guy the only thing we can think of is the auger is rubbing against the housing when it spins. Any help would be appreciated.

#2: Post by **Randy G.** » March 7th, 2016, 12:08 pm

I would think that there would be some visual indication where this was taking place (scraping marks, shiny areas, etc.). You certainly cannot use this grinder until the problem is solved.

Is it still happening? If so, and you have access to the suspected area, mark the rubbing parts with a dark magic marker or sharpie and run it again. The area of friction should be easily seen that way.

March 7th, 2016, 1:25 pm

I will try that when I get home, but even if it is rubbing the actual housing as it spins or the cover plate. How would you remedy something like that? Me and the tech guy thought that maybe the auger is slightly off balance causing it to hit the edges of the housing. Have you heard of this problem before?

#4: Post by **Randy G.** » March 7th, 2016, 3:29 pm

I have not used that grinder nor am, I specifically familiar with it. If it was purchased new I would consider getting it replaced and also call Bunn and see what they say. I have to think that any spinning part that is off center could be seen if the burr was turned at slow speed by hand, or it would cause vibrations when running. But metal shavings? That's not good.

March 7th, 2016, 7:03 pm

I would agree. Metal shavings are not good at all. The church purchased the grinder used. Originally I spoke with technical support at Bunn and we both thought it would need a new auger rotor. But when I turn it by hand there is no visible " wobble". when I got home and ran it a few times, no metal shavings. When I put the coffee in it started to get louder and cause metal shavings. I took your advice and and marked the edges of the rotor and the back. Turns out the edges are fine...its actually hitting on the back. So its the actual cap that contains the adjustment screw.

#6: Post by **ira** » March 7th, 2016, 7:06 pm

Take the adjustment dial off and post a picture of the insides with both burrs in place. There is a metal hat that sits over the end of that assembly, if it's missing you get metal shavings. I believe that's about the only reason you can get metal shavings. Or maybe a seized bearing on the end of the adjuster.

Ira

March 7th, 2016, 7:24 pm

I will post a picture when I get back home. That metal cap is in place. I marked the cover plate with a sharpie and when I turn it on and pull the cover back off. The sharpie marks are gone. Some how even with tension on the adjustment screw it is hitting that cover she it spins.

#8: Post by **ira** » March 7th, 2016, 7:55 pm

That cover holds the shear plate in place and should touch the outside edge of the bearing on the end of the adjustment shaft. Make sure that bearing spins and that the metal cover only touches the part that spins. There should be a raised rim pressed on the outside of the bearing that sticks up and the cup should only touch that raised edge. That part comes as an assembly and if someone decided to replace that bearing and didn't remove and replace that sleeve it would not be good. It's readily available for about $80 if that's the problem. If that's the problem and a church member has a lathe, they could probably fix it for you in a few minutes. I could if you were in Los Angeles.

Ira

March 8th, 2016, 9:24 am

Are you saying that little black thing on the end of the adjustment screw? That actually touches the metal cap.Because that doesn't spin.also thought it might be the actual auger rotor, which I have.

#10: Post by **ira** » March 8th, 2016, 1:21 pm

First you put on the auger, then slide the double slotted drive piece in, next place the shear plate in the slot on hold it in place with the metal cup.

On the other side is the adjusting screw attached to the the big adjusting knob. On the end of it should be a bearing which has a ring pressed on the outer race which is the only thing that should contact the metal cup we put on last in the steps above.

Ira