KitchenAid Food Grinder Attachment: THE PROBLEM

I used this Food Grinder Attachment (FGA) with my Artisan KitchenAid (KA) today and found a major fault. I have seen the same problem described on Amazon.com and other places where reviews can be published. The best description was made by bwalt822 on ChowHound and it can be read in the thread here: http://chowhound.chow.com/topics/759360. 


The FGA was bought December 2011 so it only applies to the models sold in that time.


Basically, the auger shaft (which looks like stainless steel) is rubbing (as it rotates) against the center hole of the grinding plate (also appears to be stainless steel). The rubbing is causing small metal particles to be ground off, either from the plate or the auger. If no food is run through the FGA, then the metal shavings will stay on the plate. However, once meat juices or small particles are squeezed through the center of the plate, around the auger shaft, the juice (and probably fat) carry the shavings out into the meat. The meat around the center is thus colored grey.

Here is what bwalt822 wrote:

It may seem rather bold of me to say this but I am certain that KitchenAidUSA is wrong about where the grey ooze is coming from. The oil impregnated copper bearing is in the rear of the grinder where the auger shaft sticks through the housing and into the mixer. If this bearing did discharge an oil it would be mixed into the meat and it wouldn't be noticeable.

I used my grinder for the first time last night and I am 100% sure of the source of the ooze that I also experienced. It originates where the metal auger shaft rotates against the metal grinding plates. The ooze is metal dust mixed with fat and oil from the meat being ground. If you look at the shaft where it contacts the grinding plate you will see groves that are formed from the rubbing. Where do you think the metal that used to be where the groves are went? Does anyone notice that this black ooze looks very similar to the black ooze that might be found around a previously clean oiled or greased bearing? You wont get this ooze while grinding dry items like bread crumbs because it falls into the bread crumbs as a very fine powder which isn't as noticeable as drops of what looks like black grease. You also probably wont notice it when grinding very wet items like tomatoes because it will mix in with the juice and thin out to the point where you cant see it anymore. 

In any case if someone were to have the ooze tested I am certain all you would find is steel particles and animal fat. It is also not related to overheating as my grinder and meat was still cold when I finished. The reason that it may take a few minutes for the oozing to start is because enough dust has to be created and it takes a little bit for the animal grease to be pushed out of the center hole and collect the dust.

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I read your post [referring to Sunshine842's post] and I'm going to disagree. There is no oil in the grinder to leak and there is no way for oil to be transported from the mixer to the grinder. If there was a problem on the mixer side you would surely see a lot of the black substance on the square drive shaft. The center hole in the grinding plate is the origin of the black substance, I saw it dripping out of there and only there last night. The only place the substance was present was near the interface between the axle and the grinding plate. Oil cannot pass along the metal axle underneath the plastic auger and out through that hole. 

The grinding plate center hole is essentially a poor bushing and i'm guessing the quality of the metal in the axle isnt the highest grade steel either. This machine operates slowly enough to be able to rub metal dust off without making a lot of noise. I hope the issue will go away once the axle seats with the grinding plate. 

Additionally the grooves on the shaft gave a source for the metal dust. It doesn't take much metal dust to turn a little bit of fat black.

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Again, have you actually seen the problem or are you trying to apply your knowledge of a machine shop to a meat grinder? [Again, responding to Sunshine842] 

I'm not doubting that grease and oil can flow from small holes but why would it only flow through a rotating part and then out of the device that at the furthest point from any possible oil source without flowing anywhere else. The nearest source for the oil is the copper bearing on the other side of the auger and then after that its the mixer itself. I would certainly see it on the side of the auger closest to the copper bearing can purportedly leak small amounts of oil. The small bits of fat wrapped around the auger upstream from area where the leak was visible were still perfectly clean and white which proves that it originates at the metal to metal interface of the grinder plate.
Otherwise the oil would have to leak out of the bearing, travel along the axle, around a tight o ring, then under a very tight fitting plastic piece, then underneath the fat that builds up near the grinding plate, and then out of only the center hole. All the while it leaks nowhere else and leave no trace of a leak on the axle around the bearing. 

I had followed kitchenaidUSA's directions and still had the problem.

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Ok i just did some testing because I am going to make sausage tomorrow and dont want a bunch of black spots in the sausage. 

I assembled the grinder and then ran it dry for a few minutes. Almost immediately metal dust started dropping from the axel/grinding plate interface and there was a very quiet squeaking noise. There was no "leftover machine grease" anywhere else which shows that KitchenAidUSA is full of it. Then not wanting to run the machine dry for too long I put some crisco on the areas where the metal rubs. It quickly became dirty with the metal dust and eventually melted from the heat. A few minutes after the crisco melted i turned it off, cleaned it and repeated. The next time there did not seem to be as many shavings as I believe what was causing it is being rubbed down. After a few more repeats there a lot less grey ooze and the crisco does not melt very fast which is indicative of less friction and less rubbing. So I think these grinder just need a break in period. 

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Yeah Kitchenaid is full of it, their customer service just says whatever will delay customers enough to have the 1 year warranty expire. If they had to admit what the real problem is they would end up doing a recall or shipping out new plates, blades, and augers to anyone that wanted them. Meat heated to the point of carbonizing, lol. It cooks and grinds the meat at the same time saving you hours in the kitchen!!!