# Anyone broken the gear on the Grizzly mini-mill?



## HMF (Sep 30, 2011)

From what I have read, there is a "sacrificial' plastic gear under the plate the motor fixes to that breaks quite easily when the mill is under stress?

Has anyone broken that and had to replace it with one from Little Machine Shop?


Nelson


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## Hawkeye (Sep 30, 2011)

If the Grizzly is the same as the HF X2, then it is the same as the one I have. The gear train exploded after a couple of years of faithful service. When I was looking for the LMS site, I found quite a bit of information on replacing the gears with a belt-drive system. There are kits available, but I have a shop, so I tend to make what I can.

I had some aluminum plate in the scrap bin and picked up a sewing machine belt at a repair shop. This works so well, I'd recommend converting your mini-mill even if the gears haven't thrown chunks yet.




Mike


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## hq308 (Oct 1, 2011)

I broke one of the plastic gears on my X2 clone, the one thats connected to the change lever. To change it I had to take the head off the column, as you can only get to it from the back of the head. While I had it apart I also noted another plastic gear on the spindle as well as the one that runs directly off the motor, making it 3 plastic gears in total. 

I plan to do something similar to Hawkeye when my machining skills are a little better.


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## Hawkeye (Oct 1, 2011)

I worked out dimensions suitable for space available, then kept checking ratios by math until UI thought it would work. It does. Not an original concept. Kits are available (not from me) if you don't have time to make your own. A quick search like "mini-mill belt drive" should find lots of references.




Mike


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## hq308 (Oct 1, 2011)

Thanks Mike ::thumbzup::

I am aware of the commercially available kits (Little Machine Shop is one that springs to mind) but without modifications they won't fit my mill as it's an upgraded version of the X2 with a bigger electronics box (not sure what else you'd call it) that gets in the way of the pivot for the new motor mount. I can move the box down but I have to do an air spring conversion first.


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## hq308 (Oct 2, 2011)

Here's a couple of pics of the gears, the gear on the left is the one at the top of the gear change mechanism, the one in the middle is the one that is on the spindle and the one on the right (the one I broke  ) goes on the gear selector shaft. The spindle gear and the selector gear are both inside the head, which needs to be removed from the column to access them.



An this is what the broken gear looks like. :-[


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