# Making gears on a GO 727 Mill



## iron man (Oct 27, 2013)

My Atlas compound gear went out and I was not going to pay $80 for a used one so it sounded like a good project. I made a quick setup with the rotary table I modified and started in.

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Since Grizzly does not have any instructions for this rotary table a good fella here on the forum helped me by making me a spread sheet for the gear tooth spacing. Here I am cutting the small gear first out of steel I also made the mandrel to hold the cutter since the grizzly one was only 5/8 and the cutter hole was 7/8. I also made the tail stock.

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Here is the finished gear not bad for my first one on this little mill.

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Now I made a mandrel to hold the gear blank I made from stress proof steel. I have started to cut the large gear now.

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Here it is for the first cut I did not take a full depth cut I made three cuts all together.

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Here is the finished gear the small one is pressed into the large one all ready for use in my Atlas 10" lathe.


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## iron man (Oct 28, 2013)

Sure Shawn the reason I did not make three cuts and then index was because I have seen these knee mills jump a few thousands when the cutter starts . The best way to keep the depth uniform with this mill anyway is make your depth adjustment and leave it along untill you are done then change depth and index again it also is a little less confusing for me anyway. These are steel with a pretty good depth of cut so I was trying to not be to hard on this little mill.. Ray


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## Shotgun (Feb 11, 2021)

This was a while back, but would you happen to remember what size gear cutter you used?

I'm looking for a 52 tooth gear, and the guys on ebay are asking around $50.  For that, I can get a cutter, make my own gear, and then have gear AND a cutter.


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## Mitch Alsup (Feb 12, 2021)

iron man said:


> Sure Shawn the reason I did not make three cuts and then index was because I have seen these knee mills jump a few thousands when the cutter starts . The best way to keep the depth uniform with this mill anyway is make your depth adjustment and leave it along untill you are done then change depth and index again it also is a little less confusing for me anyway. These are steel with a pretty good depth of cut so I was trying to not be to hard on this little mill.. Ray



Slitting Saws and Cutters are designed to take a full cut in one go.


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## derfatdutchman (Feb 15, 2021)

Shotgun said:


> This was a while back, but would you happen to remember what size gear cutter you used?
> 
> I'm looking for a 52 tooth gear, and the guys on ebay are asking around $50.  For that, I can get a cutter, make my own gear, and then have gear AND a cutter.


For a 52 tooth gear you would need a number 3 involute gear cutter. You will need to know what pitch of the gear is 6,8,12,24,32 or 48 so you buy the correct cutter.


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