I am starting on my Gantry router and the steel should be here tomorrow. I have lots (~140) of 12mm and half inch holes that need to be tapped for the rails and am looking for suggestions.  How do the "auto tappers" work. Do they reverse when you pull up? do they auto reverse by themselves? do they mount via a r8 for example or do they have a shaft that can be put in a Jacobs chuck and used in a plain old drill press?  who makes them? Sorry for all the questions, I hand tapped a couple of half inch in 1/4 inch steel yesterday and came to the conclusion that it is going to suck to do all the tap holes by hand.

Thanks,

Chad
 

Check this out http://www.tapmatic.com/index.htm

Do you know what taps you are going to need??? A hand tap isn't going to do it

Thanks Brian. Tapping heads, that is what I was looking for. Have my msc big book out and boy are those things Pricey! Did a re count and came up with 276 tapped holes ranging from #10 to 1/2.
I will be able to enter the "worlds strongest wrist contest" after I am done.
I purchased good hss spiral taps for everything so I think those will work. I guess I am going to have to bite the bullet and purchase one. 

Thanks for the link, now that I know what I am looking for I will do some digging and find something that will work.

Thanks,

CHad