[rickst29]

In my older TM, the swing hitch A-frame head was custom built an out-of-business dealer, who knew the factory swing hitch of those years to be waeak on d prone to cracking.

But, like other TM owners replacing an older atwood jack, I needed to widen to lower 2" hole the accept the 2-1/4" outer cylinder of a more modern (and stronger) jack.
I bought a 2-1/4" hole saw (a 'Milwaukee' saw new from ebay), but I had some pretty severe issues with it - primarily the fact that I did not have a 2" hole saw (using a compatible arbor) to insert as an inner guide through the existing hole.

I tried using a 2" plastic bottle lid as an "insert", reaching slightly below the teeth of the Milwaukee hole saw - but I had issues with the "insert" spinning off the drill bit arbor and falling the the floor as i worked. The fact that my Milwaukee bit was not uterly perfect in roundess didn't help, that caused more vibration to shake my insert loose.

In the end, with the job only 1/2 done, I switched to a using a rounded file by hand (with oi as lubricant). The cutting was much more precise. to my surprise, I also found the cutting speed to be pretty fast. (About 5 minutes, 10 minutes if I'd done the whole job by hand).

My end result is pretty good, but I wasted considerable time with the drill. I SHOULD HAVE use the file to begin with, or taken the removable "swing hitch" head to a machine shop for alignment in a quality drill press.