Posted by RichardN on 12/12/2017 17:24:03:
As much as I like the designs here, some of which I have considered making, for an occasional use, is there an issue with just using the saddle handwheel for movement with a keyway cutter held on the topslide? I appreciate a few turns of the handle each stroke is less convenient than a single swing of a lever, but the same overall effect?
I've done at least one job like that on my Drummond M-type, a 5/32 keyway in an old Myford-style cast iron change gear. It works but very tedious. If I had more than one gear to do, I would rig up something like Rod Jenkins posted above, a long handle attached to the top slide.
On the Myford ML7 I would be wary that the apron casting is fairly flimsy Mazak attached to the saddle by three 1/4" Allen bolts so too much racking back and forth might be a bit much for it. (The Mighty Drummond's apron is a piece of 9/16" thick steel plate held on by 3/8" bolts so more durable.)
I plan to make a rig like the one Rod posted, but with the addition of three-position stop so it can be used for graduating hand dials etc. I have found that on homemade graduating tools it's hard to get rid of that last thou or two of slop between moving ram and body, which makes it difficult when cutting lines only four thou deep. So the topslide should provide a readymade precision slideway with zero slop.