The gear ratio between transmission plastic gear and motor shaft gear is not a whole number. The machine is used for X axis,if you want to used for Y axis,a SUPPORT PLATE will be needed. X-axis power feed for Bridgeport type milling machines.
My vertical mill is not a supported model, but I was able to adapt this 450oz/in unit to a LHS drive using a steel plate, few sprockets and a length of chain. the handle has different detents behind it, and it can be converted to a horizontal mount pretty easy. drive shaft was 8mm, so a type 25 chain fit with some relief around what used to be the bevel gear.
It's Chinese, but with modifications (lathe work) you can get it to work fine
I got it to work with making a new shaft bushing. When set up properly, it IS noisy in both directions. It is made in China, so don't expect it to be of American quality. It did not fit my Enco mill because of my 5/8 shaft and the bearing in my original end plate. I had to drill and tap new holes to fit in my endplate. Maybe for other makes of mills, it will bolt in. Adjusting the gear mesh is a challenge, but has to be done properly or you will ruin the gears in a short amount of time.
The unit is very nicely made and has worked well on my machine. The one thing perhaps could be better is the lock ring for the graduated dial could be made from brass or steel instead of plastic.