Series II head mount to Series I ram?

I'm no expert, but VERY unlikely! I did a round-ram M-head to J-head update, and while VERY worthwhile, it was no bolt-on swap. the bolt circle was totally different. I suspect it would be the same on this. There's both a height difference and a "throat" difference to be concerned with. Also, you need to consider the WEIGHT of the head.

Jon

Thanks. I haven't seen the machines side by side in a while and didn't realize there was a huge difference in size. I moved the headless Bridgeport into my garage last night, avoiding tonight's snowstorm. Slid it off my landscape trailer and rolled it into place. Not too bad of a move, really. It's a 9 x 42 with 12" y travel, B'port power feed. Now it's time to get to work on the chiwanese heads.

I've got a 1 HP 1J head. It seems to be PLENTY of power for me! I had something pull loose from the vise, and after I'd shut the motor OFF, it twisted the head to about 45 degrees, with the end mill working up the side of the part, and me ducking for cover, expecting hot shapnel! I can't imagine how any machine with swivels in the head mount could really use much more power than that.

Most of the Series II machines had a rigid mount for the head.

Jon

I don't know about that. If the head is in good shape, and the bearings were installed by somebody that knows how to do it, that may actually be a good price. I paid more than that for a 1J in rather rough condition. The quill was seized in the housing, all small bearings in the motor and back gear mechanism were shot. But, the main spindle bearings had apparently been replaced, as they were still filled with the run-in lube.

In my case, I was upgrading a round-ram machine from M head to 1J, and it was the best thing I ever did for that mill!

Jon

Probably a marketing thing. It seems like manufacturers have been boosting the HP of the motors without changing anything else.

Well ... part of it is that I believe that the 1HP 1J head is step pulleys which you change by hand. The 2J which I have has the continuously variable speed pulley assembly, and I believe that those are rather inefficient, so you need more horsepower to do the same task.

And the Series II, I think, has a larger spindle, so it needs more torque and HP to drive larger cutters.

Enjoy, DoN.