Upgrading My Vertical Mill
I bought a used Sherline Model 5000 vertical mill several years ago. I've mentioned in the past the problems that I have had with the limited capacity of the standard mill vise that comes with this vertical mill, and my mildly clever solution to the problem. However, the problem remained that the Model 5000 only has about 3" of travel in the Y-axis--and except for the very smallest workpieces, that just isn't enough. You can reorient a part to do the movement in the X-axis--but that only goes so far.
Anyway, I was thinking a few weeks ago about replacing the base (on which the Y-axis moves) and the lead screw as a way of expanding the Y-axis travel--but then I searched to see if anyone offered such an upgrade. Sherline will sell you what seems to be the Model 5400 base, which gets you a couple more inches of travel--but it's expensive, especially compared to the A2Z Corporation's extended travel base and lead screw, which cost me $255 plus shipping.
There were no instructions with it, and it took a couple of emails back and forth to figure out how to install the lead screw correctly with the existing wheels. But it does work, and works well. As you can see from the attached picture, I now about 9" of Y-axis travel--enough that I would need to add more height extenders between the mill column and motor/quill assembly to take advantage of all that travel.
Pretty obviously, as you add more extenders, you are likely compromising vertical accuracy. I probably will never use all the travel that this base gives me--but if I needed more travel in exchange for less Z-axis accuracy, it's available. The longer base also weighs a lot more, and makes the whole assembly more stable. (You can bolt the base down to a table, but then you lose the flexibility of being able to pick it up and move it to another work location.)