Table Levelling
It is precisely the behaviour of the machine when you stop moving it that indicates whether the table is "level" or not. In the early days we used to use a spirit level, and I even heard of one customer using surveyors’ equipment to level the table. But now, as I said, we rely on what the machine is doing to indicate whether the table is adjusted correctly for the machine. The energy chain exerts its own tiny forces, you see, so "level" becomes an ideal concept.
Move the head to one end of the table and test the behaviour by nudging it back and forward across the table. You’re looking for a consistent amount of roll in each direction proportional to the force of your nudge. You’ll find it easier to wind the feet up and down if you first move the machine to the other end of the table (which you will have to do anyway to get that end of the table right). Keep testing at each end of the table until satisfied. The middle should look after itself if the ends are OK, although this area is more important than the ends because that’s where you do most of the work. If the machine still rolls off at the middle, you’ll have to sacrifice the ends to justify the mean (middle). If your machine stands on carpet, you’ll probably find you have to do this a couple of times until the pile settles.
For longways adjustment we developed "the rubber band test" (purists only). Take one large rubber band and put it around the spool pin on top of the machine. Now use it to drag the machine in one direction and note the stretch in the band required to keep the machine moving at constant speed. Now reverse the direction. You’re looking for the same stretch in both directions. The rubber band is a primitive force gauge.