With the table on the track and properly adjusted to move smoothly the procedure for removing the table smoothly is as follows:
With the vacuum broken, look through the alignment telescope and note the position of the ``delayed'' target. This is because one has to remove the short delay dihedral and this step will make it easier to re-align.
Locate cart free of limit switch, >1.5" from "Home."
Remove diehdral from optics table.
Unplug the cables.
With the air ON, put plastic shim stock between the magnets and the pull-down metal strips. For the two magnets on top, 0.025" shim stock (white) seems fine, and for the 4 side magnets the 0.030" coral (orange) shim stock was ok.
If necessary (for one of the carts), remove the right angle cable assembly to allow access to 2 of the screws in the next step.
For the following steps, keep careful track of your screws. The screws are all slightly different lengths and you will need to use the correct length for re-assembly.
Slowly and uniformly, unscrew the 6 screws that hold one of the top magnets to the table. This will lower the top magnet onto the white shim. Remove 5 of the 6 screws, but leave on of the screws that go through the table still attached to the magnet (but not suspending it) in order to keep the table from moving along the track. This will ensure that all of the magnets will be planted at the same places for a fixed position of the table.
Gently lower the 2nd top magnet -- this time take out all 6 screws.
Do the same for each of the 4 side magnets. You probably have to hold the shim in place by hand until the magnet clamps it in place and keeps it from falling.
If you just wanted access to motor assembly and magnets, then you can slide the air table away on the air bearings. If you want to remove the table then turn off the air now and continue the instructions.
Remove limit switch (3 screws from top)
Remove side plate along with air hoses to allow the pads to be secured to table before removal.
With rubber bands, JIG-CP1 and JIG-ML1, secure the pads to the table so that they won't fall off when the table is lifted. This is to make sure the roller ball bearings do not fall out and get lost. If they do, order new ones (5/16" diameter). JIG-CP1 is screwed into place where the side plate used to be and holds up the inner edges of the top air bearings. JIG-ML1 is used to secure the large (western) air bearing (although on one table, this may be secured in a permanent fashion. Secure the side bearing and outer edges of the top two air bearings with rubber bands looped around the table. See figure # perhaps. Alternatively, one can disconnect the hoses and slide the air pads out the side, but this will require adjusting the height of the air table which may lead to difficulties in adjusting the orientation when re-installing the table.
With all air bearings secured (or removed), carefully lift the cast table straight up and off the track, and lie it somewhere upside down. You can now access all these pads.
The part of the anorad table that is left behind is the long strip that contain the motor windings, the hall sensors, and of course the 6 pull-down magnets.
To continue you will need to remove the block at the south end of the delay line which holds the HeNe reflectors (remove bottom plate, then lift off) and also the limit spring.
The top magnet closest to the end prevents us from sliding the motor off the end because of a small sheet betal obstruction attached in the middle of the winding holder, which holds some cabling.
There are two ways around this obstruction: Either "Harvest" the southern
top magnet (see instructions on "Planting
and Haresting the Pull-down Magnets") or you can remove the obstruction.
Either way you
must first, remove the top panel, by removing about 10 screws which should be put on fairly tight.
We recommend harvesting the southern magnet using JIG-CP2 and accompanying metal shims. See separate instructions. Alternatively, if you choose to remove the obstruction then do so by removing two small screws.
The motor windings can now be slid off then end of the track -- being careful to keep wires from snagging on the top magnets.
The 6 (or 5 remaining) magnets can now be removed with JIG-CP2 (see separate instructions.) Before doing continuing, mark the position of the magnets so you can plant them at the right places if (when) you want to reverse the process. The 6 (or 5 remaining) magnets can now be removed with JIG-CP2 (see separate instructions.)
Estimated time: 1 hour